A protective adhesive tape for semiconductor sealing and molding, and a method of manufacturing and using the same

Abstract

The application provides a protective adhesive tape for semiconductor sealing and molding, a preparation method and application thereof. The protective adhesive tape for semiconductor sealing and molding comprises a substrate layer and an adhesive layer. The preparation raw material of the adhesive layer comprises a thermoplastic polyamide-imide resin and a thermosetting polyamide-imide resin. The substrate layer and the adhesive layer made of the specific raw material are matched, so that the obtained protective adhesive tape for semiconductor sealing and molding has excellent adhesive property, can temporarily protect the semiconductor lead frame, prevents the semiconductor lead frame from being damaged and guarantees the stability of lead welding. Meanwhile, the protective adhesive tape for semiconductor sealing and molding also has excellent high-temperature stability, does not decompose after long-time high-temperature use, is easy to tear off after use and has no residual glue, and does not cause pollution to the lead frame.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor packaging technology, and specifically relates to a protective tape for semiconductor sealing molding. Background Technology

[0002] Integrated circuit packaging involves first fixing the IC circuit chip onto a lead frame, then soldering the lead pads on the chip surface to the lead terminals on the lead frame using wires to achieve electrical interconnection, and finally encapsulating and protecting it with a molding compound, retaining only the external leads used for external connections, thus forming a packaged IC circuit.

[0003] With the increasing demands for higher density, smaller area, and thinner semiconductor packages in recent years, various semiconductor package structures have been proposed. For such semiconductor packages, a semiconductor package structure has been developed that seals only one side of the package (the semiconductor element side) while exposing the lead frame on the back side for external connection (e.g., QFN, Quad Flat Non-leaded). Using this semiconductor package structure, smaller area and thinner profile can be achieved.

[0004] Currently, in the process of manufacturing semiconductor packages, a common practice is to attach a temporary protective film to one side of the lead frame, fix the semiconductor components to the other side of the lead frame, and then seal the semiconductor components with resin potting compound. This method can prevent the molding compound from wrapping around to the back of the lead frame during the molding process, thus preventing contamination of the lead frame.

[0005] However, for semiconductor packages, the assembly process involves prolonged high-temperature treatment, such as in the die bonding stage, die bond curing, wire bonding, and resin potting. After the above high-temperature treatment, in the process of peeling the temporary protective film off the sealant, sometimes the temporary protective film is firmly bonded to the lead frame and potting resin layer, which makes it impossible to peel off the temporary protective film normally, or even causes the temporary protective film to break.

[0006] Therefore, in order to solve the above technical problems, there is an urgent need to develop a high-temperature resistant and easily peelable protective tape for semiconductor sealing molding. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a protective tape for semiconductor sealing and molding and its preparation method. The protective tape for semiconductor sealing and molding can temporarily protect the semiconductor lead frame, prevent the lead frame from deforming and ensure the stability of lead soldering. At the same time, it has excellent high temperature resistance, and will not decompose even after long-term high-temperature treatment and can still be easily peeled off from the lead frame without contaminating the lead frame.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a protective tape for semiconductor sealing molding, the protective tape for semiconductor sealing molding comprising a substrate layer and an adhesive layer;

[0010] The raw materials for preparing the adhesive layer include thermoplastic polyamide-imide resin and thermosetting polyamide-imide resin.

[0011] The protective tape for semiconductor sealing provided by this invention includes a substrate layer and an adhesive layer. The raw materials for preparing the adhesive layer include thermoplastic polyamide-imide resin and thermosetting polyamide-imide resin. The thermoplastic polyamide-imide resin does not undergo a chemical reaction (including chain growth and network structure formation) after heating, while the thermosetting polyamide-imide resin continues to undergo a chemical reaction after heating to form a network structure. By combining the two, after heat treatment, the thermoplastic polyamide-imide resin can penetrate through the network structure formed by the thermosetting polyamide-imide resin, forming a through-network structure. This effectively enhances the cohesive force of the adhesive layer, giving it excellent adhesion performance at high temperatures.

[0012] This invention uses a substrate layer and an adhesive layer made from the aforementioned specific raw materials to create a protective tape for semiconductor sealing and molding that has excellent adhesion properties. It can provide temporary protection for the semiconductor lead frame and ensure the stability of lead soldering. At the same time, the protective tape for semiconductor sealing and molding also has excellent high-temperature stability and will not decompose even after prolonged high-temperature use. It is easy to remove after use without leaving any residue and will not contaminate the lead frame.

[0013] Preferably, the thickness of the substrate layer is 15~50 μm, such as 20 μm, 25 μm, 30 μm, 35 μm, 40 μm or 45 μm.

[0014] Preferably, the coefficient of thermal expansion of the substrate layer is less than 20 ppm / ℃, for example, 18 ppm / ℃, 16 ppm / ℃, 14 ppm / ℃ or 12 ppm / ℃.

[0015] Preferably, the substrate layer is a polyimide film.

[0016] Preferably, the polyimide film is a polyimide film that has undergone corona treatment.

[0017] Preferably, the dyne value of the corona-treated polyimide film is greater than 58, for example, 60, 62, 64, 66 or 68.

[0018] Preferably, the mass ratio of the thermoplastic polyamide-imide resin to the thermosetting polyamide-imide resin is 100:(1~10), for example, 100:2, 100:3, 100:4, 100:5, 100:6, 100:7, 100:8 or 100:9, etc.

[0019] In a preferred embodiment of the present invention, the mass ratio of thermoplastic polyamide-imide resin to thermosetting polyamide-imide resin in the adhesive layer is further defined. If the mass ratio is too high, the cohesive force of the adhesive layer will be reduced, resulting in residual adhesive after peeling. If the mass ratio is too low, the movement of the molecular chains of the thermoplastic polyamide-imide resin in the adhesive layer will be restricted, thereby making hot-press bonding impossible.

[0020] Preferably, the glass transition temperature (Tg) of the thermoplastic polyamide-imide resin is 170~230℃, such as 180℃, 190℃, 200℃, 210℃ or 220℃.

[0021] Preferably, the thermoplastic polyamide-imide resin has a weight-average molecular weight of 200,000 to 1,000,000, such as 300,000, 400,000, 500,000, 600,000, 700,000, 800,000, or 900,000. If its weight-average molecular weight is too high, it will lead to difficulty in dissolving. If its weight-average molecular weight is too low, it will easily cause insufficient mechanical strength of the adhesive layer, which will easily lead to cohesive failure and leave residue after removal.

[0022] Preferably, the glass transition temperature (Tg) of the thermosetting polyamide-imide resin after curing is 230~320℃, such as 240℃, 250℃, 260℃, 270℃, 280℃, 290℃, 300℃ or 310℃.

[0023] Preferably, the thermosetting polyamide-imide resin has a weight-average molecular weight of not less than 50,000, such as 60,000, 70,000, 80,000, 90,000 or 100,000.

[0024] Preferably, the raw materials for preparing the adhesive layer also include a solvent.

[0025] Preferably, the solvent comprises any one or a combination of at least two of N'N-dimethylformamide, N'N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,4-dioxane or γ-caprolactone.

[0026] In a second aspect, the present invention provides a method for preparing a protective tape for semiconductor sealing as described in the first aspect, the method comprising: mixing thermoplastic polyamide-imide resin and thermosetting polyamide-imide resin in a solvent, coating the mixture onto the surface of a substrate layer, and drying it to obtain the protective tape for semiconductor sealing.

[0027] Preferably, the drying temperature is 70~200℃, such as 90℃, 110℃, 130℃, 150℃, 170℃ or 190℃.

[0028] Thirdly, the present invention provides a method for sealing and molding a semiconductor, the method comprising: hot-pressing a protective tape for sealing and molding a semiconductor as described in the first aspect onto the back of a punched lead frame plate, and then sequentially performing die bonding, die bonding adhesive curing, wire bonding, molding and post-curing, and finally peeling off the protective tape for sealing and molding the semiconductor to complete the sealing and molding of the semiconductor.

[0029] Preferably, the hot pressing temperature is 200~250℃, such as 210℃, 220℃, 230℃ or 240℃.

[0030] Preferably, the pressure of the hot pressing is 2~5 MPa, such as 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa or 4.5 MPa.

[0031] Preferably, the hot pressing time is 10~20 s, such as 12 s, 14 s, 16 s or 18 s.

[0032] Fourthly, the present invention provides the application of a protective tape for semiconductor sealing as described in the first aspect in semiconductor packaging.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The semiconductor sealing and molding protective tape provided by this invention includes a substrate layer and an adhesive layer. The raw materials for preparing the adhesive layer include thermoplastic polyamide-imide resin and thermosetting polyamide-imide resin. By combining the substrate layer and the adhesive layer made from the above-mentioned specific raw materials, the resulting semiconductor sealing and molding protective tape has excellent adhesion properties, which can provide temporary protection for the semiconductor lead frame, prevent its occurrence, and ensure the stability of lead soldering. At the same time, the semiconductor sealing and molding protective tape also has excellent high-temperature stability, and will not decompose even after long-term high-temperature use. It is easy to tear off after use without leaving any residue and will not contaminate the lead frame. Attached Figure Description

[0035] Figure 1 A cross-sectional structural diagram of the protective tape for semiconductor sealing and molding provided by the present invention;

[0036] Wherein, 1-substrate layer, 2-adhesive layer. Detailed Implementation

[0037] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention.

[0038] The following is some information about the raw materials involved in the specific embodiments of the present invention:

[0039] (1) Thermoplastic polyamide-imide resin A: FC-2403 from Dongguan Shangda New Materials Co., Ltd., with a Tg of 180℃ and a weight-average molecular weight of 500,000;

[0040] (2) Thermoplastic polyamide-imide resin B: FC-D900 from Dongguan Shangda New Materials Co., Ltd., with a Tg of 190℃ and a weight-average molecular weight of 800,000;

[0041] (3) Thermoplastic polyamide-imide resin C: FC-1500 from Dongguan Shangda New Materials Co., Ltd., with a Tg of 250℃ and a weight-average molecular weight of 500,000;

[0042] (4) Thermoplastic polyamide-imide resin D: FC-D400 from Dongguan Shangda New Materials Co., Ltd., with a Tg of 160℃ and a weight-average molecular weight of 500,000;

[0043] (5) Thermoplastic polyamide-imide resin E: SE23 from Nantong Bolian New Materials Co., Ltd., with a Tg of 180℃ and a weight-average molecular weight of 100,000;

[0044] (6) Thermosetting polyamide-imide resin A: FC-3910M from Dongguan Shangda New Materials Co., Ltd., with a Tg of 260℃ after curing;

[0045] (7) Thermosetting polyamide-imide resin B: HR-16NN from Toyobo Co., Ltd. of Japan, with a Tg of 320℃ after curing;

[0046] (8) Polyimide film: GF100 from advanced PI material in South Korea, with a thickness of 25 μm and a coefficient of thermal expansion of 17ppm / ℃.

[0047] Example 1

[0048] A protective tape for semiconductor sealing and molding, the cross-sectional structure of which is shown in the figure. Figure 1 As shown, it includes a substrate layer 1 and an adhesive layer 2;

[0049] The thickness of the substrate layer 1 is 25 μm, specifically a polyimide film after corona treatment, with a dyne value of 70 for the corona-treated surface.

[0050] The raw materials for preparing adhesive layer 2 include, by weight, 100 parts of thermoplastic polyamide-imide resin A, 5 parts of thermosetting polyamide-imide resin A, and 315 parts of N'N-dimethylacetamide;

[0051] The method for preparing the protective tape for semiconductor sealing and molding provided in this embodiment includes the following steps:

[0052] (1) Thermoplastic polyamide-imide resin A, thermosetting polyamide-imide resin A and N'N-dimethylacetamide are mixed to obtain a glue solution with a solid content of 25%;

[0053] (2) First, the polyimide film is subjected to corona treatment. Then, the adhesive obtained in step (1) is coated on the corona-treated surface of the polyimide film at a speed of 20 m / min using a micro-grooving method. The coating thickness is 5 μm. Finally, it is dried in an oven. The temperatures of each drying channel in the oven from front to back are 70℃, 100℃, 140℃, 200℃, 200℃, 120℃ and 80℃, respectively. After cooling, the film is wound up to obtain the protective tape for semiconductor sealing molding.

[0054] Example 2

[0055] A protective tape for semiconductor sealing molding, having the same cross-sectional structure as in Example 1, includes a substrate layer and an adhesive layer;

[0056] The thickness of the substrate layer is 25 μm, specifically a polyimide film after corona treatment, with a dyne value of 70 for the corona-treated surface.

[0057] The raw materials for preparing the adhesive layer include, by weight, 100 parts of thermoplastic polyamide-imide resin B, 2 parts of thermosetting polyamide-imide resin B, and 306 parts of N'N-dimethylacetamide;

[0058] The method for preparing the protective tape for semiconductor sealing and molding provided in this embodiment includes the following steps:

[0059] (1) Thermoplastic polyamide-imide resin B, thermosetting polyamide-imide resin B and N'N-dimethylacetamide are mixed to obtain a glue solution with a solid content of 25%.

[0060] (2) First, the polyimide film is subjected to corona treatment. Then, the adhesive obtained in step (1) is coated on the corona-treated surface of the polyimide film at a speed of 20 m / min using a micro-grooving method. The coating thickness is 5 μm. Finally, it is dried in an oven. The temperatures of each drying channel in the oven from front to back are 70℃, 100℃, 140℃, 200℃, 200℃, 120℃ and 80℃, respectively. After cooling, the film is wound up to obtain the protective tape for semiconductor sealing molding.

[0061] Example 3

[0062] A protective tape for semiconductor sealing molding differs from Example 1 only in that the amount of thermosetting polyamide-imide resin A added to the raw materials of the adhesive layer is 10 parts by weight, while the other substances, structural parameters and preparation methods are the same as in Example 1.

[0063] Example 4

[0064] A protective tape for semiconductor sealing molding differs from Example 1 only in that the amount of thermosetting polyamide-imide resin A added to the raw materials of the adhesive layer is 1 part by weight, while the other substances, structural parameters and preparation methods are the same as in Example 1.

[0065] Example 5

[0066] A protective tape for semiconductor sealing molding differs from Example 1 only in that thermoplastic polyamide-imide resin B is used instead of thermoplastic polyamide-imide resin A. All other materials, structural parameters and preparation methods are the same as in Example 1.

[0067] Example 6

[0068] A protective tape for semiconductor sealing molding differs from Example 1 only in that thermosetting polyamide-imide resin B is used instead of thermosetting polyamide-imide resin A. All other materials, structural parameters and preparation methods are the same as in Example 1.

[0069] Comparative Example 1

[0070] A protective tape for semiconductor sealing molding differs from Example 1 only in that thermosetting polyamide-imide resin is not added to the raw materials of the adhesive layer; all other substances, structural parameters, and preparation methods are the same as in Example 1.

[0071] Comparative Example 2

[0072] A protective tape for semiconductor sealing molding differs from Example 2 only in that the amount of thermosetting polyamide-imide resin B added to the raw material of the adhesive layer is 15 parts by weight, while the other substances, structural parameters and preparation methods are the same as in Example 2.

[0073] Comparative Example 3

[0074] A protective tape for semiconductor sealing molding is different from Example 1 only in that thermoplastic polyamide-imide resin C is used instead of thermoplastic polyamide-imide resin A. All other materials, structural parameters and preparation methods are the same as in Example 1.

[0075] Comparative Example 4

[0076] A protective tape for semiconductor sealing molding differs from Example 1 only in that thermoplastic polyamide-imide resin D is used instead of thermoplastic polyamide-imide resin A. All other materials, structural parameters and preparation methods are the same as in Example 1.

[0077] Comparative Example 5

[0078] A protective tape for semiconductor sealing molding differs from Example 1 only in that thermoplastic polyamide-imide resin E is used instead of thermoplastic polyamide-imide resin A. All other materials, structural parameters and preparation methods are the same as in Example 1.

[0079] Performance testing:

[0080] (1) Room temperature peelability: Under the conditions of 220℃, 4 MPa and 15 s, the semiconductor sealing molding protective tape was hot-pressed onto the unpunched substrate of the same material as the punched lead frame (material is CW-003A). After cooling to room temperature, the 180° peel force was tested by an electronic tensile tester under the conditions of temperature 25℃±1℃ and humidity 50%±5%.

[0081] (2) At 220℃, 4 MPa and 15 s, the semiconductor sealing molding protective tape was hot-pressed onto the back of the packaging lead frame, and the processes of die bonding, die bonding adhesive curing, wire bonding, molding and post-curing were performed in sequence. After the packaging steps were completed, the semiconductor sealing molding protective tape was peeled off from the lead frame and packaging material and the following tests were performed.

[0082] ① Excessive use of molding compound: The test method is to peel off the tape after molding and observe under a 100x microscope whether the molding compound has overflowed to the side of the tape.

[0083] ② Residual adhesive removal of tape: The test method is to peel off the tape after the plastic sealing is completed and observe whether there is any hot melt adhesive residue on the frame surface in contact with the tape under an 8x optical microscope;

[0084] ③Ease of tape removal: The test method is to check whether the tape is easy to peel off after the plastic sealing is completed, and whether the substrate will break.

[0085] ④ Tape removal frame contamination: The test method is to peel off the tape after the plastic sealing is completed and observe whether there is hot melt adhesive residue on the lead frame under a 100x optical microscope.

[0086] The semiconductor sealing and molding protective tapes provided in Examples 1-6 and Comparative Examples 1-5 were tested according to the above test method. The test results are shown in Table 1.

[0087] Table 1

[0088] Peel strength at room temperature (gf / cm) Plastic sealant overflow Tape removal of residue Ease of tape removal Tape removal of frame contamination Example 1 357 No overflow No residue easy Pollution-free Example 2 294 No overflow No residue easy Pollution-free Example 3 279 No overflow No residue easy Pollution-free Example 4 424 No overflow No residue easy Pollution-free Example 5 320 No overflow No residue easy Pollution-free Example 6 317 No overflow No residue easy Pollution-free Comparative Example 1 394 No overflow Large amount of residual glue difficulty Adhesive layer contamination Comparative Example 2 74 There is overflow No residue easy Molding material contamination Comparative Example 3 5 There is overflow No residue easy Molding material contamination Comparative Example 4 Substrate fracture No overflow No residue difficulty Pollution-free Comparative Example 5 357 No overflow There is residual glue difficulty Adhesive layer contamination

[0089] According to the data in Table 1:

[0090] The protective tapes for semiconductor sealing and molding provided in Examples 1-6 have a room temperature peel strength of 279-357 gf / cm, good sealing performance, and no plastic sealant overflow during use. After use, they can be easily peeled off from the lead frame and packaging material without residue or pollution.

[0091] Compared with Example 1, no thermosetting polyamide-imide resin was added to the raw materials of the adhesive layer in Comparative Example 1, resulting in lower cohesive strength of the obtained protective tape. Residual adhesive will appear after peeling it off from the lead frame and encapsulation material at the end of use.

[0092] Compared with Example 2, the amount of thermosetting polyamide-imide resin added to the adhesive layer of Comparative Example 2 was too high, resulting in a decrease in the peel strength of the resulting protective tape and a reduction in its protective effect.

[0093] Compared with Example 1, the thermoplastic polyamide-imide resin in the adhesive layer of Comparative Example 3 has an excessively high Tg, which also leads to a lower peel strength and reduced protective effect of the resulting protective tape.

[0094] Compared with Example 1, the thermoplastic polyamide-imide resin in the adhesive layer of Comparative Example 4 has a low Tg, which results in excessive peel force of the protective tape after hot pressing, which in turn causes the substrate to break when the film is peeled off.

[0095] Compared to Example 1, the molecular weight of the thermoplastic polyamide-imide resin in the raw material of the adhesive layer in Example 5 is too low, which also results in lower cohesion of the protective tape. Residual adhesive will appear after peeling it off from the lead frame and encapsulation material at the end of use.

[0096] The applicant declares that this invention illustrates a protective tape for semiconductor sealing molding, its preparation method, and its application through the above embodiments. However, this invention is not limited to the above process steps, meaning that this invention does not necessarily rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of the raw materials used in this invention, additions of auxiliary components, and selection of specific methods all fall within the protection and disclosure scope of this invention.

Claims

1. A protective tape for semiconductor sealing molding, characterized in that, The protective tape for semiconductor sealing molding includes a substrate layer and an adhesive layer; The raw materials for preparing the adhesive layer include thermoplastic polyamide-imide resin and thermosetting polyamide-imide resin in a mass ratio of 100:(1~10); The glass transition temperature of the thermoplastic polyamide-imide resin is 170~230℃; The thermoplastic polyamide-imide resin has a weight-average molecular weight of 200,000 to 1,000,000.

2. The protective tape for semiconductor sealing molding according to claim 1, characterized in that, The thickness of the substrate layer is 15~50 μm.

3. The protective tape for semiconductor sealing molding according to claim 1, characterized in that, The coefficient of thermal expansion of the substrate layer is less than 20 ppm / ℃.

4. The protective tape for semiconductor sealing molding according to claim 1, characterized in that, The substrate layer is a polyimide film.

5. The protective tape for semiconductor sealing molding according to claim 4, characterized in that, The polyimide film is a polyimide film that has undergone corona treatment.

6. The protective tape for semiconductor sealing molding according to claim 5, characterized in that, The dyne value of the corona-treated polyimide film is greater than 58.

7. The protective tape for semiconductor sealing molding according to claim 1, characterized in that, The glass transition temperature of the thermosetting polyamide-imide resin after curing is 230~320℃.

8. The protective tape for semiconductor sealing molding according to claim 1, characterized in that, The weight-average molecular weight of the thermosetting polyamide-imide resin is not less than 50,000.

9. The protective tape for semiconductor sealing molding according to claim 1, characterized in that, The raw materials for preparing the adhesive layer also include solvents.

10. The protective tape for semiconductor sealing molding according to claim 9, characterized in that, The solvent includes any one or a combination of at least two of N'N-dimethylformamide, N'N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,4-dioxane or γ-caprolactone.

11. A method for preparing a protective tape for semiconductor sealing as described in any one of claims 1 to 10, characterized in that, The preparation method includes: mixing thermoplastic polyamide-imide resin and thermosetting polyamide-imide resin in a solvent, coating the mixture onto the surface of a substrate, and drying it to obtain the protective tape for semiconductor sealing molding.

12. A method for sealing and molding a semiconductor, characterized in that, The sealing molding method includes: hot-pressing the semiconductor sealing molding protective tape as described in any one of claims 1 to 10 onto the back of the punched lead frame board, and then sequentially performing die bonding, die bonding adhesive curing, wire bonding, molding and post-curing, and finally peeling off the semiconductor sealing molding protective tape to complete the semiconductor sealing molding.

13. The sealing molding method according to claim 12, characterized in that, The hot pressing temperature is 200~250℃.

14. The sealing molding method according to claim 12, characterized in that, The pressure of the hot pressing is 2~5 MPa.

15. The sealing molding method according to claim 12, characterized in that, The hot pressing time is 10~20 s.

16. The application of a semiconductor sealing and molding protective tape as described in any one of claims 1 to 10 in semiconductor packaging.

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