Features Articles
With every Apex comes an outpouring of new standards, and this year’s conference was no exception.
As the demands of PCBs for automotive applications assert themselves as a unique class, the industry standards are being adapted in sync. To that end, IPC-6012, the longstanding bare board qualification spec, now has an automotive supplement, reflecting the “superclass” of reliability for that sector above and beyond Class 2.
Given that auto electronics are shrinking, the IPC task group has eliminated visual inspection in favor of AOI on all layers and recommends use of AVI (automated visual inspection) of the finished PCB.
The cleanliness testing requirement has also been rewritten. The automotive addendum includes a recommendation of tests to be used in Production Part Approval Process (PPAP) documentation.
0201mm chip capacitors and resistors are entering production now in advanced package-in-package modules and should soon become widely used in ordinary printed circuit board designs.
Measure changes in package dimensions during NPI.
Use partial CT to reveal trace discontinuities at incoming inspection.
In last month’s column, I suggested using x-ray inspection equipment more typically used for the investigation and quality control of assembled PCBs to check bare boards ahead of their use in assembly. Such equipment is often already onsite and readily available to the assembler. The benefits of enhanced magnification and resolution this equipment can usually offer toward inspection of representative bare boards ahead of assembly is, I contend, an opportunity to provide additional confidence that all is well in the bedrock of PCBA. Furthermore, the cause of any future issues, if they occur, can be more easily narrowed down to the assembly process, design or components. The example I gave related to the possible issue of poor drilling quality in the board vias and how, in x-ray images, the plating variability can be readily seen, especially if the via is buried within the board and optical inspection is not possible. Variable plating quality, however, such as voiding in the central termination of a QFN (see “QFN Inspection: Don’t Forget the Edge!” December 2018 column), can often be relatively obvious for an operator to see when it occurs in the x-ray image such that if it is not present and all looks consistent and appropriate, then other subtler issues may not be considered fully, or missed entirely.
Press Releases
- E-tronix Hosts Webinar with Laser Wire Solutions CEO on Advancing Medical Manufacturing Through Laser Technology
- Niche Electronics Completes Transition to Enhanced Leadership Team
- Aegis Software Expands its Presence in France and Partners with STPGroup
- Altus Adds Breakthrough Automated Inline Laser Depaneling System to its Line-Up