A method for manufacturing an edge emitting laser assembly

Abstract

A method for manufacturing an edge-emitting laser component includes the following steps: Step 1: hollowing out the copper foil at the cutting path position on the bottom of the first substrate; Step 2: manufacturing an EEL device using the first substrate; Step 3: printing solder paste, printing the solder paste on the pad of the second substrate; Step 4: printing or dispensing thermosetting adhesive; Step 5: mounting; Step 6: reflow soldering. Before manufacturing the EEL device, the copper foil at the cutting path position on the back of the first substrate used to manufacture the EEL device is hollowed out to solve the problem of burrs generated by subsequent cutting in advance, which is convenient for machine recognition during mounting and thus improves the AOI recognition accuracy, so that the X / Y position of mounting will not exceed the range; the EEL device is pre-fixed on the second substrate by thermosetting adhesive before reflow soldering, and then mounted and reflow soldered after the pre-fixing is completed, so that the device will not be affected by the traction force of the melting and solidification of the solder paste during reflow soldering, and the device is not easy to be displaced or fall off, which is beneficial to improving the quality of the finished product.

Description

Technical Field

[0001] The invention relates to the technical field of sensor manufacturing, and in particular to a process for improving the accuracy of a side-standing laser. Background Art

[0002] The sensor manufacturing field is a circuit assembly technology that mounts pinless or short-lead surface-mount components on the surface of a printed circuit board or other substrate, and assembles them by soldering through reflow soldering or dip soldering.

[0003] SMT reflow soldering is to use solder paste to core the EEL device to be soldered on the printed circuit board, and then heat it to melt the solder in the solder paste and flow again, infiltrating the area to be soldered, and forming solder joints after cooling, thereby achieving the purpose of soldering the EEL device to the printed circuit board.

[0004] In the reflow process, there are the following three problems:

[0005] First, when it comes to the step of cutting the device, due to the ductility of the copper foil, copper burrs will be generated in the cutting direction, resulting in inaccurate AOI recognition (the principle is to locate the center according to the positions of the four corners of the object to be identified. If there are burrs at the four corners, the center positioning will be inaccurate), and then the X / Y position of the mounting will exceed the range, and the rotation angle will deviate;

[0006] Second, when the left and right sides of the device are soldering, the difference in shrinkage when the solder paste melts and solidifies will cause unbalanced forces on both sides, pulling the device to one side, causing the device to tilt vertically. Lightweight devices (such as ultra-small structures) are more susceptible to this.

[0007] Third, the solder paste is easily splashed onto the soldering area after passing through the high-temperature furnace temperature. Summary of the invention

[0008] In view of the shortcomings of the background technology, an object of the present invention is to provide a method for improving the manufacturing of an edge-emitting laser component.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A method for manufacturing an edge-emitting laser assembly comprises the following steps:

[0011] Step 1: hollowing out the copper foil at the cutting path position at the bottom of the first substrate;

[0012] Step 2: using the first substrate to manufacture an EEL device;

[0013] Step 3: Solder paste printing: printing the solder paste on the pads of the second substrate;

[0014] Step 4: Printing or dispensing the thermosetting adhesive, distributing the thermosetting adhesive on the mounting area of ​​the second substrate by printing or dispensing;

[0015] Step 5: mounting, placing the EEL device obtained in step 2 on its side and mounting it on the mounting area of ​​the second substrate;

[0016] Step 6: Reflow soldering to melt the solder paste and firmly solder the EEL device to the second substrate.

[0017] Furthermore, in step 2, the first substrate is manufactured through the processes of die bonding, wire bonding, packaging injection molding and cutting in sequence to obtain an EEL device.

[0018] Furthermore, in step 2, an ink barrier layer is provided on a side of the pad of the first substrate close to the EEL chip.

[0019] Furthermore, in step 3, the pad of the second substrate is provided with a copper-nickel-gold plating layer.

[0020] Furthermore, in step 3, the solder paste uses water-soluble lead-free solder paste.

[0021] Furthermore, in the step 3, the solder paste is printed on the pads of the second substrate by a steel mesh jig, a scraper or a screen printer.

[0022] Furthermore, in step 4, the thermosetting adhesive is distributed at a central position on a connection line at the right edge of the pad of the second substrate.

[0023] Furthermore, in step 4, the diameter of the thermosetting adhesive is 4 to 7 mm.

[0024] Furthermore, in the step 4, the thermosetting adhesive needs to be cured in a curing furnace after being distributed.

[0025] Furthermore, in step 5, the EEL device is aligned and attached to the mounting area of ​​the second substrate by a mounting machine, a vacuum pen or special tweezers.

[0026] The beneficial effects of the present invention are:

[0027] 1. The present invention proposes a method for manufacturing an edge-emitting laser component. Before manufacturing the EEL device, the copper foil at the cutting path position on the back side of the first substrate used to manufacture the EEL device is hollowed out, so as to solve in advance the problem of burrs caused by subsequent cutting, facilitate machine recognition during mounting, and thus improve the AOI recognition accuracy, so that the X / Y position of mounting will not exceed the range and the rotation angle will not deviate; the EEL device is pre-fixed on the second substrate (PCB board) by thermosetting adhesive printing or dispensing before reflow soldering, and then mounted and reflow soldered after the pre-fixing is completed, so that the device will not be affected by the traction force of the melting and solidification of the solder paste during reflow soldering, and the device is not easy to be displaced or fall off, which is beneficial to improving the quality of the finished product.

[0028] 2. The present invention proposes a method for manufacturing an edge-emitting laser component, wherein the solder paste adopts a water-soluble lead-free solder paste. Even if the solder paste is subjected to a high-temperature furnace temperature and the flux is easily splashed onto the soldering area, the residue can be subsequently cleaned by simply rinsing with pure water. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 A schematic flow chart of a method for manufacturing an edge-emitting laser assembly of the present invention;

[0031] Figure 2 is a bottom schematic diagram of the first substrate;

[0032] Figure 3 is a front view of the EEL device;

[0033] Figure 4 is a side view of the EEL device;

[0034] Figure 5 is a side view of an edge-emitting laser assembly;

[0035] Figure 6 is a top view of an edge-emitting laser assembly;

[0036] In the figure, 10, first substrate; 101, cutting road; 102, first pad; 103, ink barrier layer; 20, EEL chip; 30, second substrate; 301, second pad. DETAILED DESCRIPTION

[0037] Combine the following Figure 1-6 The present invention is described in detail.

[0038] A method for manufacturing an edge-emitting laser assembly comprises the following steps:

[0039] Step 1: hollowing out the copper foil at the position of the cutting path 101 at the bottom of the first substrate 10;

[0040] Step 2: Using the first substrate 10 to manufacture an EEL device;

[0041] Step 3: solder paste printing, printing the solder paste on the pads of the second substrate 30;

[0042] Step 4: Printing or dispensing the thermosetting adhesive, distributing the thermosetting adhesive on the mounting area of ​​the second substrate 30 by printing or dispensing;

[0043] Step 5: mounting, placing the EEL device obtained in step 2 sideways and mounting it on the mounting area of ​​the second substrate 30;

[0044] Step 6: Reflow soldering to melt the solder paste and firmly solder the EEL device and the second substrate 30 together.

[0045] Specifically, Figure 2 As shown, the copper foil is arranged at the four corners around the bottom of the first substrate 10. The bottom of the first substrate 10 refers to the side of the first substrate 10 that is placed on the second substrate 30 and abuts against the second substrate 30. The EEL device is an edge-emitting laser. The EEL edge-emitting laser is mainly composed of the first substrate 10 and the EEL chip 20 horizontally arranged on the first substrate 10. The light emitting direction of the EEL edge-emitting laser is the side of the chip, that is, the EEL edge-emitting laser emits light laterally. Due to this structural constraint, the prior art usually uses a triangular reflection lens to adjust the light path in order to change the light emitting direction from horizontal to vertical. However, in this embodiment, the light emitting direction is changed from horizontal to vertical. Figure 5-6 As shown, the EEL device is placed sideways on the mounting area of ​​the substrate, so that the EEL chip 20 is perpendicular to the horizontal plane, and the EEL edge-emitting laser itself emits light in the vertical direction. The EEL device and the second substrate 30 are firmly welded together to form an edge-emitting laser assembly.

[0046] Before manufacturing the EEL device, the copper foil at the cutting path 101 on the back side of the first substrate 10 used to manufacture the EEL device is hollowed out to solve the problem of burrs caused by subsequent cutting in advance, to facilitate machine recognition during mounting and thus improve the AOI recognition accuracy, so that the X / Y position of the mounting will not exceed the range and the rotation angle will not deviate.

[0047] The pad of the second substrate 30 is referred to as the second pad 301 in this embodiment; thermosetting adhesive is a polyolefin compound, which is a common material and has the property of being cured by heat. The thermosetting adhesive itself is insulated. The thermosetting adhesive printing or dispensing in step 4 pre-fixes the EEL device on the second substrate 30 (PCB board) before reflow soldering. After the pre-fixing is completed, it is mounted and reflow soldered, so that the device will not be affected by the traction force of the melting and solidification of the solder paste during reflow soldering, and the device is not easy to be displaced or fall off, which is beneficial to improve the quality of the finished product; a stepped steel mesh is also used to complete the brushing of the thermosetting adhesive. When using the stepped steel mesh, pay attention to avoid and protect the position of the solder paste so that the position of the solder paste will not be affected by the brushing of the thermosetting adhesive.

[0048] In this embodiment, in step 2, the first substrate 10 is manufactured to obtain an EEL device by sequentially performing processes of die bonding, wire bonding, encapsulation injection molding, and cutting. The encapsulation injection molding is to seal and protect the edge emitting laser chip and the wire bonding by transparent epoxy resin molding compound. The specific steps of the processes of die bonding, wire bonding, encapsulation injection molding, and cutting refer to the common knowledge and prior art in the relevant field.

[0049] In this embodiment, in step 2, an ink barrier layer 103 is provided on the side of the pad of the first substrate 10 close to the EEL chip 20. The entire manufacturing process needs to undergo multiple reflows. After the solder paste on the pad of the second substrate 30 melts, it crawls onto the pad of the first substrate 10. In order to prevent the solder paste from continuing to flow after crawling onto the pad of the first substrate 10 and then penetrating into the package injection molding area where the EEL chip 20 is built, the substrate is optimized and upgraded, and an ink barrier layer 103 is provided at the junction of the pad of the first substrate 10 and the packaging glue (encapsulation protection EEL chip 20 and welding wire area) to prevent the tin from penetrating into the package injection molding area, thereby improving the product's ability to undergo multiple reflows. The pad of the first substrate 10 is referred to as the first pad 102 in this embodiment.

[0050] In this embodiment, in step 3, the pads of the second substrate 30 are provided with a copper-nickel-gold plating layer. After the copper-nickel-gold plating layer is used, the tin surface on the product is fuller.

[0051] In this embodiment, in step 3, the solder paste is water-soluble lead-free solder paste. In this way, in the subsequent board washing process, only pure water washing is needed to clean the residue, which is simple and convenient.

[0052] In this embodiment, in step 3, solder paste is printed on the pads of the second substrate 30 by a steel mesh fixture, a scraper or a screen printer.

[0053] In this embodiment, in step 4, the thermosetting adhesive is distributed at a central position on the right edge connection line of the pad of the second substrate 30 .

[0054] In this embodiment, in step 4, the diameter of the thermosetting adhesive is 4 to 7 mm.

[0055] In this embodiment, in step 4, after the thermosetting adhesive is distributed, it needs to be cured in a curing furnace.

[0056] In this embodiment, in step 5, the EEL device is aligned and attached to the mounting area of ​​the second substrate 30 by a mounting machine, a vacuum suction pen or special tweezers.

[0057] After step 6 reflow soldering, the following steps can be added:

[0058] Step 7: AOI optical inspection: Use automatic optical inspection (AOI) equipment to perform optical inspection on the soldered PCB to ensure the soldering quality; Step 8: Repair: Manually repair the detected soldering defects; Step 9: Depaneling: Divide the soldered PCB into individual circuit boards; Step 10: Grinding: Perform surface treatment on the PCB, such as edge grinding, deburring, etc.; Step 11: Washing: Clean the PCB to remove residues generated during the soldering process.

[0059] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for manufacturing an edge-emitting laser assembly, characterized in that: The following steps are involved: Step 1: hollowing out the copper foil at the cutting path position at the bottom of the first substrate; Step 2: using the first substrate to manufacture an EEL device; Step 3: Solder paste printing: printing the solder paste on the pads of the second substrate; Step 4: Printing or dispensing the thermosetting adhesive, distributing the thermosetting adhesive on the mounting area of ​​the second substrate by printing or dispensing; Step 5: mounting, placing the EEL device obtained in step 2 on its side and mounting it on the mounting area of ​​the second substrate; Step 6: Reflow soldering to melt the solder paste and firmly solder the EEL device to the second substrate.

2. A method for manufacturing an edge emitting laser assembly as claimed in claim 1, characterized in that: In step 2, the first substrate is manufactured through the processes of die bonding, wire bonding, packaging injection molding and cutting to obtain an EEL device.

3. The method for manufacturing an edge emitting laser assembly according to claim 1, characterized in that: In the step 2, an ink barrier layer is provided on a side of the pad of the first substrate close to the EEL chip.

4. The method for manufacturing an edge emitting laser assembly according to claim 1, characterized in that: In step 3, the pads of the second substrate are provided with a copper-nickel-gold plating layer.

5. The method for manufacturing an edge emitting laser assembly according to claim 1, characterized in that: In step 3, the solder paste uses water-soluble lead-free solder paste.

6. The method for manufacturing an edge emitting laser assembly according to claim 1, characterized in that: In the step 3, the solder paste is printed on the pads of the second substrate by using a steel mesh fixture, a scraper or a screen printer.

7. The method for manufacturing an edge emitting laser assembly according to claim 1, characterized in that: In step 4, the thermosetting adhesive is distributed at a central position on the right edge connection line of the pad of the second substrate.

8. The method for manufacturing an edge emitting laser assembly according to claim 1, characterized in that: In step 4, the diameter of the thermosetting adhesive is 4 to 7 mm.

9. The method for manufacturing an edge emitting laser assembly according to claim 1, characterized in that: In step 4, after the thermosetting adhesive is distributed, it needs to be cured in a curing furnace.

10. The method for manufacturing an edge emitting laser assembly according to claim 1, characterized in that: In step 5, the EEL device is aligned and attached to the mounting area of ​​the second substrate by a mounting machine, a vacuum pen or special tweezers.

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