The first step of PCB iṣelọpọ ni lati ṣeto ati ṣayẹwo Ifilelẹ PCB. Ohun ọgbin iṣelọpọ PCB gba awọn faili CAD lati ile -iṣẹ apẹrẹ PCB. Niwọn igba ti sọfitiwia CAD kọọkan ni ọna kika faili alailẹgbẹ tirẹ, ohun ọgbin PCB yi wọn pada si ọna iṣọkan-Gerber RS-274X tabi 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.

Ninu ọkan ninu awọn PCBS ti a ṣe ni ile, ipilẹ PCB ti wa ni titẹ lori iwe nipa lilo itẹwe laser ati lẹhinna gbe lọ si igbimọ ti o ni idẹ. Bibẹẹkọ, ninu ilana titẹjade, nitori itẹwe naa ni itara si aaye aipe aipe inki, o jẹ dandan lati fi inki kun pẹlu peni epo.

Iwọn kekere ti iṣelọpọ dara, ṣugbọn ti a ba gbe abawọn yii lọ si iṣelọpọ ile -iṣẹ, yoo dinku ṣiṣe iṣelọpọ pupọ. 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.

Core ọkọ gbóògì

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. PCB 4-fẹlẹfẹlẹ ni a ṣe bakanna, ṣugbọn pẹlu awo kan pataki kan ati awọn fiimu Ejò meji.

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. Fiimu naa fẹsẹmulẹ nigbati o ba farahan si ina, ti o ṣe fiimu aabo lori bankanje idẹ ti awo ti o ni idẹ.

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. Ninu apẹrẹ PCB iwe ti itẹwe laser ti tẹlẹ, toner dudu ti bo pẹlu bankanje idẹ lati ni idaduro. 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.

Fiimu ti ko ni itọju lẹhinna wẹ pẹlu lye ati pe Circuit bankanje ti a beere fun ni a bo nipasẹ fiimu ti a mu larada.

Inner core board etching

Bọtini idẹ ti a ko fẹ lẹhinna ni a fi kuro pẹlu ipilẹ to lagbara, bii NaOH.

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

Mojuto awo liluho ati ayewo

A ti ṣe awo ipilẹ ni aṣeyọri. 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. Ẹrọ naa yoo ṣe afiwera laifọwọyi pẹlu awọn aworan apẹrẹ PCB lati ṣayẹwo awọn aṣiṣe.

Ni igba akọkọ ti meji fẹlẹfẹlẹ ti PCB lọọgan ti a ti ṣe

laminated

Nibi a nilo ohun elo aise tuntun ti a pe ni iwe ti a ṣe itọju ologbele (Prepreg), eyiti o jẹ igbimọ ipilẹ ati igbimọ pataki (nọmba Layer PCB & GT; 4), ati alemora laarin awo mojuto ati bankanje idẹ ti ita, ṣugbọn tun ṣe ipa ninu idabobo.

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. Nipasẹ gbigbe abẹrẹ counterpoint, awọn fẹlẹfẹlẹ meji ti pẹpẹ irin ni aṣeyọri, ẹrọ naa bi o ti ṣee ṣe lati fun pọ aaye laarin awo irin, ati lẹhinna ti o wa pẹlu awọn eekanna.

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. Lẹhinna a ti yọ awo aluminiomu ti a tẹ silẹ. Awo aluminiomu tun ṣe ipa kan ni yiya sọtọ awọn PCBS oriṣiriṣi ati aridaju bankanje didan ti o dan lori fẹlẹfẹlẹ ti PCB. Awọn ẹgbẹ mejeeji ti PCB ni a bo pẹlu fẹlẹfẹlẹ ti bankanje idẹ ti o dan.

liluho

How do you connect the four non-touching layers of copper foil together in a PCB? PCB ti kọkọ ni akọkọ nipasẹ awọn iho, lẹhinna ni irin lati ṣe itanna.

Ẹrọ liluho X-ray ni a lo lati wa igbimọ pataki ti fẹlẹfẹlẹ ti inu. Ẹrọ naa yoo wa laifọwọyi ki o wa ipo iho lori igbimọ mojuto, lẹhinna ṣe awọn iho ipo fun PCB lati rii daju pe liluho atẹle jẹ nipasẹ aarin ipo iho.

Place a sheet of aluminum on the punch machine and then place the PCB on top. Bi liluho jẹ ilana ti o lọra ti o lọra, lati le mu ilọsiwaju ṣiṣẹ, awọn lọọgan PCB 1 si 3 yoo di papọ fun perforation ni ibamu si nọmba awọn fẹlẹfẹlẹ PCB. Lakotan, PCB ti oke ni a bo pẹlu fẹlẹfẹlẹ ti aluminiomu, awọn fẹlẹfẹlẹ oke ati isalẹ ti aluminiomu ki nigbati liluho ba wọ inu ati jade, bankanje idẹ lori PCB kii yoo ya.

The operator then only needs to select the correct drilling procedure and the drilling machine does the rest automatically. Bọtini lilu ni a ṣe nipasẹ titẹ afẹfẹ, pẹlu iyipo ti o pọju ti awọn iyipo 150,000 fun iṣẹju kan, eyiti o ga to lati rii daju ogiri iho dan.

Rirọpo ti bit lu jẹ tun ṣe adaṣe nipasẹ ẹrọ ni ibamu si eto naa. The smallest drill can be 100 microns in diameter, while a human hair is 150 microns in diameter.

Ninu ilana laminating iṣaaju, iposii ti o yo ti jade si ita PCB, nitorinaa o nilo lati yọ kuro. Ẹrọ milling ku n ge ẹba PCB ni ibamu si awọn ipoidojuko XY ti o pe.

Ojutu kemikali ti idẹ lori ogiri iho

Niwọn igba ti o fẹrẹ to gbogbo awọn apẹrẹ PCB lo awọn perforations lati sopọ awọn fẹlẹfẹlẹ oriṣiriṣi ti awọn laini, asopọ ti o dara nilo fiimu micron 25 micron lori ogiri iho. This thickness of copper film is achieved by electroplating, but the hole wall is made of non-conductive epoxy resin and fiberglass board. Nitorinaa, igbesẹ akọkọ ni lati ṣajọ fẹlẹfẹlẹ kan ti ohun elo idari lori ogiri iho, ati ṣe agbekalẹ fiimu idẹ 1-micron lori gbogbo oju PCB, pẹlu ogiri iho, nipasẹ ifisilẹ kemikali. Gbogbo ilana, gẹgẹbi itọju kemikali ati mimọ, jẹ iṣakoso nipasẹ awọn ẹrọ.

PCB ti o wa titi

Nu PCB nu

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. Ko si fiimu ti o le ṣe itanna, ati pe ko si fiimu, idẹ akọkọ ati lẹhinna ṣiṣu tin. Lẹhin ti a ti yọ fiimu naa kuro, a ti gbe etching ipilẹ, ati nikẹhin a yọ tin kuro. The circuit pattern is left on the board because it is protected by tin.

Nu awọn ẹgbẹ mejeeji ti PCB bankanje idẹ sinu titẹ, atẹjade yoo jẹ ifamọra si titẹ mimu idẹ ban.

Ṣe atunṣe fiimu akọkọ PCB ti awọn ipele oke ati isalẹ ti fọtokọja nipasẹ iho ipo, ki o fi igbimọ PCB si aarin. 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. Gẹgẹbi a ti mẹnuba ṣaaju, lati rii daju pe iho naa ni elekitiriki itanna to dara, fiimu idẹ ti a ti yan lori ogiri iho gbọdọ ni sisanra ti awọn microns 25, nitorinaa gbogbo eto yoo jẹ iṣakoso laifọwọyi nipasẹ kọnputa lati rii daju pe o peye.

PCB ti o wa titi

Iṣakoso kọnputa ati idẹ elektroplating

Lẹhin ti fiimu idẹ ni itanna, kọnputa ṣeto fun fẹlẹfẹlẹ tinrin ti tin lati tun ṣe.

Lẹhin ti o ti gbe igbimọ PCB ti o ni ṣiṣan silẹ, ṣayẹwo lati rii daju pe sisanra ti idẹ ati fifẹ tin jẹ deede.

PCB lode etching

Nigbamii, laini adaṣe adaṣe pipe pari ilana etching. Ni akọkọ, nu fiimu ti a mu larada lori igbimọ PCB.

Alkali ti o lagbara lẹhinna lo lati nu kuro ni bankanje idẹ ti a ko fẹ ti o bo nipasẹ rẹ.

Lẹhinna ideri tin lori bankanje idẹ ti ipilẹ PCB ti yọ kuro pẹlu ojutu idinku tin. After cleaning, 4 layers PCB layout is completed.