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CN-116908973-B - Low-temperature SMT packaging method of optical assembly and photoelectric module

CN116908973BCN 116908973 BCN116908973 BCN 116908973BCN-116908973-B

Abstract

The invention discloses a low-temperature SMT packaging method of an optical assembly and an optoelectronic module, wherein the low-temperature SMT packaging method comprises the steps of printing solder paste on a bonding pad of a PCBA board to obtain a first PCBA board. And mounting the optical component on a bonding pad of the first PCBA board to obtain a second PCBA board. And carrying out reflow soldering treatment on the second PCBA board to obtain a third PCBA board, wherein the temperature change rate of the optical component in the reflow soldering treatment process is less than 2 ℃ per minute. And coating glue on the third PCBA plate, wherein the coating position is positioned at one end of the optical assembly, which is far away from the optical fiber connection port, so as to obtain a fourth PCBA plate. And curing the glue to obtain a fifth PCBA board. In the invention, the deformation of the optical component can be avoided, and the packaging yield of the optical component can be improved.

Inventors

  • GUO XIAOLONG
  • JIANG HUI
  • TIAN KANG
  • LIU KAI

Assignees

  • 长芯盛（武汉）科技有限公司

Dates

Publication Date
20260505
Application Date
20230721

Claims (9)

  1. 1. A low temperature SMT packaging method for an optical component, comprising: Printing solder paste on a bonding pad of a PCBA board to obtain a first PCBA board; mounting an optical component on the bonding pad of the first PCBA board to obtain a second PCBA board; Carrying out reflow soldering treatment on the second PCBA board to obtain a third PCBA board, wherein the temperature change rate of the optical component in the reflow soldering treatment process is less than 2 ℃ per minute; Coating glue on the third PCBA board, wherein the coating position is positioned at one end of the optical assembly, which is far away from the optical fiber connection port, so as to obtain a fourth PCBA board; Curing the glue to obtain a fifth PCBA board, wherein, When the second PCBA board is subjected to reflow soldering treatment, the reflow soldering treatment comprises a preheating zone, a reaction zone, a welding zone and a cooling zone which are sequentially arranged, The preheating zone is used for preheating solder paste on the PCBA board; the reaction zone is used for volatilizing soldering flux in the solder paste, and the temperature change rate of the solder paste in the reaction zone is 1.0-2.0 ℃ per second; The welding area is used for melting solder paste, and the temperature change rate of the solder paste in the welding area is 2.0-3.0 ℃ per second; the cooling zone is used for cooling the solder paste, and wherein, When the second PCBA board is subjected to reflow soldering treatment, the temperature distribution area of reflow soldering comprises ten temperature areas, The preheating zone comprises a first temperature zone, the reaction zone comprises a second temperature zone to a fifth temperature zone, the welding zone comprises a sixth temperature zone to a ninth temperature zone, the cooling zone comprises a tenth temperature zone, The temperature of the first temperature zone is the preheating temperature of the solder paste; The temperatures of the second temperature zone to the fourth temperature zone are sequentially increased by 6-12 ℃ on the basis of the first temperature zone; The temperature of the fifth temperature zone is the melting temperature of the solder paste; the temperature of the sixth temperature zone to the ninth temperature zone is sequentially increased by 10-15 ℃ on the basis of the fifth temperature zone; The temperature of the tenth temperature zone is lower than the melting temperature of the solder paste.
  2. 2. The method of low temperature SMT packaging for an optical assembly of claim 1, The peak temperature of the sixth temperature zone to the ninth temperature zone is 160-180 ℃.
  3. 3. The method of low temperature SMT packaging for an optical assembly of claim 1, And when the second PCBA board is subjected to reflow soldering, controlling the temperature change rate of the second PCBA board by controlling the speed of the second PCBA board passing through the first temperature region to the tenth temperature region.
  4. 4. A method of low temperature SMT packaging for optical assemblies according to any one of claims 1-3 wherein, The solder paste has the following parameters: preheating at 70-110 ℃; the melting temperature is 110-130 ℃; the welding temperature is 160-180 ℃.
  5. 5. A method of low temperature SMT packaging for an optical assembly according to any one of claims 1-3 wherein, The glue has the following parameters: the viscosity of the glue is 45-65Pa.s, and the thixotropic index of the glue is 0.01-0.05.
  6. 6. A method of low temperature SMT packaging for an optical assembly according to any one of claims 1-3 wherein, When the optical component is mounted on the bonding pad of the first PCBA board, after the optical component is mounted on the bonding pad, the surface and mounting accuracy of the optical component are detected.
  7. 7. A method of low temperature SMT packaging for an optical assembly according to any one of claims 1-3 wherein, When the second PCBA board is subjected to reflow soldering, a reflow soldering jig is used for bearing the second PCBA board, a metal cover with holes is arranged above the reflow soldering jig, and the metal cover covers the second PCBA board.
  8. 8. The method of low temperature SMT packaging for an optical assembly of claim 7, The reflow soldering jig comprises a carrier bar and a cover plate, The carrier strip is provided with 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 hole and the size of the second through hole are smaller than the size of the second PCBA board, so that the second PCBA board is erected on the groove, and when 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 Kong Birang is the components on the upper surface of the PCBA board.
  9. 9. An optoelectronic module comprising a PCBA and an optical component, wherein the optical component is affixed to the PCBA using the low temperature SMT packaging method of any one of claims 1-8.

Description

Low-temperature SMT packaging method of optical assembly and photoelectric module Technical Field The present invention relates generally to the field of microelectronic packaging technology. More particularly, the present invention relates to a low temperature SMT packaging method for optical components. Background Microelectronic packages include packages and assemblies of printed circuit boards, which are assembled components onto Printed Circuit Boards (PCBs), including on-board packaging units and interconnections of devices, as well as control of impedance, fine-grained wiring, and low dielectric constant materials. Such as a display card of a computer, a PCI data acquisition card, etc., belong to such a package. A common technique for such packaging is Surface Mount Technology (SMT), which is an assembly and production method that applies electronic components directly to the surface of a Printed Circuit Board (PCB). SMT does not require the insertion of components through holes, but rather the direct soldering of components to the board by reflow soldering. The SMT process mainly comprises three stages, namely solder paste printing, solder paste leaking printing on a bonding pad of a PCB (printed Circuit Board) to prepare for welding of components, component placement, accurate installation of surface assembly components on fixed positions of the PCB, and reflow soldering, namely solder paste melting to firmly bond the surface assembly components and a PCB. The optical component is a common component for fixing an optical fiber, and is used for connecting an optical signal transmitting device with the optical fiber or connecting the optical fiber with an optical signal receiving device so as to realize the coupling of optical signals. The state of the optical component assembled on the PCBA board is shown in fig. 3, the optical component has a fixed optical path and an interface for connecting the optical fibers, and because the aperture of the interface for connecting the optical fibers is in the micron order, if the optical component is installed by adopting the existing SMT, the optical path or the interface of the optical component may be deformed or the shell may be cracked after being heated. Moreover, positional interference is likely to occur between the optical component to be packaged and the packaged component, and the newly added solder material may overflow to the packaged component, resulting in interference with the packaged component. For example, when devices such as a resistor and capacitor and a chip are attached to a PCB board through an SMT process to form a PCBA board, if an optical component needs to be packaged on the PCBA board, it needs to be ensured that the optical component does not interfere with the resistor and capacitor, the chip, etc., and a soldering material used in the soldering process cannot overflow onto other components. In view of the foregoing, there is a need for a method for low temperature SMT packaging of optical components and PCBA boards, so as to improve the yield of optical component packaging. Disclosure of Invention In order to at least solve one or more of the technical problems mentioned above, the invention provides a low-temperature SMT packaging method of an optical component, which comprises the steps of printing solder paste on a bonding pad of a PCBA board to obtain a first PCBA board, mounting the optical component on the bonding pad of the first PCBA board to obtain a second PCBA board, carrying out reflow soldering treatment on the second PCBA board to obtain a third PCBA board, wherein the temperature change rate of the optical component in the reflow soldering treatment process is less than 2 ℃ per minute, coating glue on the third PCBA board, wherein the coating position is positioned at one end of the optical component far from an optical fiber connector to obtain a fourth PCBA board, and curing the glue to obtain a fifth PCBA board. According to one embodiment of the invention, the reflow soldering treatment comprises a preheating zone, a reaction zone, a welding zone and a cooling zone which are sequentially arranged, wherein the preheating zone is used for preheating solder paste on a PCBA board, the reaction zone is used for volatilizing soldering flux in the solder paste, the temperature change rate of the solder paste in the reaction zone is 1.0-2.0 ℃ per second, the welding zone is used for melting the solder paste, the temperature change rate of the solder paste in the welding zone is 2.0-3.0 ℃ per second, and the cooling zone is used for cooling the solder paste. According to one embodiment of the invention, the temperature distribution area of reflow soldering comprises ten temperature areas, the preheating area comprises a first temperature area, the reaction area comprises a second temperature area to a fifth temperature area, the welding area comprises a sixth temperature area to a ninth temperature area, the cooling ar