Device for improving bonding force of optical device

Abstract

The utility model relates to the technical field of optical communication, in particular to a device for improving the bonding force of an optical device, which comprises an optical fiber array, a photoelectric detector and a circuit board, the tail end of the optical fiber array is coupled with the photoelectric detector, and the optical fiber array and the photoelectric detector are fixed on the circuit board; a copper net is arranged on the upper surface of the circuit board, the copper net is fixedly connected with the circuit board, the optical fiber array is provided with a base, the base is attached to the copper net, and the copper net is used for improving the bonding force between the base and the circuit board. The copper net is attached to the surface of the circuit board, and then the optical fiber array is attached to the copper net, so that the bonding force between the optical fiber array and the circuit board is effectively improved, and the optical fiber array and the circuit board are kept in a stable connection state in the reliability test process.

Description

Technical Field

[0001] The utility model relates to the technical field of optical communication, in particular to a device for improving the bonding force of optical devices. Background Art

[0002] The chip on board (COB) process is to fix the bare chip directly on the printed circuit board (PCB), and then electrically connect it to the PCB through gold wire bonding. The high-speed COB optical module includes two links: transmit (TX) and receive (RX). The TX link converts high-speed electrical signals into optical signals, and the RX link converts optical signals into electrical signals. The RX link includes a fiber array (FA), a photon detector (PD), a transimpedance amplifier (TIA), and a digital signal processing (DSP). FA introduces the optical signal input by the optical module to the PD, and the PD converts the optical signal into a weak electrical signal. The weak electrical signal is amplified by the TIA and input into the DSP to shape and regenerate the high-speed electrical signal. After FA and PD are coupled, glue is used to fix FA on PCB, and then reliability test is carried out on optical module. Reliability test includes long-term high temperature, double 85 test, etc. The double 85 test is more stringent. In the environmental test chamber, humidity of 85% and temperature of 85℃ are maintained for at least 1000 hours. Therefore, how to ensure that FA can be firmly fixed on PCB during reliability test, especially double 85 test, without debonding, hollowing and other performance-affecting situations is the key problem that needs to be solved in this field.

[0003] In view of this, overcoming the defects of the prior art is an urgent problem to be solved in the field of this technology. Utility Model Content

[0004] The technical problem to be solved by the utility model is how to ensure that during the reliability test, especially the double 85 test, the FA can be firmly fixed on the PCB without the problems of debonding, hollowing and other situations that affect the performance.

[0005] The utility model adopts the following technical solutions:

[0006] On the one hand, a device for improving the adhesion of optical devices is provided, comprising: an optical fiber array 1, a photodetector 2 and a circuit board 3; the end of the optical fiber array 1 is coupled to the photodetector 2, and the optical fiber array 1 and the photodetector 2 are fixed on the circuit board 3;

[0007] A copper mesh 30 is provided on the upper surface of the circuit board 3, and the copper mesh 30 is fixedly connected to the circuit board 3. The optical fiber array 1 is provided with a base 10, and the base 10 is attached to the copper mesh 30. The copper mesh 30 is used to improve the adhesion between the base 10 and the circuit board 3.

[0008] Preferably, the mesh of the copper mesh 30 is one of a small mesh, a medium mesh and a large mesh.

[0009] Preferably, the side length of the small grid is 0.175 mm ± 0.01 mm.

[0010] Preferably, the side length of the middle grid is 0.25 mm±0.01 mm.

[0011] Preferably, the side length of the large grid is 0.5 mm±0.01 mm.

[0012] Preferably, the small grid, the medium grid and the large grid are in the shape of quadrilaterals.

[0013] Preferably, the base 10 is in a shape of a circle, a triangle, a quadrilateral, a pentagon, or a hexagon.

[0014] Preferably, the base 10 and the copper mesh 30 are fixedly connected by gluing.

[0015] Preferably, the bottom surface roughness Ra of the base 10 is less than 1 nm.

[0016] Preferably, the circuit board 3 and the copper mesh 30 are fixedly connected by gluing.

[0017] Compared with the prior art, the beneficial effect of the present invention is that by attaching a copper mesh 30 to the surface of the circuit board 3 and then attaching the optical fiber array 1 to the copper mesh 30, the adhesion between the optical fiber array 1 and the circuit board 3 is effectively improved, so that the optical fiber array 1 and the circuit board 3 remain in a firmly connected state during the reliability test.

[0018] In a preferred embodiment, by processing the bottom surface of the base 10 of the optical fiber array 1 to have a certain degree of roughness, the firmness of the bonding between the optical fiber array 1 and the copper mesh 30 is further ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following briefly introduces the drawings required for use in the embodiments of the present utility model. Obviously, the drawings described below are only some embodiments of the present utility model, and for ordinary technicians in this field, other drawings can also be obtained based on these drawings without creative work.

[0020] Figure 1 It is a top view of a device for improving the bonding force of an optical device provided by an embodiment of the utility model;

[0021] Figure 2 This is a front view of a device for improving the bonding strength of an optical device provided by an embodiment of the utility model;

[0022] Figure 3 This is a schematic diagram of a small grid of a copper mesh of a device for improving the bonding strength of an optical device provided by an embodiment of the utility model;

[0023] Figure 4 This is a schematic diagram of a middle grid of a copper mesh of a device for improving the bonding strength of an optical device provided by an embodiment of the utility model;

[0024] Figure 5 This is a schematic diagram of a large grid of a copper mesh of a device for improving the bonding strength of an optical device provided by an embodiment of the utility model;

[0025] Figure 6 It is a schematic diagram of an optical fiber array base of a device for improving the bonding force of an optical device provided by an embodiment of the utility model.

[0026] Wherein, the accompanying drawings are marked as follows:

[0027] 1-fiber array, 10-base, 2-photodetector, 3-circuit board, 30-copper mesh, 4-glue layer. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0029] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as open inclusion, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "examples", "specific examples" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner, that is, although they may be carried in the embodiments or examples of the above terms due to reasons such as the order and position of appearance, it is not limited to that they can be carried in combination by one embodiment or example.

[0030] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0031] In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more. In addition, for example, the same type of noun may be described as two independent individuals by adding "A" or "B" at the end. In this case, the corresponding features defined as "A" and "B" are only used to distinguish the description of the same type of individuals, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0032] When describing some embodiments, the expressions "coupling", "coupling" and "connection" and their derivatives may be used. For example, when describing some embodiments, the term "connection" may be used to indicate that two or more components are in direct physical or electrical contact with each other. For another example, when describing some embodiments, the term "coupling" may be used to indicate that two or more components are in direct physical or electrical contact. However, the terms "connection" or "coupling" may also refer to two or more components that are not in direct contact with each other, but still cooperate or interact with each other, such as "optical path coupling", "wireless connection", etc. The embodiments disclosed here are not necessarily limited to the contents of the present utility model.

[0033] In the description of the present utility model, the expression "A and / or B" (where A and B are used to formally represent specific characteristic contents) will be involved, and the corresponding expressions include the following three combinations: only A, only B, and a combination of A and B.

[0034] As used herein, “about,” “substantially,” or “approximately” includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0035] In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] Embodiment 1:

[0037] Embodiment 1 of the present utility model provides a device for improving the bonding strength of an optical device, such as Figure 1 As shown, it includes: an optical fiber array 1, a photodetector 2 and a circuit board 3; the end of the optical fiber array 1 is coupled to the photodetector 2, and the optical fiber array 1 and the photodetector 2 are fixed on the circuit board 3; after the optical signal passes through the optical fiber array 1, it is incident on the photosensitive surface of the photodetector 2 at the end of the optical fiber array 1, and the photodetector 2 converts the optical signal into a weak electrical signal and transmits it to the transimpedance amplifier (not shown in the figure), and the transimpedance amplifier amplifies the weak electrical signal and inputs it into the DSP (not shown in the figure) for processing. A copper mesh 30 is provided on the upper surface of the circuit board 3, and the copper mesh 30 is fixedly connected to the circuit board 3, as shown in FIG. Figure 2 As shown, the optical fiber array 1 is provided with a base 10, and the base 10 is attached to the copper mesh 30, and the copper mesh 30 is used to improve the bonding force between the base 10 and the circuit board 3. Specifically, the circuit board 3 and the copper mesh 30 are fixedly connected by gluing; the base 10 and the copper mesh 30 are fixedly connected by gluing, and a glue layer 4 is provided between the copper mesh 30 and the base 10.

[0038] For the copper mesh 30, in the actual research process, such as Figure 3-Figure 5As shown, the mesh of the copper mesh 30 is one of a small mesh, a medium mesh and a large mesh; in addition, two methods are used as control groups: no copper mesh 30 is set on the circuit board 3, that is, the optical fiber array 1 is directly attached to the surface of the circuit board 3, and no mesh is set on the copper mesh 30, that is, the copper sheet is directly attached to the circuit board 3, and the optical fiber array 1 is attached to the copper sheet. After the reliability test, it is finally concluded that when the copper mesh 30 adopts a large mesh, the adhesion between the optical fiber array 1 and the circuit board 3 is the strongest, and there is no debonding, hollowing and other performance-affecting conditions after the test. The medium mesh and the small mesh are followed, and there are different degrees of debonding and hollowing phenomena; the copper sheet and the optical fiber array 1 are directly attached to the circuit board 3. The debonding and hollowing phenomena of the optical fiber array 1 attached to the copper sheet are more serious, and the bonding between the optical fiber array 1 and the circuit board 3 is very unsatisfactory.

[0039] A copper mesh 30 is arranged in the area where the circuit board 3 is bonded to the optical fiber array 1. In addition to improving the bonding force between the optical fiber array 1 and the circuit board 3, the copper mesh 30 also plays the functions of electromagnetic shielding and heat dissipation. The copper mesh 30 can effectively shield electromagnetic interference, protect the optical fiber array 1 from external electromagnetic interference, and ensure the purity and stability of the signal; secondly, the copper mesh 30, as a metal material, has good heat dissipation performance. The copper mesh 30 is arranged between the circuit board 3 and the optical fiber array 1, which can effectively help the circuit board 3 and the optical fiber array 1 to dissipate heat, and prevent the optical fiber array 1 and other key components from being damaged due to overheating.

[0040] For the above reliability test, in one embodiment, the side length of the small grid is 0.175mm±0.01mm, the side length of the medium grid is 0.25mm±0.01mm, and the side length of the large grid is 0.5mm±0.01mm. The above-listed sizes are all examples, and the actual sizes of the small grid, the medium grid and the large grid can be specifically formulated according to the size of the base 10 of the optical fiber array 1. Among them, the shape of the small grid, the medium grid and the large grid is a quadrilateral. In addition to the quadrilateral, the small grid, the medium grid and the large grid can also be a circle, a triangle or other shapes, which are not specifically limited here. In this embodiment, in order to facilitate processing and arrangement, the small grid, the medium grid and the large grid are all squares, and the above-mentioned sizes are the side length sizes of the squares.

[0041] For the base 10 of the optical fiber array 1, Figure 6As shown, the shape of the base 10 is one of a circle, a triangle, a quadrilateral, a pentagon and a hexagon. In the actual application process, it is found that when the base 10 is a quadrilateral, the bonding effect between the base 10 and the copper mesh 30 is the strongest, so the base 10 used in this embodiment is a quadrilateral. At the same time, in order to further ensure the bonding effect between the base 10 and the copper mesh 30, the bottom surface roughness Ra of the base 10 is less than 1nm. When the bottom surface of the base 10 is smooth, the bonding force between the base 10 and the copper mesh 30 is the strongest. As the bottom surface roughness of the base 10 increases, the bonding force between the base 10 and the copper mesh 30 gradually weakens.

[0042] In summary, by attaching the copper mesh 30 on the surface of the circuit board 3 and then attaching the optical fiber array 1 on the copper mesh 30, the bonding force between the optical fiber array 1 and the circuit board 3 is effectively improved, so that the optical fiber array 1 and the circuit board 3 remain firmly connected during the reliability test. In the preferred embodiment, by processing the bottom surface of the base 10 of the optical fiber array 1 into a shape with a certain degree of roughness, the firmness of the bonding between the optical fiber array 1 and the copper mesh 30 is further ensured.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for improving the adhesive force of an optical device, characterized in that: include: An optical fiber array (1), a photodetector (2) and a circuit board (3); the end of the optical fiber array (1) is coupled to the photodetector (2), and the optical fiber array (1) and the photodetector (2) are fixed on the circuit board (3); A copper mesh (30) is provided on the upper surface of the circuit board (3), the copper mesh (30) being fixedly connected to the circuit board (3), the optical fiber array (1) being provided with a base (10), the base (10) being attached to the copper mesh (30), and the copper mesh (30) being used to improve the bonding force between the base (10) and the circuit board (3).

2. The device for improving the adhesive force of an optical device according to claim 1, characterized in that: The mesh of the copper mesh (30) is one of a small mesh, a medium mesh and a large mesh.

3. The device for improving the adhesive force of an optical device according to claim 2, characterized in that: The side length of the small grid is 0.175 mm ± 0.01 mm.

4. The device for improving the adhesive force of an optical device according to claim 2, characterized in that: The side length of the middle grid is 0.25 mm ± 0.01 mm.

5. The device for improving the adhesive force of an optical device according to claim 2, characterized in that: The side length of the large grid is 0.5 mm ± 0.01 mm.

6. The device for improving the adhesive force of an optical device according to claim 2, characterized in that: The small grid, the medium grid and the large grid are in the shape of quadrilaterals.

7. The device for improving the adhesive force of an optical device according to claim 1, characterized in that: The shape of the base (10) is one of a circle, a triangle, a quadrilateral, a pentagon and a hexagon.

8. The device for improving the adhesive force of an optical device according to claim 7, characterized in that: The base (10) and the copper mesh (30) are fixedly connected by gluing.

9. The device for improving the adhesive force of an optical device according to claim 8, characterized in that: The bottom surface roughness Ra of the base (10) is less than 1 nm.

10. The device for improving the adhesive force of an optical device according to any one of claims 1 to 9, characterized in that: The circuit board (3) and the copper mesh (30) are fixedly connected by gluing.

Images