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CN-122028327-A - Manufacturing method for preventing circuit board solder resist ink plug hole from overflowing

CN122028327ACN 122028327 ACN122028327 ACN 122028327ACN-122028327-A

Abstract

The invention relates to the technical field of circuit board processing, and discloses a manufacturing method for preventing oil spilling of a circuit board solder mask ink plug hole, which comprises the following steps of S1, preparing a substrate, and processing a via hole on the substrate; S2, forming electroplated copper on the via hole, S3, manufacturing an outer layer circuit on the surface of the substrate, S4, attaching a cover film on the surface of the substrate, bonding the cover film with the base copper through baking, S5, printing solder resist ink, firstly filling the solder resist ink into the via hole, and then printing the solder resist ink on the surface of the substrate, S6, pre-baking, performing primary hardening treatment on the solder resist ink on the substrate, exposing, transferring a pattern onto the solder resist ink on the surface of the substrate, developing, flushing the unexposed solder resist ink, exposing the base copper and windowing, retaining the exposed solder resist ink on the surface of the substrate, performing UV curing on the solder resist ink after the development of the surface of the substrate, and S7, post-baking to completely cure the thermal reaction of the solder resist ink. And the UV curing rapidly hardens and shapes the solder resist ink, so that oil spilling is effectively prevented.

Inventors

  • ZHANG JINFA
  • Zhu Bingguang
  • CHEN CHUNLONG

Assignees

  • 广州美维电子有限公司

Dates

Publication Date
20260512
Application Date
20260304

Claims (10)

  1. 1. The manufacturing method for preventing the solder mask ink plug hole of the circuit board from overflowing is characterized by comprising the following steps of: s1, preparing a substrate, and processing a via hole on the substrate; S2, forming electroplated copper in the via hole; S3, manufacturing an outer layer circuit on the surface of the substrate; S4, attaching a cover film on the surface of the substrate, and combining the cover film with the bottom copper through baking; S5, printing solder resist ink, firstly filling the solder resist ink into the through holes of the substrate, and then printing the solder resist ink on the surface of the substrate; s6, pre-baking, and performing primary hardening treatment on the solder resist ink on the substrate; Exposing, namely transferring the pattern to solder resist ink on the surface of the substrate; developing, flushing unexposed solder resist ink, exposing the copper base and windowing, and retaining the exposed solder resist ink on the surface of the substrate; UV curing, namely UV curing is carried out on the solder resist ink after the surface of the substrate develops; s7, post-baking to enable the solder resist ink on the substrate to be completely solidified through thermal reaction.
  2. 2. The method for preventing overflow of solder resist ink via of circuit board according to claim 1, wherein in the step S6 of UV curing, the UV energy is any size of 100-600 mj/cm 2 , and the UV power is any size of 2000-600W.
  3. 3. The method for preventing oil spilling in solder mask ink plug holes of circuit board according to claim 1, wherein in the step of UV curing in step S6, UV energy is 200-400 mj/cm 2 , and UV power is 2500-3500w.
  4. 4. The method for preventing overflow of solder resist ink via of circuit board according to claim 2 or 3, wherein in the step S6, UV speed is 4.0-5.0 m/min.
  5. 5. The method for preventing oil spilling in solder mask ink plug holes of circuit boards according to claim 1, wherein in step S7, the post baking time is any size of 50-60 min, and the post baking temperature is any size of 150-160 ℃.
  6. 6. The method for preventing overflow of solder resist ink through holes on a circuit board according to claim 1, wherein in the pre-baking step of step S6, the surface of the substrate printed with solder resist ink is left to stand upwards and put into an oven, the pre-baking time is any size of 30-40 min, and the pre-baking temperature is any size of 70-80 ℃.
  7. 7. The method for preventing overflow of solder resist ink via hole of circuit board according to claim 6, wherein the standing time is 0.25-4 h at the pre-baking stage of step S6.
  8. 8. The method according to claim 6 or 7, wherein in the exposure step of step S6, the resist DI exposure machine is used to expose the resist ink on the surface of the substrate to ultraviolet light, and the resist ink remaining on the substrate is subjected to a cross-linking reaction by exposure to transfer the pattern onto the resist ink on the surface of the substrate.
  9. 9. The method for preventing overflow of solder resist ink via of circuit board according to claim 1, wherein in step S2, the substrate is first subjected to shadow processing, and a graphite conductive layer is deposited on the wall of the via hole; hot-pressing and laminating dry films on the surfaces of two sides of the substrate; Exposing the dry film by using an exposure machine to perform a crosslinking reaction, transferring a hole plating pattern onto the dry film, and exposing the dry film at the position of the via hole; Dissolving the unexposed dry film by a developing machine to expose the bottom copper, so as to form an electroplating hole pattern; And carrying out pattern electroplating on the through holes of the substrate, and controlling the electroplated copper to a set thickness.
  10. 10. The method for preventing oil spill of a solder resist ink plug hole for a circuit board according to claim 1, wherein in step S4, plasma cleaning is performed after the cover film is combined with the base copper to remove contaminants and coarsen the surface of the substrate, and then the micro etching with super-coarsen liquid is performed to further remove oxides, grease and impurities on the surface of the substrate.

Description

Manufacturing method for preventing circuit board solder resist ink plug hole from overflowing Technical Field The invention relates to the technical field of circuit board processing, in particular to a manufacturing method for preventing oil spilling of a circuit board solder mask ink plug hole. Background In the production process of a flexible circuit board or a PCB, the solder mask ink plug hole refers to a process of filling and blocking a via hole on the circuit board by using solder mask ink. Through filling the solder resist ink into the via hole, the flatness of the board surface can be improved, and the welding short circuit is effectively prevented. At present, the existing flexible circuit board adopts a three-layer laminated board structure, the thickness of the board is 0.25mm, the copper plating process of the flexible circuit board requires pattern electroplating through holes, the aperture is 0.25mm, and the maximum thickness of electroplated copper (without bottom copper) is not more than 25 mu m. The solder resist process requires that the substrate is plugged and then the solder resist ink is printed, and the solder resist ink is used for single-sided manufacturing by TechniFlex LCL F/110G solder resist ink. Because of the limitation of space design distance, when surface solder resist ink is printed after hole plugging, part of ink can cover the bonding pad, so that the thickness of the solder resist ink in the hole plugging area is obviously thicker and reaches more than 30 mu m. During the high temperature of post bake, the solder resist ink in this area expands thermally and overflows from the solder resist fenestration edge to the bond pad, adversely affecting the bond pad size. Aiming at the problems, the sectional baking is carried out in the post-baking stage, and the post-baking time is prolonged by sectional heating. However, the temperature rise and the board baking time are long, the production efficiency is low, the cost is high, the risk of the expansion and contraction change of the circuit board is high, and the problem of overflow of the solder resist ink plug holes cannot be effectively solved by sectional baking only to relieve the overflow degree of the solder resist ink. Disclosure of Invention The invention aims to solve the technical problems that the post-baking stage has long temperature rise and board baking time, low production efficiency and high cost, the risk of expansion and contraction change of a circuit board is high, and the sectional baking only relieves the overflow degree of the solder resist ink, so that the problem of overflow of the solder resist ink plug holes can not be effectively solved. In order to solve the technical problems, the invention provides a technical scheme of a manufacturing method for preventing oil spilling of a circuit board solder mask ink plug hole, which comprises the following steps: the manufacturing method for preventing the solder mask ink plug hole of the circuit board from overflowing comprises the following steps: s1, preparing a substrate, and processing a via hole on the substrate; S2, forming electroplated copper in the via hole; S3, manufacturing an outer layer circuit on the surface of the substrate; S4, attaching a cover film on the surface of the substrate, and combining the cover film with the bottom copper through baking; S5, printing solder resist ink, firstly filling the solder resist ink into the through holes of the substrate, and then printing the solder resist ink on the surface of the substrate; s6, pre-baking, and performing primary hardening treatment on the solder resist ink on the substrate; Exposing, namely transferring the pattern to solder resist ink on the surface of the substrate; developing, flushing unexposed solder resist ink, exposing the copper base and windowing, and retaining the exposed solder resist ink on the surface of the substrate; UV curing, namely UV curing is carried out on the solder resist ink after the surface of the substrate develops; s7, post-baking to enable the solder resist ink on the substrate to be completely solidified through thermal reaction. Further, in the UV curing stage of step S6, the UV energy is of any size of 100-600 mj/cm 2, and the UV power is of any size of 2000-600W. Further, in the UV curing stage of step S6, the UV energy is of any size of 200-400 mj/cm 2, and the UV power is of any size of 2500-3500W. Further, in the UV curing stage of step S6, the UV speed is any magnitude of 4.0 to 5.0 m/min. Further, in step S7, the post-baking time is any size of 50 to 60 minutes, and the post-baking temperature is any size of 150 to 160 ℃. Further, in the pre-baking stage of the step S6, the surface of the substrate printed with the solder resist ink is placed upwards and placed into an oven, the pre-baking time is any size of 30-40 min, and the pre-baking temperature is any size of 70-80 ℃. Further, in the pre-baking stage of step S6, the standing time is an