A laser chip mounting position correction mounting device and correction method

Abstract

This invention discloses a laser chip assembly position correction mounting device and its usage method, including a robotic arm, a gripping device, a CCD camera, a point laser emitter, a photodetector, a TO tube socket, and a tube tongue. The gripping device and CCD camera are both vertically positioned and fixed adjacent to each other on the robotic arm. The CCD camera is located on the right side of the gripping device, and the gripping device is capable of horizontal rotation. Several photodetectors are symmetrically distributed on both sides of the point laser emitter in the horizontal direction, with each side's photodetectors extending outwards sequentially. The laser emitted by the point laser emitter is perpendicular to the vertical plane where the photodetectors are located. The tube tongue is fixed to the TO tube socket, and the horizontal tube tongue and the point laser emitter are located on the same axis. This invention effectively solves the problems of existing packaging technologies, such as the tendency for manual calibration of COS mounting positions to lead to die contamination, low efficiency, and high cost.

Description

Technical Field

[0001] This invention relates to the field of chip assembly position correction equipment technology, and specifically to a laser chip assembly position correction mounting device and correction method. Background Technology

[0002] The information disclosed in the background section of this invention is intended only to enhance the understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] After decades of development, semiconductor lasers have become increasingly familiar to society due to their advantages such as small size, light weight, high electro-optical conversion efficiency, long lifespan, and high reliability. They have gradually replaced traditional gas and solid-state lasers in fields such as communications, medical, display, industrial manufacturing, and security. The popularization and diversification of applications have led to increasingly higher requirements for the packaging quality of semiconductor lasers. At the same time, end users' expectations for the price of semiconductor lasers are decreasing. The improvement in quality and the decrease in price have posed a great challenge to semiconductor packaging technology.

[0004] Currently, the packaging methods for TO coaxial semiconductor lasers are mainly divided into two types: silver paste mounting and gold-tin mounting. Silver paste mounting involves first depositing an indium solder on one side of a heat sink or a gold-tin solder on the other, and then, under specific process conditions, bonding the chip to the heat sink to form a COS (co-on-a-chip). Silver paste is then used to bond the COS to the socket, and finally, baking completes the packaging. Gold-tin mounting, on the other hand, uses a heat sink with gold-tin solder on both sides, and under specific process conditions, bonding the chip, heat sink, and socket together.

[0005] Patent document CN 208753723 U discloses a alignment device for semiconductor laser chips. The process involves first bonding the COS (Chip-on-Semiconductor) to the socket's tongue using silver paste, then manually aligning the die with the socket under light to correct the assembly position, and finally baking to cure the COS. However, this patented technology is only applicable to indium process packaging and not to gold-tin process packaging, limiting its application scope. Furthermore, the manual alignment after bonding the COS to the socket tongue is problematic because the silver paste is not baked and cured. During alignment, the silver paste can easily contaminate the laser chip die cavity surface, causing product failure and affecting yield. Additionally, manual alignment is inefficient and costly. Summary of the Invention

[0006] In view of this, the present invention provides a laser chip assembly position calibration device and calibration method, which can effectively solve the problems of easy die contamination, low efficiency, and high cost caused by manual calibration of COS assembly position in existing packaging technologies. Specifically, the present invention discloses the following technical solution.

[0007] In a first aspect, this invention discloses a laser chip assembly position correction mounting device, comprising: a robotic arm, a gripping device, a CCD camera, a point laser emitter, a photodetector, a TO tube socket, and a tube tongue. The gripping device and the CCD camera are both vertically positioned and fixed adjacent to each other on the robotic arm. The CCD camera is located on the right side of the gripping device, and the gripping device is capable of horizontal rotation. The point laser emitter is positioned such that its emitted laser can illuminate the light-emitting cavity surface of the chip or COS held on the gripping device. A plurality of photodetectors are symmetrically distributed on both sides of the point laser emitter in the horizontal direction, with the photodetectors on each side extending outwards in sequence. The laser emitted by the point laser emitter is perpendicular to the vertical plane where the photodetectors are located. The tube tongue is fixed to the TO tube socket, and the horizontal tube tongue and the point laser emitter are located on the same axis.

[0008] Furthermore, the gripping device is a vacuum nozzle with a suction port at its lower end, used to pick up the die or COS, and then move it to a position in front of the point laser emitter under the action of the robotic arm for the next calibration process.

[0009] Furthermore, the photodetectors on both sides of the point laser emitter are fixed on the mounting plate.

[0010] Furthermore, with the gripping device carrying the die or COS moving to the front of the point laser emitter as a reference, the TO socket and the tongue are both located on the left side of the gripping device at this time.

[0011] Secondly, this invention discloses a method for calibrating the mounting position of a laser chip, comprising the following steps:

[0012] (1) Driven by the robotic arm, the gripping device is moved to the area where the COS is located and grips it. Then the gripped COS is moved to the front of the point laser emitter.

[0013] (2) Turn on the point laser emitter so that the emitted laser beam illuminates the light-emitting cavity surface of the die on the COS. The resulting reflected laser beam then illuminates the photodetector, and the illuminating position of the reflected laser beam is determined. When the illuminating position is within the set area, the coaxiality is determined to meet the product packaging requirements and no adjustment is needed. Otherwise, the coaxiality is determined to not meet the requirements.

[0014] (3) For the COS whose coaxiality does not meet the requirements, the gripping device rotates in the horizontal direction until the irradiation position of the reflected laser beam of the COS is located in the set area, thereby completing the coaxiality adjustment.

[0015] (4) For COS whose coaxiality meets the product packaging requirements and does not require adjustment, or whose coaxiality meets the product packaging requirements after the above adjustments, the CCD camera identifies it and calculates the distance from which the light-emitting cavity surface of the COS protrudes from the gripping device. Then, driven by the robotic arm, the gripping device moves linearly to the left to the tongue with adhesive, and adjusts the position of the COS by moving left and right to ensure that the relative positions of the two vertical planes of its light-emitting cavity surface and the end face of the tongue are consistent, that is, the protrusion of the die is consistent. The gripping device releases the COS, so that it is bonded to the tongue with adhesive, and the mounting is completed.

[0016] Further, in step (1), the COS includes a die and a heat sink. The die is bonded to the upper surface of the heat sink.

[0017] Furthermore, the heat sink includes any one of the following: a prefabricated single-sided gold-tin heat sink with gold-tin solder on the upper surface, or a prefabricated double-sided gold-tin heat sink with gold-tin solder on both the upper and lower surfaces.

[0018] Furthermore, when the heat sink is a prefabricated double-sided gold-tin heat sink with gold-tin solder on both the upper and lower surfaces, the tube tongue is located in the eutectic stage, and the adhesive described in step (4) is no longer applied to the tube tongue.

[0019] Furthermore, in step (4), the adhesive includes any one of silver paste, tin paste, epoxy resin, etc.

[0020] Furthermore, in step (2), by changing the area of ​​the photodetector, different coaxiality requirements can be corrected.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects:

[0022] 1. The laser chip assembly position correction mounting device and correction method of the present invention can accurately correct the coaxiality of COS assembly through laser calibration. Simultaneously, CCD camera recognition can control the COS protrusion amount, ensuring the consistency of product assembly quality after COS mounting.

[0023] 2. The laser chip assembly position correction mounting device and correction method of the present invention will not touch the chip cavity surface during the calibration process, which can effectively avoid problems such as chip damage or cavity surface contamination caused by manual light calibration, and improve the output rate of mass production.

[0024] 3. The laser chip assembly position correction mounting equipment of the present invention can meet different coaxiality adjustment requirements by adjusting the area of ​​the photodetector. It also accommodates various mounting processes such as silver paste and gold solder, making it more versatile and practical. Attached Figure Description

[0025] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0026] Figure 1 This is a schematic diagram of the laser chip assembly position correction mounting device in the following embodiments.

[0027] Figure 2 The following is a front view of the point laser emitter and photodetector in the embodiments below.

[0028] Figure 3 The following is a schematic diagram of the assembly of the tongue, core, and heat sink in the embodiments below.

[0029] The labels in the diagram represent: 1-robotic arm, 2-grabbing device, 3-CCD camera, 4-point laser emitter, 5-photodetector, 6-TO tube socket, 7-tube tongue, 8-tube core, 9-mounting plate, 10-heat sink. Detailed Implementation

[0030] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0031] For ease of description, the terms "up," "down," "left," and "right" appearing in this invention only indicate that they correspond to the up, down, left, and right directions in the accompanying drawings. They do not limit the structure and are merely used to facilitate the description of the invention and to simplify the description. They do not indicate or imply that the device or component referred to needs to have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, any methods and materials similar to or equivalent to those described can be applied to the methods of this invention.

[0032] Example 1

[0033] refer to Figure 1 , Figure 2 and Figure 3Example: A laser chip assembly position correction mounting device includes: a robotic arm 1, a gripping device 2, a CCD camera 3, a point laser emitter 4, a photodetector 5, a TO tube socket 6, and a tube tongue 7. Specifically:

[0034] The robotic arm 1 is positioned at the top, with the gripping device 2 and CCD camera 3 both vertically arranged and fixed adjacent to each other on the robotic arm 1. This allows the gripping device 2 to grasp the COS (Coil-on-Screen) under the drive of the robotic arm 1. The COS consists of a die 8 and a heat sink 10, with the die 8 bonded to the upper surface of the heat sink 10. The gripping device 2 is a vacuum nozzle with a suction port at its lower end, used to pick up the COS. Under the action of the robotic arm 1, it moves to a position in front of the point laser emitter 4 for the next calibration step. It should be understood that the gripping device 2 can also employ any other suitable mechanism, as long as it has the function of gripping and releasing the COS. The CCD camera 3 is located to the right of the gripping device 2, and the gripping device 2 can rotate horizontally under the drive of the robotic arm 1.

[0035] The point laser emitter 4 is positioned such that its emitted laser beam illuminates the light-emitting cavity surface of the die 8 or COS held on the gripping device 2. Several photodetectors 5 are symmetrically distributed on both sides of the point laser emitter 4 in the horizontal direction, with each side's photodetectors 5 extending outwards in sequence. The photodetectors 5 on both sides of the point laser emitter 4 are fixed to the mounting plate 9. The laser emitted by the point laser emitter 4 is perpendicular to the vertical plane containing the photodetectors 5. Furthermore, different coaxiality requirements can be achieved by changing the area of ​​the photodetectors 5.

[0036] The tongue 7 is fixed to the TO tube seat 6, and the horizontal tongue 7 and the point laser emitter 4 are located on the same axis. With the gripping device 2 carrying the die 8 or COS moving to the front of the point laser emitter 4 as a reference, the TO tube seat 6 and the tongue 7 are both located to the left of the gripping device 2 at this time.

[0037] Example 2

[0038] A laser chip assembly position correction mounting method, using the laser chip assembly position correction mounting equipment described in Example 1 as the operating device, includes the following steps:

[0039] (1) Driven by the robotic arm 1, the gripping device 2 is moved to the area where the COS is located and grips it. Then, the gripped COS is moved to the front of the point laser emitter 4. In this embodiment, the COS is formed by alloying the die 8 and the heat sink 10 together using an indium process.

[0040] (2) Turn on the point laser emitter 4 so that the emitted laser beam irradiates the light-emitting cavity surface of the die on the COS. The reflected laser beam then irradiates the photodetector 5 and determines the irradiation position of the reflected laser beam. When the irradiation position is within the set area, it is determined that the coaxiality meets the product packaging requirements, that is, the vertical line of the center of the die cavity surface is consistent with the center axis of the base shank, and no adjustment is required. Otherwise, it is determined that the coaxiality does not meet the requirements (one of the reasons for the coaxiality not meeting the requirements is that the die or heat sink is misaligned during assembly, or the heat sink is displaced or rotated due to vibration before the silver paste is cured).

[0041] (3) For the COS whose coaxiality does not meet the requirements, the gripping device 2 rotates in the horizontal direction until the irradiation position of the reflected laser beam of the COS is located in the set area, thereby completing the coaxiality adjustment.

[0042] (4) For COS whose coaxiality meets the product packaging requirements and requires no adjustment, or whose coaxiality meets the product packaging requirements after the above adjustments, the CCD camera 3 identifies it and calculates the distance from the light-emitting cavity surface of the COS to the gripping device 2. Then, driven by the robotic arm 1, the gripping device 2 moves linearly to the left to the silver paste-coated tongue 7, and adjusts the position of the COS by moving left and right to ensure that the distance from its light-emitting cavity surface to the end face of the tongue 7 is consistent with that of other COS, that is, the amount of the die protruding is consistent. Figure 3 As shown at mid-distance a. The gripping device 2 releases the COS, allowing it to bond with the tongue 7 using silver paste, completing the mounting process. The gripping device 2 then begins the next round of calibration and mounting, operating in the same manner as above.

[0043] Example 3

[0044] A method for calibrating the mounting position of a laser chip, similar to Embodiment 2 above, differs in that: the heat sink 10 is a prefabricated single-sided gold-tin heat sink with a gold-tin solder on the upper surface, thereby transforming the COS formed by the die 8 and the heat sink into a COS that is die-bonded using a single-sided gold-tin process.

[0045] Example 4

[0046] A method for calibrating the mounting position of a laser chip, similar to Embodiment 2 above, differs in that: the heat sink 10 is a prefabricated double-sided gold-tin heat sink with gold-tin solder on both its upper and lower surfaces. In this case, the tongue 7 is located in the eutectic stage, and the adhesive described in step (4) is no longer applied to the tongue 9. As can be seen from Embodiments 2-4 above, the method for calibrating the mounting position of the laser chip can accommodate various mounting processes such as silver paste and gold-tin solder, thus having a wider range of applications and greater practicality.

[0047] Finally, it should be noted that any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention. Although specific embodiments of this invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of this invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of this invention are still within the scope of protection of this invention.

Claims

1. A method for calibrating the assembly position of a laser chip, characterized in that, The following laser chip assembly position correction mounting equipment is used as the operating device, which includes: a robotic arm, a gripping device, a CCD camera, a point laser emitter, a photodetector, a TO tube socket, and a tube tongue; wherein: the gripping device and the CCD camera are both vertically arranged and fixed adjacent to each other on the robotic arm, the CCD camera is located on the right side of the gripping device, and the gripping device can rotate horizontally; the point laser emitter is positioned such that the laser emitted can illuminate the light-emitting cavity surface of the chip or COS held on the gripping device; several photodetectors are symmetrically distributed on both sides of the point laser emitter in the horizontal direction, and the photodetectors on each side are arranged sequentially and extend outward; the laser emitted by the point laser emitter is perpendicular to the vertical plane where the photodetectors are located; the tube tongue is fixed on the TO tube socket, and the horizontal tube tongue and the point laser emitter are located on the same axis; The calibration mounting method includes the following steps: (1) Driven by the robotic arm, the gripping device is moved to the area where the COS is located and grips it; then the gripped COS is moved to the front of the point laser emitter; (2) Turn on the point laser emitter so that the laser emitted by it irradiates the light-emitting cavity surface of the die on the COS. The reflected laser beam generated by it irradiates the photodetector and determines the irradiation position of the reflected laser beam. When the irradiation position is within the set area, it is determined that the coaxiality meets the product packaging requirements and no adjustment is needed; otherwise, it is determined that the coaxiality does not meet the requirements. (3) For the COS whose coaxiality does not meet the requirements, the gripping device rotates in the horizontal direction until the irradiation position of the reflected laser beam of the COS is located in the set area, thereby completing the coaxiality adjustment. (4) For COS whose coaxiality meets the product packaging requirements and does not require adjustment or whose coaxiality meets the product packaging requirements after the above adjustments, the CCD camera identifies it and calculates the distance of the light-emitting cavity surface of the COS protruding from the gripping device; then the gripping device moves linearly to the left under the drive of the robotic arm to the tongue with adhesive, and adjusts the position of the COS by the left and right movements of the gripping device to ensure that the relative positions of the two vertical planes of the light-emitting cavity surface and the end face of the tongue are consistent, that is, the protrusion of the tube core is consistent. The gripping device releases the COS and makes it bonded to the tongue with adhesive to complete the mounting.

2. The laser chip assembly position calibration mounting method according to claim 1, characterized in that, The gripping device is a vacuum nozzle, with a suction port at its lower end.

3. The laser chip assembly position calibration mounting method according to claim 1, characterized in that, The photodetectors on both sides of the point laser emitter are fixed on the mounting plate.

4. The laser chip assembly position calibration mounting method according to any one of claims 1-3, characterized in that, With the gripping device carrying the die or COS moving to the front of the point laser emitter as a reference, the TO socket and the tongue are both located on the left side of the gripping device at this time.

5. The laser chip assembly position calibration mounting method according to claim 1, characterized in that, In step (1), the COS includes a die and a heat sink; wherein the die is bonded to the upper surface of the heat sink.

6. The laser chip assembly position calibration mounting method according to claim 5, characterized in that, The heat sink includes either a prefabricated single-sided gold-tin heat sink with gold-tin solder on the upper surface or a prefabricated double-sided gold-tin heat sink with gold-tin solder on both the upper and lower surfaces.

7. The laser chip assembly position calibration mounting method according to claim 6, characterized in that, When the heat sink is a prefabricated double-sided gold-tin heat sink with gold-tin solder on both the upper and lower surfaces, the tube tongue is located in the eutectic stage, and the adhesive described in step (4) is no longer applied to the tube tongue.

8. The laser chip assembly position calibration mounting method according to any one of claims 1-7, characterized in that, In step (4), the adhesive includes any one of silver paste, tin paste, and epoxy resin.

9. The laser chip assembly position calibration mounting method according to any one of claims 1-7, characterized in that, In step (2), different coaxiality requirements are corrected by changing the area of ​​the photodetector.

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