If a PCB doesn’t have any free edges to hold or clamp the PCB firmly due to components close to the edge, what solution can you offer to handle boards through an auto routing machine?
N. J.
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Ask the Experts Comments
From a stencil viewpoint when the claps are too close to apertures the stencil can not gasket to the board because the clips prevent it.
It is possible to do a relief etch on the bottom side of the stencil in the area of the clips to allow good gasketing. This is a common practice and is effective.
For over 18 years, Dr. Coleman has been the vice president of technology for Photo Stencil, working closely with customers to understand their printing requirements. His efforts have resulted in several new stencil products.
"Routing is the most reliable and low-stress option to depaneling assembled PCBs. Odd shaped and small PCBs can be held securely in place until the last cut by means of a custom fixture that is specially designed for the circuit card with pins and side wall mounts.
In addition, the boards are assisted in holding their position with a bottom side vacuum suction that not only secures the board but also keeps dust and debris to a minimum during the depaneling process.
For ease of pick up of multiple assembled circuit boards on one panel after tab cutting, a tray within the fixture can be set to easily lift all boards in one removal step."
Michelle is the Sales and Marketing Manager of Seika Machinery, Inc. She is an active member of the SMTA taking on a past position as Chapter President and currently Secretary, Co-Chairs the MSD Council and serves on several committee positions.
I would use or buy a vacuum plate, these are available from machine shop supply distributors. They are typically about an inch thick, have a vacuum pump and hose.
Clamp the plate to your router table and lay the PC board on the vacuum plate. The vacuum should easily hold it in place.
Hope that solves your problem.
Now I am curious how you plan to support the board during component assembly and soldering.
Mr. Bliss has 20+ years experience creating process methods that improve profitability by maximizing hidden unused capacity and throughput. Ken has expertise in all areas of manufacturing specializing in electronics assembly.
Check with the manufacturer of your auto routing machine to see if they offer a tooling plate with tooling pins. These will support and position the board without any edge clamps.
Edward Zamborsky, Regional Sales Manager OK International Inc. Mr. Zamborsky serves as one of OK's technology advisors to the Product Development group. Ed has authored articles and papers on topics such as; Low Volume SMT Assembly, Solder Fume Extraction, SMT Rework, BGA Rework, Lead Free Hand Soldering, Lead Free Visual Inspection and Lead Free Array Rework.
