MC Assembly: Achieving a Zero-defect Culture

Estimated reading time: 4 minutes

MC Assembly has earned a reputation for quality in an industry that must deal with a complex set of variables each day. Faced with very complex PCBA and box builds, the company recently unveiled the approach it takes to keep everything running smoothly in the fast-paced world of electronics manufacturing.

"We've invested in a layered approach of service offerings, state-of-the-art manufacturing, inspection and test capital equipment, all managed by a very robust quality management system (QMS) to try to achieve a zero-defect culture," said Jake Kulp, MC Assembly’s vice president for New Business Development.

The secret to the company’s commitment to quality begins before anything is manufactured. MC Assembly starts by optimizing their customers’ bill of materials. This is accomplished by minimizing outdated components and offering newer alternative parts that are form, fit and function like the original part but are more stable and sustainable.

MC Assembly can also optimize manufacturing designs through a design for manufacturability (DFM) processes as well as maximizing test coverages through a design for testing (DFT) process to ensure that MC Assembly can validate the work it performs meets each customer’s specifications. MC Assembly also engineers digital work instructions, accurate thermal profiles to run its reflow ovens, and production aids (Poka-yoke) to exact specifications required to make the product right the first time.

Robust inspections are performed on incoming materials with the goal of stopping all non-conforming material at MC Assembly’s docks. Material conformance is again verified when kits are picked and when SMT products are setup on the required feeders for use in the chip shooters and pick-and-place operations. 2D bar codes are applied to serialize the custom PCBs (unpopulated printed circuit boards) for a variety of tracking purposes. Finally, MC Assembly’s paperless factories offer real advantages over their competition that still uses paper prints and work instructions.

“We have placed in-line 3D solder paste inspection (SPI) stations on every SMT line, inspecting 100 percent of every solder deposition and verifying they will produce the correct IPC 610 solder joint,” Kulp said. “This has greatly increased first pass yields on the complex PCBAs we build. Considering that a very large percentage of solder mistakes, that are usually found after the solder reflow process have their root causes based in misapplied solder paste, it is easy to justify the investments we have made in these inspection stations.”

In-line color automated optical inspection (AOI) is also placed on every SMT line at MC Assembly. Golden PCBAs are used to train these automatic inspection stations to verify correct parts placement, solder applications and part alignment. Off-line 3D X-ray and 3D AOI tools are used to uncover possible defects such as incomplete BGA solder ball collapse and the head in pillow type of tombstoning that standard color AOI will miss.

MC Assembly engineering attempts to design manufacturing processes where hand soldering is minimized whenever possible. Selective soldering, through the use of wave pallets, floor standing machines and bench-top robotics, is used to decrease the need for hand soldering that can contribute to operator errors. This automation also lowers recurring labor costs, increases scalability and because this process is designed at the bid stage of every new job these quality and cost savings are spread over the entire product life cycle.

“MC Assembly started as a test house in 1984 and that strong tradition of PCBA and box level test carries on today,” Kulp said. “Boards are tested with flying probes, in circuit and functional test methods according to the product’s design. The box builds are tested functionally and often environmentally stress screened to uncover any potential failures. When the final products leave MC Assembly, we’ve used the strictest controls through the manufacturing cycle and validated the product and our workmanship so the product meets our customer’s specifications.”

This commitment to quality and attention to detail has served MC Assembly well over its three-decade history as a leading mid-tier electronics manufacturing service provider, Kulp said.

“Despite the complexity and variety of products we make, this layered approach towards zero defects ensures that quality is built into every shipment we make,” he said. “This approach to quality has earned us the right to build for many world leaders in the markets we serve and when our customers take possession of the products that we have built, they are confident they will perform as they were designed.”

About MC Assembly

MC Assembly (http://www.mcati.com), based in Melbourne, Florida, with additional operations in Billerica, Mass., and Zacatecas, Mexico, is a national leader in the contract manufacturing arena with annual revenues of approximately $200 million. It provides turnkey solutions to original equipment manufacturers and focuses on assembly of medium volume, medium mix printed circuit boards assemblies (PCBAs) and box builds. MC Assembly’s capabilities include surface mount and pin-through-hole interconnection technologies, PCB and box build, DFM, DFT, DFA engineering, in-circuit, functional and environmental testing, and full box-build direct order fulfillment.