2D

Abbre­vi­a­tion of two-dimen­sion­al. It refers to things that take up space or hap­pen in two dimen­sions (plane).

2.5D-integration

An advanced tech­nique for semi­con­duc­tor pack­ag­ing where dice are placed on an inter­pos­er that uses through-sil­i­con vias and redis­tri­b­u­tion lay­ers for inter­con­nect­ing the dice. Despite being close­ly pack­aged, dice in this con­fig­u­ra­tion com­mu­ni­cate through off-chip sig­nal­ing, akin to their oper­a­tion when placed in sep­a­rate pack­ages on a stan­dard cir­cuit board.

3D

Abbre­vi­a­tion of three-dimen­sion­al. It refers to things that take up space or hap­pen in three dimensions.

3D-packaging

The process of stack­ing dif­fer­ent inte­grat­ed cir­cuit dice with­in a sin­gle pack­age, using inter­posers for elec­tri­cal con­nec­tions. Unlike 3D inte­gra­tion, this method does not involve alter­ing the sil­i­con itself but focus­es on pack­age-lev­el stack­ing. It pro­vides ver­sa­til­i­ty in com­bin­ing var­i­ous tech­nolo­gies and mate­ri­als and is less com­plex than 3D inte­gra­tion, offer­ing a prac­ti­cal solu­tion for inte­grat­ing diverse com­po­nents in a sin­gle package.

3D IC

A 3D inte­gra­tion tech­nique that uses 3D inte­gra­tion to cre­ate mul­ti­ple stacks of dice stacked on top of each and 2.5D inte­gra­tion to con­nect the stacks using a sil­i­con inter­pos­er. In jest, this is some­times called the 5.5D IC because it com­bines 2.5D and 3D.

3D-integration

Ver­ti­cal­ly stack­ing and inter­con­nect­ing sil­i­con wafers or dice to func­tion as a sin­gle device. This tech­nique, which uses through-sil­i­con vias for direct lay­er-to-lay­er com­mu­ni­ca­tion, aims to enhance device per­for­mance and func­tion­al­i­ty in a com­pact space. It is char­ac­ter­ized by its ver­ti­cal inte­gra­tion approach, improved sig­nal trans­mis­sion speed, reduced pow­er con­sump­tion, and the need for pre­cise align­ment and bond­ing meth­ods, mak­ing it a com­plex yet effi­cient man­u­fac­tur­ing process.

A

See ampere.

absolute permittivity

A mea­sure of a material’s abil­i­ty to polar­ize in response to an applied elec­tric field and there­by store elec­tri­cal ener­gy. It is often denot­ed ε. It quan­ti­fies the elec­tric polar­iz­abil­i­ty of a dielec­tric. The high­er the absolute per­mit­tiv­i­ty, the more a mate­r­i­al can polar­ize and the more ener­gy it can store when sub­ject­ed to an elec­tric field.

AC

See alter­nat­ing cur­rent.

active component

A com­po­nent that requires an exter­nal pow­er source to func­tion or can pro­vide pow­er to a cir­cuit. These com­po­nents are involved in func­tions like ampli­fi­ca­tion, rec­ti­fi­ca­tion, sig­nal pro­cess­ing, and pow­er gen­er­a­tion. Exam­ples include tran­sis­tors, diodes, inte­grat­ed cir­cuits, and batteries.

advanced packaging

Refers to inno­v­a­tive and sophis­ti­cat­ed tech­niques in semi­con­duc­tor encap­su­la­tion that aim to improve per­for­mance, reduce size, and inte­grate addi­tion­al fea­tures. This sub­set of semi­con­duc­tor pack­ag­ing goes beyond tra­di­tion­al meth­ods to address chal­lenges in high-per­for­mance com­put­ing, minia­tur­iza­tion, and com­plex cir­cuit inte­gra­tion. 3D pack­ag­ing and Sys­tem in Pack­age (SiP) are key tech­nolo­gies in advanced packaging.

AEM

See anion exchange mem­brane.

AEM electrolysis

See anion exchange mem­brane elec­trol­y­sis.

AEM electrolyzer

See anion exchange mem­brane elec­trolyz­er.

AEM water electrolysis

See anion exchange mem­brane elec­trol­y­sis.

AEM water electrolyzer

See anion exchange mem­brane water elec­trolyz­er.

ALD

See atom­ic lay­er depo­si­tion.

ALK

See alka­line.

ALK electrolysis

See alka­line elec­trol­y­sis.

ALK electrolyzer

See alka­line elec­trolyz­er.

ALK water electrolysis

See alka­line elec­trol­y­sis.

ALK water electrolyzer

See alka­line water elec­trolyz­er.

alkaline

Adjec­tive describ­ing a sub­stance that is water sol­u­ble and has a pH greater than 7.0 or a solu­tion of such a substance.

alkaline electrolysis

Elec­trol­y­sis char­ac­ter­ized by hav­ing elec­trodes oper­at­ing in a liq­uid alka­line elec­trolyte solu­tion, typ­i­cal­ly potas­si­um hydrox­ide (KOH) or sodi­um hydrox­ide (NaOH).

alkaline electrolyzer

Elec­trolyz­er for alka­line elec­trol­y­sis. Alka­line water elec­trol­y­sis is an impor­tant application.

alkaline water electrolysis (AKLWE)

Elec­trol­y­sis by means of an alka­line elec­trolyz­er for the pur­pose of split­ting water into hydro­gen and oxy­gen. Its major advan­tage is that a high-cost noble met­al cat­a­lyst is not required; a low-cost elec­trolyte solu­tion is used instead. How­ev­er, alka­line water elec­trol­y­sis has sev­er­al draw­backs com­pared to pro­ton exchange mem­brane elec­trol­y­sis. Most notable are low­er ener­gy effi­cien­cy, sen­si­tiv­i­ty to changes in pow­er input, and less puri­ty of the pro­duced hydrogen.

alkaline water electrolyzer

Alka­line elec­trolyz­er built for the pur­pose of water elec­trol­y­sis. See also alka­line water elec­trol­y­sis.

alternating current (AC)

A type of elec­tri­cal cur­rent in which the direc­tion of the flow of elec­trons switch­es back and forth at reg­u­lar inter­vals or cycles.

ampere (A)

The SI unit of elec­tric cur­rent rep­re­sents a flow of one coulomb of charge per second.

anion

A neg­a­tive­ly charged ion is formed when an atom or mol­e­cule has excess neg­a­tive charge in the form of elec­trons. Dur­ing elec­trol­y­sis, anions have a ten­den­cy to accu­mu­late at the anode (pos­i­tive elec­trode) in an elec­trolyte solution.

anion exchange membrane

A mem­brane that selec­tive­ly allows the pas­sage of anions while most­ly block­ing cations or neu­tral mol­e­cules com­mon­ly used in var­i­ous elec­tro­chem­i­cal process­es like elec­trol­y­sis and fuel cells.

anion exchange membrane electrolysis

Elec­trol­y­sis char­ac­ter­ized by hav­ing elec­trodes on each side of an anion exchange mem­brane.

anion exchange membrane electrolyzer

Elec­trolyz­er for anion exchange mem­brane elec­trol­y­sis. Anion exchange mem­brane water elec­trol­y­sis is an impor­tant application.

anion exchange membrane water electrolysis (AEMWE)

Elec­trol­y­sis by means of an anion exchange mem­brane elec­trolyz­er for the pur­pose of split­ting water into hydro­gen and oxy­gen. Its major advan­tage is that a high-cost noble met­al cat­a­lyst is not required; a low-cost tran­si­tion met­al cat­a­lyst can be used instead. How­ev­er, it is still in the ear­ly research and devel­op­ment stage, while alka­line water elec­trol­y­sis is in the mature stage, and pro­ton exchange mem­brane elec­trol­y­sis is in the com­mer­cial stage.

anion exchange membrane water electrolyzer

Anion exchange mem­brane elec­trolyz­er built for the pur­pose of water elec­trol­y­sis. See also anion exchange mem­brane water elec­trol­y­sis.

anode

An elec­trode of a polar­ized elec­tri­cal device through which con­ven­tion­al cur­rent enters the device. Elec­trons flow from the device to the anode. In elec­tro­chem­i­cal cells, oxi­da­tion occurs at the anode. In pro­ton exchange mem­brane elec­trolyz­ers, irid­i­um is used in the anode.

anti-corrosion material

Mate­r­i­al that resists cor­ro­sion and is used to pro­tect oth­er mate­ri­als, e.g., plat­inum, is used in electrolyzers.

atomic layer deposition (ALD)

A thin film depo­si­tion tech­nique that deposits mate­ri­als lay­er by lay­er at the atom­ic lev­el. Dur­ing atom­ic lay­er depo­si­tion, pre­cur­sor gas­es are pulsed into a reac­tion cham­ber sequen­tial­ly, allow­ing for pre­cise film thick­ness and com­po­si­tion con­trol. This method ensures high-qual­i­ty and uni­form films even on com­plex surfaces.

available surface area

In the con­text of an elec­tro­chem­i­cal cell, such as those used in pro­ton exchange mem­brane (PEM) elec­trolyz­ers, avail­able sur­face area refers to the area of the elec­trode sur­faces that active­ly par­tic­i­pate in elec­tro­chem­i­cal reactions.

balance of plant (BoP)

All the sup­port­ing com­po­nents and sys­tems required to oper­ate an elec­trolyz­er effec­tive­ly, exclud­ing the elec­trolyz­er stack itself.

ball grid array (BGA)

A chip pack­ag­ing scheme in which the bot­tom of the pack­age is cov­ered in a grid-like pat­tern of sol­der balls. These sol­der balls pro­vide the elec­tri­cal con­nec­tions between the chip and the sub­strate it is sol­dered onto, such as a print­ed cir­cuit board.

bandgap

The ener­gy dif­fer­ence between the valence band’s top and the con­duc­tion band’s bot­tom. It is a cru­cial para­me­ter that deter­mines the elec­tri­cal con­duc­tiv­i­ty of a semi­con­duc­tor. A larg­er bandgap means more ener­gy is required for an elec­tron to move from the valence band to the con­duc­tion band. Semi­con­duc­tors with a small bandgap are more eas­i­ly excit­ed and can con­duct elec­tric­i­ty more read­i­ly. In con­trast, those with a large bandgap are less conductive.

bipolar plate

A slim, flat com­po­nent, often made of graphite or met­al, fea­tur­ing intri­cate chan­nels on its sur­face. It’s used with­in the elec­trolyz­er stack, where it serves a dual pur­pose: con­nect­ing the anode of one cell to the cath­ode of anoth­er while also man­ag­ing water and gas flow. Its thin­ness and chan­nel design are cru­cial for effi­cien­cy, mak­ing it a key ele­ment in the stack’s over­all performance.

BGA

See ball grid array.

black hydrogen

Hydro­gen gen­er­at­ed from low­er-grade coal, like lig­nite, through a process known as coal gasi­fi­ca­tion. Black hydro­gen pro­duc­tion is high­ly pol­lut­ing, releas­ing a con­sid­er­able amount of car­bon diox­ide and oth­er harm­ful emis­sions due to the com­bus­tion of coal. See also green hydro­gen, blue hydro­gen, grey hydro­gen, and brown hydro­gen.

blue hydrogen

Hydro­gen gen­er­at­ed from nat­ur­al gas through process­es such as steam methane reform­ing or autother­mal reform­ing, where the car­bon emis­sions are cap­tured and stored, reduc­ing its envi­ron­men­tal impact. See also green hydro­gen, grey hydro­gen, brown hydro­gen, and black hydro­gen.

brown hydrogen

Hydro­gen gen­er­at­ed from high­er-grade coal through a process known as coal gasi­fi­ca­tion. Brown hydrogen’s pro­duc­tion is high­ly pol­lut­ing, releas­ing a con­sid­er­able amount of car­bon diox­ide and oth­er harm­ful emis­sions due to the com­bus­tion of coal. See also green hydro­gen, blue hydro­gen, grey hydro­gen, and black hydro­gen.

bump

See sol­der balls.

CAGR

See com­pound annu­al growth rate.

cap

See capac­i­tor.

capacitance

The abil­i­ty of a capac­i­tor to store an elec­tric charge is mea­sured in farads (F). It rep­re­sents the charge a capac­i­tor can hold for a giv­en volt­age across its terminals.

capacitor

An elec­tron­ic com­po­nent that stores and releas­es elec­tri­cal ener­gy con­sists of two con­duct­ing plates sep­a­rat­ed by an insu­lat­ing mate­r­i­al, which is dielec­tric. Some­times abbre­vi­at­ed cap.

carbon dioxide (CO₂)

A col­or­less, odor­less gas that aris­es from var­i­ous nat­ur­al process­es, such as res­pi­ra­tion and vol­canic erup­tions, and human activ­i­ties, pri­mar­i­ly burn­ing fos­sil fuels. Ele­vat­ed car­bon diox­ide lev­els in the atmos­phere are a chief con­trib­u­tor to the green­house effect, glob­al warm­ing, and cli­mate change. Lim­i­ta­tion of green­house gas emis­sions is a pri­ma­ry goal for those advo­cat­ing for fos­sil-free ener­gy sources.

carbon nano-growth tool

Equip­ment designed to facil­i­tate the growth or syn­the­sis of car­bon-based nanos­truc­tures, such as nanofibers, nan­otubes, or graphene.

carbon nanofiber (CNF)

A type of nanofiber com­posed of car­bon atoms. These fibers exhib­it unique mechan­i­cal, elec­tri­cal, and ther­mal prop­er­ties, mak­ing them suit­able for var­i­ous appli­ca­tions. Grow­ing car­bon nanofiber is Smoltek’s core competence.

carbon nanotechnology

The study, manip­u­la­tion, and appli­ca­tion of car­bon-based nanoscale struc­tures, includ­ing car­bon nanofibers, nan­otubes, and graphene.

carbon-free

Refers to process­es, activ­i­ties, or ener­gy sources that do not release car­bon diox­ide (CO₂) into the atmos­phere. For exam­ple, renew­able ener­gy sources like solar and wind pow­er are con­sid­ered car­bon-free because they gen­er­ate elec­tric­i­ty with­out emit­ting CO₂. See also car­bon-neu­tral and fos­sil-free.

carbon-neutral

Means that any CO₂ released into the atmos­phere from a cer­tain activ­i­ty is bal­anced out by an equiv­a­lent amount of CO₂ being removed. This can be achieved through var­i­ous means, such as car­bon off­set­ting, where CO₂ emis­sions are com­pen­sat­ed for by fund­ing renew­able ener­gy projects, tree plant­i­ng, or oth­er activ­i­ties that absorb CO₂. See also car­bon-free and fos­sil-free.

catalyst

A sub­stance that facil­i­tates a chem­i­cal reac­tion with­out under­go­ing any per­ma­nent chem­i­cal change itself.

catalyst support

A mate­r­i­al on which a cat­a­lyst is dis­persed or attached increas­ing the avail­able sur­face area and sta­bil­i­ty of the catalyst.

cathode

An elec­trode of a polar­ized elec­tri­cal device through which con­ven­tion­al cur­rent leaves the device. Elec­trons flow to the device from the cath­ode. In elec­tro­chem­i­cal cells, reduc­tion occurs at the cathode.

cation

A pos­i­tive­ly charged ion is formed when an atom or mol­e­cule has an excess pos­i­tive charge lack­ing one or sev­er­al elec­trons. In an elec­trolyte solu­tion, cations move toward the cath­ode dur­ing electrolysis.

cell

See elec­tro­chem­i­cal cell.

cell area

The sur­face area of the elec­trodes where the elec­tro­chem­i­cal reac­tions occur in an elec­tro­chem­i­cal cell.

chemical vapor deposition (CVD)

A method used to pro­duce thin films or coat­ings on a sub­strate by chem­i­cal­ly react­ing gaseous pre­cur­sors at or near the sub­strate sur­face. The sub­strate is exposed to one or more vapor­ized pre­cur­sor mate­ri­als dur­ing this process. As these pre­cur­sors come into con­tact with the sub­strate, they react or decom­pose, form­ing a sol­id deposit. Chem­i­cal vapor depo­si­tion is the main process when grow­ing car­bon nanofibers.

chip

See inte­grat­ed cir­cuit.

chip-on-board (COB)

A chip pack­ag­ing scheme where the semi­con­duc­tor die is mount­ed direct­ly onto a cir­cuit board and then cov­ered with a pro­tec­tive epoxy or sim­i­lar material.

circuit board

A flat board made from non-con­duc­tive mate­r­i­al with con­duc­tive traces etched or print­ed on it, on which elec­tron­ic com­po­nents are mount­ed and elec­tri­cal­ly connected.

climate change

Refers to sig­nif­i­cant changes in glob­al tem­per­a­tures and weath­er pat­terns over extend­ed peri­ods. While cli­mate change is a nat­ur­al phe­nom­e­non, cur­rent pat­terns are heav­i­ly influ­enced and accel­er­at­ed by human activ­i­ties, espe­cial­ly the burn­ing of fos­sil fuels. This has led to var­i­ous envi­ron­men­tal and soci­etal chal­lenges, includ­ing more fre­quent and severe weath­er events, altered ecosys­tems, and ris­ing sea lev­els. Var­i­ous inter­na­tion­al frame­works, includ­ing the Sus­tain­able Devel­op­ment Goals, the UN Frame­work Con­ven­tion on Cli­mate Change, and the Paris Agree­ment, out­line nec­es­sary mea­sures to address cli­mate change. These include reduc­ing emis­sions, adapt­ing to cli­mate-relat­ed impacts, and secur­ing the fund­ing need­ed for these adap­ta­tions. Encour­ag­ing the use of fos­sil-free ener­gy sources and green hydro­gen is essen­tial in the effort to halt cli­mate change.

climate crisis

A term empha­siz­ing the urgent and severe nature of cli­mate change. It high­lights the imme­di­ate need for action to address the esca­lat­ing chal­lenges of ris­ing tem­per­a­tures, sea-lev­el rise, extreme weath­er events, and oth­er man­i­fes­ta­tions of dis­rupt­ed cli­mate pat­terns. Due to the cri­sis, many new tech­nolo­gies are being devel­oped and are expect­ed to reach large mar­kets in the future.

CMOS

Abbre­vi­a­tion of com­ple­men­tary met­al-oxide-semi­con­duc­tor, which comes from the use of com­ple­men­tary and sym­met­ri­cal pairs of p‑type and n‑type MOS­FETs where the MOSFET hav­ing a met­al gate elec­trode placed on top of an oxide insu­la­tor, which in turn is on top of a semi­con­duc­tor mate­r­i­al. Since one tran­sis­tor of the MOSFET pair is always off, the series com­bi­na­tion draws sig­nif­i­cant pow­er only momen­tar­i­ly dur­ing switch­ing between on and off states. Con­se­quent­ly, CMOS devices do not pro­duce as much waste heat as oth­er forms of log­ic. CMOS is also used in a gen­er­al sense to refer to both the type of cir­cuit­ry that uses CMOS tech­nol­o­gy and the process of man­u­fac­tur­ing with CMOS technology.

CNF

See car­bon nanofiber.

CNF-MIM

Smoltek’s trade­mark car­bon nanofiber enhanced met­al-insu­la­tor-met­al capac­i­tors.

CO₂

See car­bon diox­ide.

COB

See chip-on-board.

complementary metal-oxide-semiconductor (CMOS)

See CMOS.

component

A spe­cif­ic device or ele­ment with­in a tech­ni­cal sys­tem, such as an elec­tri­cal or elec­tron­ic cir­cuit, serves a dis­tinct pur­pose, such as mod­i­fy­ing, ampli­fy­ing, or direct­ing elec­tri­cal cur­rent or sig­nals. Elec­tron­ic com­po­nents can be as sim­ple as resis­tors or capac­i­tors or as com­plex as inte­grat­ed cir­cuits and are the fun­da­men­tal build­ing blocks for design­ing and assem­bling elec­tri­cal cir­cuits and systems.

Compound annual growth rate (CAGR)

A mea­sure that shows the con­sis­tent growth rate of, for instance, a mar­ket or an invest­ment over mul­ti­ple years. It helps under­stand how much an invest­ment has grown on aver­age each year over a spe­cif­ic period.

conductivity

See elec­tri­cal con­duc­tiv­i­ty.

conduction band

A band of ener­gy lev­els above the valence band where elec­trons can move freely through the mate­r­i­al, thus con­tribut­ing to elec­tri­cal con­duc­tiv­i­ty. When elec­trons in a semi­con­duc­tor gain enough ener­gy (for exam­ple, from heat or light), they can be excit­ed from the valence band into the con­duc­tion band, allow­ing the mate­r­i­al to con­duct elec­tric current.

connector

A device for con­nect­ing two dif­fer­ent parts to trans­mit elec­tric sig­nals or power.

corrosion

The nat­ur­al process by which mate­ri­als dete­ri­o­rate due to reac­tions with their envi­ron­ment, often result­ing in the for­ma­tion of oxides or salts of the orig­i­nal mate­r­i­al. Anti-cor­ro­sion mate­ri­als can be used to pro­tect materials.

Cu-Cu connection

A type of bond made direct­ly between two cop­per sur­faces, used in advanced pack­ag­ing semi­con­duc­tors.

current

Refers to the flow of elec­tric charge car­ri­ers, such as elec­trons or ions, through a con­duc­tor or cir­cuit. It rep­re­sents the rate at which elec­tric charges move past a spec­i­fied point in the cir­cuit, and it’s mea­sured in units of amperes (A).

current density

The amount of elec­tric cur­rent flow­ing through a spe­cif­ic cross-sec­tion­al area of a material.

customer sample

See engi­neer­ing sam­ple.

CVD

See chem­i­cal vapor depo­si­tion.

D2W

See die-to-wafer.

direct current (DC)

A type of elec­tri­cal cur­rent where the flow of elec­trons is con­sis­tent and moves in one direction.

DC

See direct cur­rent.

decoupling capacitor

A capac­i­tor is used in cir­cuits to sep­a­rate AC and DC sig­nals, pre­vent­ing noise dis­tur­bances from affect­ing oth­er parts of the circuit.

deposition

The process of deposit­ing a mate­r­i­al, often in the form of a thin film or coat­ing, onto a sur­face. Depo­si­tion tech­niques are wide­ly used in var­i­ous indus­tries, includ­ing elec­tron­ics and man­u­fac­tur­ing, to cre­ate lay­ers with spe­cif­ic properties.

design-in

Incor­po­rat­ing a spe­cif­ic com­po­nent or tech­nol­o­gy into a product’s ini­tial design phase.

design-win

A sit­u­a­tion where a com­po­nent or tech­nol­o­gy sup­pli­er gets its prod­uct cho­sen for use in a new prod­uct devel­oped by a manufacturer.

dice

Plur­al form of die.

die

A small block of semi­con­duc­tor mate­r­i­al has been processed to cre­ate an elec­tri­cal cir­cuit in which a large num­ber of minia­tur­ized tran­sis­tors and oth­er elec­tron­ic com­po­nents are insep­a­ra­bly assem­bled and elec­tri­cal­ly interconnected.

die-to-wafer (D2W)

A man­u­fac­tur­ing con­cept in which indi­vid­ual dice are elec­tri­cal­ly and mechan­i­cal­ly con­nect­ed to a wafer, often used in advanced pack­ag­ing and 3D inte­gra­tion.

dielectric

An insu­lat­ing mate­r­i­al that an applied elec­tric field can polar­ize.

dielectric constant

An old­er term fre­quent­ly used for rel­a­tive per­mit­tiv­i­ty. Stan­dards orga­ni­za­tions have dep­re­cat­ed this term in favor of rel­a­tive per­mit­tiv­i­ty due to poten­tial ambiguities.

DIP

See dual in-line pack­age.

discrete

Com­po­nents sep­a­rate or dis­tinct from each oth­er, like resis­tors or capac­i­tors, as opposed to inte­grat­ed cir­cuits.

deep trench capacitor (DTC)

A capac­i­tor inte­grat­ed into a semi­con­duc­tor sub­strate by cre­at­ing deep recess­es, called trench­es, to max­i­mize the sur­face area and, there­fore, the capac­i­tance in a small foot­print. Also known as trench sil­i­con capac­i­tors (TSC) and sil­i­con capac­i­tors (SiCap).

Doctor of Philosophy (Ph.D.)

An advanced aca­d­e­m­ic degree that rep­re­sents the high­est lev­el of for­mal edu­ca­tion in many fields. It is typ­i­cal­ly pur­sued after com­plet­ing under­grad­u­ate (Bachelor’s) and post­grad­u­ate (Master’s) degrees, although in some cas­es, stu­dents can tran­si­tion direct­ly from a Bachelor’s to a Ph.D. pro­gram. It is the high­est lev­el of degree a stu­dent can achieve. Typ­i­cal­ly, earn­ing a Ph.D. involves con­duct­ing orig­i­nal research that con­tributes new knowl­edge or under­stand­ing to a spe­cif­ic field of study. The process usu­al­ly includes exten­sive research, com­ple­tion of a dis­ser­ta­tion or the­sis, and suc­cess­ful defense of this work before a pan­el of experts. Ph.D. pro­grams can vary in length but often take sev­er­al years to com­plete and require a deep lev­el of com­mit­ment to study­ing and research­ing a spe­cial­ized area of interest.

dopants

Impu­ri­ty atoms are added to a semi­con­duc­tor mate­r­i­al dur­ing a process referred to as dop­ing to mod­i­fy its elec­tri­cal prop­er­ties. Depend­ing on their atom­ic struc­ture, dopants can intro­duce either extra elec­trons (for n‑type) or cre­ate “holes” (for p‑type) in the semiconductor.

doping

Inten­tion­al­ly adding spe­cif­ic impu­ri­ties, called dopants, into a semi­con­duc­tor mate­r­i­al to mod­i­fy its elec­tri­cal prop­er­ties. Depend­ing on the type of impu­ri­ty added, a semi­con­duc­tor can become either n‑type or p‑type. Dop­ing con­trols the con­cen­tra­tion and type of charge car­ri­ers in the mate­r­i­al, enabling the cre­ation of var­i­ous semi­con­duc­tor devices.

DTC

See deep trench capac­i­tor.

dual in-line package (DIP)

A chip pack­ag­ing scheme with a rec­tan­gu­lar hous­ing with two par­al­lel rows of elec­tri­cal pins or leads extend­ing from its sides. These pins facil­i­tate the con­nec­tion of the IC to cir­cuit boards.

ECM

See elec­trolyz­er cell mate­r­i­al.

electrical conductivity

A mate­r­i­al that eas­i­ly allows the flow of elec­tric charge. Met­als are a typ­i­cal exam­ple of high­ly con­duc­tive mate­ri­als, but cer­tain semi­con­duc­tors can also be con­duc­tive, par­tic­u­lar­ly when doped with impu­ri­ties that alter their elec­tri­cal properties.

electric field

An invis­i­ble field that sur­rounds charged par­ti­cles or objects and extends through­out the space around them. This field exerts elec­tric forces on oth­er charged par­ti­cles with­in its influ­ence, shap­ing the behav­ior of elec­tric charges and their inter­ac­tions. Under­stand­ing elec­tric fields is essen­tial for grasp­ing the dynam­ics of elec­tri­cal­ly charged entities.

electro-deposition

A process that uses an elec­tric cur­rent to reduce dis­solved met­al cations so that they form a thin, coher­ent met­al coat­ing on an elec­trode. This method is com­mon­ly used in indus­tries for plat­ing, refin­ing, and syn­the­siz­ing mate­ri­als. Also known as electroplating.

electrochemical

The branch of chem­istry that deals with the rela­tion­ship between elec­tric­i­ty and chem­i­cal reac­tions. Elec­tro­chem­i­cal process­es involve the move­ment of elec­trons between mol­e­cules, often result­ing in a chem­i­cal change.

electrochemical cell

A device that can gen­er­ate elec­tri­cal ener­gy from elec­tro­chem­i­cal reac­tions occur­ring in it or use the elec­tri­cal ener­gy sup­plied to it to facil­i­tate elec­tro­chem­i­cal reac­tions in it. It typ­i­cal­ly con­sists of two elec­trodes immersed in an elec­trolyte. Bat­ter­ies, fuel cells, and elec­trolyz­er cells are com­mon exam­ples of elec­tro­chem­i­cal cells.

electrode

An elec­tri­cal con­duc­tor used to make con­tact with a non­metal­lic part of a cir­cuit (e.g., a semi­con­duc­tor or an elec­trolyte). See also anode and cath­ode.

electrolysis

An elec­tro­chem­i­cal process where an elec­tric cur­rent is passed through an elec­trolyte to dri­ve a non-spon­ta­neous chem­i­cal reac­tion. See also water elec­trol­y­sis.

electrolyte

A medi­um con­tain­ing ions that are elec­tri­cal­ly con­duct­ing through the move­ment of those ions but not con­duct­ing electrons.

electrolyzer

A device that car­ries out elec­trol­y­sis, e.g., is used to split water into hydro­gen and oxygen.

electrolyzer cell

An elec­tro­chem­i­cal cell used in an elec­trolyz­er. Elec­trol­y­sis takes place in elec­trolyz­er cells.

electrolyzer cell material (ECM)

Gen­er­al term for mate­ri­als that are part of an elec­trolyz­er cell. The term cov­ers elec­trolyte (the pro­ton exchange mem­brane in a PEM elec­trolyz­er), cat­a­lysts (irid­i­um in a PEM elec­trolyz­er), elec­trodes (anode och cath­ode), porous trans­port lay­ers, and bipo­lar plates.

electrolyzer cell stack

See elec­trolyz­er stack.

electrolyzer stack

A col­lec­tion of elec­trolyz­er cells assem­bled togeth­er in a series or par­al­lel con­fig­u­ra­tion to increase the pro­duc­tion capac­i­ty of the elec­trolyz­er. Elec­trolyz­ers uti­lize elec­trolyz­er stacks rather than indi­vid­ual elec­trolyz­er cells.

electrolyzer test system (ETS)

A spe­cial­ized set­up used for eval­u­at­ing and test­ing the per­for­mance of elec­trolyz­ers. An elec­trolyz­er test sys­tem is designed to sim­u­late var­i­ous oper­at­ing con­di­tions and para­me­ters that an elec­trolyz­er might encounter in real-world applications.

electroplating

See elec­tro-depo­si­tion.

embedded capacitor

A capac­i­tor is embed­ded with­in a print­ed cir­cuit board (PCB), a sub­strate-like PCB (SLP), or anoth­er sub­strate instead of being mount­ed onto a PCB, SLP, or oth­er sub­strate. Embed­ding capac­i­tors allows for more effi­cient use of space and can improve the per­for­mance of high-speed circuits.

engineering sample

A pre-pro­duc­tion ver­sion of a future prod­uct pro­vid­ed to prospec­tive cus­tomers for test­ing, feed­back, or mar­ket­ing purposes.

equivalent series inductance (ESL)

A mea­sure of the inher­ent induc­tive reac­tance found in real-world capac­i­tors. While an ide­al capac­i­tor is con­sid­ered to have no induc­tive reac­tance, actu­al capac­i­tors exhib­it some due to their mate­ri­als and con­struc­tion. This induc­tive behav­ior is rep­re­sent­ed as an induc­tor in series with the ide­al capac­i­tor and is termed the equiv­a­lent series inductance.

equivalent series resistance (ESR)

A mea­sure of the inher­ent resis­tive loss­es with­in a real-world capac­i­tor or induc­tor. While ide­al capac­i­tors and induc­tors are con­sid­ered to have no resis­tance, actu­al com­po­nents exhib­it some resis­tance due to their mate­ri­als and con­struc­tion. This resis­tive char­ac­ter­is­tic is effec­tive­ly rep­re­sent­ed as a resis­tor in series with the ide­al com­po­nent and is termed the equiv­a­lent series resistance.

ESL

See equiv­a­lent series induc­tance.

ESR

See equiv­a­lent series resis­tance.

ETS

See the elec­trolyz­er test sys­tem.

F

See farad.

fabless

A com­pa­ny that designs semi­con­duc­tor devices but relies on third-par­ty man­u­fac­tur­ing facil­i­ties for pro­duc­tion, i.e., does not own its fab­ri­ca­tion facilities.

farad (F)

The SI unit of capac­i­tance.

film catalyst

A thin lay­er of cat­alyt­ic mate­r­i­al used to facil­i­tate or enhance cer­tain chem­i­cal reac­tions dur­ing the semi­con­duc­tor man­u­fac­tur­ing process. These reac­tions can be essen­tial for process­es like chem­i­cal vapor depo­si­tion or oth­er growth mechanisms.

flip chip

A method where the die is “flipped” so that its active area faces down­ward, mak­ing direct elec­tri­cal con­nec­tions to the sub­strate or pack­age. This is in con­trast to tra­di­tion­al meth­ods where the chip’s active area faces upward, and con­nec­tions are made via wire bonding.

footprint

The phys­i­cal space occu­pied by a com­po­nent on a cir­cuit board or with­in an inte­grat­ed cir­cuit lay­out. This term can describe both the size and shape of the com­po­nent, as well as its ori­en­ta­tion and place­ment. A small­er foot­print gen­er­al­ly allows for a denser pack­ing of com­po­nents, which can be cru­cial in minia­tur­ized electronics.

form-factor

Refers to the phys­i­cal shape and size of an elec­tron­ic com­po­nent. When con­sid­er­ing inte­grat­ing com­po­nents into prod­ucts, space con­straints and com­pat­i­bil­i­ty with oth­er com­po­nents are crucial.

fossil-free

Describes ener­gy sources, tech­nolo­gies, or prac­tices not depen­dent on coal, oil, or nat­ur­al gas. Fos­sil-free alter­na­tives reduce envi­ron­men­tal harm, pro­mot­ing a health­i­er plan­et. In the con­text of green hydro­gen, fos­sil-free sig­ni­fies hydro­gen pro­duc­tion meth­ods that exclude the use of fos­sil fuels, there­by pro­duc­ing clean­er ener­gy. See also car­bon-free and car­bon-neu­tral.

fuel cell

A device that con­verts chem­i­cal ener­gy from a fuel into elec­tric­i­ty through an elec­tro­chem­i­cal reac­tion. It typ­i­cal­ly con­sists of an anode, a cath­ode, and an elec­trolyte. Com­mon fuels include hydro­gen or methanol, and the most com­mon oxi­dant is oxy­gen from the air. Unlike bat­ter­ies, which store ener­gy, fuel cells con­tin­u­ous­ly gen­er­ate elec­tric­i­ty as long as fuel and an oxi­dant are supplied.

gas diffusion layer (GDL)

An elec­trolyz­er cell mate­r­i­al with a porous struc­ture designed to facil­i­tate the trans­port of gas­es, enhanc­ing the cell’s per­for­mance. See also the porous trans­port lay­er.

global warming

The long-term increase in Earth’s aver­age sur­face tem­per­a­ture is pri­mar­i­ly due to the high­er con­cen­tra­tions of green­house gas­es in the atmos­phere. This warm­ing is pri­mar­i­ly attrib­uted to human activ­i­ties, par­tic­u­lar­ly the com­bus­tion of fos­sil fuels. Glob­al warm­ing is a sig­nif­i­cant dri­ver behind the broad­er changes observed in our cli­mate system.

GDL

See gas dif­fu­sion lay­er.

gray hydrogen

See grey hydro­gen.

green hydrogen

Hydro­gen pro­duced using renew­able ener­gy sources like wind, solar, or hydro­elec­tric pow­er. Typ­i­cal­ly, green hydro­gen is pro­duced with PEM elec­trolyz­ers. See also blue hydro­gen, grey hydro­gen, brown hydro­gen, and black hydro­gen.

greenhouse effect

A nat­ur­al process in which cer­tain gas­es in the Earth’s atmos­phere, like car­bon diox­ide and methane, trap heat from the sun. This trapped heat warms the plan­et and makes it hos­pitable for life. How­ev­er, human activ­i­ties, espe­cial­ly the burn­ing of fos­sil fuels, have increased the con­cen­tra­tions of these gas­es, inten­si­fy­ing the green­house effect and lead­ing to a rise in glob­al temperatures.

greenhouse gas

Gas­es that trap heat in the Earth’s atmos­phere, con­tribut­ing to the green­house effect and, con­se­quent­ly, glob­al warm­ing. The pri­ma­ry green­house gas­es include car­bon diox­ide, methane, nitrous oxide, and flu­o­ri­nat­ed gas­es. Reduc­ing the emis­sion of these gas­es, espe­cial­ly from human activ­i­ties, is cru­cial for slow­ing or revers­ing the impacts of cli­mate change. Pro­mot­ing fos­sil-free ener­gy and green hydro­gen can help in mit­i­gat­ing these emissions.

grey hydrogen

Hydro­gen gen­er­at­ed from nat­ur­al gas through process­es such as steam methane reform­ing or autother­mal reform­ing, where the car­bon emis­sions are not cap­tured and stored, result­ing in sig­nif­i­cant car­bon diox­ide emis­sions into the atmos­phere. See also green hydro­gen, blue hydro­gen, brown hydro­gen, and black hydro­gen.

grow

The syn­the­sis or for­ma­tion of mate­ri­als, espe­cial­ly crys­tals, under con­trolled conditions.

H

See hen­ry or hydro­gen.

H₂

See hydro­gen gas.

H2LAB

Smoltek’s in-house hydro­gen laboratory.

henry (H)

The SI unit of induc­tance.

heterogeneous integration

The process of inte­grat­ing dif­fer­ent semi­con­duc­tor tech­nolo­gies into a sin­gle sys­tem. This can involve com­bin­ing com­po­nents of dif­fer­ent mate­ri­als or using dif­fer­ent man­u­fac­tur­ing process­es to achieve a sys­tem with opti­mized per­for­mance, func­tion­al­i­ty, and pow­er efficiency.

high-performance computing (HPC)

A branch of com­put­ing that deals with devel­op­ing and using super­com­put­ers and par­al­lel pro­cess­ing tech­niques to solve com­plex com­pu­ta­tion­al prob­lems. High-per­for­mance com­put­ing sys­tems are char­ac­ter­ized by their abil­i­ty to quick­ly process vast amounts of data. They are used in sci­en­tif­ic research, engi­neer­ing sim­u­la­tions, and data analysis.

homogeneous integration

The inte­gra­tion of semi­con­duc­tor devices or sys­tems made from the same mate­r­i­al sys­tem or process. It’s about com­bin­ing like with like to achieve a par­tic­u­lar functionality.

HPC

See high-per­for­mance com­put­ing.

hydrogen (H)

A chem­i­cal ele­ment with the sym­bol H and atom­ic num­ber 1. It’s a col­or­less, odor­less, and high­ly flam­ma­ble gas and is the universe’s light­est and most abun­dant ele­ment. At stan­dard con­di­tions, hydro­gen is a gas of H₂ molecules.

hydrogen gas

Gaseous hydro­gen con­sist­ing of mol­e­cules with two hydro­gen atoms (H₂).

IC

See inte­grat­ed cir­cuit.

impedance

A mea­sure of the oppo­si­tion a com­po­nent or cir­cuit presents to the flow of alter­nat­ing cur­rent (AC). Imped­ance encom­pass­es both resis­tance and reac­tance. It is typ­i­cal­ly rep­re­sent­ed in ohms (Ω) and deter­mines how a com­po­nent or cir­cuit will respond to an applied AC voltage.

inductance

A prop­er­ty of a com­po­nent in a cir­cuit that oppos­es changes in cur­rent flow. It results from the mag­net­ic field gen­er­at­ed around an elec­tri­cal con­duc­tor when cur­rent flows through it. Induc­tance is mea­sured in hen­rys (H). It plays a cru­cial role in AC cir­cuits, espe­cial­ly in fil­ter­ing and ener­gy stor­age applications.

inductor

An elec­tron­ic com­po­nent that stores ener­gy in the form of a mag­net­ic field when elec­tric cur­rent flows through it. Typ­i­cal­ly con­struct­ed as a coil of wire, its pri­ma­ry prop­er­ty is induc­tance, which oppos­es rapid changes in cur­rent flow. Induc­tors are com­mon­ly used in fil­ter­ing appli­ca­tions, ener­gy stor­age, and cir­cuits where mag­net­ic fields are necessary.

insulator

A mate­r­i­al that does not con­duct elec­tric­i­ty. Insu­la­tors are used to pre­vent the flow of elec­tric current.

integrated circuit (IC)

① Syn­ony­mous with die.

② The final, func­tion­al unit con­sist­ing of one or more dice enclosed in a pro­tec­tive cas­ing. This encap­su­la­tion pro­vides not only phys­i­cal pro­tec­tion but also facil­i­tates exter­nal con­nec­tiv­i­ty through pins or leads and aids in heat man­age­ment. In this form, the IC is ready for inte­gra­tion into elec­tron­ic systems.

intellectual property (IP)

Refers to cre­ations of the mind, such as inven­tions, lit­er­ary and artis­tic works, designs, sym­bols, names, and images used in com­merce. Intel­lec­tu­al prop­er­ty is pro­tect­ed by law, allow­ing cre­ators or IP hold­ers to earn recog­ni­tion or finan­cial ben­e­fits from what they invent or cre­ate. In com­put­ing, this can include soft­ware code, algo­rithms, patents on hard­ware designs, trade­marks, and copy­rights on soft­ware applications.

interconnect

An elec­tri­cal­ly con­duc­tive path that con­nects tran­sis­tors and oth­er elec­tron­ic com­po­nents in an inte­grat­ed cir­cuit. It can also refer to an elec­tri­cal­ly con­duc­tive path that con­nects a die to the package’s con­nec­tors or two dice.

internet of things (IoT)

A con­cept where­in every­day objects are embed­ded with sen­sors, soft­ware, and oth­er tech­nolo­gies to con­nect and exchange data with oth­er devices and sys­tems over the inter­net. This inter­con­nect­ed­ness allows for more direct inte­gra­tion of the phys­i­cal world into com­put­er-based sys­tems, lead­ing to improved effi­cien­cy, accu­ra­cy, and eco­nom­ic ben­e­fits. Exam­ples include smart ther­mostats, wear­able fit­ness track­ers, and con­nect­ed house­hold appliances.

interposer

A sub­strate, often made of sil­i­con, glass, or organ­ic mate­ri­als, that is used in advanced pack­ag­ing. It acts as an inter­me­di­ary lay­er where one or more dice are mount­ed and elec­tri­cal­ly con­nect­ed through inter­nal inter­con­nects. These inter­con­nects facil­i­tate com­mu­ni­ca­tion between dif­fer­ent dice or tran­si­tion from a fine pitch on a die to a wider pitch on the pack­age through a Redis­tri­b­u­tion Lay­er (RDL). Inter­posers may also inte­grate addi­tion­al func­tion­al­i­ties like capac­i­tors.

ion

An atom or mol­e­cule that has acquired a net elec­tric charge due to the gain or loss of one or more elec­trons. Ions are essen­tial in var­i­ous chem­i­cal and elec­tro­chem­i­cal process­es, includ­ing con­duct­ing elec­tric­i­ty in solu­tions and form­ing ion­ic compounds.

IoT

See the inter­net of things.

IP

See intel­lec­tu­al prop­er­ty.

Ir

See irid­i­um.

iridium (Ir)

A shiny, sil­very-white noble met­al with the sym­bol Ir. Irid­i­um is one of the most cor­ro­sion-resis­tant met­als. It is one of the rarest ele­ments in Earth’s crust, with esti­mat­ed annu­al pro­duc­tion and con­sump­tion of only 7–8 tonnes, mak­ing it very expen­sive. It is the only met­al that can be used in PEM elec­trolyz­ers as a cat­a­lyst.

JDA

See joint devel­op­ment agree­ment.

joint development agreement (JDA)

A con­trac­tu­al rela­tion­ship between two or more enti­ties to col­lab­o­rate on a spe­cif­ic project or ini­tia­tive, typ­i­cal­ly involv­ing research, devel­op­ment, or inno­va­tion. Such agree­ments out­line each party’s respon­si­bil­i­ties, roles, and rights, as well as the allo­ca­tion of any poten­tial rev­enues, intel­lec­tu­al prop­er­ty rights, and oth­er key terms relat­ed to the project.

joint venture (JV)

A con­trac­tu­al rela­tion­ship between two or more enti­ties to col­lab­o­rate by pool­ing resources to achieve a spe­cif­ic task or busi­ness goal. In a joint ven­ture, each par­tic­i­pant is respon­si­ble for prof­its, loss­es, and costs asso­ci­at­ed with the ven­ture. How­ev­er, the enter­prise oper­ates inde­pen­dent­ly from the par­tic­i­pants’ oth­er busi­ness interests.

joint venture agreement (JVA)

Agree­ment between two or more par­ties gov­ern­ing the for­ma­tion and oper­a­tion of a joint ven­ture.

JV

See joint ven­ture.

JVA

See joint ven­ture agree­ment.

landside

Refers to the side of a semi­con­duc­tor pack­age that has inter­con­nec­tors intend­ed for con­nec­tion to a cir­cuit board.

landside capacitor (LSC)

A capac­i­tor attached to the land­side of an inte­grat­ed cir­cuit. When serv­ing as a decou­pling capac­i­tor, its prox­im­i­ty to the die allows it to effec­tive­ly main­tain a sta­ble pow­er sup­ply to the inte­grat­ed cir­cuit. Con­straints like sub­strate size and the height of sol­der balls or con­nec­tions often influ­ence its dimen­sions and form factor.

Letter of Intent (LoI)

A writ­ten doc­u­ment express­ing two or more par­ties’ inten­tion to enter into a par­tic­u­lar agree­ment. It is often used in busi­ness trans­ac­tions such as merg­ers and acqui­si­tions. While typ­i­cal­ly not legal­ly bind­ing in terms of the deal itself, it can include bind­ing pro­vi­sions relat­ed to con­fi­den­tial­i­ty, exclu­siv­i­ty, or time­lines. An LOI is a pre­cur­sor to a for­mal con­tract, indi­cat­ing seri­ous inter­est from the sender about a par­tic­u­lar action or event.

LICC

See low induc­tance chip capac­i­tor.

LoI

See let­ter of intent.

Long run tests

Exper­i­ments or eval­u­a­tions con­duct­ed over an extend­ed peri­od (typ­i­cal­ly 1,000 hours or more) to assess the per­for­mance, dura­bil­i­ty, and reli­a­bil­i­ty of a sys­tem, com­po­nent, or process. These tests are cru­cial for under­stand­ing how a prod­uct or sys­tem behaves under pro­longed use or expo­sure to var­i­ous conditions.

Lifetime

The dura­tion for which a prod­uct, sys­tem, or com­po­nent is expect­ed to func­tion effec­tive­ly before it requires replace­ment or becomes too inef­fi­cient or unre­li­able to use. It’s a mea­sure of the longevi­ty and dura­bil­i­ty of an item under nor­mal oper­at­ing conditions.

low inductance chip capacitor (LICC)

A capac­i­tor designed to have low induc­tance, min­i­miz­ing the unwant­ed effects of induc­tance in elec­tron­ic cir­cuits. These capac­i­tors are often used in high-fre­quen­cy appli­ca­tions where reduc­ing induc­tance is crit­i­cal for main­tain­ing sig­nal integrity.

LSC

See land­side capac­i­tor.

m

See mil­li.

mA

Mil­liampere; see mil­li and ampere.

make-to-order (MTO)

A man­u­fac­tur­ing strat­e­gy where prod­ucts are pro­duced based on cus­tomer orders. Instead of main­tain­ing large inven­to­ries, com­pa­nies using MTO process­es man­u­fac­ture goods as orders are received, allow­ing for cus­tomiza­tion and reduc­ing excess inventory.

make-to-stock (MTS)

A man­u­fac­tur­ing approach where prod­ucts are pro­duced in antic­i­pa­tion of cus­tomer demand and stocked in inven­to­ry. This strat­e­gy is suit­able for prod­ucts with sta­ble and pre­dictable demand, allow­ing for faster deliv­ery to customers.

MEA

See mem­brane elec­trode assem­bly.

membrane

A thin lay­er of mate­r­i­al that serves a spe­cif­ic func­tion in elec­tro­chem­i­cal cells, such as bat­ter­ies, fuel cells, and elec­trolyz­ers. A mem­brane acts as a phys­i­cal bar­ri­er between dif­fer­ent com­part­ments of the cell, like sep­a­rat­ing the anode and cath­ode in an elec­trolyz­er, selec­tive­ly allow­ing cer­tain ions or mol­e­cules to pass through while block­ing oth­ers. While allow­ing ions to pass, mem­branes also pro­vide elec­tri­cal insu­la­tion between the two sides of the cell.

membrane electrode assembly (MEA)

A pre-assem­bled part used in fuel cells, PEM elec­trol­y­sers and AEM elec­trol­y­sers. In the mid­dle, there is a mem­brane ( PEM or AEM). One side is called the anode side, and the oth­er is called the cath­ode side, depend­ing on whether they are con­nect­ed to the pos­i­tive or neg­a­tive ter­mi­nal of a pow­er source. Adja­cent to the sides of the mem­brane is a cat­a­lyst. A PEM elec­trolyz­er uses irid­i­um on the anode side and plat­inum on the cath­ode side. At the end of each side is a porous trans­port lay­er that allows water and gas to be trans­port­ed to or from the mem­brane and cat­a­lyst, depend­ing on the function.

memorandum of understanding (MoU)

A for­mal but non-bind­ing agree­ment between two or more par­ties out­lin­ing the terms and details of an under­stand­ing, includ­ing the require­ments and respon­si­bil­i­ties of each par­ty. It can include bind­ing pro­vi­sions relat­ed to con­fi­den­tial­i­ty, exclu­siv­i­ty, or time­lines. An MoU is often used in sit­u­a­tions where par­ties either don’t imply a legal com­mit­ment or in sit­u­a­tions where the par­ties can­not cre­ate a legal­ly enforce­able agree­ment. It serves as a guide to the expec­ta­tions and is often a pre­cur­sor to a for­mal contract.

metal-insulation-metal capacitor (MIM capacitor)

A type of capac­i­tor struc­ture where a dielec­tric mate­r­i­al is sand­wiched between two met­al lay­ers, com­mon­ly used with inte­grat­ed cir­cuits.

micro (µ)

A pre­fix indi­cat­ing one-mil­lionth (10^-6) of a unit, such as a microsec­ond or a micrometer.

microchip

See inte­grat­ed cir­cuit.

milli (m)

A pre­fix indi­cat­ing one-thou­sandth (10^{-3</) of a unit, such as a mil­ligram (mg) or a mil­lime­ter (mm).}

MIM

See met­al-insu­la­tion-met­al.

MLCC

See mul­ti-lay­er ceram­ic capac­i­tor.

Moore’s law

An obser­va­tion made by Gor­don Moore in 1965 which pre­dicts that the num­ber of tran­sis­tors on a chip will dou­ble approx­i­mate­ly every two years, lead­ing to expo­nen­tial increas­es in com­put­ing pow­er and decreas­es in cost per transistor.

MOSFET

MOSFET is a met­al-oxide-semi­con­duc­tor field-effect tran­sis­tor. It is a type of tran­sis­tor often used in elec­tron­ic cir­cuits for ampli­fi­ca­tion and switch­ing pur­pos­es. It is known for its high effi­cien­cy, fast switch­ing speeds, and com­pact size. MOS­FETs have three ter­mi­nals: gate, source, and drain. By apply­ing a volt­age to the gate ter­mi­nal, an elec­tric field is cre­at­ed, allow­ing or block­ing the flow of cur­rent between the source and drain ter­mi­nals. Due to their low pow­er con­sump­tion and high-speed switch­ing capa­bil­i­ties, MOS­FETs are foun­da­tion­al com­po­nents in dig­i­tal inte­grat­ed cir­cuits.

MoU

See mem­o­ran­dum of under­stand­ing.

MTO

See make-to-order.

MTS

See make-to-stock.

multi-layer ceramic capacitor (MLCC)

A type of capac­i­tor con­struct­ed with mul­ti­ple lay­ers of dielec­tric and met­al lay­ers, result­ing in a com­pact struc­ture with high capac­i­tance.

mΩ

Mil­liohm; see mil­li and ohm.

n

See nano.

n‑type

Refers to a semi­con­duc­tor in which the major­i­ty of charge car­ri­ers are elec­trons. This is achieved by intro­duc­ing dopants into the semi­con­duc­tor mate­r­i­al with few­er valence elec­trons than the mate­r­i­al itself. The “n” stands for neg­a­tive, indi­cat­ing the electron’s neg­a­tive charge.

nano (n)

A pre­fix indi­cat­ing one-bil­lionth (10^-9) of a unit, such as a nanosec­ond or nanometer.

nanofiber

A fiber with a diam­e­ter on the nanoscale. Due to their minute size, nanofibers pos­sess high sur­face area-to-vol­ume ratios, lead­ing to enhanced mate­r­i­al prop­er­ties that dif­fer sig­nif­i­cant­ly from those of their bulk counterparts.

nanoscale

The scale of mea­sure­ment at the nanome­ter lev­el. A nanome­ter (nm) is a unit of length equal to one bil­lionth of a meter. When some­thing is described as being on the nanome­ter scale, it typ­i­cal­ly means that its dimen­sions or fea­tures are less than 100 nanometers.

nanostructure

A struc­ture with at least one dimen­sion in the nanoscale. These struc­tures often exhib­it phys­i­cal and chem­i­cal prop­er­ties dis­tinct from bulk mate­ri­als due to their small size and high sur­face area.

NDA

See the non-dis­clo­sure agree­ment.

nF

Nano­farad; see nano and farad.

nm

Nanome­ter; see nano.

non-disclosure agreement (NDA)

A legal­ly bind­ing con­tract between two or more par­ties that estab­lish­es a con­fi­den­tial rela­tion­ship. The agree­ment spec­i­fies that cer­tain infor­ma­tion shared between the par­ties must not be dis­closed to third par­ties. Often used in busi­ness set­tings when pro­pri­etary infor­ma­tion, trade secrets, or sen­si­tive data is shared, the non-dis­clo­sure agree­ment ensures that such details remain con­fi­den­tial and are not used for any pur­pose oth­er than what’s out­lined in the agree­ment. Vio­lat­ing the terms can result in legal penalties.

ohm (Ω)

The SI unit for mea­sur­ing resis­tance in elec­tri­cal com­po­nents.

p

See pico.

p‑type

Refers to a semi­con­duc­tor in which the major­i­ty of charge car­ri­ers are “holes” (miss­ing elec­trons, cre­at­ing a pos­i­tive charge). This is achieved by intro­duc­ing dopants into the semi­con­duc­tor mate­r­i­al with few­er valence elec­trons than the mate­r­i­al itself. The “p” stands for pos­i­tive, indica­tive of the pos­i­tive charge of the hole.

p–n junction

A bound­ary or inter­face between two regions of a semi­con­duc­tor material—one doped with pos­i­tive charge car­ri­ers ( p‑type) and the oth­er doped with neg­a­tive charge car­ri­ers ( n‑type). The p–n junc­tion is a fun­da­men­tal com­po­nent in semi­con­duc­tor devices. When a volt­age is applied across the junc­tion in a spe­cif­ic direc­tion, it allows cur­rent to flow (for­ward bias). In the oppo­site direc­tion, it blocks the cur­rent flow (reverse bias). This behav­ior is cru­cial for the func­tion­al­i­ty of diodes, tran­sis­tors, and oth­er semi­con­duc­tor devices in elec­tron­ic circuits.

package

See semi­con­duc­tor pack­ag­ing.

pad

An exposed region of met­al on a sub­strate, such as a cir­cuit board or a die, to which an elec­tri­cal inter­con­nects to anoth­er device or sys­tem is created.

passive component

A com­po­nent that does not require an exter­nal pow­er source to oper­ate and does not ampli­fy sig­nals. Pas­sive com­po­nents can store, fil­ter, or dis­si­pate ener­gy. Exam­ples include resis­tors, capac­i­tors, and induc­tors.

pattern catalyst

A cat­a­lyst that is selec­tive­ly placed or formed in spe­cif­ic pat­terns, typ­i­cal­ly on a sub­strate or sur­face. This pat­terned arrange­ment can be vital in process­es like grow­ing car­bon nanofibers, as it dic­tates the growth sites and direc­tion­al­i­ty of the nanofibers.

PCB

See cir­cuit board.

PECVD

See plas­ma-enhanced chem­i­cal vapor depo­si­tion.

PEM

See pro­ton exchange mem­brane.

PEM electrolysis

See pro­ton exchange mem­brane elec­trol­y­sis.

PEM electrolyzer

See pro­ton exchange mem­brane elec­trolyz­er.

PEM water electrolysis

See pro­ton exchange mem­brane elec­trol­y­sis.

PEM water electrolyzer

See pro­ton exchange mem­brane water elec­trolyz­er.

permittivity

See absolute per­mit­tiv­i­ty.

pH

① A scale used to spec­i­fy the acid­i­ty or basic­i­ty of an aque­ous solution.

② Pico­hen­ry; see pico and hen­ry.

Ph.D.

See Doc­tor of Phi­los­o­phy.

pico ℗

A pre­fix indi­cat­ing one-tril­lionth (10^-12) of a unit, such as a picosec­ond or picometer.

pin

A con­nec­tor designed as a pin intend­ed to be sol­dered into holes on a cir­cuit board.

plasma

One of the four fun­da­men­tal states of mat­ter, along­side sol­id, liq­uid, and gas. It is char­ac­ter­ized by the elec­trons being sep­a­rat­ed from their par­ent atoms or mol­e­cules. This sep­a­ra­tion of charged par­ti­cles gives plas­ma unique prop­er­ties, includ­ing elec­tri­cal con­duc­tiv­i­ty and the abil­i­ty to respond to elec­tro­mag­net­ic fields.

plasma enhanced chemical vapor deposition (PECVP)

A process used to deposit thin film mate­ri­als from a gas state (vapor) to a sol­id state on a sub­strate. The process uti­lizes plas­ma to reduce the required tem­per­a­ture com­pared to stan­dard chem­i­cal vapor depo­si­tion (CVD).

platinum (Pt)

Plat­inum (Pt) is a shiny, sil­very-white met­al with the sym­bol Pt. Known for its remark­able resis­tance to cor­ro­sion and high melt­ing point, plat­inum is a high­ly durable noble met­al. It is rel­a­tive­ly scarce in the Earth’s crust, con­tribut­ing to its high val­ue and cost. In the realm of pro­ton exchange mem­brane (PEM) fuel cells and elec­trolyz­ers, plat­inum plays a cru­cial role as a cat­a­lyst, par­tic­u­lar­ly on the cath­ode side, where it effi­cient­ly facil­i­tates the reduc­tion of oxy­gen in fuel cells and the pro­duc­tion of hydro­gen in electrolyzers.

polarization curve

A graph­i­cal rep­re­sen­ta­tion of the volt­age ver­sus cur­rent of an elec­tro­chem­i­cal cell, which pro­vides infor­ma­tion about the per­for­mance and effi­cien­cy of the cell.

polarization

The phe­nom­e­non where there is a sep­a­ra­tion or shift in the cen­ters of pos­i­tive and neg­a­tive charges with­in a mate­r­i­al leads to an inter­nal elec­tric dipole. This can be induced by an exter­nal elec­tric field or as an inher­ent prop­er­ty of the mate­r­i­al. The extent of this sep­a­ra­tion deter­mines the material’s polar­iz­abil­i­ty, which influ­ences var­i­ous elec­tri­cal prop­er­ties, such as capac­i­tance and per­mit­tiv­i­ty.

porous transport electrode (PTE)

An elec­trode with a porous trans­port lay­er. The term is used in PEM elec­trolyz­ers to include the cat­a­lyst depo­si­tion on the elec­trode in con­trast to the MEA, where the cat­a­lyst is usu­al­ly coat­ed on the PEM membrane.

porous transport layer (PTL)

An elec­trolyz­er cell mate­r­i­al with a porous struc­ture designed to facil­i­tate the trans­port of gas­es or liq­uids, enhanc­ing the cell’s performance.

power rails

Lines or tracks in an elec­tron­ic cir­cuit that deliv­er pow­er to the com­po­nents of the circuit.

precursors

Start­ing mate­ri­als that under­go a change to pro­duce some­thing else. In the con­text of chem­i­cal vapor depo­si­tion and plas­ma-enhanced chem­i­cal vapor depo­si­tion, pre­cur­sors are the spe­cif­ic gas­es or vapors intro­duced into the reac­tion cham­ber that will react to form the desired sol­id mate­r­i­al on a surface.

printed circuit board (PCB)

See cir­cuit board.

proton exchange membrane (PEM)

A syn­thet­ic poly­mer mem­brane that is a sol­id-state elec­trolyte, often used in PEM-elec­trolyz­ers for water elec­trol­y­sis and fuel cells.

proton exchange membrane electrolysis

Elec­trol­y­sis char­ac­ter­ized by hav­ing elec­trodes on each side of a pro­ton exchange mem­brane.

proton exchange membrane electrolyzer

An elec­trolyz­er using a pro­ton exchange mem­brane. This device is employed for the pro­duc­tion of hydro­gen through water elec­trol­y­sis. The pro­ton exchange mem­brane plays a piv­otal role by allow­ing pro­tons to pass through while block­ing elec­trons, facil­i­tat­ing the sep­a­ra­tion of hydro­gen and oxy­gen from water. PEM-elec­trolyz­ers are uti­lized in var­i­ous indus­tries, includ­ing ener­gy and man­u­fac­tur­ing, for gen­er­at­ing green hydro­gen, a valu­able resource in pur­su­ing sus­tain­able and envi­ron­men­tal­ly friend­ly prac­tices. A mas­sive indus­tri­al scale-up of pro­duc­tion of PEM elec­trolyz­ers is ongo­ing to meet the needs of the extreme­ly fast-grow­ing green hydro­gen market.

proton exchange membrane water electrolysis (PEMWE)

Elec­trol­y­sis using a pro­ton exchange mem­brane elec­trolyz­er to split water into hydro­gen and oxy­gen. Its main advan­tages are rapid adap­ta­tion to fluc­tu­a­tions in elec­tric­i­ty sup­ply, high ener­gy effi­cien­cy, and very clean hydro­gen. How­ev­er, the main dis­ad­van­tage is the use of irid­i­um as a cat­a­lyst; irid­i­um is a rare and expen­sive metal.

proton exchange membrane water electrolyzer

Pro­ton exchange mem­brane elec­trolyz­er built for the pur­pose of water elec­trol­y­sis. See also pro­ton exchange mem­brane water elec­trol­y­sis.

Pt

See plat­inum.

PTE

See porous trans­port elec­trode.

PTL

See porous trans­port lay­er.

raman spectroscopy

A tech­nique used to study the make­up and char­ac­ter­is­tics of mate­ri­als by shin­ing a laser light on them and observ­ing how the wave­length shifts in scat­tered light. The shift­ed inten­si­ty can reveal infor­ma­tion about the mol­e­cules in the mate­r­i­al. This method is wide­ly used to iden­ti­fy sub­stances and under­stand their properties.

RDL

See the redis­tri­b­u­tions lay­er.

reactance

A com­po­nent of imped­ance that explic­it­ly rep­re­sents oppo­si­tion to changes in alter­nat­ing cur­rent (AC) due to either capac­i­tance or induc­tance. Reac­tance does not dis­si­pate ener­gy as induc­tance does. Instead, it results in a phase shift between volt­age and cur­rent in an AC cir­cuit. It’s mea­sured in ohms (Ω) and can be either capac­i­tive (neg­a­tive reac­tance) or induc­tive (pos­i­tive reactance).

redistribution layer (RDL)

A lay­er in advanced pack­ag­ing of semi­con­duc­tors that reroutes and redis­trib­utes elec­tri­cal con­nec­tions from the ini­tial lay­out to a dif­fer­ent layout.

relative permittivity

The ratio of a material’s absolute per­mit­tiv­i­ty (ε) to the absolute per­mit­tiv­i­ty of a vac­u­um (ε₀). It is often denot­ed ε_r or κ. Rel­a­tive per­mit­tiv­i­ty is a dimen­sion­less quan­ti­ty and pro­vides a com­par­a­tive mea­sure of how well a mate­r­i­al can become polar­ized in response to an elec­tric field rel­a­tive to the absolute per­mit­tiv­i­ty of a vacuum.

resistance

A prop­er­ty of a com­po­nent in a cir­cuit that quan­ti­fies the loss in flow of elec­tric cur­rent, result­ing in the con­ver­sion of elec­tri­cal ener­gy into heat. Resis­tance is quan­ti­fied in ohms (Ω) and is a fun­da­men­tal con­cept in elec­tron­ic cir­cuits, deter­min­ing how much a com­po­nent or mate­r­i­al will resist the cur­rent flow.

resistor

An elec­tron­ic com­po­nent designed to intro­duce a spe­cif­ic amount of resis­tance into a cir­cuit, there­by lim­it­ing or con­trol­ling the flow of elec­tric cur­rent.

semiconductor

① A mate­r­i­al whose elec­tri­cal con­duc­tiv­i­ty lies between that of con­duc­tors (like met­als) and insu­la­tors (like glass). Semi­con­duc­tors can con­duct more elec­tric­i­ty by dop­ing, mak­ing them essen­tial for mod­ern elec­tron­ics. Devices like tran­sis­tors, diodes, and inte­grat­ed cir­cuits are built using semi­con­duc­tors. Com­mon semi­con­duc­tor mate­ri­als include sil­i­con and gal­li­um arsenide.

② In com­mon par­lance, it may also refer to com­po­nents, usu­al­ly inte­grat­ed cir­cuits, made from semi­con­duc­tor materials.

③ In com­mon par­lance, it may also refer to the indus­try pro­duc­ing semi­con­duc­tor components.

semiconductor packaging

The process of enclos­ing or encap­su­lat­ing a die or dice to pro­vide mechan­i­cal sup­port, pro­tect from phys­i­cal dam­age, dis­si­pate heat, and pro­vide elec­tri­cal con­nec­tions. Exam­ples of elec­tri­cal con­nec­tions are dual in-line pack­age (DIP), ball grid array (BGA), and chip-on-board (COB).

silicon capacitor (SiCap)

See deep trench capac­i­tor.

SiCap

See deep trench capac­i­tor.

SiP

See sys­tem-in-pack­age.

SLP

See sub­strate-like PCB.

SMD

See sur­face-mount­ed device.

SmolGrow

Smoltek’s trade­mark for a pro­pri­etary tech­nol­o­gy to grow car­bon nanofibers in pre­cise­ly defined patterns.

Smoltek ECM

Smoltek’s trade­mark for a porous trans­port lay­er enhanced with car­bon nanofibers cov­ered by an atom­ic lay­er of plat­inum for cor­ro­sion pro­tec­tion and with irid­i­um atoms on the outside.

SoC

See sys­tem-on-chip.

solder ball

A con­nec­tor shaped like a ball intend­ed to be sol­dered to a pad on a cir­cuit board or anoth­er sub­strate.

solder bump

See sol­der balls.

solid-state electrolyte (SSE)

An elec­trolyte that is in a sol­id form.

sputter

Sput­ter­ing is a method where atoms are eject­ed from a sol­id or liq­uid tar­get mate­r­i­al due to the bom­bard­ment of the tar­get by ener­getic par­ti­cles, typ­i­cal­ly ions of an inert gas like argon. The dis­lodged atoms con­dense onto a near­by sub­strate, form­ing a thin film. This tech­nique is com­mon­ly used in indus­tries such as elec­tron­ics for deposit­ing met­als or con­duc­tive films onto surfaces.

substrate

The under­ly­ing mate­r­i­al or lay­er often serv­ing as a base on which process­es occur or mate­ri­als are deposit­ed, espe­cial­ly in elec­tron­ics and semi­con­duc­tors.

substrate-like PCB (SLP)

An advanced type of PCB that close­ly mim­ics the prop­er­ties of a semi­con­duc­tor sub­strate, offer­ing enhanced elec­tri­cal per­for­mance and minia­tur­iza­tion capa­bil­i­ties. Char­ac­ter­ized by their ultra-fine line and space widths, typ­i­cal­ly below 25 microm­e­ters, SLPs enable the inte­gra­tion of more com­po­nents on a small­er sur­face area, mak­ing them ide­al for com­pact, high-per­for­mance elec­tron­ic devices.

surface-mounted device

An elec­tron­ic com­po­nent designed to be mount­ed and sol­dered direct­ly onto the sur­face of a cir­cuit board or oth­er substrate.

system-in-package (SiP)

A semi­con­duc­tor pack­age that con­tains mul­ti­ple com­po­nents, such as proces­sors, mem­o­ry, and capac­i­tors, in a sin­gle pack­age allow­ing for a more com­pact and inte­grat­ed solution.

system-on-chip (SoC)

An inte­grat­ed cir­cuit that con­sol­i­dates the nec­es­sary elec­tron­ic cir­cuits of var­i­ous com­put­er com­po­nents on a sin­gle chip. Well-known exam­ples are proces­sors for com­put­ers or mobile phones, which have ded­i­cat­ed func­tions for graph­ic pro­cess­ing (GPU), cen­tral pro­cess­ing (CPU), cache mem­o­ry, neur­al engines, and the like, all inte­grat­ed on a sin­gle chip.

titanium (Ti)

A strong, lus­trous met­al with a sil­very-gray appear­ance and the chem­i­cal sym­bol Ti. Renowned for its excep­tion­al strength-to-weight ratio, tita­ni­um is high­ly resis­tant to cor­ro­sion, even in sea­wa­ter. It is the ninth most abun­dant ele­ment in the Earth’s crust, but its extrac­tion and pro­cess­ing are chal­leng­ing, which con­tributes to its val­ue. In the con­text of elec­tro­chem­i­cal appli­ca­tions, tita­ni­um is not typ­i­cal­ly used as a cat­a­lyst in PEM elec­trolyz­ers.[b]

through-silicon vias (TSV)

Ver­ti­cal elec­tri­cal con­nec­tions that pass com­plete­ly through a sil­i­con wafer or die. Through-sil­i­con vias are used to con­nect the front and back sides of a wafer or die, enabling the 3D inte­gra­tion of semi­con­duc­tor com­po­nents.

transistor

A semi­con­duc­tor com­po­nent used to ampli­fy or switch elec­tron­ic sig­nals and pow­er is fun­da­men­tal to mod­ern elec­tron­ic devices.

trench silicon capacitor (TSC)

See deep trench capac­i­tor.

TSC

See deep trench capac­i­tor.

ultra-thin capacitor

A capac­i­tor with an extreme­ly small phys­i­cal thick­ness. A dis­crete ultra-thin capac­i­tor typ­i­cal­ly has a thick­ness in the range of 100 µm (0.1 mm). They are used in appli­ca­tions where space is at a pre­mi­um, like smart­phones and smartwatches.

V

See volt.

valence band

The ener­gy lev­els of the valence elec­trons. This band is com­plete­ly filled with elec­trons in intrin­sic (pure) semi­con­duc­tors at absolute zero tem­per­a­ture. When ener­gy is pro­vid­ed (e.g., through heat), elec­trons in the valence band can gain enough ener­gy to jump to the con­duc­tion band, leav­ing behind holes. The move­ment of these elec­trons and holes under an elec­tric field enables semi­con­duc­tors to con­duct electricity.

valence electron

An elec­tron in the out­er­most shell of an atom. These elec­trons deter­mine an atom’s chem­i­cal prop­er­ties and its abil­i­ty to bond with oth­er atoms. In the con­text of semi­con­duc­tors, the behav­ior of valence elec­trons plays a crit­i­cal role in deter­min­ing the con­duc­tiv­i­ty of the mate­r­i­al, espe­cial­ly when dopants are introduced.

volatile

A term describ­ing sub­stances that can quick­ly turn into a gas or vapor. For exam­ple, water is volatile because it evap­o­rates eas­i­ly when heated.

volt (V)

The SI unit of elec­tri­cal poten­tial ener­gy and volt­age. One volt is equiv­a­lent to one joule of elec­tric poten­tial ener­gy per coulomb of charge.

voltage

The dif­fer­ence in elec­tri­cal poten­tial ener­gy. It acts as an elec­tri­cal pres­sure that dri­ves the elec­tric cur­rent in a cir­cuit. It is mea­sured in volts.

W2W

See wafer-to-wafer.

wafer

A thin slice of semi­con­duc­tor, such as sil­i­con, used for the fab­ri­ca­tion of inte­grat­ed cir­cuits.

wafer bonding

A process for join­ing two wafers togeth­er direct­ly or using an inter­me­di­ate lay­er. This tech­nique can be used for cre­at­ing com­plex mul­ti-lay­ered semi­con­duc­tor struc­tures or devices.

wafer level package (WLP)

A type of semi­con­duc­tor pack­ag­ing where the pack­ag­ing process is applied direct­ly at the wafer lev­el, rather than to indi­vid­ual die after the wafer has been diced. This can result in a more com­pact and cost-effec­tive pack­age com­pared to tra­di­tion­al pack­ag­ing methods.

wafer-to-wafer (W2W)

A process in which entire wafers are bond­ed or aligned to one anoth­er, often used in advanced pack­ag­ing and 3D inte­gra­tion.

water electrolysis

Elec­trol­y­sis of water for the pur­pose of split­ting water into hydro­gen and oxygen.

water electrolyzer

An elec­trolyz­er used to split water into hydro­gen and oxygen.

wire bonding

A tech­nique that uses thin wires, often made of gold or alu­minum, to cre­ate elec­tri­cal inter­con­nects, typ­i­cal­ly between a die and a cir­cuit board.

year-over-year (YoY)

A com­par­i­son of a sta­tis­tic or met­ric between two con­sec­u­tive years. It’s used to see if some­thing has grown, shrunk, or stayed the same from one year to the next, typ­i­cal­ly shown as a percentage.

YoY

See year-over-year.

ε

See absolute per­mit­tiv­i­ty.

ε₀

See rel­a­tive per­mit­tiv­i­ty.

ε_r

See rel­a­tive per­mit­tiv­i­ty.

κ

See rel­a­tive per­mit­tiv­i­ty.

µ

See micro.

µF

Micro­farad; see micro and farad.

Ω

See ohm.