multilayer pcb manufacturing process

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PCB Manufacturing Guide At Hi5, we make all our PCBs with love and care Find out what goes on behind the scenes at Hi5 Electronics.

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Page 1: Multilayer PCB Manufacturing Process

PCB Manufacturing GuideAt Hi5, we make all our PCBs with

love and care

Find out what goes on behind the scenes at Hi5 Electronics.

Page 2: Multilayer PCB Manufacturing Process

You convert a board design into Gerber files and send it to us via the online prototype shop. Our operatives will check over the design and give it initial

approval.

Step 1

Page 3: Multilayer PCB Manufacturing Process

We’ll create a negative image of your design so the black bits turn white and the white bits turn black. The negative is printed on transparent film and we

punch registration holes to keep the layers aligned.

Step 2

Page 4: Multilayer PCB Manufacturing Process

We take a copper panel and coat it with a photosensitive film called the photoresist. Next, we add the transparent negative film and shine a UV light

through the gaps and onto the photo-resistant copper.

Step 3

Page 5: Multilayer PCB Manufacturing Process

After UV treatment, the photoresist covered by ‘white’ tracks will have hardened, leaving excess ‘black’ parts nice and soft. We etch the soft area off

using an alkali solution leaving only the useful copper covered by photoresist.

Step 4

Page 6: Multilayer PCB Manufacturing Process

We etch away all the useless copper (using a different alkaline solution) to leave the inner tracks still intact. We also strip off the last bit of photoresist to

leave the strips shiny and fresh.

Step 5

Page 7: Multilayer PCB Manufacturing Process

Now it’s time to layer up our multilayer board. We take the internal layers prepared in step five and sandwich them between copper foiled ‘pre-preg’.

The layers are aligned exactly using the pre-drilled holes and bonded together in a heat-press.

Step 6

Page 8: Multilayer PCB Manufacturing Process

Component holes are drilled according to the Gerber files. We then ‘Black Hole’ the pads to connect each layer of the board together, using a thin layer

of conductive film.

Step 7

Page 9: Multilayer PCB Manufacturing Process

Again, we laminate the outer layers with a dry photoresist. This time though, UV light leaves the tracks and pads soft and, instead, hardens the area around

these.

Step 8

Page 10: Multilayer PCB Manufacturing Process

We place the board in a special bath where the tracks act as ‘attracting-cathodes’ in the metal solution. This helps build up an extra thick layer of

electroless copper on the tracks.

Step 9

Page 11: Multilayer PCB Manufacturing Process

We protect the tracks with a tin edge resist . Then we etch away the photoresist, unwanted copper and finally the tin to leave the sparkling copper

tracks.

Step 10

Page 12: Multilayer PCB Manufacturing Process

The boards have some time to rest while we give them a quick check over.

Step 11

Page 13: Multilayer PCB Manufacturing Process

Most boards have an epoxy-ink solder mask to protect the copper surface. We cover the board in the mask before cutting out the bits covering tracks and

holes.

Step 12

Page 14: Multilayer PCB Manufacturing Process

We apply an immersion silver, or electroless nickel and immersion gold (ENIG), finish over the holes. We also add a silkscreen legend to show which

component goes where.

Step 13

Page 15: Multilayer PCB Manufacturing Process

We ship promptly and securely.

Visit the Hi5 Electronics online shop and get a PCB made to your specifications.