Novel Temporary Bonding and Debonding for Semiconductor Packaging

As IoT, AI and Big Data drive the need for new and enhanced information, data, autonomous driving and communications devices, these devices must adapt to new form factors and diverse functionalities. The diversity of information and communication devices such as smartphones, laptops, data servers for cloud computing, smart mobility, and other smart mobile devices are driving the need for new forms of semiconductor chip architectures and semiconductor die packages.

Examples of these innovations through time are shown in Figure 1 (Update on JEDEC Thermal Standards September 17, 2012 Electronics Cooling). The new varieties of package designs are requiring new assembly and manufacturing processes and materials such as thinner wafers and temporary bonding-debonding adhesives, among others.

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To illustrate the changes in wafer dimensions with the changes in chip packages over time, Figure 2 shows how processed wafers have been getting larger and thinner over the past several decades. (Ultrathin Wafer Pre-Assembly and Assembly Process Technologies: A Review, May 2015). This trend requires that during the manufacturing process, particularly in wafer-level back-end assembly and packaging operations, thin wafers need a temporary support while in process to ensure they are handled without damage and maintain high yields.

A Track Record of Innovation

nGt_Temporary Bonding_1 copyWith a strong commitment to R&D that goes back to our founding more than a decade ago, nanoGriptech is continually developing new and effective dry adhesive temporary bonding films (Figure 3) requiring minimal process steps, and providing clean bonding-debonding processes with the lowest possible residue and the potential for reusability.

As a result of our R&D efforts, we have developed a dry adhesive tape called Setex GeckoTape. It complements our gripping (Setex GeckoGrip®) and fastening (Setex Ultra-Thin Fastener) technologies forming the trio of product lines we manufacture.

Practical Solutions Based on Know-How

To enable a most effective and high yield package manufacturing process, we have applied our knowledge of the low residue and repeatable SetexTM dry adhesive tapes for advanced package manufacturing.   As a result, we are well on our way to having commercial temporary bonding tape solutions, and we intend to continue advancing our dry adhesive tapes technology to enable higher temperature bonding-debonding processes in advanced packaging.

Our dry adhesive temporary bonding-debonding solution can be more effective than spin-on adhesives and glue-based tapes. The Setex dry adhesive temporary bonding solution has the potential to offer these benefits:

  • Lower residue providing higher yield process
  • A compact process requiring fewer tools and a smaller footprint in the fab
  • The potential for re-usability, significantly reducing materials cost for the process

To the best of our knowledge, Setex GeckoTape is the world’s first-of-its-kind dry adhesive tape technology that consists of a pressure-sensitive solution for temporary bonding-debonding processes in advanced packaging. (Figure 4)

nGt_Temporary Bonding_1 copy 2Depending upon the application, Setex dry adhesive tapes can be single- or double-sided. They may also be combined with conventional pressure-sensitive adhesive (PSA) backings or integrated with other tapes to provide higher yields than alternative technologies. Moreover, Setex GeckoTape’s highly desirable adhesive properties give the material versatility for a wide range of applications.

A key feature of our Setex GeckoTape dry adhesive technology is that it can be customized with respect to its microstructures and geometries for achieving desired adhesive properties based on type of carriers and wafers used. For example, in Figure 5 we show a graph of shear strength versus peel strength.

Through our advanced manufacturing process, we have developed a unique understanding of how the shape of each microfiber can change the adhesion properties. Figure 5 shows dialed-in shear and peel adhesion for 10 different microfiber geometries where each set of microfiber geometries is manufactured with the same resin material. The diameters of our microstructured fibers that create adhesion forces typically range from 10 µm to 150 µm, allowing for high resolution interaction with microscale dies and components on wafers.

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Lastly, our Setex dry adhesive tapes offer good process control to achieve very low total thickness variation (TTV), which is typically less than 20 µm, and can withstand temperatures up to 100°C (212°F). We continue to develop dry adhesive tapes for higher temperature processes and for achieving less than 5 µm of TTV.

To learn how Setex GeckoTape can help you improve uptime and yield...

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