BSTJ 30: 2. April 1951: Pyrolytic Film Resistors: Carbon and Borocarbon. (Grisdale, R.O.; Pfister, A.C.; Van Roosbroeck, W.)

24.4 MB·English

Pyrolytic Film Resistors: Carbon and Borocarbon
By R, 0, GRISDALE, A C. PFISTER, and W. ras ROOSBROECK.

1, Aseaonucrras
N-IDEAL resistor wonkl pores a naistane prey als to

‘value and constan’ wilh ine, tsoperature, volage sad Irequensy
rsd coitons of ue ia the sppeton for bic es intends. Wite-
‘er venir, wi ean yelzenes to “sesisanceaeies" suggest were
the fit toe rpfoyed, approach to idee a a musber of respects. The
aavet, Fowever, of applictfns cequring resto ita bin vals of
Tessie of se ie ado genta etait over augmestes ranges i
‘puting contin son mae he rain of the eal sone eal
Morcover cept gest progres in the Developsent of itn alo sa
in the dawn of evo som Get, ee get ef 2 comenaicions
te lecroniesunties uooalaed the doveiomaent of weston aaler
tial cheaper ska canbe proc from wre wl ssa es hae

seuvinies, Nonctale txbl've terials weve acumlly nine,
‘on though ome these poste eesti me mec propesie Wik
fhe tomporativey fess sible, The ndastdee aor requse restore bang
She adeantages of the ven-veae types ant which st eke sae tine are
ghly sue ar etable. The pooblet, thes, i iat of parting precision
ial ability to nonmetallic naive wataile or of exploying metalic

‘nih ele, sires, carbides unt norometaic wrens sae ax
can getmaainn, av slicon ane amg ey lea whi hace

We eupeyed in making redatore? Whi nae of thew cu be fabs
eiely ae mera, it hes base incessingl eppareat that, to meet
{he complex requires of wera ciety, these metals mus further,
hie cnpayed in specie geomet fous, hus, the tend towaude ws of
inceesingly higher Irmpncies tequies that the resistive materia be em
plied sn ln form inner to avoid vesistance italy sulting fom,
He “skin eect” or from excesive values uf senclance: The Glan type of
Testor posses ucla advantage for igh feegvensy aplintons*
find ya fort las therfore oe expend the deveooment of lms of
aris ive matric metal and ley

‘Matalin, pono chenialy or by bigh-eaciut evaporation, have
wen studied extensively, Pore Serna mle Ter lene eet
232 Rn Eastin SINICA JOUHKAL, APRN, 19ST

dest of sesitance lrg shan ans sma and considerable attention hat
ncequently been gen ln tee in ally ls of ree teres tore
‘icfickent ut eves though cela sich lie hive speci seistanes con
fiery gicnter than pore metil, their resitien sll exe 30 low that
‘sceptiany hin Sime mn orp! inorder to ebtai high vales of
teistanee ‘The spelie resistance tis leprae coeiient forthe
Thi alloy fas nay depart ry frm thove ehstactartie of the bulk
neal The apparent spec rear my be legr Un tat of the balk
Sheal by ots of mgt, he leprae eect of resistance
“Eoin negeive ard ge mapitade. Associated with thos diferenes,
ich am he sacred te depuruzes i stzuclate Seem that of the olk
Theta, there irs dese stabity of the electrical characters of the
Sins Hesnnse of thi veny hin metal ms cam Ho emlye, ad s
{esitances® ofS io 1,00 has cen to epeezene the presen bale wee
Umit However, wits these Bite motl aly Elms can, wth cae, be made
foyredtstalersisir, Other “mctle” such ne german sal ave
leo ren investi od we i of ver high fim rettances ave en
prev frm hy, tae tnerntur ookioents of resistance eee and
Fata potentials tthe fim terminus moe tno

Sindy of metal in rect ss thie In! fv the yoeset day, a eli,
to le mecsenity of employing nor nesalie waters of High spice rei
ghee ithe feito esos 0 Ue ny satel ti ae he
Years ctbon as jovol fy ie act gency setizinctory, both be
‘hun i posecesa realrey gh specie rtance ar bewe3 i are
ee posted in fm foe.

‘Due ely emplapel mera ef plug cauboa na rosso inves
tie napeaton of aris laden Tiuie“peint” 20 tao since on sla
fngoleting ltr and subsequent cuvieg ofthe "ein: fn tn imps se
requisite cond lviy ead amechanial stability, The cabo parties ea
Dloed may Ie of expt, potolm coke, ee chanel ot Zuraace earboo
blk, of wuabizaion ofthese, Matrce of geal varia types have
‘beenemilayel, ging fom orgate areas soap, ure fonal
dehy, snd scone resing ta sow mecking ingen sue. The Si rss.
‘ce of sch li is naz depeadan on the nse ofthe punt vehi
On the tye af cabot pitzaent, end a ebe curing cons

tis charset of erher-pgmented fins Ia tae resistances epee
sen Ue itepeted contentions of «Lae miler of single eontzts be
‘Ss ean particles embeesd in an eset insulting matet. Such
ontct, wile no "la" the true of sila contact it the telephone

gee ‘Gina onthe wane ofthese th ne Ue
‘evwouvne nam assisoms cuales aoe powocaaeont 21S

‘wsnsmitter re stil dial c conto and reproduce. ‘The ils restate
dlepeeds peace othe catact anes aad on Vu elastic papers othe
ontet assuage These ates tut depend ot ie aaiaage of the
‘patie during cing on dilerencesin he shermal expansin coeticn's at
‘hematite partic, snl the hase; one Nw of the rari ater
Jig ili Cong Liga almorpions and on other fats all of
whic alt the salty terpeatare ies of sistance

Th vir af The ample vatie oi nih compete corgi fe rote
wort aeievement ve atsned Ga oped Dey ad ees] 2
Jit characterizing oreeatdey carbon campsite. esses of he Slo,
Inve, Nevertheless, these sestors sues serous shortcoming, inereat ia
their sritnres,emiong which are namereally Inge and variable expen
ture cotcents of essence, lack of avalablty to ele and constant toler
nce, atively lo power andngeapacily, ae poor stably wth Ui
Temperature an hamiiy. Talon, uc’ nafslure exh ee, many
tines uate tha iernal eu, whieh iy eraceratie af om at soe
Pages a Uae an Urq exit ape valle ict

Tn omer to poovie& carbon fl free om ms: of these undesirable
prertes, the ravnn of omsogenens carbon fle be the Sve
eitocarbor spore as nor wide et! nc tft thos tat he
oneest wank cancer The owls ann fs hy the thermal
{erjunitvy of hyde materia, ver thn ioteron, as
Pry flected in sntiuity and before the present century, thease af
och yay tke easbon is a eins was uggs Tis ul i gly
to pas vo dorades, ever, that pysuyte varboa resins have. Tue
emmy nel, rns Fat te pacts 298 bee
Treel nglyov i inept nef ee ing the is
hence The pepore a! thispagerietopmeest more spec iafrmation
fn shestnactores al pryert Pea thew ios al fod the fearing
Sf ts intention on the prcion ned properties of protic eacbon
restore of proved stbiity and enlcged es of explication. A partial:
Ajo ts presen cone tho mrt evelgrwnt of the oro
cess nec her -aieten of yeti ene Uy che cor
poration uf boron peraits the psocuetion uf nn tlie rsa which ae
‘uslent of superior to Ge nie wound tp

Trait carbon resitors'-> comprise homogeneous esvbon fms, of
speriistositance appmahly greater than for metab neetnce aye,
slichae prc reno sia rrctry hate in contin
‘ins of thickrameecontrodab.e oer wide rage. especie reitane sf
ean even inte thinness Sirs extn the eae ein bly 30
‘ht ely geometrical or ueshanical factors determine the miu ste
27k ux om mvarme necmvteat OURKA, Anza 1954

‘hieknes. The reson eae pode in ules angi rom a action of
fvohin co tes of megln, el certain versions, ey exhibit escepton-
Ay high order a stably? Harauae of te reuivlyhih speci eicance
hear, tbe “ein dep igh fcgueacieexeeds that of a hikes
Flin eiphned so thot there ero ners in sesistance due to ane.
"Tho ample with the fart that ds eoniuratons a nherenly low zent=
nueva be exilayed, perils advatageoae wee of thee mies 2 Ye
Tigh requencies urbe yn eiably prtected from onidain, pyeOyc
CGrbon flas ean diaspate very lege. amine a amor pet uri eet
without permarestchatge, sliea of pone aévantage De eertan
igh Srequeney

emit tei otherwise favors characteristics and growing scseptanes,
pprobic ovlun resistors hoe Te feerar Wy wear variate be
{Enuse of ch lative dang mages of thir temperntare ints of
estanc, This zltively Ig wisulate magaituce ef che tea erate co
cider resistance, nkch ss negative, hae served ae deleseeut to
the tne a ipeohtc carton ratte wate fi rereterstis Woald be
there etal ha no Leen found, however, that che inozpeation
fa few percent of lor fn yyslyte carbon ns reduc the tenperatare
eins a rslance to values mer than are avalable, on the ae
se in wisesreun (ye. Furth, this improve i seasncenied by an
Sneteases tenes of este valve, Ava real ul hes eprovemeris
Fitna appears thatthe Batoestbon mice lich xl abdul fd
‘nieaprnd we, sees the stability of renee valu of the wre oud
(ppe for moc appeaions and supaces it foe spa

2. Tex Proper ar Pyseuen Cennow Fras
2A The Teste of Paetsis

Pyrolyic carton fins are prose over The surfaces of stably rear~
tory and chemically stale objects inert nto = ested enlosre in it
Ietcnce of «hyiwarboa gar or vapor. ‘Tese Gn, which rest fom the
Tveljsle or “cracking” or thera decoepostian of the hjlezsoms, dee
Der in ss watuce end properties both othe pyrolying conn cal
2 the charter of the pert surlae. The pyro my be car
‘ed vt ly suaintining sable vapor pressure ofthe Fysrratban in ar
dnerae evacuated forme ory copying a suitable serie asco date
the hydeossbon and to transport it through the furnace at atmospheric
pressue. Bott tchniqces have been state, and wa bsevable éiferences
Tr flepropetce were four be, because of thes gee simply, cast
fas yates igerating et aemespberi peau were empayed in che wotk 20
be described, Tae principal ravi ae Lis ceice are that ontinumus cea
lng yarns con be employed ad hal xen and rely auetable con
Ll the conten of the force atmosphere con be mainte

"The foreaceomplyed in peeing pyrite carbon fins over the suface
of elairsal vrai es ray, feet, he either ofthe bac type”
tr the continuous type?" th whi ae eal ae ped sence,
Tr each etn, sitae presntons ae necssay in cider that ih ad
Ineent, cian ns be pers on the vod surface,

Fige 1 shows a furnace of the bat type suitable for small sale po
edn, Im the batch proses x tanger oscilting eight refactor
ore isemployed us the pyrolyzing chamber. Esto this coe is onde a quan-
‘iy af eyimerial cern roc, ok ceramics of other shapes, together with
quay of ales sand or other geanular material whic serves to support
‘he rds and to prevent damage to the ot ce eas a8 Ley are ome,
"his Moutng” material ase hese inlonee ox Uae quit uf Ue El ad
fn the flee carbon eet, In sale proces here she rade main
"i il eit in te fare cig eg, t woul be virally im
posile ca achieve the requte uniforms in esting corto, Thi,

art, dae ote eet thal Fe campsten uf che alps capendnt
forthe lenath of time i seman fe Svrsee, o,f other words, on its
‘elsity and the actual peth it tmsverecs threueh the cating camber.
Rotation o oatlation ofthe core with she rmutaneraadotscubling of
‘ie ele ene shat ech a Lee na statin! has, exe to he
tune decoaition conditions a8 any her,

‘With she furnace cone Ieee with ceramic rods and sad, cought
to the descedtemperatare—usualy from about 97S deg Cte 1340 dex C
Tile being Hae iba inert gut such a eng fore ienson of
The hyreethon. Whe erie equiier fe alain’, the costing
(gir smiled andl permitted tn flow fie Ue reqte ime, The hyn
shor supply then shutoff ae he furan ore cal while § ow af
teyensire itrogen fe inane, Te hs ee fdas, hi procedure
Sfolioned, clan, nicer a strongly adherent earhon ais ea be po-
flue suceaully ah conan as,

a Fig. 2 is hstated typical ootinuous furan? which onsit af
‘ive zse nous which the cere rade fo be euod ate passed uur
‘vatcaly in sequence, The Bist ofthese as been termsé& “pees tg”™
dhe as purpore eto eis te rods to ¢ tommpernture at lest as high,
5 Ut of Lae net allowing “cncting” zon before they come into eoutact
ith the coatig gases. Though ths preheating zone thee mina 3
fa ofa nec ys, suchas wtuogen, moving in te sume dct a the
sss ad ezptying into the conting gone, At the uretion ofthe predeting
St coating tre the costing gif ulmi thigh velocity through
‘ral jes a Cpe a to itn thong mixing in the race tao
nding Fe ceting
ale of te poteating

pie, Ta eas vey of ae pasng ve ma
Smaller thar Ht thea 8 patenting sone

one dele. This iagetber nih Fe Higher er

28 rae wi, ava reuse guUna, APRIL LL

sane, event entry of he rang ges to the pszheatng one ether ly
haw or by diesion

"From the onl ame, dt ceed res enter “paling” o “alter iat
ing coe, caring essage thang kick (ey ane Brg ey ney =
oom lemyertire. Thrvagh thie zre, i dinette councereurers to that
Of the by Bete fe mats! m fw ol anypeoealtcage, oF of zis
site smell alftensc iydrogen, inet hos hoe ew vetly pes
Ilequetel to deasidize comment ritmgen eset by the sion of
{Sam amount of hydigen dressage er x calle such as plleinized
‘Amina pt gouga dng ond omission tn the evel zoae. To
Drevent ents ol vtingsione nsec the cola aone, he cousterow of
os tug this mone main aver aL @ higher Tinea veloiy. All gus
finite tothe forte an stasted at ths junction beeween the costing
find caning sone To pds uteri norm rs the 10s
they ave stn! aout ee axes thay acrance thigh the Frac

"At recoils Iyivaton eongeatatons in te etmoepaete,
pg ng i fora ove mae of tho rating ze ems ection ia oth che
Iie ral saaisuousfeszace,Inmesetelysirmaling be rd sustaces
tr other sta ish epostion tales pac, howe, there isa Fog
Feet oes te camden sor, eb i aone i whieh “he eran
fer bet fam the setae to the gasoncirs hy eudtion ace tom Oy
fonts, Th walled ane edge 2f chi endocen zor ie “ern
Fiderd tobe te hownlry ol tla zion of genes lyse Noe the
Ty of the farmer imager, will the conduction one eon:igaoas Le
Tt aufecs, being mre iene, =taonary region in whi lif pose
ence ace opora i The geospatial ary
fubstanece which #0 vol pratee the cauducton zone aypmeihly sl
‘which, icrere do wot dest apprecialy onthe mal cs. The cause
[CF this tae tthe sutace texperane ofthe em eveeds al of
fhe hows wf the yaaa, ce she infra a Us lexperatare wat
aad the smseiacedsigosty grin the heavier pasties of soot and tar
felt difoe vay from te wines TF ths tenberatare gracient is re
sete as ky te intodaction of tel ral aka hater gi, thon there x
Droiued pn its surface # si asl resi etoved sooty coating. Tt oe
Ths ss st, the contnms pra ctaai reds are preheat e
Inf city ft the coating gore aod thas Use eauton-entod rods 7 pm
tect in the eoling son omy tlt with Furnace eluents of higher

22 Freee Variaber Coming the Rate of Carbon Deposition

“The thins of pyle eas nis depen wl aly om Ce aa
fare 9! the ydewacboa eplayed, nt alk li eoscenteation in the
Dinonyite raye aesstors: ckapow en aonocamton 219

80 alte othe rnaing chamber, on he empertine of his chamber,
[onthe duriitof prays, Thereof deyestionafeschon's inp
ent of tis duration excepe during the dust nemeats! dition whe the
ina deposits fort serve to catalyze subsequet reaction, whave slay
ate i onnarly quik acho In ig. 3 te Elma resistance of earbon
fs produced in a batch Garage is shown es funtion ofthe srt of
pasion, Tnlaedi the ign in- scaegving D l hikrs hich
5 sessed na ser etn ig inversely proportional to then reistance
‘over the vg sr, Tv ney he ean ts eapes con
nt dein at

ice i
ig i Pe
re H
2 ye
Ht
|

“The plying tamper, me han say other sng coneton, de
teria the actual rate of depnition of prove eabon. gute 4 gives
{he insofar given sarlion plpi,inerely proportional
lhe leet rte, i tints esa Fanti of enpene
in dyuarieequiliary eed ilostrtes the nest for pracee tempentare
contol when fins of costant atl repartee to
rede

Thane ia the hylmeurbon concmiton ithe feneaee atmosphere
ieerene he rate uf extn depen, ae ako Hig. forthe cee of
‘methane, which gies che dependence om restance an concession for
2) rare ay seacme mecca Joweval, APR 1951

‘sed duction of pyvlyis, Ie wil hero thatthe sate of deposition is
‘ot propestionsl tr the concentration, a chaaye in concentration by @

rope

[

soit ences Sain previ ome

“ Let
i SU. Lf
i Pitt rye
al TO ee

gf ean i xn eon comets 8

ven percentage jocag geeler change in rate of depmstion at Le
foncerations ta thigh

“The rate af elu clon nth tempestare,conceteation, an dr
tion ofpuolsisall eld estan va uti the geometry of Beste,
Dein dependent, or exe on te stance beteen the furace wall ae