The first step of PCB Ishlab chiqarish – bu PCB tartibini tartibga solish va tekshirish. PCB ishlab chiqarish zavodi PCB dizayn kompaniyasidan SAPR fayllarini oladi. Har bir SAPR dasturiy ta’minoti o’ziga xos fayl formatiga ega bo’lgani uchun, PCB zavodi ularni yagona formatga o’tkazadi-Kengaytirilgan Gerber RS-274X yoki Gerber X2. Then the engineer of the factory will check whether the PCB layout conforms to the production process, whether there are any defects and other problems.

Uyda ishlab chiqarilgan PCBSlardan birida, PCB sxemasi lazer printer yordamida qog’ozga bosiladi va keyin mis bilan qoplangan taxtaga o’tkaziladi. Biroq, bosib chiqarish jarayonida, printer siyoh tanqisligi nuqsoniga moyil bo’lgani uchun, siyohni yog’li qalam bilan qo’lda to’ldirish kerak.

Ishlab chiqarishning oz miqdori yaxshi, lekin agar bu nuqson sanoat ishlab chiqarishiga o’tkazilsa, bu ishlab chiqarish samaradorligini ancha pasaytiradi. Therefore, the factory generally adopts the way of photocopying, printing the PCB layout on the film. If it is a multi-layer PCB, the layout of each layer will be arranged in order.

The film is then punched with counterpoint holes. Counterpoint holes are very important, and are then used to align materials on each layer of the PCB.

Asosiy taxta ishlab chiqarish

Clean the copper clad plate, if dust may cause the final circuit short circuit or break.

The figure below is an illustration of an 8-layer PCB, which is actually made up of 3 copper-clad plates (core boards) plus 2 copper films and then glued together with semi-cured sheets. The production sequence starts from the core board (four or five layers of lines) in the middle, and is continuously stacked together before being fixed. 4 qatlamli PCB xuddi shunday qilingan, lekin faqat bitta yadroli plastinka va ikkita mis plyonka.

Transfer of inner PCB layout

Therefore, the two-layer circuit of the most central Core plate should be made first. After the copper-clad plate is cleaned, the surface is covered with a photosensitive film. Film yorug’lik ta’sirida qattiqlashadi, mis qoplamali plastinkaning mis plyonkasi ustida himoya plyonka hosil qiladi.

Insert two layers of PCB layout film and two layers of copper clad board, and finally insert the upper layer of PCB layout film to ensure that the upper and lower layers of PCB layout film stacking position is accurate.

Photosensitizer uses UV lamp to irradiate the photosensitive film on copper foil. The photosensitive film is solidified under the transparent film, and the photosensitive film is not solidified under the opaque film. The copper foil covered by solidified photosensitive film is the PCB layout line needed, equivalent to the role of laser printer ink of manual PCB. Oldingi lazer printerining qog’ozli PCB sxemasida qora toner saqlanishi uchun mis folga bilan qoplangan. In this case, the copper foil covered with black film will corrode away, while the transparent film will be preserved as the photosensitive film solidifies.

Keyin quritilmagan plyonka eritma bilan yuviladi va kerakli plyonka plyonkasi quritilgan plyonka bilan qoplanadi.

Inner core board etching

The unwanted copper foil is then etched away with a strong base, such as NaOH.

Tear off the cured photosensitive film to expose the copper foil needed for PCB layout circuit.

Yadro plitalarini burg’ulash va tekshirish

Yadro plitasi muvaffaqiyatli tayyorlandi. Then make the opposite hole in the core plate for easy alignment with other raw materials.

Once the core board is pressed with other layers of PCB, it cannot be modified, so it is very important to check. Xatolarni tekshirish uchun mashina avtomatik ravishda PCB sxemasi bilan solishtiriladi.

PCB plitalarining dastlabki ikki qatlami tayyorlandi

laminatlangan

Here we need a new raw material called semi-cured sheet (Prepreg), which is the core board and core board (PCB layer number & GT; 4) va yadro plitasi va tashqi mis folga orasidagi yopishtiruvchi, lekin izolyatsiyalashda ham rol o’ynaydi.

The lower layer of copper foil and two layers of semi-solidified sheet have been in advance through the positioning hole and the lower iron plate fixed position, and then the good core plate is also put into the positioning hole, and finally in turn two layers of semi-solidified sheet, a layer of copper foil and a layer of pressure aluminum plate covered on the core plate.

In order to improve work efficiency, the factory will stack three different PCB boards together and then fix them. The upper iron plate is magnetically attracted to facilitate counterpoint with the lower iron plate. Qarama -qarshi ignani joylashtirish orqali temir plastinkaning ikki qatlamli tayanch punkti muvaffaqiyatli, temir plastinka orasidagi bo’shliqni iloji boricha siqib chiqaradi, so’ngra mixlar bilan o’rnatiladi.

PCB board clamped by iron plate is placed on the support, and then into the vacuum hot press for lamination. The heat in the vacuum hot press melts the epoxy resin in the semi-cured sheet, holding the core and copper foil together under pressure.

After laminating, remove the top iron plate that presses the PCB. Keyin bosimli alyuminiy plastinka chiqariladi. Alyuminiy plastinka, shuningdek, har xil PCBSni izolyatsiyalashda va tenglikni tashqi qatlamida mis plyonkaning silliqligini ta’minlashda muhim rol o’ynaydi. Both sides of the PCB are covered with a layer of smooth copper foil.

burg’ulash

Mis folga tegmaydigan to’rtta qatlamni tenglikni ichida qanday ulash mumkin? PCB birinchi navbatda teshiklar orqali burg’ulashadi, so’ng elektr tokini o’tkazish uchun metalllanadi.

Rentgen burg’ulash mashinasi ichki qatlamning yadro taxtasini topish uchun ishlatiladi. Mashina yadro taxtasida teshikning joylashishini avtomatik ravishda topadi va joylashtiradi, so’ngra quyidagi burg’ulash teshik pozitsiyasining o’rtasidan o’tishini ta’minlash uchun tenglikni joylashtiruvchi teshiklarni o’rnatadi.

Place a sheet of aluminum on the punch machine and then place the PCB on top. Burg’ilash nisbatan sekin jarayon bo’lgani uchun, samaradorlikni oshirish maqsadida, tenglikni qatlamlari soniga qarab teshilish uchun 1 dan 3 tagacha bir xil tenglikni platalari yig’iladi. Nihoyat, yuqori PCB alyuminiy qatlami, alyuminiyning yuqori va pastki qatlamlari bilan qoplangan, shuning uchun matkap ichkariga va tashqariga burg’ulash paytida, tenglikdagi mis folga yirtilmaydi.

The operator then only needs to select the correct drilling procedure and the drilling machine does the rest automatically. Matkap uchi havo bosimi bilan boshqariladi, maksimal aylanish tezligi daqiqada 150,000, bu devorning tekisligini ta’minlash uchun etarlicha yuqori.

Matkap uchini almashtirish ham dasturga muvofiq mashina tomonidan avtomatik ravishda amalga oshiriladi. The smallest drill can be 100 microns in diameter, while a human hair is 150 microns in diameter.

Oldingi laminatsiya jarayonida eritilgan epoksi PCB tashqi tomoniga ekstrudirovka qilingan, shuning uchun uni olib tashlash kerak edi. Kalıplama frezeleme mashinasi, tenglikdagi XY koordinatalariga muvofiq, tenglikni atrofini kesadi.

Misning teshik devoriga kimyoviy tushishi

Deyarli barcha PCB dizaynlari turli qatlamli chiziqlarni ulash uchun teshiklardan foydalanganligi uchun, yaxshi ulanish uchun teshik devoriga 25 mikronli mis plyonka kerak bo’ladi. This thickness of copper film is achieved by electroplating, but the hole wall is made of non-conductive epoxy resin and fiberglass board. Shuning uchun, birinchi navbatda, teshik devorida o’tkazgichli material qatlamini to’plash va kimyoviy cho’kma orqali butun devor yuzasida, shu jumladan teshik devorida 1 mikronli mis plyonka hosil qilish kerak. Kimyoviy tozalash va tozalash kabi butun jarayon mashinalar tomonidan boshqariladi.

Ruxsat etilgan PCB

PCBni tozalang

Delivery of PCB

Chemical precipitation of copper film

Transfer the layout of the outer PCB

Next, the layout of the outer PCB will be transferred to the copper foil. The process is similar to that of the PCB layout of the inner core board, which is transferred to the copper foil using photocopied film and photosensitive film. The only difference is that the positive plate will be used as the board.

The transfer of inner PCB layout introduced above adopts the subtraction method and adopts the negative plate as the board. PCB covered by solidified photosensitive film is circuit, clean the unsolidified photosensitive film, exposed copper foil is etched, PCB layout circuit is protected by solidified photosensitive film. The outer PCB layout is transferred by the normal method, and the positive plate is used as the board. The area covered by a cured film on a PCB is a non – line area. After cleaning the uncured film, electroplating is carried out. Hech qanday plyonkani elektroliz qilish mumkin emas, plyonka ham yo’q, avval mis, keyin qalay bilan qoplangan. Filmni olib tashlaganingizdan so’ng, gidroksidi aşındırma amalga oshiriladi va nihoyat qalay chiqariladi. The circuit pattern is left on the board because it is protected by tin.

Mis folga PCB ning har ikki tomonini matbuotga tozalang, press mis folga qolip bosilishiga sezgir bo’ladi.

O’rnatish teshigidan yuqori va pastki qavatlarning PCB tasmasini joylashtiring. The photosensitive film under the transmittance film is then solidified by UV lamp irradiation, which is the line that needs to be preserved.

After cleaning the film that is not needed and has not been cured, inspect it.

Clamp the PCB and electroplate the copper. As mentioned before, in order to ensure that the hole has good electrical conductivity, the copper film electroplated on the hole wall must have a thickness of 25 microns, so the whole system will be automatically controlled by computer to ensure its accuracy.

Ruxsat etilgan PCB

Computer control and electroplating copper

After the copper film is electroplated, the computer arranges for a thin layer of tin to be replated.

Kalay bilan qoplangan PCB kartasini tushirgandan so’ng, mis va qalay qoplamasining qalinligi to’g’riligini tekshiring.

PCB -ning tashqi ko’rinishi

Keyinchalik, avtomatlashtirilgan yig’ish liniyasi qazish jarayonini yakunlaydi. Birinchidan, PCB kartasidagi quritilgan plyonkani tozalang.

Keyin kuchli gidroksidi u bilan qoplangan kiruvchi mis plyonkani tozalash uchun ishlatiladi.

Keyin PCB sxemasining mis folga ustidagi qalay qoplamasi qalayni tozalash eritmasi bilan chiqariladi. After cleaning, 4 layers PCB layout is completed.