A new COB photosensitive assembly structure based on laser welding

Abstract

The utility model relates to camera module manufacturing technical field discloses a novel COB photosensitive assembly structure based on laser welding, including photosensitive element body, the right side of photosensitive element body is provided with PCB circuit board, the upper of photosensitive element body is provided with transparent substrate. With laser welding photosensitive element body and PCB circuit board, replace traditional gold wire welding, save DA machine platform, through accurate control laser parameter, realize low melting point tin cream's quick melting and solidification, are used for welding photosensitive element body and PCB circuit board, realize electric connection, and avoid to cause thermal damage to photosensitive element body and PCB circuit board, need not expensive DA machine platform, utilize existing glass material and laser equipment, reduce equipment investment, process simplification, be suitable for more manufacturer production COB module, laser welding process precision is high, fast, promote production efficiency, transparent substrate reusable conductive circuit design, reduce material waste.

Description

Technical Field

[0001] This utility model relates to the field of camera module manufacturing technology, specifically a novel COB photosensitive assembly structure based on laser welding. Background Technology

[0002] In the current field of optoelectronics, with the continuous advancement of technology, the performance requirements of various optoelectronic devices are increasing, posing more stringent challenges to the assembly structure and processes of their internal components. Among these, COB (Chip on Board) technology, as an important packaging method that enables high-density chip integration, has been widely used in optoelectronic device manufacturing.

[0003] Using glass of a special thickness, which has high transmittance for specific wavelengths of laser light (such as near-infrared and visible light), laser energy can effectively pass through the glass without significant absorption, thus preventing crosstalk. The core of melting copper through glass with short-pulse lasers lies in utilizing the high peak power and ultrashort pulse characteristics of the laser to overcome the linear absorption limitations of the material, achieving efficient energy transfer and localized processing. In practical applications, optimization is required based on specific laser parameters, material properties, and optical path design. This method can melt copper (solder paste, gold, etc.) in glass without damaging it.

[0004] Currently, COB process photosensitive modules require gold wire soldering on a DA machine to achieve conductive connection between the sensor and the circuit board. However, DA machines are relatively expensive, and some small module manufacturers cannot afford this cost. Utility Model Content

[0005] (a) Technical problems to be solved

[0006] The purpose of this invention is to provide a novel COB photosensitive assembly structure based on laser welding, in order to solve the problem mentioned in the background art that the photosensitive module of COB process needs to use a DA machine to weld gold wires to achieve conductive connection between the sensor and the circuit board. However, DA machines on the market are relatively expensive, and some small module manufacturers cannot afford this cost.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, this utility model provides the following technical solution: a novel COB photosensitive assembly structure based on laser welding, comprising a photosensitive element body, a PCB circuit board disposed on the right side of the photosensitive element body, a transparent substrate disposed above the photosensitive element body, and the transparent substrate being located at the joint between the photosensitive element body and the PCB circuit board, with one side located above the photosensitive element body and the other side located above the PCB circuit board.

[0009] Preferably, conductive PADs are uniformly distributed on the upper right side of the photosensitive element body, and conductive PADs are uniformly distributed on the upper left side of the PCB circuit board, with low-melting-point solder paste applied to the outer side of the conductive PADs.

[0010] Preferably, electroplated gold is disposed on the lower right side of the transparent substrate, and the electroplated gold is located above the conductive PAD of the photosensitive element body and the transparent substrate, and a fixing adhesive is disposed between the photosensitive element body and the PCB circuit board.

[0011] Preferably, the fixing adhesive is a thermally conductive epoxy resin adhesive with a thermal conductivity of not less than 1.5 W / (m·K). While fixing the photosensitive element body to the PCB circuit board, it can also help conduct the heat generated by the photosensitive element body to the PCB circuit board for heat dissipation.

[0012] Preferably, the edge of the transparent substrate is provided with a downwardly extending baffle structure, which covers the outside of the joint between the photosensitive element body and the PCB circuit board to prevent external contaminants from entering the assembly structure from the joint.

[0013] Preferably, the conductive PAD surface is provided with an anti-oxidation coating, which is a chemically plated nickel-gold layer with a nickel layer thickness of 3-5 μm and a gold layer thickness of 0.05-0.1 μm, in order to improve the corrosion resistance and welding reliability of the conductive PAD4.

[0014] Preferably, the laser welding employs a short-pulse laser welding process, with a laser pulse frequency of 10-50 kHz, a pulse width of 1-10 ms, and a laser energy density controlled at 5-15 J / cm². 2 By precisely controlling the laser parameters, the low-melting-point solder paste is rapidly melted and solidified, and used to solder the photosensitive element body to the PCB circuit board to achieve electrical connection, while avoiding thermal damage to the photosensitive element body and the PCB circuit board.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] 1. This novel COB photosensitive assembly structure based on laser welding uses laser welding to weld the photosensitive element body to the PCB circuit board, replacing traditional gold wire welding and eliminating the need for a DA machine. By precisely controlling the laser parameters, it achieves rapid melting and solidification of low-melting-point solder paste for welding the photosensitive element body and the PCB circuit board, realizing electrical connection and avoiding thermal damage to the photosensitive element body and the PCB circuit board. It eliminates the need for expensive DA machines, utilizes existing glass materials and laser equipment, reduces equipment investment, simplifies the process, and is suitable for more manufacturers to produce COB modules. The laser welding process has high precision and speed, improving production efficiency. The transparent substrate can be reused for conductive circuit design, reducing material waste. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0018] Figure 2 This is a schematic cross-sectional view of the present invention.

[0019] Figure 3 This is a magnified schematic diagram showing the detailed structure of the low-melting-point solder paste of this utility model.

[0020] Figure 4 This is a magnified schematic diagram showing the detailed structure of the partial electroplating gold of this utility model.

[0021] In the diagram: 1. Photosensitive element body; 2. PCB circuit board; 3. Transparent substrate; 4. Conductive PAD; 5. Low melting point solder paste; 6. Electroplated gold; 7. Fixing adhesive; 8. Edge guard structure. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] Please see Figure 1 - Figure 4 This utility model provides a technical solution: a novel COB photosensitive assembly structure based on laser welding, including a photosensitive element body 1, a PCB circuit board 2 disposed on the right side of the photosensitive element body 1, a transparent substrate 3 disposed above the photosensitive element body 1, and the transparent substrate 3 is located at the joint between the photosensitive element body 1 and the PCB circuit board 2, with one side located above the photosensitive element body 1 and the other side located above the PCB circuit board 2.

[0024] Conductive PADs 4 are evenly distributed on the upper right side of the photosensitive element body 1 and on the upper left side of the PCB circuit board 2. Low melting point solder paste 5 is applied to the outer side of the conductive PADs 4. Electroplated gold 6 is applied to the lower right side of the transparent substrate 3, and the electroplated gold 6 is located above the conductive PADs 4 on the photosensitive element body 1 and the transparent substrate 3. Fixing adhesive 7 is applied between the photosensitive element body 1 and the PCB circuit board 2. The fixing adhesive 7 is a thermally conductive epoxy resin adhesive with a thermal conductivity of not less than 1.5 W / (m·K). While fixing the photosensitive element body 1 and the PCB circuit board 2, it can also help conduct the heat generated by the photosensitive element body 1 to the PCB circuit board 2 for heat dissipation.

[0025] The transparent substrate 3 has a downwardly extending baffle structure 8 at its edge, which covers the outer side of the joint between the photosensitive element body 1 and the PCB circuit board 2 to prevent external contaminants from entering the assembly structure from the joint. The conductive PAD 4 has an anti-oxidation plating layer on its surface, which is a chemically plated nickel-gold layer with a nickel layer thickness of 3-5 μm and a gold layer thickness of 0.05-0.1 μm to improve the corrosion resistance and welding reliability of the conductive PAD 4. The laser welding adopts a short-pulse laser welding process with a laser pulse frequency of 10-50 kHz, a pulse width of 1-10 ms, and a laser energy density controlled at 5-15 J / cm2. By precisely controlling the laser parameters, the low-melting-point solder paste 5 is rapidly melted and solidified for welding the photosensitive element body 1 and the PCB circuit board 2 to achieve electrical connection and avoid thermal damage to the photosensitive element body 1 and the PCB circuit board 2.

[0026] Working principle: When using this novel COB photosensitive assembly structure based on laser welding, conductive PADs 4 are provided on the right side of the photosensitive element body 1 and the upper left side of the PCB circuit board 2 for structural and electrical connections. Low-melting-point solder paste 5 is coated on the outside of the conductive PADs 4, and electroplated gold 6 on the lower right side of the transparent substrate 3 covers the conductive PADs 4 to form a welding path. A short-pulse laser welding process is adopted, with the laser pulse frequency set at 10-50kHz, the pulse width controlled at 1-10ms, and the laser energy density maintained at 5-15J / cm². 2 During welding, precisely controlled laser energy acts on low-melting-point solder paste 5, causing it to melt rapidly and connect the photosensitive element body 1 to the conductive PAD 4 of the PCB circuit board 2. Subsequently, the solder paste solidifies rapidly, achieving a stable electrical connection. Due to the high energy density and short action time characteristics of laser welding, it can ensure welding quality while avoiding thermal damage to the photosensitive element body 1 and the PCB circuit board 2, ensuring that the component performance is not affected. The joint between the photosensitive element body 1 and the PCB circuit board 2 is bonded with fixing adhesive 7, and the edge-blocking structures 8 on both sides below the transparent substrate 3 cover the joint to prevent external contaminants from entering the assembly structure from the joint.

[0027] Finally, it should be noted that the above content is only used to illustrate the technical solution of this utility model, and is not intended to limit the scope of protection of this utility model. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model do not depart from the essence and scope of the technical solution of this utility model.

Claims

1. A novel COB light-sensitive assembly structure based on laser welding, comprising a light-sensitive element body (1), characterized in that: A PCB circuit board (2) is provided on the right side of the photosensitive element body (1), and a transparent substrate (3) is provided above the photosensitive element body (1). The transparent substrate (3) is located at the seam between the photosensitive element body (1) and the PCB circuit board (2), with one side above the photosensitive element body (1) and the other side above the PCB circuit board (2).

2. The novel COB light-sensing assembly structure based on laser welding according to claim 1, characterized in that: Conductive PADs (4) are evenly distributed on the upper right side of the photosensitive element body (1), and conductive PADs (4) are evenly distributed on the upper left side of the PCB circuit board (2). Low melting point solder paste (5) is provided on the outer side of the conductive PADs (4).

3. The novel COB light-sensing assembly structure based on laser welding according to claim 1, characterized in that: Electroplated gold (6) is provided on the lower right side of the transparent substrate (3), and the electroplated gold (6) is located above the conductive PAD (4) of the photosensitive element body (1) and the transparent substrate (3). Fixing adhesive (7) is provided between the photosensitive element body (1) and the PCB circuit board (2).

4. The novel COB light-sensing assembly structure based on laser welding according to claim 3, characterized in that: The fixing adhesive (7) is a thermally conductive epoxy resin adhesive with a thermal conductivity of not less than 1.5 W / (m·K). While fixing the photosensitive element body (1) and the PCB circuit board (2), it can also help conduct the heat generated by the photosensitive element body (1) to the PCB circuit board (2) for heat dissipation.

5. The novel COB light sensitive assembly structure based on laser welding according to claim 1, characterized in that: The transparent substrate (3) has a downwardly extending edge structure (8) at its edge. The edge structure (8) covers the outside of the joint between the photosensitive element body (1) and the PCB circuit board (2) to prevent external contaminants from entering the assembly structure from the joint.

6. The novel COB light sensitive assembly structure based on laser welding according to claim 2, characterized in that: The conductive PAD (4) has an anti-oxidation coating on its surface. The anti-oxidation coating is a chemically plated nickel-gold layer with a nickel layer thickness of 3-5 μm and a gold layer thickness of 0.05-0.1 μm, in order to improve the corrosion resistance and welding reliability of the conductive PAD (4).

7. The novel COB light sensitive assembly structure based on laser welding according to claim 1, characterized in that: The laser welding employs a short-pulse laser welding process, with a laser pulse frequency of 10-50kHz, a pulse width of 1-10ms, and a laser energy density controlled at 5-15J / cm². 2 By precisely controlling the laser parameters, the low melting point solder paste (5) is rapidly melted and solidified, and used to solder the photosensitive element body (1) and the PCB circuit board (2) to achieve electrical connection, while avoiding thermal damage to the photosensitive element body (1) and the PCB circuit board (2).

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