Document ykZayRRRqxLjmmOK9k4NkeMVd

mmrnm rnmmmmm *Jf "*' " -' LIA15839 2m BriaKkaa LEAD INDUSTRIES ASSOCIATION, INC. mc w vomc. m. v. loot? waa/j p m mggn* Fredrick C. Diaqua director of Besearch A Developneal Alpha Metals, Inc. m m m m m mmi pmw mpmmi]ih p ip i > p m'wnJWHwnwffwnw| In 1963, 53,262 tcoa of lead wars need In colder. 12.Sf of the lead mu ucod In eutcnobllee, 10$ la oanc, 2.5$ la coatings, end 65$ for other purpoe--. Before discussing the aorksts for solder, it night be worthwhile de scribing briefly what colder le end cue of lte properties which ache It a versatile notorial. Solder le crayoeed priserlly of lead aad tin. Various ether eluenta each ae direr, entlnocy, cetkeim, Indian, etc., era added to lead and/or tin o to produce eoldere of different properties, the properties thick neks It so useful la eo wany areas aret 1. Ite corrosion resistance to ataoepberle attack. 2. Its lew Melting point eoaparad to eoat netale. 3. Its ability to alloy with or wet a (real neny netale or alloys. 4. Its ductility and ease of fornlag end shaping. 5. Ite electrical conductivity. Cbe or sore of these properties neks it ideally salted to cations share it is Tin alone, while need as a solder in sene oases, is not u suitable for general work as tla-laed alloys. Lead when added to tin reduoss the ooet, the nalting point, end i^arovea the wetting properties. It is far these that lead la such an lapcrtant Ingredient of To disease all the Markets for solder today la lapoeslble because of the tine available end to e greeter extent because of uy Inadequate knowledge of ell of the aarkste. I will Mention e fee of the sera Important usee and Markets far solders. First, I will Indicate the uses of solder In the sots. Motive industries, which accounts for 22.9$ of the total lead used la soldar. In the aatcnobdle, soldar finds aany applications. It la used, of course. In the electrical ooMpooants which operate the electrical syrtsn. tvery light bulb In the ear including the seeled been headlights t w solder to Insure asTiiMetsed BKBWV anp.i % .a iJBWBWjPifi jiwyiweesje mrm soma aid ns xmro .. Coot *4 reliabla electrical corrections. The vibration and shock autasohilea are subject*! to, Bake mschsnical connections in electrical syrtsm* too unde pendable and a eoldsrad connection Is used. Solder used in the electrloel syrtsas oontains frost 40 to 70% leed, Cn e weight basis, Most of the lead 1s used In the automobile as a filler natal. In new cars, these alloy* called body adders or body leads contain as much ss 97% lsad, the balance being tin. "Tbs solder Is supplied In bar font and la used to fill dents and Inperfections In the body prior to painting. The body shop also usee body solder, although of s higher tin alloy, for ease of working. The third astjor category for use of adder In automobiles Is In the radiators. A radiator is eclosed of s series of tubes anl fins usually mads of copper or brass which are assembled, fluxed and dipped into Molten solder to seel the Joints. Radiators designed to operate at higher tcoperstures and pres sures have gradually dictated tbs use of higher leed alloys because of their higher Malting points. In the past fifteen years, solder baa bean challenged as a Material la the autoantlve Industry and has successfully withstood the challenge. Welding and wire wrap techniques hers been largely Ineffective la replacing solder for electrical connecttons. Plastics, primarily opcodes containing iron powder, have been atteapted as a replaceaent for body solder for new car Manufacture, hit higher cost sad difficulty In worlds with this type of Material have Made than inferior to eolder. There has, however, been More general acceptance of the plastic fillers in the automotive repair shops because the price differen tial is not ss great with respect to the higher tin content body solders la use for repair wrk. The greatest threat to the use of eolder in radiator* has cons fixe attempts to replace the copper and brass radiators with aladous. This change, while desirable because of the weight sad cost redaction to be gained by the use of aluminum, Is mo t s than offset by the ycoMane of Joining alias!iv. 10% of the leed uaed In eolder goes to the can Industry. Solder la ased primarily to protect the steel fhe corrosion and is widely uaed for cans Manu factured to contain Materials other than foods, such aa gasoline, oil and other non-food products. The lead content of the eolder is generally 70 to 8Of. Another Isqportant, though relatively --11 Market for solder 1* the coating field, which eonsuMMas 2.5% of the lead used In solder. Bare, ss la containers, the solder la used for corrosion protection, but la also uaed to preserve the eolderablllty of surfaces. Millions of resistor, capacitor, diode, translator, lug and terminal laeda are coated with solder and without the protection this eoetlng provides, prsssnt catenated soldering production techniques would be lagioeelhle. Approximately 6591 of leed used in solder la used for unclassified purposes. While no breakdown of this figure Is available, it Is likely Uet a large portion of It la used by the electronic lnduetrlee. This la a vast and rapidly growing Industry which should use mo t s solder as tins goes on. The past 20 years have-seen treaMndoue developments in the electronlo* lnAistry. A number of Major developments have been achieved during this period without tdiich our computer Industry sad apses program would not have been posslhls. -2 - mmmmm imiw u h MVV--M--SHVaaK--'  fi r~T fi -)n fflrUmmir -l-- ---- .tilreel LIA15841 -<g. 50LC3 AMD ITS KUUStS - - -Coat'4 The first development tots that of printed circuits. Tha conventional electronic circuit consisted of a natal chassis on which ware mounted, re sistors, capacitor*, tub**, tunars and othor components. Thao* wars Inter connected with insulated wires soldered by hand with an iron and cor* solder to terminal po*ta. Th result was a group of wlr** looking llks a bowl of spaghetti. Tha metal chassis was heavy and tha unit was largo bacauaa spaoa had to ba proridad to hand solder aach connection. A printed circuit consists of a copper circuit pattarn on a plestle Insulating base. Bolas ara drillad or punched in tha plastic to accomodate laads froci coepcnants, tha coaponaots ara inserted in tha top of tha beard and tha whole aaeeohly la soldered In #**1C sacends hy dipping in a bath of 60/10 or 63/17 solder. Tbs original interest in tha printed circuit approach stsensd from tha attraetir* cost reduction possibilities and this has been accomplish*!. Many girls hand soldering aach oonnaction hava now bemi replaced by a soldering machine which soldara hundreds of connection* simultaneously in a fraction of tha tisa it can ba dona by band. This technique has resulted In a major ehang* in tha fora in which solder is used. Mich of tha solder supplied as wira contain!^ tha flux and hasted with a soldaring iron is now being supplied in ingot fwm for use in tha dip eoldar pot*. Tha flux Is applied to the board parlor to dip soldering. Actually, a printed circuit assembly contains aore solder than tha saaa aiaeaMy aada by cccrantional hand soldaaring techniques. Tbo reason for this is that in printed circuits tha solder not only Makes the connections, but at tha aaaa tins corera the conductor pattern as well. In hand soldering, the solder is used only at isolated connections. Vhila tha usage cf adder has gone up in printed circuit soldering, the aaount of lend used has rsnslned fairly constant. The reason for this is that in band soldering, higher lead alloys containing a* arch as 70S lead can ba effectively used; but In printed circuits, 37% lead la the saitmi which can be used because of lack of high takersture stability of the printed circuit board Material. In addition to tha eeoncmie advantage provided by printed circuits, ssverul other outstandind advantages havs developed, (toe of these Is that of space saving. The conductor patterns can ba placed very close together, it possible to reduee the space occupied by the aseanhly to a Tha dramatic change can be seen in the else of co^utera today as compared to those of twenty years ago. Mow, one roc* will bold equipment which used to require a whole building. The weight reduction, accomplished by using printed circuits, has been a real boon to the aviation and space progress tdtere airborne slop- tronle shipment must be as light as possible for obvious reseat*. & second major development which has e,^lamented that of the printed circuit waa that of a1-conductors. These are essentially solid materials which perform the functions of amplification and rectification of the well- known vacuum tube. The transistor or diode is many times essller then m vacuus tube. A hundred translators oan occupy the same speoe as one vaoma tubs. This has been a major contributing factor to tbe reduction in else of electronic equipment. Ssmi-conductor# use very little energy end throw off very little heat. Twenty years ago, the ceding eystsn, to remove tbs heat genaratsd by thousands of vaeuun tubes, was as large as the counter Itself. Mow, since translators produos no heat, the sealing systems ara practically eliminated. * Rspemmmmsw - J- .tj.ifti ji.j.jnyi isnmm*pwp temmem ----- ------ - --'- - ***.*. e--^--- | - --< * Bousza. uts> m Muon --cootu Solder pli/i an important rola In the seni-cenductor industry. lead alloy* ara used a* doping alloy* in Diking actlr* geraalnlta* and silicon dric. Soldar 1* used to attach tba gerwlniue crystal to tb* baa# tab. It is also usad to herwtlcally aaal tha transistor can to tha haadar. It is usad to coat tha surface of tha can and header for corrosion protaction, and finally It is usad to coat tha leads to provide soldarabllity. Thus, It can be seen that soldar is rltal to the wnufacture of seni-conductors. Tha ccnputar is tha heart of tha apace program. Without it, tha retrieval and rapid analysis of data ao necessary to success could not be achieved. It is also the nerve call of our cawerclal airlins operations and cur entire defense and crssainlcatl one syrtaa. A *Jor effort Is now under way to increase tha reliability of these electronic *ystas. Cne of the areas under Intensive study is tha soldered connection. Several alsslle failurea have bean traced to faulty soldered connectlens. Thera baa recently hens a concerted effort by tba welling Industry to replace soldering with welding, but it baa yet to be proved that welding aa a technique is acre reliable than soldering. Ganerally, a faulty soldered connection Is caused by poor workmanship, rather than by tha adder. The aaaa can be expected of the welded connection, since so uch depends on operation technique. Those of us In tha soldar Industry ara proud of tha part soldar has played In the electronic Industry. Whan it is realised that exotic and ccnplax electronic systma depend cn tha soldered connection far proper functioning, solder can truly be can#* "the agnlficent trifle." is I Indicated before, ao break-dow by Industries Is available on tha lead used In soldar for tha 6J)t listed as unclassified. In addition to the electronic Industry, a large portion of solder la used In plnnMng where the 50-lead/SO-tln alloy baa been the standard for so aery years. This nartet should continue for nary years. The electrical Industry which produces relays, generators, transformers, etc., roasnwe miefa lead la tha form of solder and should centime to do so. While solder should continue to be used in increasing aaounts in all industries, a future threat to soldar conrssptlon in tha electronic industry lies in the trend to nlcro miniaturisation and integrated circuits. Whether this will result In aaterlally reducing the aisount of soldar used Is extrawly doubtful. Ihst experience Indicates that usually tbs reverse Is true. The Industrial revolution, instead of reduciry aaplcywot, created acre jobs. Tbs present trend toward automation will probably do the saw. I look to increasing uses for solder in tha years ahead. l V t p Presented at the 36th lnnual Neatly of the Lead Industries Aeeociatien,Ihe. at the Chase Park Fleas Hotel, 3t. Louis, Missouri, April 21-22, 1964. gm.||ieufpw