pcb size

I use 1/16" because:

1. That's the thickness the board shops stock
2. Most edge connectors and board guides are designed for that thickness
3. A board that thick is stiff enough for most uses.

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Because the more a material is used, the cheaper it becomes.. and the more likely it will be in stock.

Simon

This is what an ancient colleague of mine told me a few years ago:

1.6mm is the distance between 2 pins on a 2.54mm pitch IDC connector, therefore a 1.6mm thick PCB fits snugly in between the two rows of pins. Back in the day, an IDC connector could easily be fitted on the edge of the board, soldering each row of pins to each side of the board, making it easy peasy to build modular cards to fit onto a backplane.

More likely is that some process or tool works at maximum yield / efficiency pumping out 1.6mm glass-fibre weaves. It is the standard PCB manufacturer thickness, if you do not specify the thickness in your order/quote, they'll give you 1.6mm.

Alan

Without being too parochial, I'll point out that most PCB work during development in the 1940s and 1950s was being done in the USA. Engineers of that era were still working in fractions of an inch, with the 32nd of an inch (1 / 32 of an inch) being about the finest pitch most of them used. 1 / 32" (0.031") was a little too thin to be dimensionally stable; it broke traces quite easily using the phenolic and paper based boards of the day. 3 / 32" (0.093") was a bit thick and used too much plastic material. The compromise was 2 / 32, or 1 /16 (0.062"), which if you do the conversion comes out 1.57mm, or rounded to 1.6mm.

Jim

It is the standard PCB

ITYM 1.59 mm -> 1.6mm (exact conversion is 1.5875mm)

I see supposed "0.062" material that is < 1.5mm, so I suppose they are subsituting thinner Asian standard prepreg.

Best regards, Spehro Pefhany

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