1. Tooling Holes1 Tooling holes are non-plated holes with very tight tolerances to prevent movement between the tooling pins and the board. Tooling holes required for automated assembly and testing that stay with the board or panel are the requirement of the PCB designer. Tooling holes for PCB fabrication are the requirement of the PCB fabricator.

2. Tooling Holes2 If the automated assembly process will be performed on multiple PCBs while they are still panelized (as might be the case with smaller PCBs), the tooling holes must be defined as part of the panelization by the PCB designer. In the case of larger PCB that will be assembled individually, the tooling holes should be placed within the PCBs borders.

3. Tooling Holes3 Incorporate at least two tooling holes at opposite corners across the longest diagonal of the PCB. Standard Tooling Hole diameters are 0.094", 0.110", and 0.125" Locate tooling holes on same (0.025" to 0.050") grid as Global fiducials. Identify tooling holes as such in the assembly drawing.

4. Tooling Holes4 The IPC-D-275 specifies that tooling holes (i.e. unsupported holes) should be tolerance specified from a Maximum Material Condition (MMC) to Least Material Condition (LMC) format. Thus a.040" +/- 0.002" hole is specified as 0.038--0.042 in.

5. Tooling Holes5 Talk to the assembly house to determine the amount, size and location of tooling holes required for your particular design.

6. Tooling Holes6

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