Improving the Rework Process


Reading time ( words)

An optimized SMT assembly process typically provides a yield of nearly 100%. Technology advancements—from the solder paste printing process, SPI, and parts placement, to reflow and wave soldering and AOI—have pushed the efficiency and accuracy of these steps in the SMT process such that a board assembly should be perfect at the end of the line.

Still, EMS providers continually face the need to rework and repair PCBAs even after dialing in the perfect set-up; there will always be that insufficient solder, or excessive solder, or missing component on the board, among other issues. Chief among them is the continuous trend toward miniaturization in the industry—the ever-shrinking component sizes being placed and soldered onto boards with finer and finer pitch and spacing—which is putting a lot of pressure even in the rework and repair of such boards.

Also, with reliability being one of the top customer requirements, touching boards should be avoided because it increases the chances for damage, such as flexure or shearing of parts with the soldering iron on the back or front side, according to Gary Freedman, of Colab Engineering. He notes that every time a board passes through a repair cycle, that board will be of lesser reliability.

You need rework—there will always be a need for rework—but the more you do rework, the more touches a PCBA receives, the higher the chance its reliability decreases. What a Catch-22 situation.

For this month’s issue of SMT Magazine, we talked with BEST Inc.’s Dan Patten and Laura Ripoli, Circuit Technology Center’s Andy Price, and Freedman to find out more about the critical challenges in rework and repair of PCB assemblies, and which strategies to implement to improve the process and ensure the reliability of the boards.

Interestingly, one of the things they pointed out is the skills of the operators or technicians doing the rework. In the words of Andy Price, they should have "a tremendous amount of experience, hand skills, the ability to work using magnification for hours on end, knowledge, and patience." The skillset, according to him, is just not on the market, so you must find somebody with the right mindset and right capability to do the job. Once they are inside your doors, continuous training is required.

To read the full version of this article, which appeared in the September 2017 issue of SMT Magazine, click here.

Share


Suggested Items

Interview with Yusaku Kono: Rising Star Award Recipient

04/18/2018 | Patty Goldman, I-Connect007
The IPC Rising Star Award is given to IPC members who have taken leadership roles and provided support to IPC standards, education, advocacy and solutions to industry challenges. Their contributions have made significant impact upon IPC and industry within the past five years and will continue to have a lasting impact for many years to come.

Automotive Electronics Still in the Driver’s Seat

04/11/2018 | Stephen Las Marias, I-Connect007
The past year was one of the strongest years that the PCB supply chain and the rest of the electronics manufacturing industry in general, has seen. Everyone we talked to at the shows were optimistic that the strong growth in the industry in 2017 will continue through 2018. And most industry players point to one thing when it comes to what’s driving this strong growth—automotive electronics.

Interview with Linda Woody: Dieter Bergman IPC Fellowship Award Recipient

04/04/2018 | Patty Goldman, I-Connect007
The Dieter Bergman IPC Fellowship Award is given to individuals who have fostered a collaborative spirit, made significant contributions to standards development, and have consistently demonstrated a commitment to global standardization efforts and the electronics industry. This year, Linda Woody is one of the two recipients of the award. Here's what she has to say.



Copyright © 2018 I-Connect007. All rights reserved.