How will the heat generated by a laser beam affect my board and components during depaneling? Will it melt edge components into an ugly heap? Or demolish thin flex materials into an unrecognizable blob? We get these worst case scenario questions all the time from PCB designers and manufacturers who have relied on mechanical routers, manual cutters, and other traditional depaneling machines throughout their careers. So it is no wonder that there’s an ongoing concern about a laser’s heat affective zone (HAZ), and the thermal effect on edge components in particular.
It seems like there are more myths about UV laser depaneling than there are about the Loch Ness Monster. But unlike old Nessie, UV laser depaneling myths are much easier to debunk.
“What’s that discoloration on the edges?”
That’s the question asked most often with an element of shock and surprise by people who are using UV laser depaneling machines for the first time to cut PCBs from FR4 and polyimide. The simple answer is that some edge charring occurs on thicker materials like FR4 and the “discoloration” is a carbon residue produced on each pass of the laser. In most cases, the edge charring is just a cosmetic issue that does not affect PCB quality. The biggest concern is that the carbon dust may be conductive and may somehow contaminate or short-circuit components populating the board.
Putting together an automated SMT assembly line is like building a sports team. You’re looking for the best available player at each position and those you can count on to deliver the highest level of performance week in, week out. But like the kid with untapped talent who sits on the bench game after game, UV laser depaneling is often overlooked as a key component of the SMT assembly line.
When the roof starts to leak and the floors begin to creak, you know a home makeover is long overdue. But how do you know when your PCB manufacturing line needs an extreme upgrade to the latest technology? Printed circuit boards and their uses have evolved and changed dramatically since their introduction in the 1940s, and so have their manufacturing methods. But that doesn’t mean that everyone is on the same page when it comes to staying in tune with today’s advanced miniature boards designed for highly sophisticated electronics.