Epec's Blog | Electronics Manufacturing Solutions

Two years ago I wrote about why printed circuit board (PCB) shops in North America were continuing to close. Now, in the last two weeks, we have seen two more shops (Dynamic & Proto and ITO Industries) cease their manufacturing operations.

As the former owner and operator of three domestic PCB facilities, I can sympathize with the management and the loyal employees that tried to make the company successful. However, much of the damage is self-inflicted as I previously discussed so rather than rehash past information I wanted to discuss some of the attributes that every customer should look for in their US PCB manufacturer.

IPC 4101 (Specification for Base Materials for Rigid and Multi-Layer Printed Circuit Boards) was released for publication in December, 1997. It was released as the replacement standard for MIL-S-13949. However, it contained a majority of the exact wording from the military standard. It maintained the “slash sheet” format appendix to the standard that specifies the resin and fiber system of different PCB laminates, along with testing parameters and properties. Initially there were 41 slash sheets, but as the industry opens up to “Lead Free” and “Green” processes, the slash sheets have increased to 66, the current revision.

Shipping of lithium batteries is a very important process that requires significant investment in training and equipment. In April of 2016, new lithium battery shipping regulations were passed that forbid lithium batteries from passenger aircraft and limited the SOC (state of charge) for any battery shipped via air cargo to 30%.

When it comes to manufacturing, time is of the essence. Worries about how fast your printed circuit board (PCB) order will arrive and whether it's on time is largely in the hands of the PCB manufacturer, but what can you do to to ensure the process moves as quickly as possible?

Choosing to work with a high quality quick turn PCB services supplier is obviously the first step. As the oldest existing printed circuit board supplier in the United States, not only can we help you construct highly reliable custom products, but we can give you the tips you need to ensure your PCB orders won’t get delayed.

In 2016 there were ten printed circuit board (PCB) factories that closed in the United States, including some highly sophisticated shops that were part of the TTM/Viasystems merger. Having been involved in the closing and transfer of part numbers for fifteen PCB facilities in the past twelve years, we have some first-hand advice as to how you can best minimize the risk as you change suppliers.

As a contract manufacturer, say you receive a new circuit board part to assemble that is 6-layers with a high micro-via count, has blind and buried vias, and a lead free HASL finish. The circuit board laminate requirement for meeting the Restriction of Hazardous Substances, or RoHS compliance, is strictly Glass Transition Temperature(Tg) 170.

Bow and twist of printed circuit boards (PCB) routinely rank among the highest levels of falsely identified non-conformance because it is perhaps the least understood. Envisioning a perfectly flat rigid circuit board as the standard is a fallacy believed by many incoming inspectors. Understanding the reasons and causes for PCB bow and twist can help resolve the issue at the board design stage.

When building a lithium-ion battery pack, there will always be some sort of protection circuitry necessary that will safely separate the cells from the external connections. The protection may be as simple as a pair of charge and discharge Field Effect Transistors (FETs) with voltage and current detectors, or as complicated as adding firmware controlled fuel gauging and secondary protection.

When developing an overmold tool for a custom cable assembly, consideration needs to be given to the tactile features of the finished part. There are several areas that constitute these considerations, including the desired finish of the end part as well as the precision of the molding tool itself. The choices you make in physical features may seem insignificant, but the touch, feel, and appearance can have a real impact on the final cable assembly.

Previously, we gave you the definition for flexible circuit coverlay. Now, we go into greater depth discussing the two primary options for encapsulating the external circuit layers of a flex circuit:  polyimide coverlay and flexible liquid photoimageable (LPI) solder mask. The two materials have very different capabilities and requirements.