Issue link: https://iconnect007.uberflip.com/i/1509873
24 PCB007 MAGAZINE I OCTOBER 2023 e logic behind the 3D tools is that they do not require destructive analysis of the prod- uct, are able to provide pictures in full natu- ral color, and require only a few hours of oper- ator training to get going. In-process checks can be done with no prep on live product and complemented by coupon sampling for copper grain structure qualification. So, for the price of an AOI machine or less, the 3D scope/laser gives you a very precise engineering tool that can be used to perform a wide range of checks. 3D measurement of the shape of copper trans- mission lines post-etch, with confocal micros- copy to feedback to the signal integrity model, is also a new scheme that is being implemented with these tools. If 3D microscopy with laser profilometry is not part of your investment plan, and you are in the HDI/high speed/substrate markets, you should consider looking into it. PCB007 References 1. Online Wiki of Crystallography. Alex Stepinski is the founder and CEO of Stepinski Group, and former vice president of GreenSource Fabrication. Annealing of the copper aer plating with a con- trolled bake also changes the crystal structure, and if it is plated correctly, annealing will also make it more reliable. All these variables need to be measured and controlled to minimize pro- cess variation for producing advanced products. The Measurement Kit e fundamental measurement equipment used to perform all the checks in this arti- cle is a 3D microscope with a laser profilom- etry option (most use confocal microscopy plus lasers for profilometry). Units are avail- able from many different suppliers on the mar- ket and range from $120,000 for simple stand- alone systems up to $225,000–275,000 for units mounted on automated full panel-size gantries. e tools have been recently installed in multiple facilities in the U.S., and there is now a push to begin implementing them as part of highly automated work cells across many of the new PCB fabs. Other technologies also work for many of these applications; however, we have found that these 3D scopes with lasers provide the highest capital investment effi- ciency of all of the tools which we have evalu- ated in the NPI fab segment, due to the wide application range and ease of use to drive con- trol and improvement. Figure 1: SEM image showing grain structure examples. Grain structure engineered for high-reliability (left), and engineered for sacrificial etching (right).