Introduction

3M™ XYZ-Axis Electrically Conductive Adhesive Transfer Tape (ECATT) 9719 is part of a product line of similar materials including 9703, 9705, 9706, 9709, 9709S and 9709SL. The 9719 ECATT product consists of a 100µm thick silicone adhesive layer filled with an electrically conductive scrim comprised of non-woven nickel plated carbon fibers that allow electrical continuity between substrates through the silicone adhesive layer, and additionally provide electrical continuity through the thickness (Z-axis) and in the plane of the adhesive (X-Y planes). The silicone adhesive layer itself is protected with 50µm thick PET release liners on both the top and bottom surfaces. A diagram depicting the layers of the 9719 material is shown in Figure 1.3M ECATT materials are flexible adhesive tapes. The delicate tacky nature of these materials makes them difficult to process, resulting in deformation of the materials when processed with traditional mechanical methods. The non-contact nature of laser processing overcomes this difficulty, which enables the processing of applications with fine geometry and intricate detail. 3M ECATT materials are only suitable for laser cutting that produces smooth laser-processed edges and minimal heat-affected zones, without degrading the physical properties of the materials. Other laser processes are not suggested as they are not conducive to the intended use of these materials. Universal Laser Systems makes it simple to consistently and repeatedly process these materials to a high degree of dimensional accuracy because the non-contact nature of laser processing eliminates material deformation during processing.

Laser Processing Notes

3M 9719 ECATT was tested to assess laser processing compatibility and determine the best system configuration of laser peak power and wavelength. The PET liners absorb 9.3 micron energy more efficiently than other wavelengths, meaning less peak power was necessary to produce good results with minimum heat affects. The silicone adhesive layer also absorbs the 9.3 micron wavelength efficiently with clean edges free of heat effects along the processed path. Microscopy images taken at 300x magnification of the processed edge of the 9719 post-processing, with the liners in place and the liners removed, are shown in Figures 2 and 3, respectively. In these images it is shown that the PET liners contain most of the heat affects and discoloration, while the silicone adhesive layer itself is relatively free of heat effect and discoloration.Further inspection of the laser-processed material shows that the silicone adhesive layer is cleanly processed along the laser cutting path with the 30 watt 9.3µm CO₂ laser source. Figures 4 and 5 depict 3D-rendered microscopy images of the processed surfaces shown in Figures 2 and 3. Figure 4 shows that the PET layer reacts to the laser energy by forming a “wave” of melted material along the top surface of the processed edge. In Figure 5 the PET liners are removed from the material, showing the smooth flat surface and laser processed edge of the silicone adhesive layer, free of adverse heat effects.3M 9719 ECATT was also tested with an alternate system configuration of 10.6 micron laser energy at equivalent laser power level for comparison and determination of the effectiveness of each system configuration. The results of these tests were compared by analyzing the heat effects, quality of the processed edge, and post-processing requirements. The results of the comparison of these system configurations are listed in tabular form in Table 1 and are shown photographically in Figure 6a and 6b. Both system configurations appear viable with some reduction in quality of the results for the 10.6 micron configuration as stated in the comparison.Processing Example

3M ECATT adhesive tape applications requiring fine geometry and intricate detail without degrading the physical properties of the material can be achieved with Universal Laser Systems technology. An example demonstrating the results of laser cutting the 3M ECATT 9719 material is shown in Figure 7.Conclusion

3M 9719 ECATT is suitable for laser processing and was extensively tested to determine the most efficient processing configuration. Through this testing, it was determined that laser cutting is viable with this materia, and a 30 watt 9.3 micron CO₂ laser source is the best configuration of wavelength and power for the processing of this material. The PET liners and silicone adhesive layer efficiently absorb the 9.3 micron wavelength laser energy, and, coupled with the peak power of the 30 watt laser source, produce a clean smooth processed edge that has minimal heat-affected zone and discoloration. Other materials in this ECATT product line are expected to process similarly.