How are multi-layer PCBs made?

Question

I know how normal PCBs are etched, but every time I grab a magnifying glass and examine the edge of a multi-layer board I'm astounded by the precision that must be required during production. On top of that, some of them have buried vias and other such trickery, which must further complicate the process.

How are these boards made?

Mult-layer PCBs are made by stacking *cores* with layers of *pre-preg*. I'm making this just a comment because I'm only referring you to search terms and don't have time to get into detail now. — Olin Lathrop, Jul 23 '12 at 22:03

score 16 · Accepted Answer · answered Jul 24 '12 at 04:38

In a nutshell, to make a 4-layer board, 2 double sided boards and a separator are laminated together. You can extend this idea to 6, 8, n-layer boards. :-)

I'm astounded by the precision that must be required

Amazing isn't it? A key to manufacturing multi-layer boards is the mechanical registration system which ensures layers line up with sufficient accuracy.

score 3 · Answer 2 · answered May 23 '18 at 12:20

Generally boards are made by laminating together thin 2-layer boards with layers of "prepreg".

Throughole vias are drilled and plated after laminating. Blind vias may be produced by either controlled depth drilling or by drilling before laminating. Burried vias can be produced by drilling before laminating.

score 2 · Answer 3 · answered Mar 09 '15 at 18:02

2

Here is a nice series of videos how PCBs are made step by step http://www.eurocircuits.com/making-a-pcb-pcb-manufacture-step-by-step

answered Mar 09 '15 at 18:02

Cano64

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How are multi-layer PCBs made?

3 Answers3