Masana'antar kayan PCB sun kashe lokaci mai yawa na haɓaka kayan da ke ba da asarar sigina mafi ƙasƙanci. Don babban saurin ƙira da ƙira mai tsayi, asara za ta iyakance nisan yaɗuwar sigina da karkatar da sigina, kuma zai haifar da ɓarna da za a iya gani a ma'aunin TDR. Yayin da muke zana kowane allon da'irar da aka buga kuma muna haɓaka da'irori waɗanda ke aiki a mitoci mafi girma, yana iya zama abin sha'awa don zaɓar mafi kyawun yuwuwar jan ƙarfe a duk ƙirar da kuka ƙirƙira.

Duk da yake gaskiya ne cewa taurin jan ƙarfe yana haifar da ƙarin ɓarna da asara, yaya santsi yake buƙatar foil ɗin jan karfe na gaske? Shin akwai wasu hanyoyi masu sauƙi da za ku iya amfani da su don shawo kan asara ba tare da zaɓar jan ƙarfe mai laushi ba don kowane ƙira? Za mu dubi wadannan maki a cikin wannan labarin, kazalika da abin da za ka iya nema idan ka fara siyayya don PCB stackup kayan.

Nau'o'inPCB Copper Foil

Yawanci lokacin da muke magana game da jan karfe akan kayan PCB, ba ma magana game da takamaiman nau'in jan ƙarfe ba, muna magana ne kawai game da roughness. Hanyoyi daban-daban na saka tagulla suna samar da fina-finai masu ƙima daban-daban, waɗanda za'a iya bambanta su a fili a cikin hoton microscope na lantarki (SEM). Idan za ku yi aiki a mitoci masu girma (yawanci 5 GHz WiFi ko sama) ko kuma a cikin babban gudu, to ku kula da nau'in jan karfe da aka ƙayyade a cikin takaddar bayanan kayanku.

Hakanan, tabbatar da fahimtar ma'anar ƙimar Dk a cikin takaddun bayanai. Kalli wannan tattaunawar podcast tare da John Coonrod daga Rogers don ƙarin koyo game da ƙayyadaddun Dk. Tare da wannan a zuciya, bari mu kalli wasu nau'ikan bangon tagulla na PCB daban-daban.

Electrodeposited

A cikin wannan tsari, ana jujjuya ganga ta hanyar maganin electrolytic, kuma ana amfani da amsawar electrodeposition don "girma" foil ɗin tagulla akan drum. Yayin da ganga ke jujjuyawa, fim ɗin jan ƙarfe da ya haifar yana nannade shi a hankali a kan abin nadi, yana ba da takardar jan karfe mai ci gaba da za a iya birgima a kan laminate. Bangaren ganga na jan ƙarfe zai dace da ƙaƙƙarfan drum, yayin da gefen da aka fallasa zai kasance da ƙarfi sosai.

Rufin tagulla na PCB na lantarki

Electrodeposited jan karfe samar.
Domin a yi amfani da shi a cikin daidaitaccen tsari na ƙirƙira na PCB, za a fara haɗa ƙaƙƙarfan gefen jan karfe zuwa dielectric-gilashin guduro. Ragowar jan karfe da aka fallasa (gefen ganga) za a buƙaci a yi ta da gangan ta hanyar sinadarai (misali, tare da etching plasma) kafin a iya amfani da shi a daidaitaccen tsarin lamintar tagulla. Wannan zai tabbatar da cewa ana iya haɗa shi zuwa Layer na gaba a cikin tarin PCB.

Tagulla Mai Wutar Lantarki Mai Magance Surface

Ban san mafi kyawun lokacin da ya ƙunshi duk nau'ikan nau'ikan saman da aka yi wa magani batagulla foils, ta haka ne a sama take. Waɗannan kayan tagulla an fi sanin su da foils na baya, kodayake akwai wasu bambance-bambancen guda biyu (duba ƙasa).

Foils na baya da aka yi amfani da su suna amfani da jiyya na saman da aka shafa zuwa gefen santsi (gefen ganga) na takardar jan ƙarfe da aka ajiye. Layer na magani shine kawai sirara mai laushi wanda ke lalata tagulla da gangan, don haka zai sami ƙarin mannewa zuwa kayan dielectric. Waɗannan jiyya kuma suna aiki azaman shingen oxidation wanda ke hana lalata. Lokacin da aka yi amfani da wannan jan ƙarfe don ƙirƙirar bangarori na laminate, gefen da aka kula da shi yana haɗuwa da dielectric, kuma ɓangaren da ya rage ya kasance a bayyane. Gefen da aka fallasa ba zai buƙaci ƙarin roughening kafin etching; zai riga ya sami isasshen ƙarfi don haɗawa zuwa Layer na gaba a cikin tarin PCB.

Bambance-bambancen guda uku akan foil jan ƙarfe da aka bi da su sun haɗa da:

Babban zafin jiki elongation (HTE) jan karfe: Wannan shi ne wani electrodeposited jan karfe tsare cewa ya dace da IPC-4562 Grade 3 bayani dalla-dalla. Hakanan ana kula da fuskar da aka fallasa tare da shingen oxidation don hana lalata yayin ajiya.
Foil mai magani sau biyu: A cikin wannan foil ɗin tagulla, ana shafa maganin a bangarorin biyu na fim ɗin. Wannan abu wani lokaci ana kiransa foil-gefen drum.
Copper Resistive: Wannan ba a kayyade shi azaman jan ƙarfe da aka yi masa magani ba. Wannan foil ɗin tagulla yana amfani da murfin ƙarfe akan gefen matte na tagulla, wanda sai a murɗa shi zuwa matakin da ake so.
Aikace-aikacen jiyya na sama a cikin waɗannan kayan jan ƙarfe yana da sauƙi: ana jujjuya foil ta ƙarin baho na electrolyte waɗanda ke amfani da platin jan karfe na biyu, sannan kuma Layer iri mai shinge, sannan kuma a ƙarshe Layer na fim mai hana tarnish.

PCB tagulla foil

Hanyoyin jiyya na saman don foils na jan karfe. [Madogararsa: Pytel, Steven G., et al. "Bincike na jiyya na jan karfe da kuma tasiri akan yaduwar sigina." A cikin 2008 58th Kayan Kayan Wutar Lantarki da Taron Fasaha, shafi 1144-1149. IEEE, 2008.]
Tare da waɗannan matakai, kuna da kayan da za'a iya amfani da su cikin sauƙi a cikin daidaitaccen tsarin ƙirƙira allon tare da ƙaramin ƙarin aiki.

Nadi-Annealed Copper

Foil ɗin tagulla da aka naɗe-haɗe zai wuce nadi na tagulla ta cikin nau'ikan nadi, wanda zai yi sanyi-mirgina takardar tagulla zuwa kaurin da ake so. Ƙunƙarar takaddar foil ɗin da aka samu zai bambanta dangane da sigogin mirgina (gudu, matsa lamba, da sauransu).

Sakamakon takardar na iya zama santsi sosai, kuma ana iya ganin striations a saman takardar tagulla da aka yi birgima. Hotunan da ke ƙasa suna nuna kwatance tsakanin foil ɗin jan ƙarfe da aka yi birgima da birgima.

Kwatancen foil na tagulla na PCB

Kwatanta na electrodeposited vs. birgima-annealed foils.
Copper Low-Profile
Wannan ba lallai ba ne nau'in foil na jan karfe da za ku ƙirƙira tare da madadin tsari. Low-profile jan karfe ne electrodeposited jan karfe da aka gyara da kuma gyara tare da micro-roughening tsari don samar da matsakaicin matsakaicin roughening tare da isasshen roughening don mannewa da substrate. Hanyoyin kera waɗannan foils na tagulla na al'ada ne. Waɗannan tsare-tsare galibi ana rarraba su azaman ultra-low profile (ULP), ƙaramin bayanin martaba (VLP), da ƙananan bayanan martaba (LP, kusan matsakaicin matsakaicin micron 1).

Labarai masu alaƙa:

Me yasa ake amfani da Foil na Copper a Masana'antar PCB?

Foil ɗin Tagulla da Ake Amfani da shi a cikin Bugawar Hukumar da'ira