3M Thermally Conductive Silicone Interface Pad 5516

Laser Processing of 3M™ Thermally Conductive Silicone Interface Pad 5516

Introduction

3M™ Thermally Conductive Silicone Interface Pad 5516 is a highly conformable, slightly tacky silicone elastomer sheet filled with ceramic particles which provide thermal conductivity and desirable dielectric properties. 3M Thermally Conductive Silicone Interface Pad 5516 consists of a 1000µm silicone elastomer sheet covered on either side by a 125µm thick removable liner. A diagram depicting 3M Thermally Conductive Silicone Interface Pad 5516 is shown in Figure 1.

3M Thermally Conductive Silicone Interface Pad 5516 Layers

Figure 1. 3M Thermally Conductive Silicone Interface Pad 5516 diagram illustrating the top removable film liner (125µm), silicone elastomer layer (1000µm), and the bottom removable film liner (125µm).

3M Thermally Conductive Silicone Interface Pad 5516 is designed to improve heat transfer by conforming to surfaces and filling the gaps between heat generating components and heat sinks. For this reason, this material is primarily used for thermal management in the electronics and battery industries for applications such as LED lighting, IC cooling, and battery thermal management. The non-contact nature of laser processing enables applications to be processed with small features and fine geometry which may be difficult to achieve with traditional mechanical methods. 3M Thermally Conductive Silicone Interface Pad 5516 is only suitable for laser cutting, which produces consistent edges and minimal heat-affected zones. Other laser processes are not suggested as they are not conducive to the intended use of this material. Universal Laser Systems (ULS) makes it possible to consistently and repeatedly process this material to a high degree of dimensional accuracy with virtually no material deformation during processing.

Laser Processing Notes

3M Thermally Conductive Silicone Interface Pad 5516 was tested to assess laser processing compatibility and determine the best configuration of peak laser power and wavelength. The silicone elastomer layer in 3M Thermally Conductive Silicone Interface Pad 5516 absorbs 9.3µm energy more efficiently than other wavelengths available from ULS, meaning that laser cutting of this material can be performed at higher processing speeds with minimal discoloration using this wavelength. A microscopy image taken at 300x magnification depicting the edge of 3M Thermally Conductive Silicone Interface Pad 5516 after laser cutting is shown in Figure 2. The 3D image in Figure 3 illustrates the results of laser cutting the silicone elastomer with the system configuration of a single 75 watt 9.3µm CO₂ laser source.

3M Thermally Conductive Silicone Interface Pad 5516 Figure 2

Figure 2. Microscopy image (300x) depicting the edge of 3M Thermally Conductive Silicone Interface Pad 5516 after laser cutting, with both the cover film and paper carrier in place. The heat-affected zone measures 260µm.

3M Thermally Conductive Silicone Interface Pad 5516 Figure 3

Figure 3. 3D-rendered microscopy image (300x) illustrating the edge of 3M Thermally Conductive Silicone Interface Pad 5516 after laser cutting.

3M Thermally Conductive Silicone Interface Pad 5516 was also tested with an alternate system configuration using a 10.6µm CO₂ laser source. The results of these tests were compared by analyzing the heat effects, processed edge quality, and post-processing requirements. The results of the comparison of these system configurations are listed in tabular form in Table 1 and shown photographically in Figure 4. The 9.3µm configuration produces a noticeably better edge when cutting this material and is the recommended configuration.

Table 1. System Configuration Comparison

System Configuration	Heat-Affected Zone	Process Characteristics	Post-Processing Requirements
9.3µm (Recommended)	Minimal heat-affected zone of approximately 260µm	This configuration results in a clean edge with minimal heat effects and nominal discoloration	Post-processing requirements include the removal of slight surface deposition using mild abrasion
10.6µm	Increased heat-affected zone of approximately 320µm	This configuration results in increased discoloration and heat effects along the edge

3M Thermally Conductive Silicone Interface Pad 5516 Figure 4

Figure 4. Microscopy images (300x) of the edge resulting from laser cutting with the 9.3µm (left) and 10.6µm (right) wavelengths.

Processing Example

3M Thermally Conductive Silicone Interface Pad 5516 applications requiring fine geometry and intricate detail without degrading the physical properties of the material can be achieved with ULS technology. An example demonstrating the results of laser cutting 3M Thermally Conductive Silicone Interface Pad 5516 using the recommended system configuration is shown in Figure 5.

3M Thermally Conductive Silicone Interface Pad 5516 Figure 5

Figure 5. Example of the geometry possible by laser cutting 3M Thermally Conductive Silicone Interface Pad 5516 (film liner removed).

Conclusion

3M Thermally Conductive Silicone Interface Pad 5516 is suitable for laser processing and was extensively tested to determine the optimal processing configuration. Through this testing, it was determined that laser cutting is viable with this material and that using a 75 watt 9.3µm CO₂ laser source is the recommended system configuration. 3M Thermally Conductive Silicone Interface Pad 5516 efficiently absorbs the 9.3µm wavelength laser energy to produce a processed edge that has a minimal heat-affected zone and nominal discoloration.