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CN-121972459-A - Composite structure cleaning device and method

CN121972459ACN 121972459 ACN121972459 ACN 121972459ACN-121972459-A

Abstract

The invention discloses a cleaning device and a cleaning method for a composite structure, which relate to the field of electronic packaging and micro-nano manufacturing. The femtosecond laser and the continuous laser spot realize a specific spatial matching relationship, wherein the continuous laser is positioned at the center of the femtosecond laser and occupies only 1/4-1/10 of the femtosecond laser. The cleaning method comprises the steps of formulating different cleaning strategies aiming at the difference of the absorptivity, the thermal conductivity and the ablation threshold value of different materials of the multilayer composite structure based on the synergistic effect of the composite laser, adopting the composite laser for cleaning the material with high ablation threshold value, and adopting the single femtosecond laser for cleaning the material with low ablation threshold value. Through the accurate control of the matching relation between the composite laser light spot and the space and the laser cleaning path, the low-damage and high-precision limited-area cleaning is realized, and meanwhile, the cleaning efficiency is improved.

Inventors

  • WU LEI
  • ZHANG GUOYONG
  • YAN DEJIN
  • JIA YAOPING
  • LI JUNHUA

Assignees

  • 中国电子科技集团公司第十研究所

Dates

Publication Date
20260505
Application Date
20260121

Claims (10)

  1. 1. The composite structure cleaning device is characterized by comprising a femtosecond laser, a femtosecond low-power beam expander, a beam combiner, a continuous laser high-power beam expander, a focusing mirror and a controller; The device comprises a femtosecond laser, a continuous laser, a beam combining lens, a focusing lens, a laser spot and a laser spot, wherein the femtosecond laser is used for emitting femtosecond laser, the femtosecond laser is transmitted to the beam combining lens after being expanded by the femtosecond low-power beam expanding lens, the continuous laser is used for emitting continuous laser, the continuous laser is transmitted to the beam combining lens after being expanded by the continuous laser high-power beam expanding lens, the beam combining lens is used for combining the expanded femtosecond laser and the continuous laser to the same light path and focusing the same light path on a region to be cleaned through the focusing lens, wherein the focused light spots of the femtosecond laser and the continuous laser have a space matching relationship, the continuous laser spot is positioned at the center position of the femtosecond laser spot, and the diameter of the continuous laser spot is smaller than that of the femtosecond laser spot.
  2. 2. The composite structure cleaning device according to claim 1, wherein the diameter of a focusing light spot of the continuous laser after being expanded by the continuous laser high-power beam expander is 5-10 μm, the diameter of a focusing light spot of the femtosecond laser after being expanded by the femtosecond low-power beam expander is 20-50 μm, and the continuous laser light spot accounts for 1/4-1/10 of the femtosecond laser light spot.
  3. 3. The composite structure cleaning device of claim 1, wherein the controller is configured to: And controlling the femtosecond laser and the continuous laser so that in the cleaning process, the outermost ring of the to-be-cleaned area is processed by single femtosecond laser, and the spot repetition position of the to-be-cleaned area is processed by composite laser of continuous laser and femtosecond laser.
  4. 4. A method of cleaning a composite structure using the apparatus of claim 1, the method comprising: based on the synergistic effect of the composite lasers, a finite field cleaning strategy is prepared for ablation thresholds of different materials of the multilayer composite structure; for materials with high ablation threshold, performing compound laser cleaning by adopting the femtosecond laser and the continuous laser; And for materials with low ablation threshold values, performing single-femtosecond laser cleaning by using the femtosecond laser.
  5. 5. The method for cleaning a composite structure according to claim 4, wherein the femtosecond laser has a wavelength of 1000-1100 nm, a pulse width of 150-250 fs, a frequency of 600-800 kHz, a power of 4-20W and a spot diameter of 40-50 μm.
  6. 6. The method for cleaning a composite structure according to claim 4, wherein the wavelength of the continuous laser is 1000-1100 nm, the power is 50-300W, and the spot diameter is 20-30 μm.
  7. 7. The method for cleaning a composite structure according to claim 4, wherein the scanning speed of the femtosecond laser and the continuous laser is 2500-4000 mm/s.
  8. 8. The method of claim 4, wherein the scanning path is an outer circle zigzag spiral track during the composite laser cleaning process.
  9. 9. The method of claim 4, wherein during the single femtosecond laser cleaning, the scanning path adopts an outer circle back-shaped spiral track, and the inner circle adopts a 90-degree cross path.
  10. 10. The method of claim 4, wherein the material with a high ablation threshold comprises a gold/copper metal layer or a polymer layer, and the material with a low ablation threshold comprises a solder layer.

Description

Composite structure cleaning device and method Technical Field The invention relates to the field of electronic packaging and micro-nano manufacturing, in particular to a device and a method for cleaning a composite structure. Background The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. In the field of electronic component manufacturing/packaging and the like, cleaning of the surface of a multilayer composite structure (for example, hole cutting treatment is required to be performed on a chip mounting position after micro-strip soldering, and overflowed solder is also required to be removed) is a very critical process link, and is also a process link for restricting production automation and production efficiency of electronic equipment. The quality of the cleaning directly affects the mounting effect of the subsequent chips and the performance and reliability of the whole module/equipment. As a novel cleaning technology, the laser cleaning has the advantages of high cleaning precision, non-contact, no pollution and the like. However, for a multilayer composite structure, due to the difference of the absorptivity and the thermal conductivity of different materials to laser, single laser cleaning is difficult to meet the cleaning requirements of different layers of materials, and the materials are easily damaged in the cleaning process, so that the performance and the service life of a device are affected. Therefore, there is an urgent need for a method that can achieve low damage and efficient domain-limited cleaning of composite structures. Disclosure of Invention The invention aims to solve the problems in the prior art and provides a device and a method for cleaning a composite structure, which can realize low-damage and high-precision limited-area cleaning and improve cleaning efficiency by accurately controlling the matching relation between a composite laser spot and a space and a laser cleaning path. The technical scheme of the invention is as follows: A cleaning device for a composite structure comprises a femtosecond laser, a femtosecond low-power beam expander, a beam combiner, a continuous laser high-power beam expander, a focusing lens and a controller; The device comprises a femtosecond laser, a continuous laser, a beam combining lens, a focusing lens, a laser spot and a laser spot, wherein the femtosecond laser is used for emitting femtosecond laser, the femtosecond laser is transmitted to the beam combining lens after being expanded by the femtosecond low-power beam expanding lens, the continuous laser is used for emitting continuous laser, the continuous laser is transmitted to the beam combining lens after being expanded by the continuous laser high-power beam expanding lens, the beam combining lens is used for combining the expanded femtosecond laser and the continuous laser to the same light path and focusing the same light path on a region to be cleaned through the focusing lens, wherein the focused light spots of the femtosecond laser and the continuous laser have a space matching relationship, the continuous laser spot is positioned at the center position of the femtosecond laser spot, and the diameter of the continuous laser spot is smaller than that of the femtosecond laser spot. Further, the diameter of a focusing light spot of the continuous laser after being expanded by the continuous laser high-power beam expander is 5-10 mu m, the diameter of a focusing light spot of the femtosecond laser after being expanded by the femtosecond low-power beam expander is 20-50 mu m, and the continuous laser light spot accounts for 1/4-1/10 of the femtosecond laser light spot. Further, the controller is configured to: And controlling the femtosecond laser and the continuous laser so that in the cleaning process, the outermost ring of the to-be-cleaned area is processed by single femtosecond laser, and the spot repetition position of the to-be-cleaned area is processed by composite laser of continuous laser and femtosecond laser. The invention also provides a method for cleaning the composite structure, which uses the device, and comprises the following steps: based on the synergistic effect of the composite lasers, a finite field cleaning strategy is prepared for ablation thresholds of different materials of the multilayer composite structure; for materials with high ablation threshold, performing compound laser cleaning by adopting the femtosecond laser and the continuous laser; And for materials with low ablation threshold values, performing single-femtosecond laser cleaning by using the femtosecond laser. Further, the wavelength of the femtosecond laser is 1000-1100 nm, the pulse width is 150-250 fs, the frequency is 600-800 kHz, the power is 4-20W, and the spot diameter is 40-50 μm. Further, the wavelength of the continuous laser is 1000-1100 nm, the power is 50-300W, and the spot diameter is 20-30 mu m. Fu