Issue link: https://iconnect007.uberflip.com/i/1038326
OCTOBER 2018 I PCB007 MAGAZINE 71 Matties: Right, because you have that open-air space. Lázaro: Exactly. The ideal way to cool down a laminated panel is to keep the pressure, open the door of the press, and let the panel cool down to ambient without forcing it. In our case, we are emulating that ideal way to cool down. Matties: What sort of cool-down cycle time do you expect? Lázaro: We did test simulations on the com- puter, plus tests on the machine that is almost ready to go to GreenSource. We can go faster than today's resin sets specify. Normally, they don't want to go faster than three degrees a minute, and we are able to go to 4.5 degrees a minute. Depending on how many panels, we're talking about 30- to 45-minute cooling cycles. Matties: What you guys are doing is creating a need for the resin manufacturers to upgrade their products as this technology becomes mainstream. Lázaro: Yes, that's right. There are only two or three manufacturers of epoxy in the world. Ideally, it can be possible to heat up faster and cure faster. I'm sure they can develop faster resins. For the PCB, I think it could be possible to have a horizontal press line. You put a sin- gle panel on one side of an inline machine and get a panel laminated on the other side ready to continue to the next process. Matties: You're ahead of your time. That takes care of the press portion. What about loading? My understanding is this is a completely auto- mated system from lay-up to break down. Lázaro: Yes, but the lay-up operation of the pan- el to be laminated stays on the manual side be- cause there are many variables in the process. For instance, there are a lot of different types and thicknesses of prepregs, different thick- nesses of copper foils and a lot of variables to handle. There's still going to be manual labor, shorten the cycles is in the resins. To best le- verage this, the ramp-ups and heating speed must be inside the limits of resin as set by the manufacturer in their prepreg data sheets. The chemistry industry has been developing composites to be manufactured in the avail- able technologies in the industries: conven- tional presses with all their pros and cons. For that reason, the resins, epoxies, and compos- ites are designed to be cured in traditional ov- ens. Now that we are putting this on the mar- ket, I think it may be possible to have faster heating uniformity to shorten the cycle times and cost in a real, effective way. Matties: You just keyed in on one word—uni- formity. Do you expect a greater uniformity with the induction as well? Lázaro: Yes, we do. Like I said before, we have a prototype and an onsite machine that has been working in production for eight years. Our customers still send regular samples to make sure that the Tg and lamination capabil- ities are consistent. The reports are always ex- cellent, which means that temperature unifor- mity is very nice. A key to this is that the sen- sors in the machine are monitoring the temper- ature right at the material, not the big heavy platens like in the traditional presses. Matties: It sounds like you receive the uniform temperature across the entire panel, as well as through the thickness as it transfers. But how do you handle cooling? Is it in the same press or do you move it into a cooling press? Lázaro: The concept is a bit different. We are going in the direction of flexibility, which means the machine is ready to go the whole time. You don't need to preheat anything. Each press will do the heat profile and then the cool profile without releasing pressure. It's going to enter the stack of the panels, start the cycle and when the press opens it's ready to break down the stack at room temperature. The cool- ing is also a new and sophisticated system us- ing air flow. Energy is moved from the center towards the edges uniformly.