Multi-component SMT mounting method based on RDL rewiring, product and electronic equipment

Abstract

The invention 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, and the method comprises the following steps: S1, selecting a to-be-mounted component, the component group comprising a first component and a second component; s2, mounting a chip, an independent component and a first component in the component group on the initial bonding pad, and then carrying out first plastic package to obtain an initial component; s3, drilling holes in the bonding pad positions, where the components are not attached, of the preliminary product, and then performing metal deposition and filling at the drilling positions for electrical connection to obtain an intermediate device with a lead-out copper column; s4, performing RDL rewiring on the surface of the plastic package body of the lead-out copper column of the intermediate device; and S5, welding a second component, and performing plastic packaging to obtain a finished product device. According to the invention, while the original size of the product is not changed, the welding requirements of a plurality of components are met, and bridging among the components due to insufficient space is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of component packaging, and in particular to a multi-component SMT mounting method, product and electronic equipment based on RDL rewiring. Background Art

[0002] The integration of packaged products is getting higher and higher, and the functions are becoming 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 has also increased dramatically. However, as the number of components in the product increases, the arrangement density also increases. In order to prevent the occurrence of bridging during the reflow soldering process due to the small spacing between components, such as Figure 1 As shown in , the presence of a solder joint 102 between two components 101 requires the product size to be designed to be larger and larger. Although this solves the problem of too small spacing between components, it also poses a challenge to the lightweight and miniaturization development trend of the product. Summary of the invention

[0003] In view of the problem in the prior art that tin bridging is easily caused during reflow soldering due to too small spacing of packaged products, the present invention provides a multi-device SMT mounting method, product and electronic device based on RDL rewiring.

[0004] The present invention is achieved through the following technical solutions: A multi-component SMT mounting method based on RDL rewiring comprises the following steps: S1, selecting components to be mounted, and dividing the components to be mounted into a plurality of independent components and a plurality of component groups, wherein the component group includes a first component and a second component; S2, mounting the chip, the independent component and the first component in the component group on the initial pad, and then performing the first plastic packaging to obtain a preliminary device; S3, drilling connection holes at pad positions where no components are attached on the preliminary product, and then performing metal deposition and filling at the connection holes for electrical connection to obtain an intermediate device with lead-out copper pillars; S4, performing RDL rewiring on the surface of the plastic package of the lead-out copper pillar of the intermediate device to form a secondary pad; S5, welding the second component of the component group on the secondary pad, and performing a second plastic sealing to obtain a finished device.

[0005] Preferably, in S1, the components to be mounted are divided according to the distance between two adjacent components to be mounted.

[0006] Preferably, in S1, the distance between two adjacent components is less than 20 um.

[0007] Preferably, in S2, the height of the first plastic encapsulation body formed during the first plastic encapsulation is 80 um higher than the chip surface.

[0008] Preferably, in S3, a laser drilling process is used to drill holes on pads without components.

[0009] Preferably, in S3, the cross-sectional area of ​​the connecting hole gradually decreases from the top of the plastic encapsulation material to the surface of the pad.

[0010] Preferably, in S3, the RDL rewiring process is: coating the surface of the plastic package of the lead-out copper column of the intermediate device with photoresist, then exposing and developing the position where the pad needs to be formed, removing the photoresist at the position, then electroplating copper deposition on the exposed position, and finally removing the photoresist at the remaining positions.

[0011] Preferably, the height of the second plastic packaging body formed during the second plastic packaging is 10 um higher than the surface of the second component.

[0012] A product obtained according to the multi-component SMT mounting method based on RDL rewiring.

[0013] An electronic device comprises a product obtained according to the multi-component SMT mounting method based on RDL rewiring.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The multi-component SMT mounting method based on RDL rewiring of the present invention performs an RDL rewiring process on component pads that are too close to each other on a substrate, staggers the original pad positions, thereby avoiding bridging of components during welding. This can effectively solve the problem of tin bridging during reflow soldering caused by components being too close to each other due to the small size of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of adjacent components in an existing packaging structure; Figure 2 It is a flow chart of a multi-device SMT mounting method based on RDL rewiring of the present invention; Figure 3 It is a schematic diagram of a preliminary device in a multi-device SMT mounting method based on RDL rewiring of the present invention; Figure 4 It is a schematic diagram of a multi-device SMT mounting method based on RDL rewiring after drilling in the present invention; Figure 5 It is a schematic diagram of drilling and deposition in a multi-device SMT mounting method based on RDL rewiring of the present invention; Figure 6It is a schematic diagram of the process of RDL rewiring in a multi-device SMT mounting method based on RDL rewiring of the present invention; Figure 7 It is a schematic diagram of a finished device in a multi-device SMT mounting method based on RDL rewiring of the present invention.

[0016] In the figure, 101, component; 102, solder joint; 201, first component; 202, unmounted pad; 301, drill hole; 401, first plastic encapsulation compound; 402, lead-out copper column; 501, second plastic encapsulation compound; 502, second component. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0018] The present invention discloses a multi-device SMT mounting method based on RDL rewiring, referring to Figure 2 , including the following steps: S1, select components to be mounted, and divide the components to be mounted into multiple independent components and multiple component groups according to the distance between two adjacent components to be mounted, the component group includes a first component 201 and a second component 502, and the distance between two adjacent components is less than 20um. This step helps to reduce interference during the mounting process, improve mounting accuracy, and facilitate subsequent processing of intensive component layout.

[0019] S2, mounting the chip, the independent components and the first component 201 in the component group on the initial pad, and then performing the first plastic packaging to obtain a preliminary device (such as Figure 3 ); wherein the height of the first plastic encapsulation body formed during the first plastic encapsulation is 80 um higher than the chip surface. The first plastic encapsulation body provides a stable base for subsequent steps, while leaving enough space for subsequent laser drilling and metal deposition, thereby avoiding direct damage to the chip or components.

[0020] S3, use laser drilling technology to drill connection holes at the pad positions where no components are attached on the preliminary product (such as Figure 4 ), and then metal deposition and filling are performed at the connection hole 301 for electrical connection to obtain an intermediate device (such as Figure 5 ); wherein the cross-sectional area of ​​the connection hole 301 gradually decreases from the top of the plastic packaging material to the surface of the pad.

[0021] S4, performing RDL rewiring on the surface of the plastic package of the lead-out copper pillar 402 of the intermediate device to form a secondary pad. Figure 6The process of RDL rewiring is as follows: the surface of the plastic package of the lead-out copper pillar 402 of the intermediate device is coated with photoresist, and then the position where the pad is to be formed is exposed and developed to remove the photoresist at the position, and then the exposed position is electroplated with copper deposition, and finally the photoresist at the remaining positions is removed.

[0022] S5, welding the second component 502 of the component group on the secondary pad, and performing a second plastic sealing to obtain a finished device (such as Figure 7 ). The height of the second plastic encapsulation body formed during the second plastic encapsulation is 10 um higher than the surface of the second component 502 .

[0023] In a multi-component SMT mounting method based on RDL rewiring of the present invention, RDL rewiring is used to create new circuit connections on a first plastic package, thereby successively improving the design flexibility and integration of the product while maintaining good electrical performance.

[0024] The invention also discloses a product obtained by using a multi-component SMT mounting method based on RDL rewiring.

[0025] The invention also discloses an electronic device, including a product obtained by a multi-device SMT mounting method based on RDL rewiring.

[0026] The present invention discloses a multi-component SMT mounting method based on RDL rewiring, which performs an RDL rewiring process on component pads that are too close to each other on a substrate, staggers the original pad positions, thereby avoiding bridging of components during welding, effectively solving the technical problems in high-density component mounting, and improving mounting accuracy and electrical connection reliability. This method is not only suitable for the mounting of micro-pitch components, but also provides strong technical support for the manufacture 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, lightweight and high performance of electronic products.

[0027] The above description is only a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and substitutions, and these modifications and substitutions are also within the scope of protection covered by the claims.

Claims

1. A multi-device SMT mounting method based on RDL rewiring, characterized in that: The following steps are involved: S1, selecting components to be mounted, and dividing the components to be mounted into a plurality of independent components and a plurality of component groups, wherein the component group includes a first component (201) and a second component (502); S2, mounting the chip, the independent components and the first component (201) in the component group on the initial pad, and then performing the first plastic packaging to obtain a preliminary device; S3, drilling connection holes at pad locations where no components are attached on the preliminary product, and then performing metal deposition and filling at the connection holes (301) for electrical connection, thereby obtaining an intermediate device with lead-out copper pillars (402); S4, performing RDL rewiring on the surface of the plastic package of the lead-out copper pillar (402) of the intermediate device to form a secondary pad; S5, welding the second component (502) of the component group on the secondary soldering pad, and performing a second plastic sealing to obtain a finished device.

2. The multi-component SMT mounting method based on RDL rewiring according to claim 1, characterized in that: In S1, the components to be mounted are divided according to the distance between two adjacent components to be mounted.

3. The multi-component SMT mounting method based on RDL rewiring according to claim 2, characterized in that: In S1, the distance between two adjacent components is less than 20um.

4. The multi-device SMT mounting method based on RDL rewiring according to claim 1, characterized in that: In S2, the height of the first plastic packaging body formed during the first plastic packaging is 80 um higher than the chip surface.

5. The multi-component SMT mounting method based on RDL rewiring according to claim 1, characterized in that: In S3, a laser drilling process is used to drill holes on pads where no components are attached.

6. The multi-component SMT mounting method based on RDL rewiring according to claim 1, characterized in that: In S3, the cross-sectional area of ​​the connection hole (301) gradually decreases from the top of the molding compound to the surface of the pad.

7. The multi-component SMT mounting method based on RDL rewiring according to claim 1, characterized in that: In S3, the RDL rewiring process is as follows: the surface of the plastic package of the lead-out copper column (402) of the intermediate device is coated with photoresist, and then the position where the pad is to be formed is exposed and developed, the photoresist at the position is removed, and then copper is electroplated and deposited at the exposed position, and finally the photoresist at the remaining position is removed.

8. The multi-component SMT mounting method based on RDL rewiring according to claim 1, characterized in that: In S4, the height of the second plastic package body formed during the second plastic packaging is 10 um higher than the surface of the second component (502).

9. A product obtained by the multi-component SMT mounting method based on RDL rewiring according to any one of claims 1 to 8.

10. An electronic device, characterized in that: A product obtained by the multi-component SMT mounting method based on RDL rewiring according to any one of claims 1 to 8.

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