A multi-element SMT mounting method based on RDL re-wiring, product and electronic equipment

Abstract

The application relates to the technical field of component packaging, in particular to a multi-component SMT mounting method based on RDL rewiring, a product and electronic equipment, which comprises the following steps: S1, selecting to-be-mounted components, wherein a component group comprises a first component and a second component; S2, mounting a chip, an independent component and the first component in the component group on initial pads, then performing first plastic packaging to obtain a preliminary component; S3, drilling holes in the positions of the pads where the components are not mounted on the preliminary product, then performing metal deposition and filling on the drilled holes to realize electrical connection, and obtaining an intermediate component with lead-out copper columns; S4, performing RDL rewiring on the surface of the plastic packaging body of the lead-out copper columns of the intermediate component; and S5, welding the second component and performing plastic packaging to obtain a finished component. The application meets the welding requirements of multiple components without changing the original size of the product, and avoids bridging between components caused by insufficient space.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of component packaging, in particular to a multi-component SMT mounting method based on RDL rewiring, a product and an electronic device. BACKGROUND

[0002] The integration of packaging products is getting higher and higher, and the functions are getting more and more complex. In order to meet the needs of these advanced functions, the number of electronic components that need to be mounted during the design and manufacturing process of the product also increases sharply. However, as the number of components in the product increases, the arrangement density also increases. In order to prevent the tin bridge from occurring in the reflow soldering process due to the small distance between the components, as shown in the prior art, there is a tin bridge 102 between two components 101, which requires the product size to be designed larger and larger. Although this solves the problem of too small distance between components, it also tests the lightweight and miniaturization trend of the product. Figure 1 SUMMARY

[0003] In view of the problem of tin bridge in the reflow soldering process due to too small distance between components in the prior art, the present application provides a multi-component SMT mounting method based on RDL rewiring, a product and an electronic device.

[0004] The present application is achieved by the following technical solutions:

[0005] A multi-component SMT mounting method based on RDL rewiring, comprising the following steps:

[0006] S1, selecting a component to be mounted, and dividing the component to be mounted into a plurality of independent components and a plurality of component groups, the component group comprising a first component and a second component;

[0007] S2, mounting a chip, an independent component and a first component in the component group on an initial pad, and then performing a first molding to obtain a preliminary component;

[0008] S3, drilling a connecting hole at the position of the pad where the component is not mounted on the preliminary product, and then performing metal deposition and filling at the connecting hole to make electrical connection, to obtain an intermediate component with a lead-out copper column;

[0009] S4, performing RDL rewiring on the surface of the molding body of the lead-out copper column of the intermediate component to form a secondary pad;

[0010] S5, welding a second component of the component group on the secondary pad, and performing a second molding to obtain a finished component.

[0011] Preferably, in S1, the component to be mounted is divided according to the distance between two adjacent components to be mounted. ​

[0012] Preferably, in S1, the distance between two adjacent components is less than 20um.

[0013] Preferably, in S2, the height of the first plastic package formed in the first plastic packaging process is 80um higher than the surface of the chip.

[0014] Preferably, in S3, laser drilling process is used to drill holes on the pads without components.

[0015] Preferably, in S3, the cross-sectional area of the connecting hole gradually decreases from the top of the plastic package to the surface of the pad.

[0016] Preferably, in S3, the RDL re-distribution process is as follows: coating the surface of the plastic package of the intermediate component with a copper pillar with photoresist, exposing and developing the position where the pad is to be formed, removing the photoresist at the exposed position, then electroplating copper deposition, and finally removing the remaining photoresist.

[0017] Preferably, the height of the second plastic package formed in the second plastic packaging process is 10um higher than the surface of the second component.

[0018] A product obtained by the RDL re-distribution based multi-component SMT mounting method.

[0019] An electronic device comprising a product obtained by the RDL re-distribution based multi-component SMT mounting method.

[0020] Compared with the prior art, the present application has the following beneficial effects:

[0021] The RDL re-distribution based multi-component SMT mounting method can avoid the bridging of components during welding by staggering the original pad position through RDL re-distribution process on the pads of adjacent components on the substrate, which can effectively solve the problem of tin bridging during reflow soldering due to the small size of the product and the close proximity of the components. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a schematic diagram of adjacent components in the prior packaging structure;

[0023] Figure 2 is a flowchart of the RDL re-distribution based multi-component SMT mounting method of the present application;

[0024] Figure 3 is a schematic diagram of the preliminary component in the RDL re-distribution based multi-component SMT mounting method of the present application;

[0025] Figure 4is a schematic diagram of the drilling after the SMT mounting method of the multi-element device based on RDL rewiring of the application;

[0026] Figure 5 is a schematic diagram of the deposition after drilling in the SMT mounting method of the multi-element device based on RDL rewiring of the application;

[0027] Figure 6 is a process schematic diagram of RDL rewiring in the SMT mounting method of the multi-element device based on RDL rewiring of the application;

[0028] Figure 7 is a schematic diagram of the finished device in the SMT mounting method of the multi-element device based on RDL rewiring of the application.

[0029] In the figure, 101, element device; 102, tin connection; 201, first element device; 202, unmounted pad; 301, drilling; 401, first plastic sealing material; 402, lead-out copper column; 501, second plastic sealing material; 502, second element device. DETAILED DESCRIPTION

[0030] The application will be further described in detail below in conjunction with specific embodiments, which are an explanation of the application rather than a limitation.

[0031] The application discloses an SMT mounting method of a multi-element device based on RDL rewiring, referring to Figure 2 , comprising the following steps:

[0032] S1, selecting a to-be-mounted element device, and dividing the to-be-mounted element device into multiple independent element devices and multiple element device groups according to the distance between two adjacent to-be-mounted element devices, wherein the element device group includes a first element device 201 and a second element device 502, and the distance between the two adjacent element devices is <20um. This step helps to reduce interference in the mounting process, improve mounting precision, and facilitate subsequent processing of dense element device layout.

[0033] S2, mounting a chip, an independent element device and the first element device 201 in the element device group on an initial pad, and then performing first plastic sealing to obtain a preliminary device (such as Figure 3 ); wherein the height of the first plastic sealing body formed during the first plastic sealing is 80um higher than the surface of the chip. The first plastic sealing body provides a stable base for the subsequent steps, and at the same time leaves enough space for subsequent laser drilling and metal deposition, avoiding damage to the chip or element device.

[0034] S3, using a laser drilling process to drill a connecting hole (such as Figure 4), and then metal deposition and filling are performed at the connecting hole 301 to obtain an intermediate device with a lead-out copper column 402 (as shown in Figure 5 The cross-sectional area of the connecting hole 301 gradually decreases from the top of the plastic package to the surface of the pad.

[0035] S4, RDL rewiring is performed on the surface of the plastic package of the lead-out copper column 402 of the intermediate device to form a secondary pad. Specifically, referring to Figure 6 The process of RDL rewiring is as follows: photoresist is coated on the surface of the plastic package of the lead-out copper column 402 of the intermediate device, the position where the pad is to be formed is exposed and developed, the photoresist at the exposed position is removed, copper deposition is performed on the exposed position by electroplating, and finally the photoresist at the remaining position is removed.

[0036] S5, the second component 502 of the component group is welded on the secondary pad, and the second plastic package is formed to obtain a finished product (as shown in Figure 7 ). The height of the second plastic package formed during the second plastic package is 10 um higher than the surface of the second component 502.

[0037] The RDL rewiring based multi-component SMT mounting method creates new circuit connections on the first plastic package by RDL rewiring, and sequentially improves the design flexibility and integration of the product, while maintaining good electrical performance.

[0038] The application also discloses a product obtained by the RDL rewiring based multi-component SMT mounting method.

[0039] The application also discloses an electronic device comprising the product obtained by the RDL rewiring based multi-component SMT mounting method.

[0040] The RDL rewiring based multi-component SMT mounting method avoids bridging of components during welding by staggering the original pad positions through RDL rewiring technology on the pads of adjacent components on the substrate, effectively solving the technical problems in high-density component mounting, improving the mounting precision and the reliability of electrical connection. The method is not only suitable for the mounting of small-pitch components, but also provides strong technical support for the manufacturing of high-density integrated electronic products. Through the introduction of RDL rewiring technology, the design flexibility and integration of the device are further improved, providing a new solution for the miniaturization, lightness and high performance of electronic products.

[0041] The above merely describes the preferred embodiments of the present application, and is not intended to limit the technical solutions of the present application in any way. Those skilled in the art should understand that, without departing from the spirit and principle of the present application, the technical solutions can also be modified and replaced in several simple ways, and these modifications and replacements also all belong to the protection scope covered by the claims.

Claims

1. A method for SMT mounting of a multi-element device based on RDL re- wiring, characterized by, The method comprises the following steps: S1, selecting a component to be attached and dividing the component to be attached into a plurality of independent components and a plurality of component groups, wherein the component groups comprise first components (201) and second components (502); the component to be attached is divided according to the distance between two adjacent components to be attached, and the distance between the two adjacent components is less than 20 um; S2, mounting the chip, the independent components and the first components (201) in the component groups on the initial pads, and then performing first molding to obtain a preliminary product; S3, drilling a connecting hole at the position of the pad of the preliminary product on which no component is attached, and then performing metal deposition and filling at the connecting hole (301) to perform electrical connection, thereby obtaining an intermediate product with a copper pillar (402) for lead-out; S4, performing RDL rewiring on the surface of the molding body of the copper pillar (402) for lead-out of the intermediate product to form secondary pads; the process of the RDL rewiring is as follows: coating photoresist on the surface of the molding body of the copper pillar (402) for lead-out of the intermediate product, exposing and developing the position where the pads are to be formed, removing the photoresist at the position, then performing copper deposition on the exposed position by electroplating, and finally removing the photoresist at the remaining positions; the cross-sectional area of the connecting hole (301) gradually decreases from the top of the molding material to the surface of the pad; S5, welding the second components (502) of the component groups on the secondary pads, and performing second molding to obtain a finished product.

2. The RDL re-wiring based multi-device SMT mounting method according to claim 1, wherein, The height of the first molding body formed in the first molding is 80 um higher than the surface of the chip.

3. The RDL re-wiring based multi-device SMT mounting method according to claim 1, wherein, In S3, a laser drilling process is used to drill the hole on the pad on which no component is attached.

4. The RDL re-wiring based multi-device SMT mounting method according to claim 1, wherein, In S5, the height of the second molding body formed in the second molding is 10 um higher than the surface of the second component (502).

5. A product obtained by the RDL rewiring-based multi-component SMT mounting method according to any one of claims 1 to 4.

6. An electronic device, comprising: A product obtained by the RDL rewiring-based multi-component SMT mounting method according to any one of claims 1 to 4.

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