Cov txheej txheem kho saum npoo av ntawm PCB pawg thawj coj saib

1. Bare copper plate

Qhov zoo thiab qhov tsis zoo pom tseeb:

Qhov zoo: tus nqi qis, nto du, zoo weldability (thaum tsis muaj oxidation).

Disadvantages: easy to be affected by acid and humidity, can not be kept for a long time, need to be used up within 2 hours after unpacking, because copper is easily oxidized when exposed to air; Tsis tuaj yeem siv rau ntawm ob chav vaj huam sib luag vim hais tias sab thib ob yog oxidized tom qab thawj zaug rov ua vuam. If there are test points, solder paste must be printed to prevent oxidation, otherwise subsequent contact with the probe will not be good.

Cov tooj liab ntshiab tau yooj yim oxidized yog raug cua thiab yuav tsum muaj txheej tiv thaiv saum toj no. And some people think that gold is copper, which is not true, because that’s the protective layer over the copper. Yog li koj xav tau thaj tsam loj ntawm cov plating kub ntawm lub rooj tsav xwm hauv Circuit Court, uas yog, Kuv coj koj los nkag siab cov txheej txheem kub.

Ob, phaj kub

Kub yog kub tiag. Txawm tias txheej txheej nyias nyias suav txog ze li 10% ntawm tus nqi ntawm pawg thawj coj saib xyuas. Hauv Shenzhen, muaj ntau tus tub lag luam tshwj xeeb hauv kev tau txais cov khoom seem ntawm cov laug cam, los ntawm qee qhov txhais tau tias ntxuav tawm cov kub, yog cov nyiaj tau los zoo. Kev siv cov kub ua txheej, ib qho yog txhawm rau txhawm rau txhawm rau ua vuam, lwm qhov yog los tiv thaiv kev xeb. Txawm hais tias lawv tau ua

Cov ntiv tes kub ntawm ob peb xyoos tus nqi ntawm cov cim nco tseem ci li lawv tau ua thaum lawv tau ua los ntawm tooj liab, txhuas thiab hlau, uas tam sim no xeb rau hauv cov pob zeb tsis zoo.

Cov txheej kub plated tau siv dav hauv ntu ntawm cov khoom siv hluav taws xob, cov ntiv tes kub, cov khoom sib txuas thiab lwm txoj haujlwm. Yog tias koj pom tias lub rooj tsav xwm hauv Circuit yog qhov nyiaj tiag, qhov xav tau tsis hais, hu ncaj qha rau tus neeg siv txoj cai xov tooj, yeej yog lub chaw tsim khoom jerry tsim, tsis tau siv cov ntaub ntawv zoo, nrog rau lwm yam hlau dag ntxias cov neeg siv khoom. Peb siv cov xov tooj hluav taws xob tshaj plaws hauv xov tooj hluav taws xob Circuit Court board motherboard feem ntau yog cov phaj kub, cov phaj kub poob, lub tshuab computer, lub suab thiab lub rooj sib tham me me digital feem ntau tsis yog phaj kub.

Qhov zoo thiab qhov tsis zoo ntawm cov txheej txheem kub kub tsis yooj yim los rau:

Qhov zoo: tsis yooj yim rau oxidize, tuaj yeem khaws cia ntev, qhov saum npoo yog du, haum rau vuam qhov sib txawv me me pins thiab cov khoom siv nrog cov pob qij txha me me. Nyiam PCB pawg thawj coj nrog tus yuam sij (piv txwv li pawg thawj coj saib xov tooj). Reflow soldering tuaj yeem rov ua ntau zaus yam tsis muaj qhov poob ntawm qhov ua kom poob. Nws tuaj yeem siv los ua cov khoom siv rau COB (Chip On Board) cabling.

Qhov tsis zoo: tus nqi siab, lub zog tsis zoo, vim yog siv cov txheej txheem npib tsib xee plating, yooj yim kom muaj teeb meem phaj dub. Cov npib tsib xee txheej oxidizes nyob rau lub sijhawm, thiab kev ntseeg tau mus sij hawm ntev yog qhov teeb meem.

Tam sim no peb puas paub tias kub kub thiab kub yog nyiaj? Tsis tau. Tin.

Thib peb, tshuaj tsuag lub rooj tsav xwm hauv tin

Cov phaj nyiaj hu ua daim hlau tinjet. Spraying a layer of tin over the copper wire can also aid in welding. But it doesn’t offer the same long-term contact reliability as gold. There is no impact on soldered components, but reliability is not sufficient for pads exposed to air for a long time, such as ground pads, spring pin sockets, etc. Lub sijhawm ntev siv yooj yim oxidation xeb, ua rau muaj kev sib cuag tsis zoo. Yeej siv los ua cov khoom lag luam digital me me hauv pawg thawj coj saib, tsis muaj qhov tshwj xeeb yog tinjet board, vim li cas thiaj pheej yig.

Its advantages and disadvantages are summarized as follows:

Advantages: low price, good welding performance.

Qhov tsis zoo: Tsis tsim nyog rau kev sib txuas nyias nyias qhov sib txawv ntawm cov pins thiab cov khoom me me dhau, vim qhov tsis zoo ntawm lub tiaj tiaj ntawm tinjet phaj. Hauv kev ua PCB, nws yooj yim los tsim cov hlaws dai thiab ua rau luv Circuit Court rau cov khoom zoo. When used in the double-sided SMT process, because the second surface has been a high temperature reflow welding, it is very easy to re-melt tin spraying and produce spherical tin beads or similar water beads dripping under the influence of gravity, resulting in more uneven surface and affecting welding problems.

Nyuam qhuav pib, peb tau tham txog qhov pheej yig tshaj plaws lub teeb liab liab Circuit Court, tus miner teeb thermoelectric sib cais tooj liab substrate

Plaub, OSP txheej txheem txheej txheem

Organic welding pab zaj duab xis. Vim tias nws yog organic, tsis yog hlau, nws pheej yig dua li tin-txau.

Qhov Zoo: Nrog txhua qhov zoo ntawm cov tooj liab liab liab vuam, cov laug sij hawm tuaj yeem ua tiav.

Qhov tsis zoo: raug rau acid thiab av noo. Nyob rau hauv rooj plaub ntawm kev rov ua dua vuam dua zaum ob, lub sijhawm xav tau los ua kom tiav qhov kev xa rov qab zaum ob yog feem ntau tsis zoo. Yog tias khaws cia ntau dua peb lub hlis, nws yuav tsum rov tshwm sim. Siv li ntawm 24 teev tom qab qhib pob. OSP yog txheej txheej thaiv, yog li cov ntawv ntsuas yuav tsum tau luam tawm nrog cov tshuaj txhuam kom tshem tawm cov txheej txheej OSP qub los tiv toj rau rab koob taw tes rau kev ntsuas hluav taws xob.

Ib txoj haujlwm tseem ceeb ntawm cov yeeb yaj kiab organic no yog txhawm rau xyuas kom cov ntawv tooj liab sab hauv tsis oxidize ua ntej vuam. Cov zaj duab xis evaporates sai li sai tau thaum nws sov thaum vuam. Cov laug tuaj yeem siv los txuas cov xov tooj tooj liab rau cov khoom siv.

Tab sis nws tsis yog corrosion-resistant. Lub rooj tsav xwm OSP, nthuav tawm huab cua ntau dua kaum hnub, tsis tuaj yeem txuas cov khoom sib txuas.

Ntau lub khoos phis tawj niam txiv siv OSP thev naus laus zis. Vim tias lub rooj tsav xwm hauv Circuit loj dhau los them nyiaj kub plating.