A multi-channel optical module

Abstract

The present invention discloses a multi-channel optical module, which is composed of a core circuit unit and an optical fiber array coupling unit. A positioning support cover is additionally provided at the lower edge of the lens assembly; the positioning support cover is in the shape of an inverted and through trumpet, the shrinking end of the positioning support cover is fixedly connected to the lower edge of the lens assembly, and the flared end of the positioning support cover faces downward. More than three positioning points are provided on the printed circuit boards around the electric chip array and the optical chip array; the number of these positioning points is the same as the number of the vertex angles of the flared end of the positioning support cover and the positions are opposite, and when the lens assembly is covered on the top of the electric chip array and the optical chip array with the positioning support cover, each vertex angle of the flared end of the positioning support cover just overlaps with each positioning point. The present invention can improve the assembly efficiency so that it can meet the requirements of mass production; at the same time, it can also protect the core circuit unit.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber communication, and in particular to a multi-channel optical module. Background Art

[0002] With the promotion and in-depth application of large-capacity, high-speed optical communications, the demand for optical modules is increasing rapidly, and the market demand is also developing in the direction of multi-channel, miniaturization, and high reliability. This has created a market demand for multi-channel optical modules, and at the same time, it has put forward new requirements for the optical coupling process involved in the packaging of multi-channel optical modules.

[0003] The existing multi-channel optical module consists of two parts: the core circuit unit and the fiber array coupling unit. During the production process, since the core circuit unit and the fiber array coupling unit are two relatively independent components, it is necessary to cover the lens assembly of the fiber array coupling unit on the optical chip array of the core circuit unit, and ensure that the multi-channel optical signals emitted by the optical chip array can be accurately coupled into the optical fiber array through the lens assembly, or the external multi-channel optical signals input by the optical fiber array can be accurately coupled into the optical chip array through the lens assembly, which is the key to achieving the normal operation of the multi-channel optical module.

[0004] The method currently used to achieve the coupling between the core circuit unit and the optical fiber array coupling unit is to power on the multi-channel optical module through the coupling test device, and monitor the output optical signal size or the received optical current size of the coupling test device to determine whether the core circuit unit and the optical fiber array coupling unit have achieved coupling alignment. However, this method requires the core circuit unit to be clamped to the coupling test device each time the coupling is performed, and the lens assembly is covered on the optical chip array by manual feel, and the lens assembly needs to be moved multiple times to achieve coupling alignment. There is great randomness, low efficiency, and it is difficult to meet the time schedule requirements of mass production.

[0005] In addition, after the coupling alignment of the core circuit unit and the optical fiber array coupling unit is achieved, the lens assembly needs to be bonded to the core circuit unit. However, since the lens assembly, the electrical chip array and the optical chip array theoretically need to maintain a distance equal to the focal length of the lens assembly, direct bonding requires more glue, and the amount used is not easy to control. The glue can easily contaminate the optical chip array. Direct bonding is not only prone to glue deformation and thus coupling alignment failure, but can also damage the gold wire between the electrical chip array and the optical chip array. Summary of the invention

[0006] The present invention aims to solve the problem that it is difficult to achieve coupling alignment in existing multi-channel optical modules, and provides a multi-channel optical module.

[0007] To solve the above problems, the present invention is achieved through the following technical solutions:

[0008] A multi-channel optical module consists of two parts: a core circuit unit and a fiber array coupling unit. The core circuit unit is mainly composed of a printed circuit board, a BGA pad array, an electric chip array and an optical chip array; the BGA pad array is welded on the lower surface of the printed circuit board; the electric chip array and the optical chip array are welded on the upper surface of the printed circuit board; the BGA pad array is connected to the electric chip array through vias on the printed circuit board, and the electric chip array is connected to the optical chip array through gold wire. The fiber array coupling unit is mainly composed of a lens assembly, a fiber array and a fiber interface; the lens assembly covers the top of the electric chip array and the optical chip array; one end of the fiber array is connected to the lens assembly, and the other end is connected to the fiber interface. A positioning support cover is added at the lower edge of the lens assembly; the positioning support cover is in the shape of an inverted and through trumpet, the shrinking end of the positioning support cover is fixedly connected to the lower edge of the lens assembly, and the flared end of the positioning support cover faces downward. More than three positioning points are provided on the printed circuit boards around the electrical chip array and the optical chip array; the number of these positioning points is the same as the number of the vertex corners of the flared end of the positioning support cover and their positions are relative, and when the lens assembly with the positioning support cover is covered above the electrical chip array and the optical chip array, the vertex corners of the flared end of the positioning support cover just overlap with the positioning points.

[0009] In the above scheme, the flared end of the positioning support cover is a quadrilateral, and the number of positioning points is 4 and distributed in a quadrilateral.

[0010] In the above solution, each vertex of the expanded end of the positioning support cover is fixed to each positioning point by resin glue.

[0011] In the above solution, the positioning support cover is made of insulating and light-proof material.

[0012] Compared with the prior art, the present invention has the following characteristics:

[0013] 1. By adding positioning support covers and positioning points on the core circuit unit and the optical fiber array coupling unit, the core circuit unit and the optical fiber array coupling unit can be easily coupled and aligned during assembly without the assistance of other external test equipment, thereby making the entire assembly process of the multi-channel optical module simpler and more efficient, and meeting the time schedule requirements of mass production;

[0014] 2. Since the top corner of the positioning support cover can directly contact the positioning point, only a small amount of resin glue is needed to fix the core circuit unit and the optical fiber array coupling unit, which can avoid the coupling alignment failure caused by glue deformation caused by relying solely on glue fixation;

[0015] 3. Due to the presence of the positioning support cover, a certain gap can be retained between the lens assembly and the electrical chip array and the optical chip array. In this way, the lens assembly will not be directly pressed on the electrical chip array and the optical chip during the coupling operation. Therefore, the gold wire between the electrical chip array and the optical chip can be effectively protected, thereby ensuring the coupling success rate of the entire multi-channel optical module. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of a multi-channel optical module (when the core circuit unit and the optical fiber array coupling unit are not glued together).

[0017] Figure 2 It is a schematic diagram of the structure of a multi-channel optical module (after the core circuit unit and the optical fiber array coupling unit are glued together).

[0018] Figure 3 Schematic diagram of the structure of the core circuit unit.

[0019] Figure 4 Schematic diagram of the structure of the optical fiber array coupling unit.

[0020] Figure 5 A schematic diagram of clamping a multi-channel optical module on a coupling test device for testing.

[0021] Numbers in the figure: 1. core circuit unit; 1-1. printed circuit board; 1-2. BGA pad array; 1-3. electrical chip array; 1-4. optical chip array; 1-5. positioning point; 2. optical fiber array coupling unit; 2-1. lens assembly; 2-2. optical fiber array; 2-3. optical fiber interface; 2-4. positioning support cover; 3. coupling test device. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific examples. It should be noted that the directional terms mentioned in the examples, such as "upper", "lower", "middle", "left", "right", "front", "back", etc., are only reference to the directions of the accompanying drawings. Therefore, the directions used are only used for illustration and are not used to limit the scope of protection of the present invention.

[0023] See also Figure 1-4A multi-channel optical module is composed of a core circuit unit 1 and a fiber array coupling unit 2. The core circuit unit 1 is mainly composed of a printed circuit board 1-1, a BGA pad array 1-2, an electric chip array 1-3 and an optical chip array 1-4. The BGA pad array 1-2 is welded on the lower surface of the printed circuit board 1-1. The electric chip array 1-3 and the optical chip array 1-4 are welded on the upper surface of the printed circuit board 1-1. The BGA pad array 1-2 is connected to the electric chip array 1-3 through the vias on the printed circuit board 1-1, and the electric chip array 1-3 is bonded to the optical chip array 1-4 through gold wire. The fiber array coupling unit 2 is mainly composed of a lens assembly 2-1, a fiber array 2-2 and a fiber interface 2-3. The lens assembly 2-1 covers the top of the electric chip array 1-3 and the optical chip array 1-4. One end of the fiber array 2-2 is connected to the lens assembly 2-1, and the other end is connected to the fiber interface 2-3.

[0024] In order to facilitate the coupling alignment of the core circuit unit 1 and the optical fiber array coupling unit 2, a positioning support cover 2-4 is additionally provided at the lower edge of the lens assembly 2-1. In a preferred embodiment of the present invention, the positioning support cover 2-4 is made of an insulating and light-proof material. The positioning support cover 2-4 is in an inverted and through trumpet shape, the shrinking end of the positioning support cover 2-4 is fixedly connected to the lower edge of the lens assembly 2-1, and the flared end of the positioning support cover 2-4 faces downward. Correspondingly, more than three positioning points 1-5 are provided on the printed circuit board 1-1 around the electric chip array 1-3 and the optical chip array 1-4. The number of these positioning points 1-5 is the same as the number of the apex angles of the flared end of the positioning support cover 2-4 and the positions are opposite. When the lens assembly 2-1 covers the electric chip array 1-3 and the optical chip array 1-4 with the positioning support cover 2-4, the apex angles of the flared end of the positioning support cover 2-4 just overlap with the positioning points 1-5. Considering that the lens assembly 2-1 is mostly a cube, in a preferred embodiment of the present invention, the shrinking end and the expanding end of the positioning support cover 2-4 are both quadrilaterals. At this time, the number of positioning points 1-5 is 4 and they are distributed in a quadrilateral.

[0025] When assembling a multi-channel optical module, first place the core circuit unit 1 on the assembly platform, and let the electrical chip array 1-3 and the optical chip array 1-4 of the core circuit unit 1 face upward; then cover the lens assembly 2-1 of the optical fiber array coupling unit 2 above the electrical chip array 1-3 and the optical chip array 1-4, and ensure that the top corners of the flared end of the positioning support cover 2-4 on the lens assembly 2-1 are directly opposite to the positioning points 1-5 on the core circuit unit 1; finally, apply resin glue to the top corners and edges of the flared end of the positioning support cover 2-4, so that the lens assembly 2-1 can be fixed above the electrical chip array 1-3 and the optical chip. Since the coupling alignment problem between the core circuit unit 1 and the optical fiber array coupling unit 2 has been taken into consideration in advance during the design, when the top angle of the flared end of the support cover corresponds one-to-one with the positioning points 1-5, the core circuit unit 1 and the optical fiber array coupling unit 2 can achieve coupling alignment, that is, it can ensure that the multi-channel optical signals emitted by the optical chip array 1-4 can be accurately coupled into the optical fiber array 2-2 via the lens assembly 2-1, or the multi-channel optical signals emitted by the optical fiber array 2-2 can be accurately coupled into the optical chip array 1-4 via the lens assembly 2-1, so that the assembly of the multi-channel optical module can be achieved without any external testing equipment, thereby making the assembly process of the multi-channel optical module simpler and faster, and more suitable for mass production.

[0026] Of course, in order to further ensure the coupling alignment of the core circuit unit 1 and the optical fiber array coupling unit 2, the present invention can also use the coupling test device 3 to ensure more accurate coupling alignment of the multi-channel optical module by powering on, see Figure 5 At this time, when assembling the multi-channel optical module, first clamp the core circuit unit 1 on the coupling test device 3, with the BGA pad array 1-2 of the core circuit unit 1 facing downward and in contact with the BGA pad array 1-2 on the coupling test device 3, and the electrical chip array 1-3 and the optical chip array 1-4 of the core circuit unit 1 facing upward; then cover the lens assembly 2-1 of the optical fiber array coupling unit 2 above the electrical chip array 1-3 and the optical chip array 1-4, and ensure that the apex corners of the expanded end of the positioning support cover 2-4 on the lens assembly 2-1 are aligned with the positioning points 1-5 on the core circuit unit 1; then, The device 3 is connected to the monitoring device, and the output optical signal size or the received photocurrent size is observed by the monitoring device to determine whether the core circuit unit 1 and the optical fiber array coupling unit 2 meet the predetermined coupling alignment requirements. If the coupling alignment requirements are not met, the position of the lens assembly 2-1 is fine-tuned to make the top angle of the flared end of the support cover correspond more accurately to the positioning point 1-5, so that the core circuit unit 1 and the optical fiber array coupling unit 2 meet the predetermined coupling alignment requirements; finally, resin glue is applied to the top angles and edges of the flared end of the positioning support cover 2-4, so that the lens assembly 2-1 can be fixed above the electrical chip array 1-3 and the optical chip.

[0027] It should be noted that although the embodiments of the present invention described above are illustrative, they are not intended to limit the present invention, and therefore the present invention is not limited to the above specific embodiments. Without departing from the principles of the present invention, any other embodiments obtained by those skilled in the art under the guidance of the present invention are deemed to be within the protection of the present invention.

Claims

1. A multi-channel optical module, comprising a core circuit unit (1) and an optical fiber array coupling unit (2); The core circuit unit (1) is mainly composed of a printed circuit board (1-1), a BGA pad array (1-2), an electric chip array (1-3) and an optical chip array (1-4); the BGA pad array (1-2) is welded on the lower surface of the printed circuit board (1-1); the electric chip array (1-3) and the optical chip array (1-4) are welded on the upper surface of the printed circuit board (1-1); the BGA pad array (1-2) is connected to the electric chip array (1-3) through a via hole on the printed circuit board (1-1), and the electric chip array (1-3) is connected to the optical chip array (1-4) through a gold wire; The optical fiber array coupling unit (2) is mainly composed of a lens assembly (2-1), an optical fiber array (2-2) and an optical fiber interface (2-3); the lens assembly (2-1) covers the top of the electrical chip array (1-3) and the optical chip array (1-4); one end of the optical fiber array (2-2) is connected to the lens assembly (2-1), and the other end is connected to the optical fiber interface (2-3); Its characteristics are: A positioning support cover (2-4) is additionally provided at the lower edge of the lens assembly (2-1) of the optical fiber array coupling unit (2); the positioning support cover (2-4) is made of an insulating light-proof material; the positioning support cover (2-4) is in the shape of an inverted and through-going trumpet, the contracted end of the positioning support cover (2-4) is fixedly connected to the lower edge of the lens assembly (2-1), and the expanded end of the positioning support cover (2-4) faces downwards; More than three positioning points (1-5) are provided on the printed circuit board (1-1) around the electric chip array (1-3) and the optical chip array (1-4) of the core circuit unit (1); the number of these positioning points (1-5) is the same as the number of the top corners of the expanded end of the positioning support cover (2-4) and the positions are opposite; When the lens assembly (2-1) with the positioning support cover (2-4) covers the top of the electric chip array (1-3) and the optical chip array (1-4), each vertex of the expanded end of the positioning support cover (2-4) just overlaps with each positioning point (1-5); each vertex of the expanded end of the positioning support cover (2-4) is fixed to each positioning point (1-5) by resin glue.

2. A multi-channel optical module according to claim 1, characterized in that: The flared end of the positioning support cover (2-4) is in the shape of a quadrilateral, and at this time, the number of the positioning points (1-5) is 4 and they are distributed in the shape of a quadrilateral.

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