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SAP, mSAP, SLP—what kind of crazy acronyms have we adopted now, and how much do you really need to know? In terms of consumer electronics, there is a good chance that the smartphone attached to your hand at all times contains a PCB fabricated with this technology—or at the very least, the next-generation smartphone that you purchase will utilize mSAP technology. In terms of current-day PCB design and fabrication, that really depends on where you are now with technology. The standard subtractive-etch process serves the industry well. Developments in materials, chemistry and equipment enable the traditional PCB fabrication process to achieve feature sizes such as line and space down to 30 microns. Larger shops with more sophisticated capabilities are building this technology today. Mainstream PCB manufacturing is often limited to 50-75 microns (µm) line and space. But the electronics industry is evolving quickly. Propelled by the demand for more sophisticated electronics, the PCB design is being tasked with finer lines, thinner materials and smaller via sizes. A traditional progression is to first move to HDI technology with microvias and multiple lamination cycles for fabrication. Today’s mSAP and SAP technology offers an advanced approach, with line and space capabilities of less than 25 microns, to meet these exceedingly complex design requirements.
A Few Definitions
- Subtractive etch process: commonly used to fabricate printed circuit boards. This process begins with copper-clad laminate, which is masked and etched (copper is subtracted) to form traces
- Additive PCB fabrication: this process utilizes additive process steps, rather than subtractive process steps to form traces
- SAP: semi-additive process, adopted from IC fabrication practices
- mSAP: modified semi-additive process, adopted from IC fabrication practices
- SLP: substrate-like PCB; a PCB using mSAP or SAP technology instead of subtractive etch technology
To read the full version of this article which originally appeared in the September 2018 issue of PCB007 Magazine, click here.