Enquiries critical PCB stack up design

[alan_lee]

Hello,

Recently I received a PCB stackup design from my client that I feel the design is very odd, but I'm not sure whether the design can be fabricated or not? please refer in the following enquiries:

1) Client intended to use 3 layers(1 copper foil +1 core with 1oz of copper at top and bottom) to form a lamination prior to generate the buried Via. Can it be applied for lamination just for 3 layers?

2) for 200mil board thickness with 10mil finished hole size and 12mil of drill size. As it contains of High aspect ratio (16.7:1), will it be caused any problems for PTH process?

Thanks!

 

[Antonios]

From My known the any Multi layer board fabricated in even number of layer 2,4,6,8 etce,

 

[House_Cat]

You should call the PCB fabricator you intend to use, and ask them your questions. Different fabricators have different capabilities depending on their equipment and experience.

In general, an odd number of layers is not a good idea. Because of the unequal distribution of materials, the board will tend to warp and twist.

There are fabricators who can handle 10mil finished hole size on a 200mil board. Again, your best option is to call your fab and ask them.

 

[alan_lee]

Thanks anyway for your help. ^^

 

[hw_guy]

I believe the board will be fabricated, but the yields may suffer due to the complexities introduced with the uneven stackup and the high aspect ratio.

If this board will be used in high volume production, I wouldn't consider going with the current design unless there was no other way to design the board (this is unlikely).