Pirmais solis PCB ražošana ir organizēt un pārbaudīt PCB izkārtojumu. PCB ražošanas rūpnīca saņem CAD failus no PCB projektēšanas uzņēmuma. Tā kā katrai CAD programmatūrai ir savs unikāls failu formāts, PCB iekārta tos pārveido vienotā formātā-Extended Gerber RS-274X vai 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.

Vienā no mājās gatavotajiem PCBS PCB izkārtojums tiek drukāts uz papīra, izmantojot lāzera printeri, un pēc tam tiek pārnests uz vara pārklātu plāksni. Tomēr drukāšanas procesā, jo printerim ir nosliece uz tintes deficīta pārtraukuma punktu, tinte ir manuāli jāaizpilda ar eļļas pildspalvu.

Neliels ražošanas apjoms ir piemērots, bet, ja šis defekts tiek pārnests uz rūpniecisko ražošanu, tas ievērojami samazinās ražošanas efektivitāti. 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.

Pamatplates ražošana

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 slāņu PCB ir izgatavots līdzīgi, bet tikai ar vienu serdes plāksni un divām vara plēvēm.

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. Filma sacietē, ja tiek pakļauta gaismai, veidojot aizsargplēvi virs vara pārklātas plāksnes vara folijas.

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. Iepriekšējā lāzera printera papīra PCB izkārtojumā melnais toneris tika pārklāts ar vara foliju, lai to saglabātu. 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.

Pēc tam nesacietējušo plēvi nomazgā ar sārmu, un nepieciešamo vara folijas ķēdi pārklāj ar sacietējušo plēvi.

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.

Kodola plākšņu urbšana un pārbaude

Galvenā plāksne ir veiksmīgi izgatavota. Then make the opposite hole in the core plate for easy alignment with other raw materials.

Kad pamatplate ir nospiesta ar citiem PCB slāņiem, to nevar modificēt, tāpēc ir ļoti svarīgi to pārbaudīt. Iekārta automātiski salīdzinās ar PCB izkārtojuma rasējumiem, lai pārbaudītu kļūdas.

Ir izgatavoti pirmie divi PCB plākšņu slāņi

laminēts

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), un līmi starp serdes plāksni un ārējo vara foliju, bet tai ir arī nozīme izolācijā.

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. Through the placement of the counterpoint needle, the two layers of iron plate counterpoint successfully, the machine as far as possible to compress the space between the iron plate, and then fixed with nails.

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. Pēc tam spiediena alumīnija plāksne tiek noņemta. Alumīnija plāksnei ir arī nozīme dažādu PCBS izolēšanā un gludas vara folijas nodrošināšanā THE PCB ārējā slānī. Both sides of the PCB are covered with a layer of smooth copper foil.

urbšana

Kā jūs savienojat četrus nepieskartos vara folijas slāņus kopā PCB? PCB vispirms izurbj caur caurumiem, pēc tam metalizē, lai vadītu elektrību.

Rentgena urbjmašīnu izmanto, lai atrastu iekšējā slāņa pamatplāksni. Iekārta automātiski atradīs un atradīs urbuma pozīciju uz pamatplāksnes un pēc tam izveidos PCB pozicionēšanas caurumus, lai nodrošinātu, ka sekojošā urbšana notiek caur cauruma pozīcijas centru.

Place a sheet of aluminum on the punch machine and then place the PCB on top. Tā kā urbšana ir salīdzinoši lēns process, lai uzlabotu efektivitāti, tiks sakrautas 1 līdz 3 identiskas PCB plāksnes perforācijai atbilstoši PCB slāņu skaitam. Finally, the top PCB is covered with a layer of aluminum, the top and bottom layers of aluminum so that when the drill drills in and out, the copper foil on the PCB will not tear.

The operator then only needs to select the correct drilling procedure and the drilling machine does the rest automatically. Urbi darbina gaisa spiediens ar maksimālo rotāciju 150,000 XNUMX apgriezienu minūtē, kas ir pietiekami augsts, lai nodrošinātu gludu caurumu sienu.

Urbja nomaiņu mašīna veic arī automātiski saskaņā ar programmu. The smallest drill can be 100 microns in diameter, while a human hair is 150 microns in diameter.

Iepriekšējā laminēšanas procesā izkausētais epoksīds tika izspiests uz PCB ārpuses, tāpēc tas bija jānoņem. Frēzmašīna izgriež PCB perifēriju atbilstoši pareizām XY koordinātām.

Vara ķīmiskais nogulsnēšanās uz poru sienas

Since almost all PCB designs use perforations to connect different layers of lines, a good connection requires a 25 micron copper film on the hole wall. This thickness of copper film is achieved by electroplating, but the hole wall is made of non-conductive epoxy resin and fiberglass board. Tāpēc pirmais solis ir uzkrāt vadoša materiāla slāni uz cauruma sienas un ar ķīmisku nogulsnēšanos uz vienas PCB virsmas, ieskaitot cauruma sienu, izveidot 1 mikronu vara plēvi. Visu procesu, piemēram, ķīmisko apstrādi un tīrīšanu, kontrolē mašīnas.

Fixed PCB

Notīriet PCB

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. Nav plēves, ko var galvanizēt, un nav plēves, vispirms vara un pēc tam alvas pārklājuma. Pēc plēves noņemšanas tiek veikta sārmainā kodināšana un visbeidzot – alva. The circuit pattern is left on the board because it is protected by tin.

Clean both sides of the copper foil PCB into the press, the press will be sensitive to the copper foil mold pressing.

Piestipriniet fotokopijas augšējā un apakšējā slāņa PCB izkārtojuma plēvi caur pozicionēšanas atveri un ievietojiet PCB plāksni vidū. 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.

Fixed PCB

Computer control and electroplating copper

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

After unloading the tin plated PCB board, check to ensure that the thickness of copper and tin plating is correct.

Ārējā PCB kodināšana

Next, a complete automated assembly line completes the etching process. First, clean off the cured film on the PCB board.

A strong alkali is then used to clean off unwanted copper foil that is covered by it.

Pēc tam alvas pārklājumu uz PCB izkārtojuma vara folijas noņem ar alvas noņemšanas šķīdumu. After cleaning, 4 layers PCB layout is completed.