阅读说明：本技术 一种选择性真空树脂塞孔工艺 (Selective vacuum resin hole plugging process ) 是由 王树波 司俊峰 柯小龙 马金山 文旭波 于 2021-07-28 设计创作，主要内容包括：本发明涉及线路板制作技术领域,具体是一种选择性真空树脂塞孔工艺。包括具体步骤如下：钻孔,基板钻孔时,钻有需要树脂塞孔的孔；镀铜,对基板进行沉铜、整板电镀加工；对基板进行OSP加工；步骤四：贴膜,对基板贴干膜；褪膜,可选用无机碱褪膜液或有机碱褪膜液进行褪膜；树脂塞孔,采用整板真空塞孔机以整板涂覆方式对褪膜后的基板进行树脂塞孔；研磨,完成树脂塞孔的基板进行烘烤,进行树脂研磨。本发明提供一种实现了高厚径比大小孔同步塞孔,解决了高厚径比大小孔同时塞孔的难点,且保证各种孔内塞孔饱满,没有气泡,孔口平整无凹陷,同时适用于不同孔径的PCB板选用不同褪膜时间的褪膜液的一种选择性真空树脂塞孔工艺。(The invention relates to the technical field of circuit board manufacturing, in particular to a selective vacuum resin hole plugging process. The method comprises the following specific steps: drilling, namely drilling holes needing resin to be plugged when the base plate is drilled; copper plating, namely performing copper deposition and whole-plate electroplating processing on the substrate; carrying out OSP processing on the substrate; step four: sticking a film, namely sticking a dry film to the substrate; film removing, namely selecting inorganic alkali film removing liquid or organic alkali film removing liquid for film removing; plugging holes with resin, namely plugging the stripped substrate with resin by adopting a whole-plate vacuum plugging machine in a whole-plate coating mode; and grinding, baking the substrate with the resin plug holes, and grinding the resin. The invention provides a selective vacuum resin hole plugging process which realizes synchronous hole plugging of large and small holes with high thickness-diameter ratio, solves the difficulty of simultaneously plugging the large and small holes with high thickness-diameter ratio, ensures that the holes in various holes are full, has no bubbles, has smooth and non-concave orifices, and is suitable for PCB boards with different apertures to select film stripping liquid with different film stripping time.)

1. A selective vacuum resin hole plugging process is characterized in that: the method comprises the following specific steps:

the method comprises the following steps: drilling, namely drilling holes needing resin to be plugged when the base plate is drilled;

step two: copper plating, namely performing copper deposition and whole-plate electroplating processing on the substrate;

step three: carrying out OSP processing on the substrate;

step four: sticking a film, namely sticking a dry film to the substrate;

step five: film removing, namely selecting inorganic alkali film removing liquid or organic alkali film removing liquid for film removing;

step six: plugging holes with resin, namely plugging the stripped substrate with resin by adopting a whole-plate vacuum plugging machine in a whole-plate coating mode;

step seven: and grinding, baking the substrate with the resin plug holes, and grinding the resin.

2. The process of claim 1, wherein said step of selectively vacuum resin plugging comprises: the reaction of the inorganic base film stripping liquid is as follows: na + OH^-+R¹COOH→R¹COO-Na⁺+H₂O。

3. The process of claim 1, wherein said step of selectively vacuum resin plugging comprises: the reaction of the organic base film stripping liquid is as follows: RNH₂+R¹COOH→R¹COO^-+RNH₃ ⁺。

4. The process of claim 1, wherein said step of selectively vacuum resin plugging comprises: the film removing process of the inorganic alkali film removing liquid and the organic alkali film removing liquid comprises the following steps:

s1: diffusion/expansion: small molecules in the film removing liquid are diffused into the dry film, and the dry film gradually expands;

s2: reaction: reacting alkaline groups in the film stripping solution with carboxylic acid groups in the dry film adhesive to generate salt substances dissolved in water;

s3: interfacial attack/lysis: the molecules of the basket membrane liquid continuously attack the joint of the copper/dry film, and the basket membrane liquid permeates into the interior of the dry film to react with the dry film, so that the internal stress is increased, and the dry film starts to crack;

s4: stripping: and continuously permeating the basketing liquid into the dry film, attacking the joint of the dry film and the copper surface until the binding force is lost, and finishing basketing by the dry film.

5. The process of claim 1, wherein said step of selectively vacuum resin plugging comprises: the substrate is an epoxy substrate screen printing plate.

6. The process of claim 1, wherein said step of selectively vacuum resin plugging comprises: the baking temperature is 75-140 ℃, and the baking time is 20-35 minutes.

7. The process of claim 1, wherein said step of selectively vacuum resin plugging comprises: the resin grinding adopts non-woven fabrics and ceramic brushes to carry out resin grinding on the substrate.

Technical Field

The invention relates to the technical field of circuit board manufacturing, in particular to a selective vacuum resin hole plugging process.

Background

The vertical interconnection of the traditional multilayer printed circuit board is mainly conducted and interconnected through a through hole, and the reliability of the through hole interconnection is the key of the long-term stable operation of the multilayer printed circuit board. Along with the high densification requirement of electronic products, the printed board via hole is designed to be smaller and smaller, the thickness-diameter ratio is higher and higher, and more printed boards adopt a cardia mesopore design, a buried hole design and the like. All of the above requirements require the treatment of via holes in the manufacturing process of printed boards, and the most common method is to perform resin hole plugging treatment. The resin hole plugging process mainly comprises the modes of roll coating, extrusion, screen printing and the like at present, and the modes of plugging holes have the characteristics, but all the modes have the problems of plugging holes, sinking of orifice resin and tight combination of the resin and copper after the resin is plugged. Especially for PCB boards with various apertures with high thickness-diameter ratio, because the pressure required for plugging the holes by the large and small holes is different, the existing process adopts small pressure and multi-cutter plugs, and is easy to generate the bad phenomena of holes in the holes, resin sinking at the orifices and the like, and the adoption of the large and small holes for plugging the holes step by step has low production efficiency and high production cost.

Disclosure of Invention

The invention provides a selective vacuum resin hole plugging process which realizes synchronous hole plugging of large and small holes with high thickness-diameter ratio, solves the difficulty of simultaneously plugging the large and small holes with high thickness-diameter ratio, ensures that the holes in various holes are full, has no bubbles, has smooth and non-concave orifices, and is suitable for PCB boards with different apertures to select film stripping liquid with different film stripping time.

The technical scheme adopted by the invention is as follows: a selective vacuum resin hole plugging process is characterized in that: the method comprises the following specific steps:

the method comprises the following steps: drilling, namely drilling holes needing resin to be plugged when the base plate is drilled;

step two: copper plating, namely performing copper deposition and whole-plate electroplating processing on the substrate;

step three: carrying out OSP processing on the substrate;

step four: sticking a film, namely sticking a dry film to the substrate;

step five: film removing, namely selecting inorganic alkali film removing liquid or organic alkali film removing liquid for film removing;

step six: plugging holes with resin, namely plugging the stripped substrate with resin by adopting a whole-plate vacuum plugging machine in a whole-plate coating mode;

step seven: and grinding, baking the substrate with the resin plug holes, and grinding the resin.

The reaction of the inorganic base film stripping liquid is as follows: na + OH^-+R¹COOH→R¹COO-Na⁺+H₂O。

The reaction of the organic base film stripping liquid is as follows: RNH₂+R¹COOH→R¹COO^-+RNH₃ ⁺。

The film removing process of the inorganic alkali film removing liquid and the organic alkali film removing liquid comprises the following steps:

s1: diffusion/expansion: small molecules in the film removing liquid are diffused into the dry film, and the dry film gradually expands;

s2: reaction: reacting alkaline groups in the film stripping solution with carboxylic acid groups in the dry film adhesive to generate salt substances dissolved in water;

s3: interfacial attack/lysis: the molecules of the basket membrane liquid continuously attack the joint of the copper/dry film, and the basket membrane liquid permeates into the interior of the dry film to react with the dry film, so that the internal stress is increased, and the dry film starts to crack;

s4: stripping: and continuously permeating the basketing liquid into the dry film, attacking the joint of the dry film and the copper surface until the binding force is lost, and finishing basketing by the dry film.

The substrate is an epoxy substrate screen printing plate.

The baking temperature is 75-140 ℃, and the baking time is 20-35 minutes.

The resin grinding adopts non-woven fabrics and ceramic brushes to carry out resin grinding on the substrate.

The invention has the beneficial effects that:

the invention realizes the synchronous hole plugging of the large and small holes with high thickness-diameter ratio, solves the difficulty of simultaneously plugging the large and small holes with high thickness-diameter ratio, ensures that the holes are fully plugged in various holes, has no bubbles, has smooth and non-sunken holes, and is suitable for PCB boards with different apertures to select film stripping liquid with different film stripping time; the epoxy substrate screen printing plate etches away the copper foil after the epoxy substrate is drilled, the orifice is smooth, the phenomenon of peak blocking does not exist, and the manufacturing method is the same as the aluminum sheet screen printing plate, the manufacturing method can be repeatedly used, the service life is longer than that of the aluminum sheet screen printing plate, the one-time hole plugging yield is more than 96%, and the one-time manufacturing cost is about 2-3 times of that of the aluminum sheet screen printing plate; the redundant resin can be adhered to the position of the plate surface without resin hole plugging by sticking the dry film; the film stripping time difference of different dry films is larger, when the dry films are the same in thickness, the dry film with short film stripping time is preferred, and for the circuit board with larger pit depth, different film stripping liquids can be clearly selected.

Detailed Description

A selective vacuum resin hole plugging process is characterized in that: the method comprises the following specific steps:

the method comprises the following steps: drilling, namely drilling holes needing resin to be plugged when the base plate is drilled;

step two: copper plating, namely performing copper deposition and whole-plate electroplating processing on the substrate;

step three: carrying out OSP processing on the substrate; OSP liquid medicine adopts four nationally-formed F2(LX) PLUS;

step four: the film is pasted, a dry film is pasted on the substrate, and redundant resin can be pasted on the position, where the plate surface does not need to be plugged with the resin hole, of the plate surface through pasting the dry film;

step five: film removing, namely selecting inorganic alkali film removing liquid or organic alkali film removing liquid for film removing;

step six: plugging holes with resin, namely plugging the stripped substrate with resin by adopting a whole-plate vacuum plugging machine in a whole-plate coating mode;

step seven: and grinding, baking the substrate with the resin plug holes, and grinding the resin.

The reaction of the inorganic base film stripping liquid is as follows: na + OH^-+R¹COOH→R¹COO-Na⁺+H₂O。

The reaction of the organic base film stripping liquid is as follows: RNH₂+R¹COOH→R¹COO^-+RNH₃ ⁺。

The film removing process of the inorganic alkali film removing liquid and the organic alkali film removing liquid comprises the following steps:

s1: diffusion/expansion: small molecules in the film removing liquid are diffused into the dry film, and the dry film gradually expands;

s2: reaction: the alkaline group in the film stripping liquid reacts with the carboxylic acid group in the dry film adhesive to generate salt substances dissolved in water, and diffusion and expansion are accelerated along with the reaction;

s3: interfacial attack/lysis: the molecules of the basket membrane liquid continuously attack the joint of the copper/dry film, and the basket membrane liquid permeates into the interior of the dry film to react with the dry film, so that the internal stress is increased, and the dry film starts to crack;

s4: stripping: and continuously permeating the basketing liquid into the dry film, attacking the joint of the dry film and the copper surface until the binding force is lost, and finishing basketing by the dry film.

The main difference between the inorganic base stripping liquid and the organic base stripping liquid is represented by the difference between the diffusion speed and the expansion and rupture speed of the dry film.

The substrate is an epoxy substrate screen printing plate.

The baking temperature is 75-140 ℃, and the baking time is 20-35 minutes.

The resin grinding adopts non-woven fabrics and ceramic brushes to carry out resin grinding on the substrate.

The invention realizes the synchronous hole plugging of the large and small holes with high thickness-diameter ratio, solves the difficulty of simultaneously plugging the large and small holes with high thickness-diameter ratio, ensures that the holes are fully plugged in various holes, has no bubbles, has smooth and non-sunken holes, and is suitable for PCB boards with different apertures to select film stripping liquid with different film stripping time; the epoxy substrate screen printing plate etches away the copper foil after the epoxy substrate is drilled, the orifice is smooth, the phenomenon of peak blocking does not exist, and the manufacturing method is the same as the aluminum sheet screen printing plate, the manufacturing method can be repeatedly used, the service life is longer than that of the aluminum sheet screen printing plate, the one-time hole plugging yield is more than 96%, and the one-time manufacturing cost is about 2-3 times of that of the aluminum sheet screen printing plate; the redundant resin can be adhered to the position of the plate surface without resin hole plugging by sticking the dry film; the film stripping time difference of different dry films is larger, when the dry films are the same in thickness, the dry film with short film stripping time is preferred, and for the circuit board with larger pit depth, different film stripping liquids can be clearly selected.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.