Warp control membrane

Abstract

A warp control film includes a substrate layer, a shrinkage layer, and an adhesive layer. The substrate layer includes a first surface and a second surface opposite to the first surface. The shrinkage layer is disposed on the first surface of the substrate layer. The adhesive layer is disposed on the second surface of the substrate layer, and the adhesive layer is a pressure-sensitive adhesive. The advantage of this invention is that by disposing the substrate layer between the shrinkage layer and the adhesive layer, the substrate layer acts as an insulating layer and separates the shrinkage layer and the adhesive layer, preventing the material components of the shrinkage layer and the adhesive layer from interfering with each other. This allows the warp control film to effectively suppress the warping of an object to be attached. Furthermore, by configuring the adhesive layer as a pressure-sensitive adhesive, it can be mechanically peeled off during subsequent peeling operations, further eliminating the step of removing residual adhesive and improving process efficiency.

Description

Warp control membrane Technical Field

[0001] This invention relates to a control membrane, and more particularly to a warp control membrane with warp suppression function. Prior Technology

[0002] In recent years, in order to improve the performance and stability of semiconductors, the importance of advanced packaging technology has gradually increased. Among them, Fan-Out panel level packaging (FOPLP) is one of the main processes of advanced packaging technology.

[0003] In the packaging process, uneven stress distribution within the packaging structure can easily lead to warpage. Referring to Figure 1, to improve the warpage problem, an anti-warpage film 91 can be provided in a packaging structure 90. For example, in a conventional anti-warpage film 91, an anti-warpage layer 913 and an adhesive layer 914 are sequentially coated on a surface 912 of a substrate 911. However, the material composition of the adhesive layer 914 and the anti-warpage layer 913 can easily affect each other, thus affecting the effectiveness of the anti-warpage film 91. In addition, since the adhesive layer 914 is mostly attached to the packaging structure 90 by chemical bonding, additional chemical cleaning or grinding steps are required to remove residual adhesive when peeling off the anti-warpage film 91, which affects the product manufacturing efficiency and yield. Summary of the Invention

[0004] Therefore, the objective of this invention is to provide a warp control membrane with improved performance.

[0005] Therefore, the novel warp control film comprises a substrate layer, a shrinkage layer, and an adhesive layer.

[0006] The substrate layer includes a first surface and a second surface opposite to the first surface, and the material of the substrate layer includes polyimide (PI).

[0007] The shrinkage layer is disposed on the first surface of the substrate layer.

[0008] The adhesive layer is disposed on the second surface of the substrate layer, and the adhesive layer is a pressure-sensitive adhesive (PSA).

[0009] The advantages of this new invention are:

[0010] 1. Through a special structural design that places the substrate layer between the shrinkage layer and the adhesive layer, the substrate layer can act as an insulating layer to separate the shrinkage layer and the adhesive layer, preventing the material components of the shrinkage layer and the adhesive layer from affecting each other. Therefore, this new invention not only effectively suppresses warping of the object to be attached but also improves the overall yield of the product.

[0011] 2. Furthermore, by configuring the adhesive layer as a pressure-sensitive adhesive, the adhesive layer can be mechanically peeled off during subsequent peeling operations. Compared to the anti-warping structure of chemical adhesives, this new invention can further eliminate the step of removing residual adhesive during peeling operations, thereby improving product manufacturing efficiency. Simple Explanation of the Diagram

[0012] Other features and effects of this novel invention will be clearly presented in the embodiments with reference to the drawings, wherein: Figure 1 is a partial schematic diagram of an existing anti-warping film attached to an encapsulation structure; Figure 2 is a partial cross-sectional view illustrating an embodiment of the novel warp control membrane; Figure 3 is a partial cross-sectional view illustrating an object to be attached in this embodiment; Figure 4 is a schematic diagram of the use of this embodiment; and Figure 5 is a partial schematic diagram illustrating the direction of the force exerted on the object to be attached to warp, and the direction of the anti-warping force of the body in this embodiment. Implementation

[0013] Referring to Figures 2, 3, and 4, one embodiment of the novel warp control film is suitable for attachment to an object 81. The object 81 is, for example, an encapsulation structure, silicon, glass, a PCB, or a core board. This embodiment includes a body 1, a first release film 2, and a second release film 3.

[0014] The body 1 includes a substrate layer 11, a shrinkage layer 12, and an adhesive layer 13. The substrate layer 11 has a first surface 111 and a second surface 112 opposite to the first surface 111. In this embodiment, the substrate layer 11 is made of polyimide (PI), which has properties such as high temperature resistance, corrosion resistance, and insulation.

[0015] The shrinkage layer 12 is disposed on the first surface 111 of the substrate layer 11 and is made of epoxy resin. In this embodiment, the thickness of the shrinkage layer 12 is between 20 μm and 250 μm, for example, 50 μm to 100 μm or 50 μm to 75 μm. Since the shrinkage layer 12 is made of epoxy resin, manufacturers can adjust the coefficient of thermal expansion (CTE) of the shrinkage layer 12 to meet the practical requirements of different fan-out panels and packaging structures. For example, when the temperature range is between 30°C and 200°C, if the thickness of the shrinkage layer 12 is 50 μm, the CTE is 79.6 ppm / °C. If the thickness of the shrinkage layer 12 is 100 μm, the CTE is 81.3 ppm / °C. Since those skilled in the art can deduce the extended details of the physical properties of the shrinkage layer 12 from the above description, they will not be repeated here.

[0016] The adhesive layer 13 is disposed on the second surface 112 of the substrate layer 11. The adhesive layer 13 is a pressure-sensitive adhesive (PSA) with high viscosity, high temperature resistance up to 200°C, and resistance to acids and alkalis. In this embodiment, the adhesive layer 13 can be made of any of acrylic, silicone, rubber, or polyurethane (PU). The thickness of the adhesive layer 13 is between 5 μm and 30 μm, for example, 5 μm to 10 μm. The adhesive layer 13 is suitable for attaching the object 81 to the substrate layer, and the adhesive force between the adhesive layer 13 and the substrate layer 11 is greater than the adhesive force between the adhesive layer 13 and the object 81 to be attached.

[0017] This embodiment further measures the adhesion of the adhesive layer 13 to the steel plate (ASTM D3330) to analyze its bonding strength. When the steel plate specification is SUS#304, the tensile strength of the adhesive layer 13 is tested using a universal tensile testing machine (not shown) at a speed of 300 mm / min and an angle of 180 degrees. At room temperature, when the adhesive thickness (i.e., the thickness of the adhesive layer 13) is 10 μm, the adhesion strength is 364 gf / 25 mm, and when the adhesive thickness is 30 μm, the adhesion strength is 814 gf / 25 mm. After the adhesive layer 13 is cured at 250°C for 30 minutes, the adhesion strength is 366 gf / 25 mm when the adhesive thickness is 10 μm, and 559 gf / 25 mm when the adhesive thickness is 30 μm.

[0018] The substrate layer 11 is disposed between the shrink layer 12 and the adhesive layer 13, and the substrate layer 11 serves as an isolation layer to separate the shrink layer 12 and the adhesive layer 13, thereby preventing the material components of the shrink layer 12 and the adhesive layer 13 from affecting each other. This allows the warpage control film to effectively suppress the warpage of the object to be attached 81 and improve the overall product yield.

[0019] The first release film 2 is detachably disposed on the side of the adhesive layer 13 opposite to the substrate layer 11, and the second release film 3 is detachably disposed on the side of the shrink layer 12 opposite to the substrate layer 11. In this embodiment, the first release film 2 and the second release film 3 are made of either polyethylene terephthalate (PET) or polyolefins (PO). The first release film 2 and the second release film 3 are used to isolate the adhesive layer 13 and the shrink layer 12 from exposure to the outside environment before use, preventing the adhesive layer 13 and the shrink layer 12 from being contaminated by dust or dirt in the air, and the first release film 2 and the second release film 3 can be torn apart during use. In this embodiment, the body 1, the first release film 2, and the second release film 3 can be rolled into a cylindrical shape and then stretched to the required size during use.

[0020] Referring to Figures 2, 4, and 5, in practical application of this embodiment, the first release film 2 is first peeled off from the adhesive layer 13, allowing the adhesive layer 13 to adhere to one side of the object to be attached 81. Next, a pressure member 82 (e.g., a pressure roller) is pressed against the side of the second release film 3 opposite to the body 1 and rolled, causing the pressure member 82 to apply pressure to the body 1 through the second release film 3, thereby creating an adhesive force on the adhesive layer 13 (i.e., pressure-sensitive adhesive) of the body 1 to adhere to the object to be attached 81. Then, a cutting unit (not shown) cuts the body 1 and the second release film 3 to a predetermined size. Finally, through a curing process such as heating, the shrinkage layer 12 of the body 1 is first hardened and then cooled and shrunk, achieving the effect of correcting the warping of the object to be attached 81.

[0021] Therefore, when the object to be attached 81 warps due to asymmetric stress, the shrinkage layer 12 can generate a resistance force against the asymmetric stress, thereby reducing the warping of the encapsulation structure (i.e., the object to be attached 81). After subsequent processes are completed, the body 1 can be mechanically peeled off from the object to be attached 81. Therefore, compared with the existing method of removing the anti-warping structure by chemical means, the physical peeling method of this embodiment can reduce residual adhesive, eliminate the need for chemical cleaning or grinding to remove residual adhesive, and further reduce the risk of damaging the encapsulation structure, thereby achieving the goal of improving the yield of the encapsulation structure and process efficiency.

[0022] In summary, this novel warp control film, through its structural design of placing the substrate layer 11 between the shrink layer 12 and the adhesive layer 13, allows the substrate layer 11 to act as an intermediate insulating layer between the adhesive layer 13 and the shrink layer 12. This not only effectively controls the warp of the object to be attached 81 but also prevents the material components of the adhesive layer 13 and the shrink layer 12 from interfering with each other, thus improving the overall product yield. Furthermore, by configuring the adhesive layer 13 as a pressure-sensitive adhesive, the yield of the object to be attached 81 can be reduced due to incomplete subsequent peeling, and there is no need to remove residual adhesive through chemical cleaning or grinding. Therefore, this novel film effectively achieves its intended purpose.

[0023] However, the above description is merely an embodiment of this invention and should not be construed as limiting the scope of this invention. Any simple equivalent changes and modifications made in accordance with the scope of the patent application and the contents of the patent specification shall still fall within the scope of this invention.

[0024] 1: Ontology 11: Substrate layer 111: First Surface 112: Second Surface 12: Shrinkage layer 13: Adhesive layer 2: First release film 3: Second release film 81: Attachments to be attached 82: Pressure component 90: Packaging Structure 91: Anti-warping membrane 911: Base 912: Surface 913: Inhibits warping layers 914: Adhesive layer

Claims

1. A warpage control membrane, comprising: a substrate layer including a first surface and a second surface opposite to the first surface, the substrate layer being made of polyimide; a shrinkage layer disposed on the first surface of the substrate layer; and an adhesive layer disposed on the second surface of the substrate layer, the adhesive layer being a pressure-sensitive adhesive.

2. The warpage control membrane as described in claim 1, wherein, The shrinkage layer is made of epoxy resin.

3. The warp control membrane as described in claim 2, wherein, The thickness of the shrinkage layer is between 20μm and 250μm.

4. The warpage control membrane as claimed in claim 1, wherein, The adhesive layer is made of any of the following materials: acrylic, silicone, rubber, or polyurethane.

5. The warpage control membrane as claimed in claim 4, wherein, The thickness of the adhesive layer is between 5 μm and 30 μm.

6. The warp control film as described in claim 1, suitable for attachment to an object to be attached, wherein, The adhesive force between the adhesive layer and the substrate layer is greater than the adhesive force between the adhesive layer and the object to be attached.

7. The warpage control film as claimed in claim 1, further comprising a first release film removably disposed on the side of the adhesive layer opposite to the substrate layer, and a second release film removably disposed on the side of the shrinkage layer opposite to the substrate layer.

8. The warpage control membrane as described in claim 7, wherein, The first release film and the second release film are made of polyethylene terephthalate or any of polyolefins.

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