Ungakuvimbela kanjani ibhodi yesifunda isonteka

1, Kungani ibhodi lesifunda lidingeka ukuba licabalele kakhulu

Emgqeni wokufaka othomathikhi, uma ibhodi eliphrintiwe lingeyona ifulethi, kuzodala ukuma okunganembile, izingxenye azinakufakwa emigodini nasemaphaketheni wokufaka ebusweni webhodi, futhi kulimaze nomshini wokufaka othomathikhi. Ibhodi elifakwe ngezingxenye ligobile ngemuva kokushisela, futhi izinyawo zezinto zinzima ukusika isicaba futhi sihlanzekile. Ibhodi alikwazi ukufakwa ku-chassis noma kusokhethi emshinini, ngakho-ke kubuye kube nzima kakhulu ukuthi ifektri yomhlangano ihlangane nokubhidlika kwebhodi. Njengamanje, amabhodi aphrintiwe angene enkathini yokufakwa kwendawo nokufakwa kwe-chip, futhi izitshalo zomhlangano kufanele zibe nezidingo eziqinile kakhulu zokuqina kwebhodi.

2, Standard futhi test indlela warpage

Ngokwe-American ipc-6012 (1996 edition) <<ukuhlonza nokucaciswa kokusebenza kwamabhodi aphrintiwe aqinile>>, i-warpage ephezulu evumelekile nokuphazamiseka kwamabhodi aphrintiwe angaphezulu ayi-0.75%, no-1.5% kwamanye amabhodi. Lokhu kuthuthukisa izidingo zamabhodi aphrintiwe angaphezulu aqhathaniswa ne-ipc-rb-276 (uhlelo luka-1992). Njengamanje, i-warpage evumelekile yefektri ngayinye yomhlangano we-elekthronikhi, noma ngabe inamacala amabili noma ungqimba oluningi, ingu-1.6mm ubukhulu, imvamisa ingu-0.70 ~ 0.75%. Kumabhodi amaningi we-SMT ne-BGA, kudingeka ukuthi abe ngu-0.5%. Amanye amafektri kagesi akhuthaza ukukhuphula izinga le-warpage libe ngu-0.3%. Indlela yokuhlola i-warpage izohambisana ne-gb4677.5-84 noma i-ipc-tm-650.2.4.22b. Beka ibhodi eliphrintiwe kungxenyekazi eqinisekisiwe, faka inaliti yokuhlola endaweni enendawo enkulu kakhulu yokulwa, bese uhlukanisa ububanzi benaliti yokuhlola ngobude bomphetho ogobile webhodi eliphrintiwe ukubala i-warpage yebhodi eliphrintiwe.

3, Anti warping ipuleti ngesikhathi yokukhiqiza

1.Ukwaklanywa kobunjiniyela: izinyathelo zokuqapha ku-PCB Design:

A. Ukuhlelwa kwamashidi aphulukisiwe aphakathi kwezendlalelo kuzoba kokulingana. Isibonelo, ukushuba phakathi kwezendlalelo 1 ~ 2 no-5 ~ 6 kwezingqimba eziyisithupha kuzofanelana nenani lamashidi aphulukisiwe, ngaphandle kwalokho kulula ukugoqa ngemuva kokuhlungwa.

B. Imikhiqizo yomphakeli ofanayo izosetshenziselwa ibhodi eyisiqalo yama-multilayer kanye neshidi elipholile.

C. Indawo yephethini yomugqa ebusweni a nobuso B besendlalelo sangaphandle kufanele sisondele ngangokunokwenzeka. Uma i-surface a ingubuso obukhulu bethusi futhi indawo engu-B ithatha kuphela izintambo ezimbalwa, ibhodi eliphrintiwe lilula ukulugwedla ngemuva kokudotshwa. Uma umehluko wendawo yomugqa phakathi kwezinhlangothi zombili mkhulu kakhulu, amanye ama-grid azimele angangezwa ohlangothini oluncane lwebhalansi.

2. Ipuleti lokomisa ngaphambi kokuvala:

Inhloso yokomisa i-laminate egqoke ithusi ngaphambi kokugcwala (150 ° C, isikhathi esingu-8 ± 2 amahora) ukususa umswakama epuletini, ukuqinisa ngokuphelele i-resin epuletini nokuqhubeka nokuqeda ukucindezeleka okusele epuletini, okusizayo ukuvimbela i-plate warpage. Njengamanje, amabhodi amaningi anezinhlangothi ezimbili nangama-multilayer asalandela isinyathelo sokomisa ngaphambi noma ngemuva kokuvala. Kodwa-ke, kukhona okuhlukile kwezinye izimboni zamapuleti. Njengamanje, imithethonqubo yesikhathi sokomisa izimboni ze-PCB nayo ayivumelani, kusuka emahoreni amane kuya kwayishumi. Kunconywa ukuthi uthathe isinqumo ngokuya ngebanga lamabhodi aphrintiwe akhiqizwayo kanye nezidingo zamakhasimende ze-warpage. Zombili izindlela zingenzeka. Kunconywa ukomisa ibhodi ngemuva kokusika. Ipuleti langaphakathi nalo liyomiswa.

3.I-latitude kanye ne-latitude yeshidi elilaphekiwe:

I-warp kanye ne-weft shrinkage yeshidi elelapheki ngemuva kokunamathiswa kwehlukile, ngakho-ke i-warp ne-weft kufanele ihlukaniswe ngesikhathi sokuvalwa nokuvulwa. Ngaphandle kwalokho, kulula ukudala i-warpage yepuleti eliqediwe ngemuva kokugcotshwa, futhi kunzima ukulungisa noma ngabe ingcindezi isetshenziswa ukomisa ipuleti. Izizathu eziningi zekhasi lempi lamabhodi ama-multilayer abangelwa ukungacaci kobude nobubanzi bamashidi aphulukisiwe ngesikhathi sokuvikeleka.

Ungahlukanisa kanjani phakathi kobude nobude? Inkomba yokugingqeka yeshidi eligoqiwe elilungisiwe liyi-warp direction, futhi ububanzi bubheke kusiqondisi se-weft; Okwenziwe ngethusi, uhlangothi olude lusesiqondisweni se-weft, kanti uhlangothi olufushane lusesiqondisweni se-warp. Uma ungaqiniseki, ungabheka kumenzi noma kumhlinzeki.

4.Ukukhululeka kwengcindezi ngemuva kokuvikeleka:

Ngemuva kokucindezela okushisayo nokucindezela okubandayo, khipha ibhodi le-multilayer, usike noma ugaye i-burr, bese uyibeka phansi kuhhavini ngo-150 ℃ amahora amane, ukuze ukhulule kancane ukucindezeleka ebhodini futhi ulaphe ngokuphelele i-resin . Lesi sinyathelo asikwazi ukushiywa.

5. Ishidi lidinga ukuqondiswa ngesikhathi sokukhethwa kwe-electroplating:

Lapho i-0.4 ~ 0.6mm ultra-thin multilayer board isetshenziselwa ipuleti ebusweni i-electroplating nephethini ye-electroplating, kuzokwenziwa ama-roller akhethekile. Ngemuva kokucindezela amapuleti amancane kubha endizayo kulayini we-electroplating othomathikhi, sebenzisa induku eyindilinga ukubopha izigaxa zengcwecwe kubha yonke endizayo, ukuze kuqondiswe wonke amapuleti ku-roller, ukuze amapuleti agobekile angakhubazeki. Ngaphandle kwalesi silinganiso, ipuleti elincanyana lizogobela ngemuva kokufaka ungqimba wethusi wama-microns angama-20 noma angama-30, futhi kunzima ukukulungisa.

6.Ukupholisa ipuleti ngemuva kokushisa komoya oshisayo:

Lapho ibhodi eliphrintiwe lilinganiswa ngumoya oshisayo, kuthintwa ukushisa okuphezulu kwebhavu le-solder (cishe ama-250 ℃), bese libekwa kupuleti lemabula noma ipuleti lensimbi lokupholisa kwemvelo, bese lithunyelwa kwiprosesa yeposi yokuhlanza. Lokhu kuhle ekulweni nokuphikisana kwebhodi. Ukuze kuthuthukiswe ukugqama komphezulu wethini lomthofu, amanye amafektri afaka amapuleti emanzini abandayo ngokushesha ngemuva kokulinganiswa komoya oshisayo, futhi awakhiphele ukuyokwelashwa ngemuva kwemizuzwana embalwa. Lokhu kushisa okukodwa kanye nomthelela owodwa obandayo kungenzeka kukhiqize i-warpage, i-delamination noma i-blistering kwezinye izinhlobo zamapuleti. Ngaphezu kwalokho, kungafakwa umbhede ezintantayo emoyeni ezintweni zokupholisa.

7. Ukwelashwa kwepuleti elisontayo:

Kwimboni ephethwe kahle, ukuhlolwa kwe-flatness okungu-100% kuzokwenziwa ngesikhathi sokuhlolwa kokugcina kwamabhodi aphrintiwe. Wonke amabhodi angafaneleki azokhethwa, afakwe kuhhavini, omiswe ngo-150 ℃ nangaphansi kwengcindezi esindayo amahora angama-3 ~ 6, bese epholile ngokwemvelo ngaphansi kwengcindezi enkulu. Bese ukhipha ibhodi ngemuva kokukhululeka kwengcindezi bese uhlola ubucayi. Ngale ndlela, amanye amabhodi angagcinwa. Amanye amabhodi adinga ukomiswa nokucindezelwa kabili noma kathathu ukuze alinganiswe. Umshini we-pneumatic plate warping and straighting machine omelwe yiShanghai Huabao usetshenziswe yiShanghai Bell ukulungisa i-warpage yebhodi lesifunda. Uma lezi zinyathelo ezingenhla zokulwa nezinqubo zokulwa zingasetshenziswanga, amanye amabhodi awasizi ngalutho futhi angacishwa kuphela.