Introduction

Depaneling is a step easily overlooked in the printed circuit board (PCB) manufacturing process. A great board design, flawless circuit etching, and perfectly placed components mean nothing if individual pcbs cannot be separated from a panel without damaging components, solder joints, or the board itself. Conventional depaneling methods such as die punching, pizza cutting, and routing impose levels of mechanical stress that exacerbate these issues, leaving a substantial amount of profit in the depaneling line’s waste bin.

The percentage of us able boards removed from a panel is known as production yield. The higher the yield the better, and far too often contract manufacturers are depaneling boards at alarmingly low yield percentages. With PCB designs getting smaller and shifting away from traditional square shaping, finding the depaneling method that meets the efficiency levels original equipment manufacturers (OEMs) desire is becoming more important than ever.

Why UV?

By replacing physical tools with a virtual one (the laser beam), no contact is made with the panel and the effects of mechanical stress are wiped away – but that’s not the only way UV laser depaneling reduces the amount of stress imposed on pcbs.

When it comes to depaneling, there are two types of stress that can be imposed on the board. As we’ve discussed, one of these is mechanical stress. The other is thermal stress, which results in adverse effects caused by excess heat. The most common of effect of thermal stress is burning.

There are two primary methods of laser cutting when it comes to printed circuit board depaneling. CO2 lasers, which operate at high energy levels, produce a very hot cut which increases the chances of effects such as burning.

On the other hand, UV laser systems operate at much lower wattage than CO2 systems and produce what is known as cold ablation. So while you may say to yourself, “It’s great that lasers eliminate mechanical stress, but what if my boards get toasted,” you can rest easy knowing that the effects of thermal stress are greatly limited by the thermally cool nature of UV laser depaneling.

Other benefits

The application shown brings up another benefit of depaneling with UV lasers: the ability to work with a wide variety of materials. From standard FR4 to flexible or soft materials, UV depaneling is suited to process any board material. Polyimide, PET, PTFE, Rogers materials, and fired and unfired ceramics present no problems for the stress-free ablation of UV laser depaneling.

Additionally, as boards get smaller and move away from square shaping to fit the demand for miniaturization, UV lasers are especially adept at cutting boards with round and/or arbitrary contours. Figure 3 displays a miniature, arbitrary design that was cut free of stress by a UV laser depaneling system.

http://www.laserpcbdepanelingmachine.com/