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IPC Spec for PTH Hole Size Tolerance

Mark Lovett

#19452

IPC Spec for PTH Hole Size Tolerance | 10 April, 2002

I would like to know the Stated Specification for PTH size tolerances. Or is there a generalised acceptable limit?.

We have some PCB's with hole sizes that I consider to be way off what I would deem acceptable, ie Finished hole size should be 0.89mm, actual hole size 0.8/0.82. The PCB manufacturer is quoting +-0.1mm tolerance.

Any help or info would be much appreciated.

Thanks,

Mark.

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#19456

IPC Spec for PTH Hole Size Tolerance | 10 April, 2002

IPC-6012A, 3.4.1 has words to the effect of: Hole size tolerance and hole pattern accuracy shall be as specified in the procurement documentation.

Our fab says:

Standard Drill Sizes Drill Number ||Hole Size ||Finished Hole Size 70 ||0.028" ||0.025" 65 ||0.035" ||0.032" 58 ||0.042" ||0.039" 55 ||0.052" ||0.049" 53 ||0.0595" ||0.056" 44 ||0.086" ||0.083" 1/8" ||0.125" ||0.122" 24 ||0.152" ||0.149"

We checked the old IPC-D-275 just for laughs. For finished hole diameter 0.81 - 1.6mm [0.033 � 0.063�] tolerance is: * General design complexity [preferred]: 0.30 [0.012] * Moderate design complexity [standard]: 0.20 [0.008] * High design complexity [reduced producibility]: 0.10 [0.004]

Sounds like you did pretty well, eh?

reply »

#19457

IPC Spec for PTH Hole Size Tolerance | 10 April, 2002

IPC-6012A, 3.4.1 has words to the effect of: Hole size tolerance and hole pattern accuracy shall be as specified in the procurement documentation.

Our fab says:

Standard Drill Sizes Drill Number ||Hole Size ||Finished Hole Size 70 ||0.028" ||0.025" 65 ||0.035" ||0.032" 58 ||0.042" ||0.039" 55 ||0.052" ||0.049" 53 ||0.0595" ||0.056" 44 ||0.086" ||0.083" 1/8" ||0.125" ||0.122" 24 ||0.152" ||0.149"

We checked the old IPC-D-275 just for laughs. For finished hole diameter 0.81 - 1.6mm [0.033 � 0.063�] tolerance is: * General design complexity [preferred]: 0.30 [0.012] * Moderate design complexity [standard]: 0.20 [0.008] * High design complexity [reduced producibility]: 0.10 [0.004]

Sounds like you did pretty well, eh?

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