Tun farkon 1950s, buga kewaye hukumar (PCB) ya kasance ainihin tsarin gini na marufi na lantarki, a matsayin mai ɗaukar kayan lantarki daban-daban da cibiyar watsa siginar kewayawa, ingancinsa da amincinsa ke ƙayyade inganci da amincin duka marufi na lantarki. Tare da miniaturization, nauyi mai nauyi da buƙatun ayyuka masu yawa na samfuran lantarki, da haɓaka ayyukan ba tare da gubar da halogen ba, buƙatun amincin PCB zai zama mafi girma kuma mafi girma. Saboda haka, yadda za a sauri gano PCB AMINCI matsaloli da kuma yin daidai AMINCI kyautata ya zama daya daga cikin muhimman al’amurran da suka shafi PCB Enterprises.

Common PCB reliability problems and typical legends

Rashin solderability mara kyau

(Babu jika)

Rashin solderability mara kyau (rashin jika)

waldi na zahiri

(Pillow effect)

Talakawa dogara

Tabarbarewar faranti

Open circuit (through hole)

Bude kewaye

(Laser blind rami)

Bude kewaye

Bude kewaye (ICD)

Short circuit (CAF)

Short circuit (ECM)

Farantin kona

Duk da haka, a cikin nazarin gazawar matsalolin dogara a aikace, tsarin gazawar yanayin rashin nasara ɗaya na iya zama mai rikitarwa da bambanta. Don haka, kamar binciken shari’a, daidaitaccen tunani na nazari, tsantsar tunani mai ma’ana da hanyoyin bincike iri-iri ana buƙatar gano ainihin dalilin gazawar. In this process, any link is slightly negligent, may cause “unjust, false and wrong case”.

Gabaɗaya Tattalin Arziki Matsalolin Tarin Bayanan Fage

Bayanin bangon baya shine tushen binciken gazawar matsalolin dogaro, kai tsaye yana shafar yanayin duk binciken gazawar da ke gaba, kuma yana da tasiri mai mahimmanci akan ƙudurin tsarin ƙarshe. Therefore, prior to failure analysis, information behind failure should be collected as much as possible, usually including but not limited to:

(1) Failure range: failure batch information and corresponding failure rate

(1) Idan nau’i ɗaya na matsalolin samar da taro, ko ƙananan gazawar, to, yiwuwar sarrafa tsarin da ba daidai ba ya fi girma;

(2) Idan akwai matsaloli a cikin nau’i na farko / nau’i-nau’i masu yawa, ko rashin nasara ya yi yawa, ba za a iya cire tasirin kayan aiki da abubuwan ƙira ba;

(2) Maganin gazawa: ko PCB ko PCBA sun wuce jerin hanyoyin da za a bi kafin gazawar ta faru. Maganin gama gari sun haɗa da reflux kafin yin burodi, / siyar da ba da gubar da ba ta da gubar walƙiya da walƙiya ta hannu, da dai sauransu, lokacin da ya zama dole a fahimci dalla-dalla duk kayan da ake amfani da su a cikin tsarin pretreatment (kamar manna solder, stencil, solder waya, da dai sauransu), kayan aiki (soldering baƙin ƙarfe ikon, da dai sauransu) da kuma sigogi ( gudana kwana da kuma sigogi na kalaman soldering, hannun soldering zafin jiki, da dai sauransu) bayanai;

(3) Halin gazawa: takamaiman bayanin lokacin da PCB ko PCBA suka gaza, wasu daga cikinsu sun gaza a cikin tsarin aiwatarwa na farko kamar walda da taro, kamar ƙarancin solderability, stratification, da sauransu; Some are in the subsequent aging, testing and even use of failure, such as CAF, ECM, burning plate, etc.; Cikakken fahimtar tsarin gazawa da sigogi masu alaƙa;

Rashin nasarar nazarin PCB/PCBA

Generally speaking, the number of failed products is limited, or even only one piece, so the analysis of failed products must follow the principle of layer by layer analysis from outside to inside, from non-destruction to destruction, by all means avoid premature destruction of the failure site:

(1) Duban bayyanar

Appearance observation is the first step of failure product analysis. Through the appearance of the failure site and combined with background information, experienced failure analysis engineers can basically determine several possible causes of failure and conduct follow-up analysis accordingly. Duk da haka, ya kamata a lura cewa akwai hanyoyi da yawa don lura da bayyanar, ciki har da na gani, gilashin girma na hannu, gilashin ƙara girman tebur, stereoscopic microscope da microscope metallographic. Koyaya, saboda bambance-bambancen tushen haske, ka’idar hoto da zurfin kallo, yanayin yanayin da aka lura da kayan aikin da ya dace yana buƙatar cikakken nazari bisa abubuwan kayan aiki. An haramta yin gaggawar yanke hukunci da samar da hasashen da aka riga aka yi, wanda ke kaiwa ga kuskuren bincike na gazawa da ɓata samfuran da suka gaza masu daraja da lokacin bincike.

(2) Bincike mai zurfi mara lalacewa

Ga wasu gazawar, bayyanar bayyanar ita kaɗai ba za ta iya tattara isassun bayanan gazawar ba, ko ma ba za a iya samun maƙasudin gazawar ba, irin su delamination, walda mai kama da buɗaɗɗen ciki, da sauransu. tattara ƙarin bayani, gami da gano aibi na ultrasonic, 3D X-ray, infrared thermal Hoto, gano wurin gajeriyar kewayawa, da sauransu.

A cikin mataki na bayyanar bayyanar da bincike mara lalacewa, wajibi ne a kula da halaye na yau da kullum ko daban-daban na samfurori daban-daban na gazawar, wanda za’a iya amfani dashi don yin la’akari da hukuncin rashin nasara na gaba. Bayan an tattara isassun bayanai a lokacin bincike mara lalacewa, ana iya fara nazarin gazawar da aka yi niyya.

(3) Binciken gazawa

Binciken gazawa ba makawa ne, kuma shine mataki mafi mahimmanci, sau da yawa yana ƙayyade nasarar binciken gazawar ko gazawar. There are many methods for failure analysis, such as scanning electron microscopy & elemental analysis, horizontal/vertical section, FTIR, etc., which will not be described in this section. A wannan mataki, duk da cewa hanyar nazarin gazawar tana da mahimmanci, amma abin da ya fi muhimmanci shi ne fahimta da yanke hukunci kan matsalar tabarbarewar, da daidai kuma a sarari fahimtar yanayin gazawa da tsarin gazawa, ta yadda za a gano ainihin dalilin gazawar.

Bare kwamitin PCB bincike

Lokacin da gazawar kudi ne sosai high, da bincike na danda PCB zama dole a matsayin kari ga gazawar sa bincike. Lokacin da gazawar dalilin samu a cikin bincike mataki shi ne lahani na danda-board PCB da take kaiwa zuwa kara AMINCI gazawar, to, idan danda-board PCB yana da guda lahani, guda gazawar yanayin kamar yadda kasa samfurin ya kamata a nuna bayan wannan magani. tsari azaman samfurin da ya gaza. Idan ba a sake haifar da yanayin gazawar iri ɗaya ba, to, binciken dalilin rashin nasarar samfurin kuskure ne, ko aƙalla bai cika ba.