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CN-122028571-A - Die bonding method and die bonding system

CN122028571ACN 122028571 ACN122028571 ACN 122028571ACN-122028571-A

Abstract

The disclosure provides a die bonding method and a die bonding system, and belongs to the technical field of semiconductors. The die bonding method comprises the steps of providing a bearing film, wherein a plurality of chips are borne on the bearing film, electrodes of the chips are adhered to the bearing film, covering a flexible leveling film on one side of the chips, which is opposite to the bearing film, of the chips, keeping the flexible leveling film in a leveling and tensioning state, placing the chips covered with the flexible leveling film and the bearing film in a closed cavity, and vacuumizing the closed cavity to enable the surfaces of the chips and the flexible leveling film to be adsorbed together, so that the surfaces of the chips and the surfaces of the flexible leveling film to be adsorbed are in the same plane. The present disclosure may improve the yield of chips.

Inventors

  • HE WEIJIAN
  • CHEN YINAN
  • Zong yuan
  • YANG YU
  • CHEN JUN

Assignees

  • 京东方华灿光电(苏州)有限公司

Dates

Publication Date
20260512
Application Date
20251216

Claims (10)

  1. 1. The die bonding method is characterized by comprising the following steps of: providing a bearing film, wherein a plurality of chips are borne on the bearing film, and electrodes of the chips are adhered to the bearing film; Covering a flexible leveling film on one side of the plurality of chips, which is opposite to the bearing film, wherein the flexible leveling film is kept in a leveling and tensioning state; placing the plurality of chips covered with the flexible leveling film and the bearing film in a closed cavity; and vacuumizing the closed cavity to enable the flexible leveling films to be adsorbed with the surfaces of the chips, so that the chips and the surfaces of the flexible leveling films adsorbed by the flexible leveling films are in the same plane.
  2. 2. The die bonding method according to claim 1, wherein the flexible planarizing film is a polymer film.
  3. 3. The die bonding method according to claim 2, wherein the flexible flat film is one of a polyester film, a polyimide film, or a polyethylene film.
  4. 4. A die bonding method according to any one of claims 1 to 3, wherein the thickness of the flexible planarizing film is 0.1mm to 0.15mm.
  5. 5. A method of die bonding according to any one of claims 1 to 3, wherein said evacuating the closed cavity to adhere the flexible planarizing film to the surface of the chip comprises: and continuously pumping the air in the closed cavity until the pressure in the closed cavity is 150 mtorr-200 mtor.
  6. 6. The die bonding method according to claim 5, further comprising: After the flexible leveling film and the surfaces of the chips are adsorbed together, projecting light to the surfaces of the chips and the flexible leveling film adsorbed together; and judging whether the chips are positioned on the same plane or not according to the reflective images on the surfaces of the chips.
  7. 7. The die bonding method according to claim 6, wherein determining whether the plurality of chips are in the same plane according to the reflective image of the surface of the chip comprises: and if the average gray value of the reflective image of each chip and the gray standard deviation of each reflective image are smaller than the corresponding threshold value, the chips are positioned on the same plane.
  8. 8. The die bonding method according to any one of claims 1 to 3,6, and 7, wherein after the plurality of chips are in the same plane, the die bonding method further comprises: And respectively sucking the chips to corresponding positions of the circuit board through the die bonder.
  9. 9. The die bonding method according to any one of claims 1 to 3, 6 and 7, wherein the closed cavity is a rigid structural member having a cavity therein.
  10. 10. A die bonding system, the die bonding system comprising: the bearing unit is used for providing a bearing film, a plurality of chips are borne on the bearing film, and electrodes of the chips are adhered to the bearing film; the flexible leveling film is used for covering one side of the chip, which is opposite to the bearing film, and the flexible leveling film is kept in a leveling and tensioning state; And the airtight cavity is used for providing an airtight environment for the chips covered with the flexible leveling film and the bearing film, and is configured to enable the surfaces of the flexible leveling film and the chips to be adsorbed together after vacuumizing, so that the chips and the surfaces of the flexible leveling film to be adsorbed are in the same plane.

Description

Die bonding method and die bonding system Technical Field The disclosure belongs to the technical field of semiconductors, and in particular relates to a die bonding method and a die bonding system. Background In the process of die bonding of semiconductor packages, especially light emitting diode chips, a die bonder needs to take an image and position a chip through a Charge-Coupled Device (CCD) in a high-precision vision system to identify the precise position and electrode direction thereof, so as to guide a suction nozzle in the die bonder to perform precise pick-up and mounting. The stability and accuracy of the process directly determine the production efficiency and the product yield of the packaging link. In the related art, light emitting diode chips in the industry are shipped and provided to a packaging factory with the substrate facing upward. That is, before die bonding, the led chip needs to be flipped over after the substrate surface (usually the sapphire surface) of the chip is adsorbed, so that the electrode surface of the chip faces downward. The electrodes of the chip are then placed on the carrier film and immersed in the carrier film (i.e., a layer of adhesive coated blue film) to carry the chip. However, since the electrodes on the chip are often not symmetrically arranged about the geometric center of the chip, i.e. the electrodes have asymmetry on the chip, when the electrodes sink into the carrier film, the reaction forces suffered by each point are uneven, so that different areas of the chip generate different glue trapping depths. This phenomenon causes the same batch of chips to exhibit significant level differences on the carrier film. When a light source of the CCD in the die bonder irradiates on the surface of a chip with uneven height, uneven reflection and refraction can be generated due to the height difference, so that the acquired image is subjected to local overexposure, shadow or deformation, the identification capacity of the CCD is disturbed, the position or direction of the chip is abnormal, and the stability and the product yield of the die bonding process are greatly influenced. Disclosure of Invention The embodiment of the disclosure provides a die bonding method and a die bonding system, which can improve the yield of a light emitting diode chip. The technical scheme is as follows: The embodiment of the disclosure provides a die bonding method, which comprises the following steps: The method comprises the steps of providing a bearing film, wherein a plurality of chips are borne on the bearing film, electrodes of the chips are adhered to the bearing film, covering a flexible leveling film on one side of the chips, which is opposite to the bearing film, of the chips, keeping the flexible leveling film in a leveling and tensioning state, placing the chips covered with the flexible leveling film and the bearing film in a closed cavity, and vacuumizing the closed cavity to enable the surfaces of the chips and the flexible leveling film to be adsorbed together, so that the surfaces of the chips and the surfaces of the flexible leveling film to be adsorbed are in the same plane. In yet another implementation of the present disclosure, the flexible flat film is a polymeric film. In yet another implementation of the present disclosure, the flexible flat film is one of a polyester film, a polyimide film, or a polyethylene film. In yet another implementation of the present disclosure, the evacuating the closed cavity to allow the flexible planarizing film to adhere to the surface of the chip includes continuously pumping air from the closed cavity until the pressure of the closed cavity is 150 mtorr-200 mtor. In yet another implementation of the present disclosure, after the flexible planarizing film is adsorbed to the surfaces of the chips, light is projected to the surfaces of the chips and the flexible planarizing film, and reflected light intensity is detected, and whether the chips are in the same plane is determined according to the reflected light image of the surfaces of the chips. In still another implementation manner of the present disclosure, the determining whether the plurality of chips are in the same plane according to the reflective images of the surfaces of the chips includes determining that the plurality of chips are in the same plane if an average gray value of the reflective images of the chips and a gray standard deviation of the reflective images of the chips are less than a corresponding threshold. In yet another implementation of the present disclosure, after the chips are in the same plane, the die bonding method further includes: Sucking the chips on the same plane to the corresponding positions of the circuit board through a suction nozzle of the die bonder. In yet another implementation of the present disclosure, the closed cavity is a rigid structural member having a cavity therein. In another aspect, an embodiment of the present disclosure fu