Q&A: Can someone help me find a mechanical design guide to PCBs?
Question by mrlexington: Can someone help me find a mechanical design guide to PCBs?
I’m an ME working on a consumer electronics product made primarily from injection molded plastic that encloses a PCB. I’m unsure of what tolerances I can expect from the PCB. I need to know these tolerances so I can appropriately define boss diameter sizes and spacing as well as various other features that meet PCB to plastic. Thanks.
Best answer:
Answer by racheal m
no not to sure
Give your answer to this question below!
IPC is widely recognized as the governing standards organization by pcb manufacturers.
IPC-2221 has tables that list, for example, the flexural modulus, tensile strength, thermal expansion, and glass transistion temperatures of many different pcb dielectrics.
In the association’s own words:
“IPC-2221A is the foundation design standard for all documents in the IPC-2220 series. It establishes the generic requirements for the design of printed boards and other forms of component mounting or interconnecting structures, whether single-sided, double-sided or multilayer. Among the many updates to Revision A are new criteria for surface plating, internal and external foil thicknesses, component placement and hole tolerances. Expanded coverage is provided for material properties, dimensioning and tolerancing rules, and via structures as well as updated coupon designs for quality assurance. 112 pages. Released May 2003.”
They charge $65 for the latest copy and you can quickly get a downloadable version.
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