SYNRAD, INC. - http://www.synrad.com  
Thursday, August 19, 2004
Issue 94



Come see us at IMTS! 
September 8-15, Booth B-6258

SYNRAD's sealed CO₂ lasers are used in a variety of industrial processes including cutting, welding, drilling, and marking. This news brief showcases some of the interesting materials and products that are processed daily by Synrad's line of CO₂ lasers and marking heads.

Kiss Cutting High Density Foam

This application required a cut through adhesive backed, high-density foam without damaging the waxed paper liner; a process commonly called kiss-cutting. Achieving a proper kiss cut involves finding a balance of power and speed that provides consistent cuts through the material, yet does not damage the backing.

We set up our XY motion system with a 5-inch plano-convex lens having a 0.008”spot size with a 0.25” depth of focus. Although the foam measures 0.5” (13 mm) thick, it exhibits a waveguiding effect that allows the use of a shorter focal length lens while retaining the power density of the smaller focused beam. Using 100 watts of power and 20 PSI of nitrogen assist gas, we cut through the foam (without damaging the backing paper) at a speed of 120 IPM.

Degating Circuit Boards

 

Detail of degated area

CO₂ lasers are an effective tool for marking and cutting printed circuit boards based on FR2 (cellulose paper reinforced phenolic resin) and FR4 (glass fiber reinforced epoxy) materials. In addition to marking 2D Data Matrix codes on boards for inventory tracking, CO₂ lasers are used to degate, or trim, smaller individual boards from larger panels. Because resin- and epoxy-based materials are cut by a chemical degradation process, cut edges are typically charred as material in the cut area is burned and then removed under pressure of an inert assist gas.

In this particular application, individual boards were trimmed from two larger tab-routed panels using 60 watts of power. The degated cut area spans a length of only 0.047 to 0.063 inches (1.2–1.6 mm) so that the slight edge charring evident is not a concern. A speed of 60 inches per minute (IPM) was achieved on the 0.0345”-thick board while the 0.060”-thick board was trimmed at 40 IPM. An XY gantry provided beam motion and beam delivery through a 2.5” positive meniscus lens (0.004” spot with a 0.07” depth of focus). Nitrogen at 20 PSI provided the gas assist.

Perforating Holes Part II

This application request asked to mark characters or text on documents by perforating holes through the paper. In this case, we used an FH Series marking head and WinMark Pro software to steer the beam and control mark characteristics. The FH head was fitted with a 125 mm focusing lens in order to obtain a 180-micron (0.007”) spot size.

To create the mark, text objects, either TrueType or one of WinMark Pro’s built-in Stroke fonts, were sized and positioned as specified. For creating perforations instead of lines, we set the Spot Marking Style property to Yes and set a Spot Mark Duration of 10, to generate a series of one-millisecond pulses. Power was set to 22 watts, Velocity to 50 inches per second, and Resolution to 200. These settings created hole sizes measuring 0.008”, which is essentially the spot size of the beam. Using this marking process, representative cycle times for 0.25” high characters are around 0.30 seconds to mark eight stroke characters and 0.65 seconds to mark six bold TrueType characters. 

Read more about perforating holes! Click here

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