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

Print


Suggested Items

Engaging STEM Students at IPC APEX EXPO 2020

01/06/2020 | Nolan Johnson, I-Connect007
At this year’s IPC APEX EXPO, you’re likely to see quite a few high school students moving amongst all the normal show activities thanks to the IPC APEX EXPO STEM Outreach Program. Launched two years ago at IPC APEX EXPO 2018, the 2020 version of the STEM Outreach Program will be larger and more immersive than ever before.

BTU Discusses its Next-generation Flux Management System

12/18/2019 | Nolan Johnson, I-Connect007
At productronica 2019, Nolan Johnson spoke with Peter Franklin, managing director of BTU Europe, about BTU’s next-generation solder reflow flux management system—Aqua Scrub. A winner of the show’s Global Technology Award for Soldering, Peter breaks down the specifics of what makes Aqua Scrub such an intriguing technology.

Discover the Benefits of a Technology Center

10/23/2019 | Barry Matties, I-Connect007
Nico Fahrner, application engineer at Rehm Thermal Systems, talks with Barry Matties about the benefits prospective customers get from being able to fully test their systems in-line at Rehm’s technology centers before purchasing.



Copyright © 2020 I-Connect007. All rights reserved.