CN-122028321-A - Solder resist stamp-pad ink process for ultra-thick copper circuit board

CN122028321ACN 122028321 ACN122028321 ACN 122028321ACN-122028321-A

Abstract

The application discloses a solder resist printing ink process for an ultra-thick copper circuit board, and relates to the technical field of printed circuit board manufacturing. The process comprises the steps of obtaining line distribution data of an ultra-thick copper circuit board, dividing the surface of the ultra-thick copper circuit board into a line copper layer area and a non-line substrate area based on a partition priority strategy, adopting ink jet printing equipment to spray-print first solder resist ink in the non-line area in a partition mode, regulating ink stacking and thickness through multistage partition and spray-printing mode to realize efficient coverage of the side wall of the copper layer and high leveling filling of the substrate, carrying out staged pre-baking after spray-printing, printing second solder resist ink on the whole surface through screen printing to form a composite solder resist structure, and finally solidifying. The application effectively solves the problems of difficult coverage of the ultra-thick copper PCB solder mask on the high side wall, low production efficiency, poor quality consistency and other industry pain points. The coating property and leveling property of the solder resist ink are improved, the process period is shortened, and the production efficiency is improved.

Inventors

FANG ANDING
ZHAO CHAOGANG
CHEN GUOXING

Assignees

惠州市聚真电路板有限公司

Dates

Publication Date: 20260512
Application Date: 20260309

Claims (10)

1. A solder resist printing oil process for an ultra-thick copper circuit board is characterized by comprising the following steps of: Obtaining line distribution data of an ultra-thick copper circuit board, and dividing the surface of the ultra-thick copper circuit board into a line copper layer area and a non-line base material area according to the line distribution data; Using an ink jet printing device to jet-print first solder resist ink on the non-circuit substrate area according to a preset partition priority strategy so as to form a first solder resist layer; pre-baking and curing the first solder mask layer; And (3) screen printing second solder resist ink on the surfaces of the first solder resist layer and the circuit copper layer area to form a second solder resist layer, and performing post-curing treatment.
2. The ultra-thick copper circuit board solder mask ink process of claim 1, wherein said using an inkjet printing apparatus to jet print a first solder mask ink on said non-circuit substrate area according to a preset zone priority strategy to form a first solder mask layer comprises: performing secondary partition treatment on the non-circuit substrate region, and dividing the non-circuit substrate region into an edge transition region adjacent to the edge of the circuit copper layer region and a flat filling region far away from the circuit copper layer region; controlling the ink-jet printing equipment to jet-print the first solder resist ink in the edge transition area in a first jet-printing mode so as to form a climbing-shaped ink stack on the side wall of the circuit copper layer; Standing for a preset time; And controlling the ink-jet printing equipment to jet-print the first solder resist ink in the second jet-printing mode in the flat filling area.
3. The ultra-thick copper circuit board solder-mask ink process of claim 2, wherein said controlling said inkjet printing apparatus to jet said first solder-mask ink in a first jet pattern at said edge transition region further comprises, before: Scanning the surface of the ultra-thick copper circuit board to obtain the inclination angle of the side wall of the circuit copper layer area; the controlling the inkjet printing apparatus to jet-print the first solder resist ink in the edge transition region in a first jet-print mode includes: and adjusting the ink jet density of the first jet printing mode according to the inclination angle.
4. The ultra-thick copper circuit board solder resist ink process of claim 3, wherein said adjusting the ink jet density of said first ink jet pattern according to said tilt angle comprises: When the inclination angle shows that the side wall of the circuit copper layer area is of an inverted trapezoid structure, controlling the ink jet printing equipment to jet ink at a first ink jet density; when the inclination angle shows that the side wall of the circuit copper layer area is of an outward-expanding trapezoid structure, controlling the ink jet printing equipment to jet ink at a second ink jet density; Wherein the first ink jet density is greater than the second ink jet density.
5. The ultra-thick copper circuit board solder-mask ink process of claim 1, wherein said using an inkjet printing apparatus to jet-print a first solder-mask ink on said non-circuit substrate area according to a preset zone priority strategy to form a first solder mask layer, further comprising: Scanning the surface of the ultra-thick copper circuit board to obtain the foreign matter information of the non-circuit substrate area, wherein the foreign matter information comprises a foreign matter protrusion position and a foreign matter protrusion height corresponding to the foreign matter protrusion position; the method for forming the first solder mask layer by using the ink jet printing equipment to jet-print the first solder mask ink on the non-circuit substrate area according to a preset partition priority strategy comprises the following steps: When the spray head of the ink jet printing equipment passes through the position of the foreign matter protrusion, controlling the ink jet printing equipment to reduce the ink jet quantity according to the corresponding height of the foreign matter protrusion so as to maintain the surface flatness of the first solder mask layer.
6. The ultra-thick copper circuit board solder mask ink process of claim 1, wherein said using an inkjet printing apparatus to jet print a first solder mask ink on said non-circuit substrate area according to a preset zone priority strategy to form a first solder mask layer comprises: Acquiring copper thickness data of the circuit copper layer area; Obtaining the number of spray printing layers according to the copper thickness data, the preset single-layer spray printing thickness data and the target filling thickness; Selecting a preset number of ultra-thick copper circuit boards as test boards; completing the step of pre-baking and curing the first solder mask layer for the test board; Measuring the actual ink thickness of the first solder mask layer on the test board; comparing the actual ink thickness with the target filling thickness to obtain thickness difference information; and adjusting the number of the spray printing layers according to the thickness difference information. And controlling the ink-jet printing equipment to jet-print the first solder resist ink in the non-circuit substrate area according to a preset partition priority strategy until the number of jet printing times of the ink-jet printing equipment reaches the number of jet printing layers.
7. The ultra-thick copper circuit board solder mask ink process of claim 1, wherein said using an inkjet printing apparatus to jet print a first solder mask ink on said non-circuit substrate area according to a preset zone priority strategy to form a first solder mask layer comprises: Monitoring the temperature and viscosity of the first solder resist ink in real time; when at least one of the temperature and the viscosity exceeds a preset range, starting a temperature regulating device to regulate the temperature of an ink storage tank and a spray head of the ink-jet printing equipment; And monitoring the state of the spray hole at the spray head of the ink jet printing equipment in real time, and automatically executing a preset cleaning program if a spray hole blocking signal is detected.
8. The ultra-thick copper circuit board solder resist process of claim 6, wherein the target fill thickness is 80% to 85% of the copper thickness data.
9. The ultra-thick copper circuit board solder mask ink process of claim 1, wherein the first solder mask ink is a photo-curable solder mask ink and the second solder mask ink is a thermosetting solder mask ink, and wherein the first solder mask ink is yellow in color after curing to mask the color of the non-circuit substrate area and enhance the color development effect of the second solder mask ink.
10. The ultra-thick copper circuit board solder resist ink process of claim 6, wherein said controlling said inkjet printing apparatus to jet said first solder resist ink in said non-circuit substrate area according to a preset zone priority strategy until the number of jet printing passes reaches said number of jet printing layers comprises: And under the condition that the inkjet printing equipment performs the last inkjet printing of the first solder resist ink, controlling the inkjet printing equipment to improve the roughness of the inkjet printing so as to improve the adhesion degree between the second solder resist layer and the first solder resist layer.

Description

Solder resist stamp-pad ink process for ultra-thick copper circuit board Technical Field The application relates to the technical field of printed circuit board manufacturing, in particular to a solder resist stamp-pad ink process for an ultra-thick copper circuit board. Background With the continuous pursuit of high power, high current carrying capacity and heat dissipation performance of electronic products, ultra-thick copper Printed Circuit Boards (PCBs) are widely used in the fields of electric power, automobiles, high-end industrial control and the like. The thickness of copper foil of the traditional PCB is generally not more than 2 ounces, but with miniaturization and integration of high-power devices, the requirement on the thickness of copper in the board is continuously improved, the thickness of copper layer is promoted to be continuously increased, and a so-called ultra-thick copper circuit board is formed. In the preparation process of the ultra-thick copper PCB, the formation of the solder mask is a key link for guaranteeing the subsequent welding quality, electrical insulation performance and reliable operation. However, the special circuit structure of the ultra-thick copper circuit board brings serious challenges to the subsequent solder mask manufacturing process. Because of the extremely thick circuit copper layer, a huge height difference exists between the surface of the circuit copper layer and the non-circuit substrate area. In the conventional solder mask manufacturing process, the solder mask ink is generally directly applied by adopting a full-screen printing mode. In the face of the huge drop brought by ultra-thick copper lines, the traditional screen printing process is difficult to ensure that the ink can be completely and densely filled to the depth of a line gap, and the defects of bubbles, hollows (false coverage) or serious uneven thickness of the ink are easily generated at the root of a copper layer or in a line dense area. If the thickness of the printing ink is simply increased to cover the copper layer with high thickness, the ink in the non-circuit area is too thick, so that the problems of non-drying during pre-baking, difficulty in exposure and development, easiness in side etching, breakage of a solder resist bridge and the like are caused, and the electrical insulation reliability of the circuit board and the yield of a final product are seriously affected. Therefore, how to effectively solve the problems of difficult filling, bubble residue, poor surface flatness and the like caused by huge height difference in the solder mask manufacturing of the ultra-thick copper circuit board, develop a solder mask process capable of taking the filling effect, the binding force and the production efficiency into consideration, and the technical problem to be solved in the current PCB manufacturing field is urgent. Disclosure of Invention The present application aims to solve at least one of the technical problems existing in the prior art. Therefore, the application provides a solder mask printing oil process for an ultra-thick copper circuit board, which can improve the bonding force, the surface flatness and the electrical insulation reliability of a solder mask layer of the ultra-thick copper circuit board. The ultra-thick copper circuit board solder mask printing ink process comprises the steps of obtaining circuit distribution data of an ultra-thick copper circuit board, dividing the surface of the ultra-thick copper circuit board into a circuit copper layer area and a non-circuit substrate area according to the circuit distribution data, using an ink jet printing device to jet-print first solder mask ink on the non-circuit substrate area according to a preset partition priority strategy so as to form a first solder mask, conducting pre-baking and solidification on the first solder mask, conducting screen printing of second solder mask ink on the surfaces of the first solder mask and the circuit copper layer area so as to form a second solder mask, and conducting post-solidification treatment. The ultra-thick copper circuit board solder mask printing ink process at least has the advantages that firstly, line distribution data are acquired, a board surface is accurately divided into a line copper layer area and a non-line substrate area, a data basis is provided for subsequent fixed-point sizing, on the basis, first solder mask ink is accurately printed on the non-line substrate area by using an ink jet printing device according to a preset partition priority strategy, the filling advantages of an ink jet printing technology on micro areas and deep gaps are exerted, a first solder mask layer is constructed in the gaps of the ultra-thick copper circuit, therefore, the huge height drop between a substrate and the ultra-thick copper circuit is effectively filled, the board surface plays a role of 'pre-leveling', then, the first solder mask layer is subjected to pre-baking so