If you have even one printed board design under your belt, you have probably already been exposed to a host of unexpected problems at various stages of development. During the fabrication & manufacturing process, issues commonly arise due to misaligned holes or undesirable drill breakouts. Even if they don’t cause the board to be rejected, they can lead to problems with track separation over time. Despite them being so common, and seemingly beyond your control, what measures can you take to prepare for and prevent these issues from occurring in your designs?
Alignment and Registration Issues
Two things can cause problems when drilling the PCB: the hole is slightly misaligned from its specified position or the drill registration is slightly off. In addition, layers may shift very slightly during lamination, which results in misalignment of non-visible pads.
In addition to potential issues with drilling, mechanical stress can impact a PCB design, especially if the design is a rigid flex substrate. Over time, the integrity of copper connections on a flexible design can be compromised.
The added mechanical and thermal stress that is expected to occur in a rigid-flex design can — and will — lead to further product iterations if not addressed. It is important that the flexing and thermal stress that a copper connection to a flexible encounters are taken into consideration within the design process. If these concerns aren’t addressed or the printed board isn’t designed with these concerns in mind, they can negatively affect production yield.
Using Teardrops to Improve PCB Quality and Yield
Including teardrops in your next design is an important step for designing for manufacturability, and provides increased reliability of drill registration as well as more copper support around the drilled hole. Teardrops are easy to use in Altium Designer® to establish stronger track-to-pad, track-to-via, and track-to-track connections at the click of a mouse.
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