Low-temperature SMT packaging method of optical assembly and optoelectronic module

Abstract

This invention discloses a low-temperature SMT packaging method for optical components and an optoelectronic module. The low-temperature SMT packaging method includes: printing solder paste onto the pads of a PCBA board to obtain a first PCBA board; mounting the optical component onto the pads of the first PCBA board to obtain a second PCBA board; performing reflow soldering on the second PCBA board to obtain a third PCBA board, wherein the temperature change rate of the optical component during the reflow soldering process is less than 2°C / min; applying adhesive to the third PCBA board, with the application location located at the end of the optical component away from the fiber optic connector, to obtain a fourth PCBA board; and curing the adhesive to obtain a fifth PCBA board. This invention avoids deformation of the optical component and improves the packaging yield of the optical component.

Description

Technical Field

[0001] This invention generally relates to the field of microelectronic packaging technology. More specifically, this invention relates to a low-temperature surface-mount (SMT) packaging method for optical components. Background Technology

[0002] Microelectronic packaging encompasses the packaging and assembly of printed circuit boards (PCBs). It involves assembling components onto a PCB, including interconnecting packaged units and devices on the board, controlling impedance, fine-grained wiring, and using low-dielectric-constant materials. Examples include computer graphics cards and PCI data acquisition cards. A common technology for this type of packaging is surface mount technology (SMT), an assembly and production method that directly applies electronic components to the surface of a PCB. SMT eliminates the need for component insertion through holes; instead, it uses reflow soldering to directly solder components onto the board. The SMT process mainly includes three stages: solder paste printing: applying solder paste to the PCB pads to prepare for component soldering; component placement: accurately mounting the surface mount components to their designated positions on the PCB; and reflow soldering: melting the solder paste to firmly bond the surface mount components to the PCB.

[0003] Optical components are common parts used for fixing optical fibers. They connect optical signal transmitters to optical fibers or optical fibers to optical signal receivers, thus coupling optical signals. The optical components assembled on the PCBA board are shown below. Figure 3 As shown, the optical component has a fixed optical path and an interface for connecting optical fibers. Since the aperture of the interface connecting the optical fibers is on the micrometer scale, if existing SMT (Surface Mount Technology) is used for installation, heating may cause deformation of the optical path or interface, or even cracking of the outer casing. Furthermore, positional interference can easily occur between the optical component to be packaged and already packaged components. Newly added soldering material may overflow onto the already packaged components, causing interference. For example, when SMT processes are used to mount resistors, capacitors, chips, and other devices onto a PCB to form a PCBA (Printed Circuit Board Assembly), if an optical component needs to be packaged onto this PCBA, it is necessary to ensure that the optical component does not interfere with the resistors, capacitors, chips, etc., and that the soldering material used during the soldering process does not overflow onto other components.

[0004] In view of this, there is an urgent need to provide a method for low-temperature SMT packaging of optical components and PCBA boards in order to improve the yield of optical component packaging. Summary of the Invention

[0005] To address at least one or more of the technical problems mentioned above, this invention provides a low-temperature SMT packaging method for optical components, comprising: printing solder paste onto pads of a PCBA board to obtain a first PCBA board; mounting an optical component onto the pads of the first PCBA board to obtain a second PCBA board; performing reflow soldering on the second PCBA board to obtain a third PCBA board, wherein the temperature change rate of the optical component during the reflow soldering process is less than 2°C / min; applying adhesive to the third PCBA board, with the application location located at the end of the optical component away from the fiber optic connector, to obtain a fourth PCBA board; and curing the adhesive to obtain a fifth PCBA board.

[0006] According to one embodiment of the present invention, the reflow soldering process includes a preheating zone, a reaction zone, a soldering zone, and a cooling zone arranged sequentially. The preheating zone is used to preheat the solder paste on the PCBA board; the reaction zone is used to volatilize the flux in the solder paste, and the temperature change rate of the solder paste in the reaction zone is 1.0-2.0℃ / s; the soldering zone is used to melt the solder paste and perform soldering operations, and the temperature change rate of the solder paste in the soldering zone is 2.0-3.0℃ / s; the cooling zone is used to cool the solder paste.

[0007] According to one embodiment of the present invention, the temperature distribution area of ​​the reflow soldering includes ten temperature zones: a preheating zone including a first temperature zone, a reaction zone including second to fifth temperature zones, a soldering zone including sixth to ninth temperature zones, and a cooling zone including a tenth temperature zone. The temperature of the first temperature zone is the preheating temperature of the solder paste; the temperatures of the second to fifth temperature zones are increased by 6-12°C sequentially from the first temperature zone, and the temperature of the fifth temperature zone is the melting temperature of the solder paste; the temperatures of the sixth to ninth temperature zones are increased by 10-15°C sequentially from the fifth temperature zone; and the temperature of the tenth temperature zone is lower than the melting temperature of the solder paste.

[0008] According to one embodiment of the present invention, the peak temperature of the sixth to ninth temperature zones is 160-180°C.

[0009] According to one embodiment of the present invention, the temperature change rate of the second PCBA board is controlled by controlling the speed at which the second PCBA board passes through the first temperature zone to the tenth temperature zone.

[0010] According to one embodiment of the present invention, the solder paste has the following parameters: preheating temperature: 70-110°C; melting temperature: 110-130°C; soldering temperature: 160-180°C.

[0011] According to one embodiment of the present invention, in the fourth step, the adhesive has the following parameters: adhesive viscosity: 45-65 Pa·s, adhesive thixotropic index: 0.01-0.05.

[0012] According to one embodiment of the present invention, after the optical component is mounted onto the pad, the surface of the optical component and the mounting accuracy are detected.

[0013] According to one embodiment of the present invention, a reflow soldering fixture is used to support the second PCBA board, and a perforated metal cover is provided above the reflow soldering fixture to cover the second PCBA board.

[0014] According to one embodiment of the present invention, the reflow soldering fixture includes a carrier strip and a cover plate. The carrier strip has a groove. The cover plate is detachably embedded in the groove. The bottom of the groove is provided with a plurality of first through holes. The cover plate is provided with a plurality of second through holes corresponding to the first through holes. The size of the first through holes and the size of the second through holes are both smaller than the size of the second PCBA board, so that when the second PCBA board is mounted on the groove and the cover plate covers the second PCBA board, the first through holes avoid components on the lower surface of the PCBA board, and the second through holes avoid components on the upper surface of the PCBA board.

[0015] According to another aspect of the present invention, an optoelectronic module is provided, including a PCBA and an optical component, wherein the optical component is fixed on the PCBA by the aforementioned method.

[0016] In this invention, by setting the temperature change rate of the optical component during the reflow soldering process to less than 2°C / min, deformation of the optical component can be avoided, thus improving the packaging yield. Multi-temperature zone settings allow for controllable temperature change rates. Specific solder paste is used to achieve low-temperature SMT. The metal shield not only protects the optical component from deformation caused by hot air but also prevents it from being blown off-center during reflow soldering. The adhesive viscosity is set to prevent adhesive overflow onto the top of the optical component and other components. Clearance holes in the reflow soldering fixture protect the components on the PCBA board from interference during the packaging process. Attached Figure Description

[0017] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the invention are illustrated by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding parts, wherein:

[0018] Figure 1 A schematic diagram illustrating the steps of a low-temperature SMT packaging method for optical components is shown.

[0019] Figure 2 A schematic diagram of the light-absorbing assembly of the bonding head is shown;

[0020] Figure 3 A schematic diagram showing the mounting of optical components onto a PCBA board is shown;

[0021] Figure 4 A schematic diagram of a reflow soldering fixture carrying a PCBA board is shown. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be understood that the terms "comprising" and "including" as used in the specification and claims of this invention indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0024] It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this specification and claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0025] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0026] Figure 1 A schematic diagram of the steps of a low-temperature SMT packaging method for optical components is shown.

[0027] like Figure 1 As shown, the low-temperature SMT packaging method 100 for optical components includes: step S101, printing solder paste onto the pads of a PCBA board to obtain a first PCBA board. In this invention, the PCBA board is provided with other pre-installed components, pads for the optical components to be installed, etc.

[0028] Specifically, the PCBA board is placed on the loading platform and transported to the solder paste printing station via a conveyor belt. Machine vision identifies the positioning points of the PCBA board, and then a push rod lifts the board to align it with the stencil. Solder paste is then applied to the pads on the PCBA board where the optical components will be soldered, preparing for the soldering of the optical components. In the solder paste printing process of step S101, this invention provides a customized low-temperature solder paste with the following operating characteristics: preheating start temperature: 70-110℃, preheating end temperature: 110-130℃, preheating time: 70-110 seconds, and peak soldering temperature: 160-180℃. That is, the melting temperature of the solder paste is 110-130℃, and the soldering temperature is 160-180℃.

[0029] After printing solder paste on the pads, proceed to step S102 to mount the optical component onto the pads of the first PCBA board, thus obtaining the second PCBA board. In this invention, the optical component includes an optical coupling device, an intermediate layer, and pins. The optical coupling device is used to connect to the optical fiber, and it may deform or crack when heated. The intermediate layer is used to connect the pins and the optical coupling device, and it has poor thermal conductivity. The pins are used to connect to the PCBA to fix the optical component.

[0030] Specifically, Figure 2 A schematic diagram of the light-absorbing assembly of the bonding head is shown, such as... Figure 2 As shown, the process of accurately installing the optical component onto the fixed position of the PCBA mainly includes: the bonding head 202 picking up the optical component 201, machine vision identifying the positioning point on the PCBA, and mounting the optical component to the designated position to achieve alignment between the pins on the optical component and the PCBA.

[0031] Figure 3 A schematic diagram showing the mounting of optical components onto a PCBA board is shown, such as... Figure 3 As shown, the second PCBA board 300 has an optical component 201 mounted on it. Figure 3 The left side of the optical component is the fiber optic connector, and the right side is the part furthest from the fiber optic connector. After mounting, it is necessary to check whether the mounting accuracy meets the requirements and whether there is any damage on the surface of the optical component. Once the mounting accuracy and the surface inspection of the optical component meet the requirements, proceed to the next step S103.

[0032] In step S103, the second PCBA board is reflow soldered to obtain the third PCBA board. During the reflow soldering process, the temperature change rate of the optical component is less than 2℃ / min. The temperature change rate of the optical component is measured in two ways: First, by measuring the temperature of parts other than the pins, such as the optical coupler and intermediate layer. Second, by measuring the temperature of each part of the optical component and then calculating the average temperature.

[0033] Those skilled in the art will know that PCBA boards and solder paste have different thermal conductivity coefficients. Therefore, the temperature of the reflow oven can be controlled to meet both the temperature change rate of the optical components and the temperature change rate of the solder paste.

[0034] A reflow oven mainly consists of a preheating zone, a reaction zone, a soldering zone, and a cooling zone. The preheating zone is designed to heat the solder paste on the PCBA board, activating the active materials within it. The reaction zone allows the flux in the solder paste to fully evaporate; the temperature change rate in the reaction zone is 1.0-2.0℃ / s. The soldering zone melts the solder particles in the solder paste for soldering operations; the temperature change rate in the soldering zone is 2.0-3.0℃ / s. The cooling zone cools the solder joints.

[0035] In this invention, both the heating and cooling processes are controlled to maintain a temperature change rate of less than 2°C / min for the optical components. This prevents damage to the optical components caused by excessive temperature changes. For example, rapid temperature changes can deform the optical coupling devices, affecting the established optical path within the optical components and consequently impacting subsequent fiber coupling processes, leading to fiber coupling failure. The temperature change rate of less than 2°C / min set for the optical components in this invention effectively reduces these problems.

[0036] According to one embodiment of the present invention, the reflow soldering is subdivided into multiple temperature zones, and the temperature difference between each temperature zone is set to 6-12°C or 10-15°C.

[0037] According to one embodiment of the present invention, the temperature distribution area during the reflow soldering process is subdivided into ten temperature zones, from the first temperature zone to the tenth temperature zone. The temperature of the first temperature zone is the preheating temperature of the solder paste, where both the solder paste and the PCBA board are preheated simultaneously; the temperatures of the second to fifth temperature zones are increased by 6-12°C sequentially from the first temperature zone, corresponding to the reaction zone. The temperature range is primarily based on the reaction temperature of the solder paste flux. The temperature of the fifth temperature zone is the melting temperature of the solder paste, specifically ±15°C from the melting point of the solder paste. The temperatures of the sixth to ninth temperature zones are increased by 10-15°C sequentially from the fifth temperature zone, corresponding to the soldering zone. The temperature of the tenth temperature zone is lower than the soldering temperature of the solder paste, preferably ±10°C from the melting point of the solder paste, corresponding to the cooling zone.

[0038] By setting the temperature difference between each sub-temperature zone to 6-12℃ or 10-15℃, the rate of temperature change can be controlled at a low level, facilitating the control of the temperature change rate of the optical components. By controlling the speed at which the second PCBA board moves through each temperature zone—for example, the speed at which it moves from the first temperature zone to the tenth temperature zone—the rate of temperature change of the optical components located on the second PCBA board can be controlled. Simultaneously, the setting of ten temperature zones can better activate the active ingredients in the solder paste, resulting in more stable soldering quality.

[0039] According to one embodiment of the present invention, the peak temperature of the second PCBA board is controlled to be 160-180°C. For example, the peak temperatures of the sixth to ninth temperature zones are controlled to be 160-180°C. Because the optical components are small in size, excessively high peak temperatures are avoided to prevent damage to the optical components and deformation of the optical coupling devices caused by radiated heat.

[0040] According to one embodiment of the present invention, the third PCBA board after reflow soldering is also subject to sampling inspection. The optical components are visually inspected on an inspection platform to check for defects such as obvious deformation, displacement, or dirt; if any are found, they must be rejected. After visual inspection, the optical components are placed on a functional testing platform. Two tungsten carbide probes are connected to the positive and negative pads of the optical components, respectively. Then, a DC power supply is turned on to power the system, and the laser of the optical components is checked to see if it emits light normally. If it emits light normally, it proves that the optical component is properly soldered; otherwise, the soldering of the optical component is defective.

[0041] The soldered optical component is placed on a push-pull force testing platform. After leveling the third PCBA board, the optical component is pushed with a push pin until it is removed from the pads. The push force value fed back by the equipment is then read. If the push force value conforms to the shear force calculation formula F = Y × A, where F represents force, Y represents the shear strength of the material, and A represents the welding area of ​​the material, then the welding quality of the optical component is qualified. If it is lower, it indicates that the welding contact area is too small and there is misalignment between the optical component and the pads of the third PCBA board. This can be used to screen out unqualified third PCBA boards.

[0042] Table 1 shows a comparison of the effects of reflow soldering using the present invention and existing reflow soldering techniques.

[0043] Optical components and PCBA boards of the same type and batch were used as samples. The samples were divided into nine groups, with 10 samples in each group. Groups one through three underwent reflow soldering at the ten temperature zones of this invention; groups four through six underwent conventional reflow soldering; and groups seven through nine underwent high-temperature reflow soldering. Push-pull force tests were then conducted using the methods described above. The reflow soldering parameter ranges and average push-pull forces for each group are shown in Table 1.

[0044] Table 1.

[0045]

[0046]

[0047] It is evident that by employing the ten-zone reflow soldering and temperature control scheme of this invention, the soldering quality of optical components is significantly improved compared to ordinary reflow soldering.

[0048] Figure 4 A schematic diagram of a reflow soldering fixture carrying a PCBA board is shown.

[0049] In the third step S103, a reflow soldering fixture 400 is used to support the second PCBA board. This fixture is made of high-temperature resistant, high-density synthetic stone, ensuring good thermal conductivity and preventing displacement of the PCBA or optical components. It also suppresses heat radiation and conduction from both high-temperature and low-temperature objects, effectively ensuring temperature consistency among the components during soldering and reducing the impact of sudden temperature changes on soldering quality. Figure 4 As shown, the optical components and PCBA boards are placed in a specially designed reflow soldering fixture. The base of the fixture is made of high-temperature resistant, high-density synthetic stone, which helps to control the heating and cooling rate of the optical components to be less than 2℃ / min, preventing the optical components from cracking and deforming during heating and cooling.

[0050] like Figure 4 As shown, during the reflow soldering process of the second PCBA board, a perforated metal cover 410, preferably a stainless steel metal cover, is installed above the reflow soldering fixture to cover the second PCBA board. Before placing it in the reflow oven for reflow soldering, the metal cover 410 is placed on the second PCBA board 300, and the edge of the metal cover is engaged with the reflow soldering fixture 400. The metal cover has through holes, the positions of which do not overlap with the positions of the optical components, ensuring uniform heat distribution inside the reflow soldering fixture. The main purpose of this metal cover is to prevent the high-temperature hot air in the reflow oven from directly acting on the optical components during the reflow soldering process, which could cause deformation of the optocouplers. It also prevents the hot air in the reflow oven from blowing the optical components off-center, causing misalignment between the optical component pads and the PCBA board pads. With the metal cover, the hot air is blocked, preventing the optical components from being blown off-center. Furthermore, the through holes allow air to flow between the inside and outside of the metal cover, enabling even heat distribution.

[0051] like Figure 4As shown, according to one embodiment of the present invention, the reflow soldering fixture 400 includes a carrier strip 401 and a cover plate 402. The carrier strip 401 has a groove, and the bottom of the groove has a plurality of first through holes, each of which serves as a receiving position for a PCBA board. The first through holes can be arranged linearly or their arrangement can be adjusted according to different requirements. The cover plate 402 matches the shape of the groove and is detachably embedded in the groove. The cover plate 402 has a plurality of second through holes corresponding to the first through holes. The dimensions of the first and second through holes are both smaller than the dimensions of the second PCBA board, so that when the second PCBA board 300 is mounted on the groove and the cover plate 402 covers the second PCBA board 300, the first through holes avoid components on the lower surface of the second PCBA board 300, and the second through holes avoid components on the upper surface of the second PCBA board 300.

[0052] The cover plate 402 matching the shape of the groove means that the thickness of the cover plate 402 is the same as or slightly less than the depth of the groove, and the shape of the cover plate 402 is the same as the shape of the groove. When the cover plate 402 is placed in the groove, the periphery of the cover plate 402 abuts against the inner wall of the groove, thereby restricting the sliding of the cover plate 402. When the second PCBA board 300 is loaded between the cover plate 402 and the carrier strip 401, the upper surface of the cover plate 402 is flush with the edge of the groove.

[0053] The second PCBA board 300 is fixed between the cover plate 402 and the carrier strip 401. The carrier strip 401 supports the second PCBA board 300, and the cover plate 402 covers and presses the second PCBA board 300 for fixation. The first through hole is a clearance hole provided at the bottom of the groove to avoid components on the lower surface of the second PCBA board 300, and the second through hole is a clearance hole provided on the cover plate 402 to avoid components on the upper surface of the second PCBA board 300. Therefore, both the cover plate and the carrier strip are in contact with the PCBA board body, and fixation is achieved by clamping the PCBA board body.

[0054] During the reflow soldering process, the edge of the stainless steel metal cover contacts the edge of the carrier strip, covering the entire cover plate.

[0055] After the reflow soldering operation is completed, the process proceeds to the fourth step S104, the dispensing step, and the fifth step S105, the curing step, to further fix the optical components onto the third PCBA board.

[0056] In step S104, adhesive is applied to the third PCBA board, with the application location at the end of the optical component furthest from the fiber optic connector, resulting in the fourth PCBA board. Specifically, the third PCBA board is placed on an adhesive stacking fixture: adhesive is applied to the side of the optical component furthest from the fiber optic connector to ensure the optical component is well fixed to the PCBA. Then, in step S105, the adhesive between the fourth PCBA board and the optical component is cured. Specifically, when a thermosetting adhesive is used, the fourth PCBA board with adhesive is placed in an oven for thermosetting. After curing, the optoelectronic module is removed from the oven, resulting in the fifth PCBA board. When a UV adhesive is used, the fourth PCBA board with adhesive is irradiated with a UV optical fiber for curing, resulting in the fifth PCBA board.

[0057] In the fourth step S104, the adhesive's flowability meets the requirements for securing the optical component while limiting overflow. According to one embodiment of the invention, the adhesive viscosity is 45-65 Pa·s, and the thixotropic index is 0.01-0.05, preferably 48 Pa·s and 0.02. The adhesive is applied away from the fiber optic connector of the optical component to prevent overflow. Controlling the amount of adhesive applied prevents overflow onto the upper surface of the optical component and other components.

[0058] In step S105, during the thermosetting process of heating and curing the thermosetting adhesive, the thermal deformation of the adhesive can cause deviations in the optical component. This invention employs a specific thixotropic index to reduce the deformation of the optical component caused by adhesive curing. Furthermore, the curing temperature is lower than the deformation temperature of the optical component, further protecting it.

[0059] According to another aspect of the present invention, an optoelectronic module is provided, including a PCBA and an optical component, wherein the optical component is fixed on the PCBA using the aforementioned method.

[0060] In this invention, by setting the temperature change rate of the optical component during the reflow soldering process to less than 2°C / min, deformation of the optical component can be avoided, thus improving the packaging yield. Multi-temperature zone settings allow for controllable temperature change rates. Specific solder paste is used to achieve low-temperature SMT. The metal shield not only protects the optical component from deformation caused by hot air but also prevents it from being blown off-center during reflow soldering. The adhesive viscosity is set to prevent adhesive overflow onto the top of the optical component and other components. Clearance holes in the reflow soldering fixture protect the packaged components on the PCBA board from interference during the packaging process.

[0061] While numerous embodiments of the invention have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will occur to those skilled in the art without departing from the spirit and essence of the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in the practice of the invention. The appended claims are intended to define the scope of protection of the invention and therefore cover equivalents or alternatives within the scope of these claims.

Claims

1. A low-temperature SMT packaging method for optical components, characterized in that, include: Solder paste is printed onto the pads of the PCBA board to obtain the first PCBA board; The optical components are mounted onto the pads of the first PCBA board to obtain the second PCBA board; The second PCBA board is reflow soldered to obtain the third PCBA board, wherein the temperature change rate of the optical component during the reflow soldering process is less than 2℃ / min; The adhesive is applied to the third PCBA board, with the application position located at the end of the optical component away from the optical fiber connector, to obtain the fourth PCBA board. The adhesive is cured to obtain the fifth PCBA board; wherein... When the second PCBA board is reflow soldered, the reflow soldering process includes sequentially arranged preheating zone, reaction zone, soldering zone, and cooling zone processes. The preheating zone is used to preheat the solder paste on the PCBA board; The reaction zone is used to volatilize the flux in the solder paste, and the temperature change rate of the solder paste in the reaction zone is 1.0-2.0℃ / s; The soldering zone is used to melt solder paste for soldering operations, and the temperature change rate of the solder paste in the soldering zone is 2.0-3.0℃ / s; The cooling zone is used to cool the solder paste; and wherein... When the second PCBA board is reflow soldered, the temperature distribution area of ​​the reflow soldering includes ten temperature zones. The preheating zone includes a first temperature zone, the reaction zone includes second to fifth temperature zones, the welding zone includes sixth to ninth temperature zones, and the cooling zone includes a tenth temperature zone. The temperature of the first temperature zone is the preheating temperature of the solder paste; The temperatures of the second to fourth temperature zones are increased by 6-12℃ respectively from the first temperature zone. The temperature of the fifth temperature zone is the melting temperature of the solder paste; The temperatures of the sixth to ninth temperature zones are: 10-15℃ higher than those of the fifth temperature zone; The temperature of the tenth temperature zone is lower than the melting temperature of the solder paste.

2. The low-temperature SMT packaging method for optical components according to claim 1, characterized in that, The peak temperatures of the sixth to ninth temperature zones are 160-180℃.

3. The low-temperature SMT packaging method for optical components according to claim 1, characterized in that, When the second PCBA board is reflow soldered, the temperature change rate of the second PCBA board is controlled by controlling the speed at which the second PCBA board passes through the first temperature zone to the tenth temperature zone.

4. The low-temperature SMT packaging method for optical components according to any one of claims 1-3, characterized in that, The solder paste has the following parameters: Preheating temperature: 70-110℃; Melting temperature: 110-130℃; Welding temperature: 160-180℃.

5. The low-temperature SMT packaging method for optical components according to any one of claims 1-3, characterized in that, The adhesive has the following parameters: Adhesive viscosity: 45-65 Pa·s; Thixotropic index: 0.01-0.

05.

6. The low-temperature SMT packaging method for optical components according to any one of claims 1-3, characterized in that, When the optical component is installed onto the pad on the first PCBA board, the surface of the optical component and the mounting accuracy are detected after the optical component is installed onto the pad.

7. The low-temperature SMT packaging method for optical components according to any one of claims 1-3, characterized in that, When reflow soldering the second PCBA board, a reflow soldering fixture is used to support the second PCBA board. A perforated metal cover is provided above the reflow soldering fixture, and the metal cover covers the second PCBA board.

8. The low-temperature SMT packaging method for optical components according to claim 7, characterized in that, The reflow soldering fixture includes a carrier bar and a cover plate. The carrier strip has a groove; The cover plate is detachably embedded in the groove; The bottom of the groove is provided with a plurality of first through holes; The cover plate is provided with a plurality of second through holes corresponding to the first through hole; The dimensions of the first through hole and the second through hole are both smaller than the dimensions of the second PCBA board, so that when the second PCBA board is mounted on the groove and the cover plate covers the second PCBA board, the first through hole avoids the components on the lower surface of the PCBA board, and the second through hole avoids the components on the upper surface of the PCBA board.

9. A photoelectric module, characterized in that, It includes a PCBA and an optical component, wherein the optical component is fixed on the PCBA using the low-temperature SMT packaging method described in any one of claims 1-8.

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