# pcb size

M

#### mnkr

Jan 1, 1970
0
why most of the people use pcb thickness 1.6mm.

P

Jan 1, 1970
0
S

#### Simon Peacock

Jan 1, 1970
0
Because the more a material is used, the cheaper it becomes.. and the more
likely it will be in stock.

Simon

E

#### electronic-eng.com

Jan 1, 1970
0
mnkr said:
why most of the people use pcb thickness 1.6mm.

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
www.electronic-eng.com

R

#### RST Engineering $$jw$$

Jan 1, 1970
0
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

S

#### Spehro Pefhany

Jan 1, 1970
0
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

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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