LPKF on Stencils and Depaneling

Estimated reading time: 2 minutes

Stephan Schmidt and Mirela Orlowski of LPKF Laser & Electronics North America discuss laser technology in cutting stencils and depaneling circuit boards as a factor in shrinking component sizes and why few people in the industry realize how much of an impact the stencil can have on the manufacturing line.

Nolan Johnson: There’s a lot happening right now with smaller components, smaller step sizes between pads, smaller features on the boards, tight tolerances, as well as interfacing between the component and the board with the solder paste. What’s your perspective on the challenges as an equipment manufacturer?

Stephan Schmidt: We have an impact on two sides of the assembly world. One side is the equipment for the depaneling of PCBs because this product is at the forefront of high miniaturization. It’s used for challenging components and circuit boards that can’t be done with the traditional technologies, such as routers and pizza cutters or manual depaneling situations. If you have small components that need high tolerances, that is not possible anymore with traditional mechanical separation methods.

We also have some impact on the stencil manufacturing side, where we manufacture laser systems to cut SMT solder paste stencils. The importance of the quality of those stencils is higher now than it ever was in the past. With the tolerances in PCBs being what they are, it can only be reasonably affected by the buyer of the circuit board, and it is important that the quality of the stencil not add any negative impact.

Especially with SMT components getting smaller and smaller, we need to get the solder paste in the right spot to avoid any shorts or bridges. Having an accurate stencil goes a long way. Some manufacturers that we’ve worked with in the past have looked into this carefully and understood how important the role a relatively inexpensive item, such as a regular solder paste stencil, has in their manufacturing yield.

Once they looked into this and understood how important those things were, they decided that only stencils with a certain quality can be used, and it made a big difference in the manufacturing process. They recognize that buying a stencil that’s made on a high-quality machine versus one that is 20 years old and out of calibration makes a huge difference for them. It doesn’t come down to saving $10 on the cost of the stencil; it’s about saving thousands of dollars in the manufacturing process by buying a quality tool that is reliable for manufacturing.

To read this entire interview, which appeared in the February 2020 issue of SMT007 Magazine, click here.