Amaphakheji we-IC ancike ku- PCB ukushabalalisa ukushisa. In general, PCB is the main cooling method for high power semiconductor devices. A good PCB heat dissipation design has a great impact, it can make the system run well, but also can bury the hidden danger of thermal accidents. Ukuphathwa ngokucophelela kokuhlelwa kwe-PCB, ukwakheka kwebhodi, nokufakwa kwedivayisi kungasiza ekuthuthukiseni ukusebenza kokushiswa kokushisa kwezicelo eziphakathi nendawo namandla amakhulu.

Abakhiqizi be-Semiconductor banobunzima bokulawula amasistimu asebenzisa amadivayisi abo. Kodwa-ke, uhlelo olune-IC olufakiwe lubalulekile ekusebenzeni kwedivayisi yonke. Kumadivayisi we-IC wangokwezifiso, umklami wohlelo ngokujwayelekile usebenza eduze nomenzi ukuqinisekisa ukuthi uhlelo luhlangabezana nezidingo eziningi zokuhlakazeka kokushisa kwamadivayisi aphezulu wamandla. Lokhu kusebenzisana kokuqala kuqinisekisa ukuthi i-IC ihlangabezana namazinga kagesi nokusebenza, ngenkathi iqinisekisa ukusebenza okufanele ngaphakathi kohlelo lokupholisa lekhasimende. Many large semiconductor companies sell devices as standard components, and there is no contact between the manufacturer and the end application. Kulokhu, singasebenzisa kuphela imihlahlandlela ejwayelekile ukusiza ukufezekisa isixazululo esingcono sokuqedwa kokushisa kwe-IC nohlelo.

Ungaklama kanjani ukushabalalisa ukushisa kwe-PCB

Uhlobo lwephakeji elijwayelekile le-semiconductor alinalutho noma iphakethe le-PowerPADTM. In these packages, the chip is mounted on a metal plate called a chip pad. Lolu hlobo lwe-chip pad lusekela i-chip ngenkathi kucutshungulwa i-chip, futhi futhi luyindlela enhle yokushisa yokushabalalisa ukushisa kwedivayisi. When the packaged bare pad is welded to the PCB, heat is quickly exited from the package and into the PCB. The heat is then dissipated through the PCB layers into the surrounding air. Amaphakheji we-pad pad ngokuvamile adlulisa cishe ama-80% wokushisa angene ku-PCB phansi kwephakeji. Ukushisa okungu-20% okusele kukhishwa ngezintambo zedivayisi nezinhlangothi ezahlukahlukene zephakeji. Ngaphansi kuka-1% wokushisa kuphuma phezulu kwephakeji. Endabeni yamaphakeji angenalutho, ukwakheka okuhle kokushisa kokushisa kwe-PCB kubalulekile ukuqinisekisa ukusebenza kwensiza ethile.

Isici sokuqala sokuklanywa kwe-PCB esithuthukisa ukusebenza okushisayo ukwakheka kwedivayisi ye-PCB. Noma nini lapho kunokwenzeka, izingxenye zamandla aphezulu ku-PCB kufanele zihlukaniswe zodwa. Lesi sikhala somzimba phakathi kwezakhi zamandla aphezulu sandisa indawo ye-PCB ezungeze ingxenye ngayinye yamandla aphezulu, esiza ukufeza ukudluliswa okungcono kokushisa. Care should be taken to separate temperature sensitive components from high power components on the PCB. Lapho kungenzeka khona, izingxenye zamandla aphezulu kufanele zitholakale kude namakhona we-PCB. Ukuma okuphakathi kwe-PCB kukhulisa indawo yebhodi ezungeze izinto ezinamandla amakhulu, ngaleyo ndlela kusize ukuqeda ukushisa. Amadivayisi amabili afanayo e-semiconductor akhonjisiwe: izingxenye A no-B. Ingxenye A, etholakala ekhoneni le-PCB, inokushisa okuhlangana nge-chip okungu-5% ngaphezulu kwengxenye B, ebekwe phakathi nendawo. Ukushiswa kokushisa ekhoneni lengxenye A kukhawulwe indawo encane yephaneli ezungeze ingxenye esetshenziselwa ukushabalalisa ukushisa.

Isici sesibili ukwakheka kwe-PCB, okunethonya eliwujuqu ekusebenzeni okushisayo komklamo we-PCB. Njengomthetho ojwayelekile, lapho i-PCB inethusi eliningi, kuyanda ukusebenza okushisayo kwezingxenye zohlelo. Isimo esifanelekile sokushabalalisa ukushisa samadivayisi we-semiconductor ukuthi i-chip ibekwe ebhulokini elikhulu lethusi elipholile uketshezi. Lokhu akusebenzi ezinhlelweni eziningi, ngakho-ke bekufanele senze ezinye izinguquko ku-PCB ukuthuthukisa ukushabalalisa ukushisa. For most applications today, the total volume of the system is shrinking, adversely affecting heat dissipation performance. Larger PCBS have more surface area that can be used for heat transfer, but also have more flexibility to leave enough space between high-power components.

Uma kungenzeka, khulisa inombolo nokushuba kwezingqimba zethusi ze-PCB. Isisindo sethusi lokumisa ngokuvamile sikhulu, okuyindlela enhle kakhulu yokushisa kwayo yonke ukushisa kokushisa kwe-PCB. The arrangement of the wiring of the layers also increases the total specific gravity of copper used for heat conduction. Kodwa-ke, le wiring ivame ukufakwa ngogesi, inciphise ukusetshenziswa kwayo njengendawo yokushisa engaba khona. Isisekelo sedivayisi kufanele sifakwe izintambo ngogesi ngangokunokwenzeka kwizendlalelo eziningi zokusiza ngangokunokwenzeka ukusiza ukukhulisa ukuqhutshwa kokushisa. Izimbobo zokushiswa kokushisa ku-PCB engezansi kwensiza ye-semiconductor zisiza ukushisa ukufaka izingqimba ezishumekiwe ze-PCB bese zidlulisela emuva ebhodini.

Izendlalelo eziphezulu nezingezansi ze-PCB “yizindawo eziphambili” zokwenza ngcono ukupholisa ukusebenza. Kusetshenziswa izintambo ezibanzi nokuhamba umzila kude namadivayisi anamandla amakhulu kunganikeza indlela eshisayo yokushabalalisa ukushisa. Ibhodi elikhethekile lokuqhuba ukushisa kuyindlela enhle kakhulu yokushabalalisa ukushisa kwe-PCB. Ipuleti lokushisa elishisayo litholakala phezulu noma emuva kwe-PCB futhi lixhunywe ngomshini kudivayisi ngokuxhuma ngqo kwethusi noma imbobo eshisayo. Endabeni yokupakisha okusemgqeni (kuphela ngemikhondo ezinhlangothini zombili zephakeji), ipuleti lokuqhuba ukushisa lingabekwa ngaphezulu kwe-PCB, elibunjwe “njengethambo lenja” (maphakathi mncane njengephakethe, ithusi elikude nephakeji linendawo enkulu, lincane phakathi futhi likhulu emaphethelweni womabili). Endabeni yephakethe elinezinhlangothi ezine (elinemikhondo kuzo zonke izinhlangothi ezine), ipuleti lokuqhuba ukushisa kufanele libekwe ngemuva kwe-PCB noma ngaphakathi kwe-PCB.

Ukukhulisa usayizi wepuleti lokuqhuba ukushisa kuyindlela enhle kakhulu yokwenza ngcono ukushisa kwamaphakeji we-PowerPAD. Different size of heat conduction plate has great influence on thermal performance. Ishidi ledatha lomkhiqizo elijwayelekile liyabalela lezi zilinganiso. Kepha ukulinganisa umthelela wethusi elengeziwe kuma-PCBS wangokwezifiso kunzima. With online calculators, users can select a device and change the size of the copper pad to estimate its effect on the thermal performance of a non-JEDEC PCB. Lawa mathuluzi wokubala aqokomisa izinga lapho ukwakheka kwe-PCB kunomthelela ekusebenzeni kokushabalalisa ukushisa. For four-side packages, where the area of the top pad is just less than the bare pad area of the device, embedding or back layer is the first method to achieve better cooling. Ngamaphakheji ama-in-line amabili, singasebenzisa isitayela sephedi “inja yethambo” ukuqeda ukushisa.

Ekugcineni, amasistimu ane-PCBS emikhulu angasetshenziselwa ukupholisa. The screws used to mount the PCB can also provide effective thermal access to the base of the system when connected to the thermal plate and ground layer. Uma kubhekwa ukuhanjiswa okushisayo nezindleko, inani lezikulufo kufanele likhuliswe kuze kufike ezingeni lokuncipha kwembuyiselo. Ukuqina kwensimbi ye-PCB kunendawo epholisa kakhulu ngemuva kokuxhunywa kupuleti elishisayo. Kwezinye izinhlelo zokusebenza lapho izindlu ze-PCB zinegobolondo, impahla ye-TYPE B solder patch inokusebenza okuphezulu okushisayo kunegobolondo elipholile lomoya. Izixazululo zokupholisa, ezinjengabalandeli namaphiko, nazo zivame ukusetshenziselwa ukupholisa uhlelo, kepha zivame ukudinga isikhala esithe xaxa noma zidinga ukuguqulwa kokuklama ukukhulisa ukupholisa.

Ukuklama uhlelo olunokusebenza okuphezulu okushisayo, akwanele ukukhetha idivayisi enhle ye-IC nesisombululo esivaliwe. Ukuhlelwa kokusebenza kokupholisa kwe-IC kuncike ku-PCB namandla esistimu yokupholisa ukuvumela amadivayisi we-IC ukuthi aphole ngokushesha. Indlela yokupholisa engenziwanga eshiwo ngenhla ingathuthukisa kakhulu ukusebenza kokushabalalisa ukushisa kohlelo.