Active die bonding system and operation method thereof

Abstract

The invention belongs to the technical field of manufacturing of optical devices or systems, and particularly relates to an active die bonding system and an operation method thereof, the active die bonding system is characterized in that the active die bonding system comprises a bottom plate and an objective table, a six-axis fine tuning table is connected with a suction nozzle through an operation arm, the objective table is provided with a chip area and a die bonding area, and a four-channel combiner is connected with an optical power meter through a ceramic ferrule; the suction nozzle is connected with a vacuum pump through a pipeline and is provided with a positive / negative electrode which is connected with a power supply through a lead; the six-axis fine tuning table is operated to move the optical chip from the chip area to the ceramic substrate of the die bonding area, the optical chip is in a luminous state in the whole process, the position of the optical chip is corrected through the four-channel combiner until the power of the optical power meter is at the maximum value, and the optical chip is fixed to the ceramic substrate through glue. The beneficial effects of the invention are that the optical chip can be kept in a light-emitting state in the die bonding process, so that the position of the chip can be adjusted according to the output optical power of the ceramic ferrule, and the yield of production is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of manufacturing optical devices or systems, and in particular relates to an active die bonding system and an operating method thereof. Background Art

[0002] The coupling efficiency of optical devices is a very important indicator. It refers to the percentage of the power of the light emitted by the chip through the optical interface of the optical device to the chip's luminous power. This parameter will directly determine the final performance of the system. For example, in optical systems used for communication, the coupling efficiency of light determines the signal strength and transmission distance. Improving the coupling efficiency of light also has a great impact on improving the bandwidth and transmission speed of optical communications. In optical systems used for fiber optic sensors, in some applications that require high-precision sensing, such as fiber optic gyroscopes, fiber optic accelerometers, etc., improving the coupling efficiency of light can make the sensor signal more sensitive and accurate.

[0003] In the manufacture of optical devices, the optical chip must first be fixed on the ceramic substrate, which is what the industry calls the die bonding process. Traditional die bonding processes are all passive, that is, the optical chip does not emit light during the die bonding process, and the optical chip is fixed to the pre-designed position on the ceramic substrate by mechanical positioning or visual recognition assisted positioning. However, the passive process will inevitably be affected by the positioning accuracy of mechanical components or the visual recognition accuracy, resulting in a deviation in the position of the die bonding within a certain range. This deviation will continue to affect subsequent processes and even affect the light coupling efficiency of the entire system. This process can meet the requirements of mass production in application scenarios where the coupling efficiency requirements are not high. However, for optical devices that require very high light coupling efficiency, the yield of this process cannot meet the requirements of mass production.

[0004] The current industry manufactures this type of optical device, and the general working process is as follows: Step 1) First, apply an appropriate amount of glue on the substrate according to the designed positions of the four optical chips and the four-channel combiner; Step 2) Use manual alignment or automatic alignment of the equipment to stick and fix the four optical chips and the four-channel combiner on the ceramic substrate according to the designed positions. During this process, none of the four optical chips is powered on or emits light; Step 3) Power on all four optical chips to make them emit light, and then slightly move the ceramic ferrule near the designed position. The other end of the ceramic ferrule is connected to the optical power meter. During the process of slightly moving the ceramic ferrule, the optical power values ​​of the four channels displayed on the optical power meter are monitored in real time. When the optical power values ​​of the four channels reach the required optical power, stop moving the ceramic ferrule, and use glue to stick and fix the ceramic ferrule on the ceramic substrate. After the glue is completely cured, the optical device is completed.

[0005] In the actual production process, to ensure that the light emitted by the four optical chips can eventually enter the ceramic ferrule with a very high coupling efficiency, the requirements for the position and angle of the four optical chips are very high. Because the diameter of the core that allows light to enter the ceramic ferrule is very small, for example, the diameter of the core of the G.652D single-mode optical fiber commonly used in the optical communication industry is only 9 microns. If the position of any of the four optical chips is deviated, it will eventually result in one or more optical chips The light cannot enter the ceramic ferrule with a high coupling efficiency, the manufacturing yield is low, and batch delivery cannot be achieved. Summary of the invention

[0006] The purpose of the present invention is to provide an active die bonding system and an operating method thereof, so as to overcome the shortcomings of the prior art and adopt an active die bonding method to improve the light coupling efficiency in the manufacturing process of optical devices, thereby improving the performance of optical devices, improving the manufacturing yield, ensuring the smooth progress of batch delivery, and reducing production costs.

[0007] To achieve the above object, the present invention is implemented through the following technical solutions:

[0008] One of the technical solutions: an active crystal bonding system, including a base plate, a stage, a six-axis fine-tuning stage, a vacuum pump, a power supply and a suction nozzle. The base plate is provided with a stage and a six-axis fine-tuning stage, the six-axis fine-tuning stage is connected to the suction nozzle via an operating arm, the stage is provided with a chip area and a crystal bonding area, the chip area is used to place an optical chip, and the crystal bonding area is used to place a ceramic substrate; the suction nozzle is connected to the vacuum pump via a vacuum hose, and a power-on probe is provided on the suction nozzle, and the power-on probe is connected to the power supply via a power-on wire; the six-axis fine-tuning stage is connected to the six-axis fine-tuning stage controller through a cable, and the six-axis fine-tuning stage is operated to transfer the optical chip from the chip area to the ceramic substrate in the crystal bonding area. During the entire transfer and crystal bonding process, the optical chip is in an active luminous state, and the position of the optical chip is corrected by the four-channel combiner on the ceramic substrate until the optical power is at the maximum value, indicating that the position is correct, and the optical chip is fixed to the ceramic substrate with glue.

[0009] Furthermore, a vacuum interface is provided on the top of the suction nozzle, which is connected to the adsorption area at the bottom of the suction nozzle. Two powered probes are vertically fixedly connected to the suction nozzle. The tips of the powered probes are located outside the adsorption area and correspond to the powered area of ​​the optical chip. The tips are 10-30 μm below the plane where the adsorption area is located.

[0010] Furthermore, the nozzle is made of insulating material, including but not limited to any one of plastic, resin, rubber and wood.

[0011] Furthermore, the ceramic substrate is an optical device circuit board, on which are disposed positioning areas for four optical chips, a four-channel combiner and a ceramic ferrule, and each component is fixedly connected to the ceramic substrate with glue after positioning.

[0012] Furthermore, the vacuum pump has a pumping rate greater than 8m3 / h and a limiting absolute pressure less than 5Pa.

[0013] Furthermore, the output voltage and current of the power supply are adjustable to match the power supply parameters of the optical chip.

[0014] Furthermore, the number of channels of the four-channel combiner matches the number of optical chips.

[0015] Furthermore, the applicable specification of the optical chip is an edge-emitting laser chip, and the positive and negative pads of the chip are both on the upper surface of the chip.

[0016] Furthermore, the specification of the optical power meter is Thorlabs PM100D.

[0017] Technical Solution 2: An operating method of an active die bonding system. When assembling an optical chip and a four-channel combiner on an optical device, the optical chip is always in an active light-emitting state, and the installation positions of the optical chip and the ceramic ferrule are calibrated in real time to ensure the best installation angle. Specifically, the following steps are included:

[0018] 1) Apply glue: first apply glue on the corresponding positions of the four optical chips and the four-channel combiner on the ceramic substrate;

[0019] 2) Installing a four-channel combiner, and pasting and fixing the four-channel combiner to a predetermined position of the ceramic substrate;

[0020] 3) Install the optical chip. Use the operating arm to power up the optical chip of the first channel to make it emit light. Then, vacuum it and transfer it to the design position of the ceramic substrate. Slightly move the ceramic ferrule connected to the optical power meter. Observe the optical power value of the first channel displayed on the optical power meter in real time. When the optical power value is qualified, glue the optical chip of the first channel and the ceramic ferrule to the corresponding position of the ceramic substrate.

[0021] 4) Use the operating arm to power up the second channel optical chip to make it emit light, and then transfer it to the design position of the ceramic substrate by vacuum adsorption. Observe the optical power value of the second channel displayed on the optical power meter in real time, control the operating arm to adjust the angle of the second channel optical chip. When the optical power value is qualified, use glue to stick the second channel optical chip to the corresponding position of the ceramic substrate; repeat this step to stick the third channel optical chip and the fourth channel optical chip to the ceramic substrate in turn.

[0022] 5) Curing: After the glue is completely cured, the optical device is completed.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1) The present invention realizes active die bonding during the die bonding process. During the die bonding process, the optical chip can maintain a light-emitting state, and the position of the chip can be adjusted by looking at the output optical power of the ceramic ferrule, thereby improving the performance of the optical device and the production yield;

[0025] 2) The present invention greatly improves manufacturing efficiency, ensures product quality, and optimizes product performance. The dedicated system die bonding system also greatly reduces production costs, making mass production of high-performance optical devices possible.

[0026] 3) During the die bonding process, the position of the optical chip can be adjusted in real time according to the optical power, and it is confirmed that when the optical chip is fixed in position, the power of the optical device is at the maximum value, thereby improving the optical coupling efficiency of the optical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of an active die bonding system embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of a state where an optical chip is sucked onto a suction nozzle in an embodiment of the present invention;

[0029] Figure 3 A schematic diagram of a chip positive electrode and a chip negative electrode on an optical chip in an embodiment of the present invention;

[0030] Figure 4 A schematic diagram of a four-channel optical device structure and optical path in an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of the bottom structure of the nozzle in an embodiment of the present invention;

[0032] Figure 6 This is a schematic diagram of the optical path of a four-channel optical device in an embodiment of the present invention, in which the position of the optical chip of the second channel deviates from the designed position;

[0033] Figure 7 A schematic diagram of step-by-step determination of an optical path of a four-channel optical device according to an embodiment of the present invention;

[0034] Figure 8 Schematic diagram of the working state of the active die bonding process used in the embodiment of the present invention.

[0035] In the figure: 1-base plate, 2-six-axis fine-tuning stage, 3-operating arm, 4-suction nozzle, 5-powered probe, 6-vacuum hose, 7-powered wire, 8-stage, 9-vacuum pump, 10-power supply, 11-optical chip, 12-chip positive electrode, 13-chip negative electrode, 14-ceramic substrate, 15-four-channel combiner, 16-ceramic ferrule, 17-six-axis fine-tuning stage controller, 18-optical power meter, 19-chip area, 20-crystal bonding area, 21-adsorption area, 22-vacuum interface, 1101-first channel optical chip, 1102-second channel optical chip, 1103-third channel optical chip, 1104-fourth channel optical chip. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0037] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the specific embodiments required to be used in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the specific embodiments described below are some implementation methods of the present invention. For ordinary technicians in this field, other specific embodiments can be obtained based on these specific embodiments without paying creative work.

[0038] The components of the embodiments of the present invention generally described and shown in the specific embodiments herein can be arranged and designed in countless different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the specific embodiments is not intended to limit the scope of the invention claimed, but merely represents selected embodiments of the present invention.

[0039] See Figure 1-8 , is a schematic structural diagram of an active die bonding system embodiment of the present invention, comprising a base plate 1, a stage 8, a six-axis fine-tuning stage 2, a vacuum pump 9, a power supply 10 and a suction nozzle 4, the base plate 1 is provided with a stage 8 and a six-axis fine-tuning stage 2, the six-axis fine-tuning stage 2 is connected to the suction nozzle 4 via an operating arm 3, the stage 8 is provided with a chip area 19 and a die bonding area 20, the suction nozzle 4 is connected to the vacuum pump 9 via a vacuum hose 6, the suction nozzle 4 is provided with a power-on probe 5, the power-on probe 5 is connected to the power supply 10 via a power-on wire 7 to form a closed circuit loop, and the power-on probe 5 is divided into a positive electrode needle and a negative electrode needle.

[0040] The six-axis fine-tuning stage 2 is connected to the six-axis fine-tuning stage controller 17 through a cable. The operation of the six-axis fine-tuning stage 2 can transfer the optical chip 11 from the chip area 19 to the ceramic substrate in the solid crystal area 20. During the whole process, the optical chip 11 is in an active light-emitting state, and the position of the optical chip 11 is corrected by the four-channel combiner 15 on the ceramic substrate 14 until the optical power is at the maximum value, indicating that the position is correct. The optical chip 11 can be fixed to the ceramic substrate 14 with glue.

[0041] The six-axis fine-tuning platform 2 can perform translational motion on three mutually perpendicular axes in three-dimensional space, and can also rotate on these three axes. Figure 1 The suction nozzle 4 is fixed on the six-axis fine-tuning platform 2 in the manner shown in Figure 1 It is fixed on the suction nozzle cantilever 3 in the manner shown in the figure. In this way, when the six-axis fine-tuning stage 2 is controlled to perform six-axis spatial motion by operating the six-axis fine-tuning stage controller 17, the suction nozzle 4 will also be driven to perform six-axis spatial motion. If the optical chip 11 is sucked on the suction nozzle 4 at this time, the optical chip 11 will also be driven to perform six-axis spatial motion.

[0042] A vacuum interface 22 is provided at the top of the suction nozzle 4, and the vacuum interface 22 is connected to the adsorption area 21 at the bottom of the suction nozzle 4. Two powered probes 5 are vertically fixedly connected to the suction nozzle 4. The needle tip of the powered probe 5 is located outside the adsorption area and corresponds to the powered area of ​​the optical chip 11. The needle tip is 10-30μm below the plane where the adsorption area is located. In this way, when the optical chip 11 is sucked on the suction nozzle 4, the needle tip of the powered probe 5 is just in contact with the chip positive electrode 12 and the chip negative electrode 13 on the surface of the optical chip 11, and there is enough pressure to ensure that the contact resistance between the probe 5 and the chip positive electrode 12 and the chip negative electrode 13 on the surface of the optical chip 11 is small enough to form a reliable and stable circuit conduction. The suction nozzle 4 in the system of the present invention can be designed flexibly and specifically according to the shape and size of the optical chip 11, so as to achieve both sufficient suction and alignment and full contact between the powered probe 5 and the chip positive electrode 12 and the chip negative electrode 13.

[0043] When the vacuum pump 9 is turned on, the vacuum state it generates can be transmitted to the suction nozzle 4. When the suction nozzle 4 contacts the optical chip 11 at the specified position, the optical chip 11 will be firmly sucked on the suction nozzle 4 under the action of vacuum and atmospheric pressure. Figure 2 This is a state where the optical chip 11 is sucked onto the suction nozzle 4 .

[0044] The stage 8 can flexibly perform large-scale translation and rotation movements on the base plate 1, move the optical chip to be sucked to the bottom of the suction nozzle 4, and then control the six-axis fine-tuning stage 2 to move in a small amplitude with higher precision through the six-axis fine-tuning stage controller 17, so as to drive the suction nozzle 4 to move in a small amplitude with higher precision, so that the suction nozzle 4 contacts the upper surface of the optical chip 11, and aligns and contacts with the chip positive electrode 12 and the chip negative electrode 13 on the surface of the optical chip 11 respectively, and turns on the vacuum pump 9 to start the vacuum pumping work. Under the action of atmospheric pressure, the optical chip 11 is firmly sucked on the suction nozzle 4. At this time, the optical chip 11 will emit light, and the six-axis fine-tuning stage controller 17 is operated to raise the suction nozzle 4 to a certain height.

[0045] The six-axis fine-tuning stage controller 17 is used to control the suction nozzle 4 to move in a small range with high precision, while monitoring other parameters. When it is confirmed that the optical chip 11 is in a suitable position, the suction nozzle 4 is stopped from moving, the chip 11 is fixed with glue or other means, the vacuum pump 9 is turned off, and the six-axis fine-tuning stage controller 17 is operated to lift the suction nozzle 4, thus completing an active crystal bonding operation.

[0046] The nozzle 4 is made of insulating material, including but not limited to any one of plastic, resin, rubber, and wood. The specifications of the vacuum pump 9 are: the suction rate is greater than 8m 3 / h, and the ultimate absolute pressure is less than 5Pa. The output voltage and current of the power supply 10 are adjustable to match the power supply parameters of the optical chip 11. The number of channels of the four-channel combiner 15 matches the number of optical chips. The applicable specification of the optical chip 11 is an edge-emitting laser chip, and the positive and negative pads of the chip are both on the upper surface of the chip. The specification of the optical power meter 18 is Thorlabs PM100D.

[0047] by Figure 4 Taking the four-channel optical device shown in the figure as an example, it is composed of four optical chips 11, a ceramic substrate 14, a four-channel combiner 15 and a ceramic ferrule 16. The ceramic substrate 14 is an optical device circuit board, on which are provided four optical chips 11, a four-channel combiner 15 and a ceramic ferrule 16 fixing area. After each component is positioned, it is connected and fixed to the ceramic substrate 14 with glue. The four optical chips 11 are respectively a first channel optical chip 1101, a second channel optical chip 1102, a third channel optical chip 1103 and a fourth channel optical chip 1104. The dotted lines in the figure are optical path markings for the light emitted by the four optical chips 11 and then emitted into the core of the ceramic ferrule 16 after passing through the four-channel combiner 15.

[0048] like Figure 7 As shown, an operation method of an active die bonding system of the present invention, when assembling an optical chip and a four-channel combiner on an optical device, the optical chip is always in an active light-emitting state, and the installation positions of the optical chip and the ceramic ferrule are calibrated in real time to ensure the best installation angle, specifically comprising the following steps:

[0049] 1) Applying glue: first apply glue on the corresponding positions of the four optical chips 11 and the four-channel combiner 15 on the ceramic substrate 14;

[0050] 2) Installing the four-channel combiner, and pasting and fixing the four-channel combiner 15 to a predetermined position of the ceramic substrate 14;

[0051] 3) Installation of optical chip: Use the operating arm 3 to power up the first channel optical chip 1101 to make it emit light, and then transfer it to the design position of the ceramic substrate 14 by vacuum adsorption. Slightly move the ceramic ferrule 16 connected to the optical power meter, and observe the optical power value of the first channel displayed on the optical power meter 18 in real time. When the optical power value is qualified, use glue to stick the first channel optical chip 1101 and the ceramic ferrule 16 to the corresponding position of the ceramic substrate 14;

[0052] 4) Use the operating arm 3 to power up the second channel optical chip 1102 to make it emit light, and then transfer it to the vicinity of the designed position of the ceramic substrate by vacuum adsorption, observe the optical power value of the second channel displayed on the optical power meter 18 in real time, control the operating arm 3 to adjust the angle of the second channel optical chip 1102, and when the optical power value is qualified, use glue to stick the second channel optical chip 1102 to the corresponding position of the ceramic substrate 14; repeat this step to stick the third channel optical chip 1103 and the fourth channel optical chip 1104 to the ceramic substrate 14 in turn;

[0053] 5) Curing: After the glue is completely cured, the optical device is manufactured. This process can ensure that the light emitted by the four optical chips 11 can enter the ceramic ferrule 16 with a very high coupling efficiency, thereby improving the manufacturing yield of the optical device.

[0054] like Figure 6 As shown, when the actual pasting position of the second channel optical chip 1102 among the four optical chips 11 deviates from the theoretically designed position, the positions of the remaining three optical chips 11 are pasted at the designed positions, and the optical path of the light emitted by the second channel optical chip 1102 after passing through the four-channel combiner 15 is Figure 6 As shown by the dotted lines in the figure, it can be seen that the light emitted by the second channel optical chip 1102 is not aligned with the fiber core after passing through the four-channel combiner 15. Finally, no matter how the position of the ceramic ferrule 16 of this optical device is adjusted, it is impossible to ensure that the light emitted by the four optical chips 11 can finally enter the fiber core of the ceramic ferrule 16 with a very high coupling efficiency. At most, the light emitted by three optical chips 11 can enter the ceramic ferrule 16 with a very high coupling efficiency. The three optical chips 11 refer to the first channel optical chip 1101, the third channel optical chip 1103 and the fourth channel optical chip 1104 respectively. The light emitted by the second channel optical chip 1102 can hardly enter the fiber core of the ceramic ferrule 16.

[0055] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An active die bonding system, characterized in that: It includes a base plate, a stage, a six-axis fine-tuning stage, a vacuum pump, a power supply and a suction nozzle. The base plate is provided with a stage and a six-axis fine-tuning stage, the six-axis fine-tuning stage is connected to the suction nozzle via an operating arm, the stage is provided with a chip area and a solid crystal area, the chip area is used to place an optical chip, and the solid crystal area is used to place a ceramic substrate; the suction nozzle is connected to the vacuum pump via a vacuum hose, and a power-on probe is provided on the suction nozzle, and the power-on probe is connected to the power supply via a power-on wire; the six-axis fine-tuning stage is connected to the six-axis fine-tuning stage controller through a cable, and the six-axis fine-tuning stage is operated to transfer the optical chip from the chip area to the ceramic substrate in the solid crystal area. During the entire transfer and solid crystal process, the optical chip is in an active luminous state, and the position of the optical chip is corrected by a four-channel combiner on the ceramic substrate until the optical power is at the maximum value, indicating that the position is correct, and the optical chip is fixed to the ceramic substrate with glue.

2. The active die bonding system according to claim 1, characterized in that: A vacuum interface is provided on the top of the suction nozzle, which is connected to the adsorption area at the bottom of the suction nozzle. Two powered probes are vertically fixedly connected to the suction nozzle. The tips of the powered probes are located outside the adsorption area and correspond to the powered area of ​​the optical chip. The tips of the probes are 10-30 μm lower than the plane where the adsorption area is located, ensuring reliable contact between the tips and the adsorbed optical chip electrodes.

3. The active die bonding system according to claim 1, characterized in that: The suction nozzle is made of insulating material, including but not limited to any one of plastic, resin, rubber and wood.

4. The active die bonding system according to claim 1, characterized in that: The ceramic substrate is an optical device circuit board, on which are arranged four optical chips, a four-channel combiner and a positioning area for a ceramic ferrule. After each component is positioned, it is connected and fixed to the ceramic substrate with glue.

5. The active die bonding system according to claim 1, characterized in that: The vacuum pump has a pumping speed of more than 8 m / s. 3 / h, the ultimate absolute pressure is less than 5Pa.

6. The active die bonding system according to claim 1, characterized in that: The output voltage and current of the power supply are adjustable to match the power supply parameters of the optical chip.

7. The active die bonding system according to claim 1, characterized in that: The number of channels of the four-channel combiner matches the number of optical chips.

8. The active die bonding system according to claim 1, characterized in that: The applicable specification of the optical chip is an edge-emitting laser chip, and the positive and negative pads of the chip are both on the upper surface of the chip.

9. The active die bonding system according to claim 1, characterized in that: The specification of the optical power meter is Thorlabs PM100D.

10. An operating method of an active die bonding system, characterized in that: When assembling the optical chip and the four-channel combiner on the optical device, the optical chip is always in an active light-emitting state, and the installation position of the optical chip and the ceramic ferrule is calibrated in real time to ensure the best installation angle, which specifically includes the following steps: 1) Apply glue: first apply glue on the corresponding positions of the four optical chips and the four-channel combiner on the ceramic substrate; 2) Installing a four-channel combiner, and pasting and fixing the four-channel combiner to a predetermined position of the ceramic substrate; 3) Install the optical chip. Use the operating arm to power up the optical chip of the first channel to make it emit light. Then, vacuum it and transfer it to the design position of the ceramic substrate. Slightly move the ceramic ferrule connected to the optical power meter. Observe the optical power value of the first channel displayed on the optical power meter in real time. When the optical power value is qualified, glue the optical chip of the first channel and the ceramic ferrule to the corresponding position of the ceramic substrate. 4) Use the operating arm to power up the second channel optical chip to make it emit light, and then transfer it to the design position of the ceramic substrate by vacuum adsorption. Observe the optical power value of the second channel displayed on the optical power meter in real time, control the operating arm to adjust the angle of the second channel optical chip. When the optical power value is qualified, use glue to stick the second channel optical chip to the corresponding position of the ceramic substrate; repeat this step to stick the third channel optical chip and the fourth channel optical chip to the ceramic substrate in turn. 5) Curing: After the glue is completely cured, the optical device is completed.

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