Surface acoustic wave filter module packaging structure and packaging method therefor

Abstract

Provided in the present invention are a surface acoustic wave filter module packaging structure and a packaging method therefor. The surface acoustic wave filter module packaging structure comprises a substrate, at least one surface acoustic wave filter chip disposed on the substrate, at least one non-filter chip disposed on the substrate, a dry film layer which covers the cover surface acoustic wave filter chip and the non-filter chip, and a plastic encapsulation layer which covers the dry film layer, wherein the surface of the surface acoustic wave filter chip is fixed to the substrate by means of a first bump structure, and a first cavity is formed between the surface acoustic wave filter chip and the substrate; and the surface of the non-filter chip is fixed to the substrate by means of a second bump structure, and a second cavity is formed between the non-filter chip and the substrate. The surface acoustic wave filter module packaging structure and method of the present invention ensure that cavities can be formed between the bottoms of all the chips and the substrate, and avoid using an injection molding process for a filter based on wafer-level packaging, thereby reducing costs and the damage to the chips in the reliability stage.

Description

SAW filter module packaging structure and packaging method thereof Technical Field

[0001] The present invention relates to the technical field of chip packaging, and in particular to a multi-chip module packaging structure. Background Art

[0002] The operating principle of surface acoustic wave filters is the transmission of sound waves on the chip surface. Therefore, the packaging of the surface acoustic wave filter must ensure that there is sufficient cavity on the surface of the interdigital transducer (the working sensor of the surface acoustic wave filter), otherwise the product will not transmit any signal. Currently, conventional filter RF modules on the market use an injection molding solution based on wafer-level packaging of filters. Before the module is packaged, the filter wafer is first wafer-level packaged to form a cavity on the surface of each filter. The filter is then mounted on the RF module substrate and finally injection molded, marked and cut to complete the packaging. Technical issues

[0003] However, in the existing technology, the packaging solution for filter modules based on wafer-level packaging is relatively expensive, and the injection pressure is too high, which will bring reliability risks such as chip bump extrusion deformation and cracking. In addition, when using compression molding (C-Molding), the plastic packaging structure easily causes cavities to form on the surface of the plastic packaging layer, resulting in structural instability.

[0004] Therefore, it is necessary to provide a new SAW filter module packaging structure and packaging method to solve the above technical problems. Technical Solutions

[0005] The object of the present invention is to provide a surface acoustic wave filter module packaging structure, which can ensure that a cavity can be formed between the bottom of all chips and the substrate and has high reliability.

[0006] In order to achieve the above-mentioned purpose, the technical solution of the present invention is as follows: a surface acoustic wave filter module packaging structure, which includes a substrate, at least one surface acoustic wave filter chip arranged on the substrate, at least one non-filter chip arranged on the substrate and spaced apart from the surface acoustic wave filter chip, a dry film layer covering the surface acoustic wave filter chip and the non-filter chip, and a plastic packaging layer covering the dry film layer, the surface of the surface acoustic wave filter chip is fixed to the substrate through a first bump structure, and a first cavity is formed between the surface acoustic wave filter chip and the substrate, the surface of the non-filter chip is fixed to the substrate through a second bump structure, and a second cavity is formed between the non-filter chip and the substrate.

[0007] Preferably, the dry film layer is adhered to the surface acoustic wave filter chip and the non-filter chip by vacuum air bag lamination.

[0008] Preferably, the dry film layer is a continuous protective film.

[0009] Preferably, the dry film layer is an epoxy resin material.

[0010] Preferably, the thickness of the dry film layer is 40-50 microns.

[0011] Preferably, the diameter of the first bump structure is 180-200 microns, and / or the diameter of the second bump structure is 180-200 microns.

[0012] Preferably, a solder resist layer is provided between the substrate and the dry film layer, and a solder resist layer is also provided at a position in the first cavity where the first bump structure is not provided.

[0013] Compared with related technologies, the surface acoustic wave filter module packaging structure provided by the present invention includes a substrate, at least one surface acoustic wave filter chip arranged on the substrate, at least one non-filter chip arranged on the substrate and spaced apart from the surface acoustic wave filter chip, a dry film layer covering the surface acoustic wave filter chip and the non-filter chip, and a plastic sealing layer covering the dry film layer. The surface of the surface acoustic wave filter chip is fixed to the substrate via a first bump structure, and a first cavity is formed between the surface acoustic wave filter chip and the substrate. The surface of the non-filter chip is fixed to the substrate via a second bump structure, and a second cavity is formed between the non-filter chip and the substrate. The surface acoustic wave filter module packaging structure of the present invention can ensure that a cavity can be formed between the bottom of all chips and the substrate, avoids the use of an injection molding process for filters based on wafer-level packaging, and reduces costs and damage to chips during the reliability stage.

[0014] Another object of the present invention is to provide a packaging method for a surface acoustic wave filter module packaging structure, wherein the structure formed by the method can ensure that a cavity can be formed between the bottom of all chips and the substrate, and has high reliability.

[0015] In order to achieve the above object, the technical solution of the present invention is as follows: a packaging method for a surface acoustic wave filter module packaging structure, comprising:

[0016] providing a substrate;

[0017] Providing at least one surface acoustic wave filter chip and at least one non-filter chip, wherein a surface of the surface acoustic wave filter chip is provided with a first bump structure, and a surface of the non-filter chip is provided with a second bump structure;

[0018] Flipping the surface acoustic wave filter chip and the non-filter chip and soldering them to the surface of the substrate using surface mounting technology, so as to form a first cavity between the surface acoustic wave filter chip and the substrate, and a second cavity between the non-filter chip and the substrate;

[0019] Providing a dry film layer to cover the surface acoustic wave filter chip and the non-filter chip;

[0020] Providing a plastic sealing layer, wherein the plastic sealing layer is injection-molded to cover the dry film layer;

[0021] The individual surface acoustic wave filter module packaging structures are formed by cutting, and each individual surface acoustic wave filter module packaging structure includes the surface acoustic wave filter chip and the non-filter chip.

[0022] Preferably, the packaging method further comprises covering the substrate with a solder resist layer when providing the substrate.

[0023] Preferably, the thickness of the dry film layer is 40-50 microns. Beneficial effects

[0024] Compared with the related art, the packaging method of the surface acoustic filter module packaging structure provided by the present invention includes providing a substrate; providing at least one surface acoustic filter chip and at least one non-filter chip, the surface of the surface acoustic filter chip is provided with a first bump structure, and the surface of the non-filter chip is provided with a second bump structure; flipping the surface acoustic filter chip and the non-filter chip and soldering them to the surface of the substrate through surface mounting technology; providing a dry film layer to cover the surface acoustic filter chip and the non-filter chip to ensure that a first cavity is formed between the surface acoustic filter chip and the substrate, and a second cavity is formed between the non-filter chip and the substrate; providing a plastic sealing layer to cover the dry film layer; cutting to form a single surface acoustic filter module packaging structure, each of which includes one surface acoustic filter chip and the non-filter chip. The surface acoustic filter module packaging structure formed by the packaging method of the present invention can ensure that a cavity can be formed between the bottom of all chips and the substrate, avoids the use of the injection molding process of the filter based on wafer-level packaging, and reduces costs and damage to the chip during the reliability stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1 is a flow chart of a method for preparing a surface acoustic wave filter module packaging structure according to the present invention;

[0026] 2a to 2e are schematic diagrams of the manufacturing process of the surface acoustic wave filter module packaging structure of the present invention. Best Mode for Carrying Out the Invention

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] Referring to FIG. 2e , the present invention provides a surface acoustic wave filter (SAW) module packaging structure 100. The SAW filter module packaging structure 100 includes a substrate 1, at least one SAW filter chip 2 disposed on the substrate 1, at least one non-filter chip 3 disposed on the substrate 1 and spaced apart from the SAW filter chip 2, a dry film layer 4 covering the SAW filter chip 2 and the non-filter chip 3, a solder resist layer 5 disposed between the substrate 1 and the dry film layer 4, and a plastic encapsulation layer 6 covering the dry film layer 4. The surface of the SAW filter chip 2 is secured to the surface of the substrate 1 by providing a first bump structure 71, forming a first cavity 20 between the SAW filter chip 2 and the substrate 1. The surface of the non-filter chip 3 is secured to the surface of the substrate 1 by providing a second bump structure 72, forming a second cavity 30 between the non-filter chip 3 and the substrate 1.

[0029] The dry film layer 4 is applied to the SAW filter chip 2 and the non-filter chip 3 via vacuum balloon lamination. The dry film layer 4 forms a continuous, unbroken protective film. This prevents the ingress of other substances between the SAW filter chip 2 and the substrate 1, ensuring the formation of the first cavity 20 between the SAW filter chip 2 and the substrate 1. Similarly, it prevents the ingress of other substances between the non-filter chip 3 and the substrate 1, ensuring the formation of the second cavity 30 between the non-filter chip 3 and the substrate 1. The dry film layer 4 is made of epoxy resin and has a thickness of 40-50 microns.

[0030] The solder resist layer 5 is arranged on the surface of the substrate 1, and the solder resist layer 5 is also provided at the position where the first bump structure 71 is not provided in the first cavity 20, and the solder resist layer 5 is not provided in the second cavity 30. In this way, the first bump structures 71 will not be tin-connected to each other and other circuits on the substrate 1, thereby preventing a short circuit from occurring.

[0031] The first bump structure 71 and the second bump structure 72 are both solder balls. The diameter of the first bump structure 71 is 180-200 microns, and / or the diameter of the second bump structure 72 is 180-200 microns.

[0032] The plastic sealing layer 6 covers the dry film layer 4 through a compression molding process (C-Molding) to complete the plastic sealing. The plastic sealing layer 6 is made of epoxy resin material, and the material composition ratio of the epoxy resin forming the plastic sealing layer 6 is different from the material composition ratio of the epoxy resin forming the dry film layer 4.

[0033] Please refer to FIG. 1-2e , the packaging method of the surface acoustic wave filter module packaging structure 100 is as follows, specifically including:

[0034] S1: providing a substrate 1;

[0035] S2: providing a solder resist layer 5, covering the substrate 1 with a layer of solder resist layer 5, and removing part of the solder resist layer 5 to make way for the chip;

[0036] S3: Providing at least one surface acoustic wave filter chip 2 and at least one non-filter chip 3, wherein a first bump structure 71 is provided on the surface of the surface acoustic wave filter chip 2, and a second bump structure 72 is provided on the surface of the non-filter chip 3, wherein the first bump structure 71 and the second bump structure 72 are both solder balls, and the diameter of the first bump structure 71 is 180-200 microns, and / or the diameter of the second bump structure 72 is 180-200 microns;

[0037] S4: flip-chipping the SAW filter chip 2 and the non-filter chip 3 and soldering them to the surface of the substrate 1 using surface mount technology (SMT), so as to form a first cavity 20 between the SAW filter chip 2 and the substrate 1, and a second cavity 30 between the non-filter chip 3 and the substrate 1;

[0038] S5: providing a dry film layer 4, and covering the surface acoustic wave filter chip 2 and the non-filter chip 3 with the dry film layer 4 by vacuum air bag lamination. The dry film layer 4 is made of epoxy resin material, and the thickness of the dry film layer 4 is 40-50 μm.

[0039] S6: providing a plastic sealing layer 6 to cover the dry film layer 4, wherein the plastic sealing layer 6 is made of epoxy resin material, and the plastic sealing layer 6 covers the dry film layer 4 by injection molding;

[0040] S7: cutting to form individual SAW filter module packaging structures 100 . Each individual SAW filter module packaging structure 100 includes one SAW filter chip 2 and the non-filter core 3 .

[0041] The surface acoustic wave filter module packaging structure 100 formed by this packaging method can ensure that cavities can be formed between the bottom of all chips and the substrate 1, and has high reliability.

[0042] Compared with related technologies, the surface acoustic wave filter module packaging structure provided by the present invention includes a substrate, at least one surface acoustic wave filter chip arranged on the substrate, at least one non-filter chip arranged on the substrate and spaced apart from the surface acoustic wave filter chip, a dry film layer covering the surface acoustic wave filter chip and the non-filter chip, and a plastic sealing layer covering the dry film layer. The surface of the surface acoustic wave filter chip is fixed to the substrate via a first bump structure, and a first cavity is formed between the surface acoustic wave filter chip and the substrate. The surface of the non-filter chip is fixed to the substrate via a second bump structure, and a second cavity is formed between the non-filter chip and the substrate. The surface acoustic wave filter module packaging structure of the present invention can ensure that a cavity can be formed between the bottom of all chips and the substrate, avoids the use of an injection molding process for filters based on wafer-level packaging, and reduces costs and damage to chips during the reliability stage.

[0043] Compared with the related art, the packaging method of the surface acoustic filter module packaging structure provided by the present invention includes providing a substrate; providing at least one surface acoustic filter chip and at least one non-filter chip, the surface of the surface acoustic filter chip is provided with a first bump structure, and the surface of the non-filter chip is provided with a second bump structure; flipping the surface acoustic filter chip and the non-filter chip and soldering them to the surface of the substrate through surface mounting technology; providing a dry film layer to cover the surface acoustic filter chip and the non-filter chip to ensure that a first cavity is formed between the surface acoustic filter chip and the substrate, and a second cavity is formed between the non-filter chip and the substrate; providing a plastic sealing layer to cover the dry film layer; cutting to form a single surface acoustic filter module packaging structure, each of which includes one surface acoustic filter chip and the non-filter chip. The surface acoustic filter module packaging structure formed by the packaging method of the present invention can ensure that a cavity can be formed between the bottom of all chips and the substrate, avoids the use of the injection molding process of the filter based on wafer-level packaging, and reduces costs and damage to the chip during the reliability stage.

[0044] The above description is only an embodiment of the present invention. It should be pointed out that those skilled in the art can make improvements without departing from the creative concept of the present invention, but these improvements all fall within the scope of protection of the present invention.

Claims

1. A surface acoustic wave filter module packaging structure, characterized in that: The surface acoustic wave filter module packaging structure includes a substrate, at least one surface acoustic wave filter chip arranged on the substrate, at least one non-filter chip arranged on the substrate and spaced apart from the surface acoustic wave filter chip, a dry film layer covering the surface acoustic wave filter chip and the non-filter chip, and a plastic packaging layer covering the dry film layer. The surface of the surface acoustic wave filter chip is fixed to the substrate through a first bump structure, and a first cavity is formed between the surface acoustic wave filter chip and the substrate. The surface of the non-filter chip is fixed to the substrate through a second bump structure, and a second cavity is formed between the non-filter chip and the substrate.

2. The surface acoustic wave filter module packaging structure according to claim 1, wherein: The dry film layer is adhered to the surface acoustic wave filter chip and the non-filter chip by vacuum air bag lamination.

3. The surface acoustic wave filter module packaging structure according to claim 2, wherein: The dry film layer is a continuous protective film.

4. The surface acoustic wave filter module packaging structure according to claim 2, wherein: The dry film layer is made of epoxy resin material.

5. The surface acoustic wave filter module packaging structure according to claim 2, wherein: The thickness of the dry film layer is 40-50 microns.

6. The surface acoustic wave filter module packaging structure according to claim 1, wherein: The diameter of the first bump structure is 180-200 microns, and / or the diameter of the second bump structure is 180-200 microns.

7. The surface acoustic wave filter module packaging structure according to claim 1, wherein: A solder resist layer is provided between the substrate and the dry film layer, and a solder resist layer is also provided at a position in the first cavity where the first bump structure is not provided.

8. A packaging method for a surface acoustic wave filter module packaging structure, characterized in that: The packaging method includes providing a substrate; Providing at least one surface acoustic wave filter chip and at least one non-filter chip, wherein a surface of the surface acoustic wave filter chip is provided with a first bump structure, and a surface of the non-filter chip is provided with a second bump structure; Flipping the surface acoustic wave filter chip and the non-filter chip and soldering them to the surface of the substrate using surface mounting technology, so as to form a first cavity between the surface acoustic wave filter chip and the substrate, and a second cavity between the non-filter chip and the substrate; Providing a dry film layer to cover the surface acoustic wave filter chip and the non-filter chip; Providing a plastic sealing layer, wherein the plastic sealing layer is injection-molded to cover the dry film layer; The individual surface acoustic wave filter module packaging structures are formed by cutting, and each individual surface acoustic wave filter module packaging structure includes the surface acoustic wave filter chip and the non-filter chip.

9. The packaging method of the surface acoustic wave filter module packaging structure according to claim 8, characterized in that: The packaging method further comprises covering the substrate with a solder resist layer when providing the substrate.

10. The packaging method of the surface acoustic wave filter module packaging structure according to claim 8, characterized in that: The thickness of the dry film layer is 40-50 microns.

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