Issue link: https://iconnect007.uberflip.com/i/1498723
14 DESIGN007 MAGAZINE I MAY 2023 the balloting for the next revision of IPC-4101. It can also get some massaging along the way. If somebody wants to include that we need fracture toughness as a requirement or CAF resistance, for example, they can make a Pow- erPoint presentation. e proposer must pro- mote the new slash and say why they think it's important to the industry. Shaughnessy: Are slash sheets primarily meant for purchasing? Yes, they were designed to be used by the pur- chasing department and customer service to make it easy for them to order back and forth. Shaughnessy: It sounds like the way forward lies in creating designer-specific guidelines for materials, not amending the slash sheets. I don't think that the group would allow putting on each spec sheet what the target application area might be. Although in reverse, if we had a design guideline, we would say, "For 5G routers, these are the slash sheets that are most likely utilized". If you are trying for high CAF resistance for the auto- motive application, you could list those spec sheets that would be optimum for those. Barry Matties: Regarding the listings and spec sheets, that would include the material supplier as well? Yes, you could have it that way. But IPC as a rule doesn't single out any suppliers' names. I also think that is going too far. I might put out a survey from IPC Works that says, "We would like to have a design guide to help designers use 4101 materials. Do you think this is a good idea? Would you be willing to participate?" Based on that, IPC can create another task group for a design guide. I mean, I am not so old that I just want to see the status quo until I fall over. I'm still interested in new ideas and new places. We need some designers to lend their knowledge to this, maybe from different areas like automotive designers, telecom designers, and aerospace designers. Denny Fritz writes a chapter about design in his book, and he asked me to review the chapters on base materials. Gary Ferrari's done the same, and some oth- ers as well. We just need to capture that knowl- edge and filter it into a typical IPC document. Shaughnessy: Doug, some of our readers specify the material but others go to their fabricator and say, "What do you think we ought to use?" What's the best method? It's pretty straightforward. If you're buying high-speed, high-frequency materials, it is driven by the OEM. In the high- frequency end of it, there's no interchange of mate- rials. Each OEM has to test the material to make sure that it works in their appli- cation, then they'll spe- cifically tell the board shop they have to buy AGC A, B, C. It is never le up to the specification sheet. e companies that sell these high-speed and high- frequency materials go directly to the OEMs, skipping everyone in the middle, and then the fabricator is forced to buy the exact product that's on that list with no modifications. At the lower end of the spectrum, the fabrica- tor will tell the OEM, "is is my favorite. is is the design you have, and this is the product, the prepreg and laminate product that I like the best." So, they put that on the list. In the marketplace right now, there's more buying and selling based on exact specifications from the suppliers as opposed to a general specifica- tion sheet off the back of 4101 or 4103. In mid-range and down, the OEM asks the board shop, "In this range, what's your favor- If you're buying high-speed, high- frequency materials it is driven by the OEM.