Additive for improving photoresist stripping speed

Abstract

The invention discloses an additive for improving the stripping speed of a photoresist. The additive comprises the following components in parts by weight: 10 parts of a permeable surfactant, 20 parts of an emulsified surfactant, 10 parts of a solvent and 60 parts of water. On the premise that the use temperature and concentration of the film removing liquid are not increased, the additive has very strong seepage force, the speed of removing a photoresist from the surface of a PCB is increased, meanwhile, film scraps stripped by inorganic alkali are reduced, and the stripping speed and capability of the inorganic alkali film removing liquid can be remarkably improved.

Description

Technical Field

[0001] The invention relates to the field of circuit board cleaning agents, and in particular to an additive for improving the photoresist stripping speed. Background Art

[0002] With the rapid development of new energy vehicles, 5G communications and other industries, electronic products are shifting towards lightweight and miniaturization. As an indispensable basic component of electronic products, printed circuit boards (PCBs) have increasingly higher production process standards. The graphic transfer process is an important step in the PCB production process. Improving the stripping speed of photoresist can shorten the production cycle, improve production efficiency and reduce costs. The traditional stripping method usually uses inorganic alkalis such as potassium hydroxide or sodium hydroxide to strip the film. The disadvantage is that the stripped dry film area is large and it is easy to wrap around the equipment roller, which is not conducive to equipment maintenance and affects production efficiency. With the improvement of PCB production accuracy, many have begun to use organic alkalis such as amines as stripping liquids. The disadvantage is that they contain neurotoxin solvents, and the COD and NH3-N are high, which is harmful to the environment. The stripping speed is affected by many factors, including the chemical properties of the photoresist, the concentration of the stripping solution, temperature and time.

[0003] The photoresist stripping liquid accelerator for PCB is an additive designed to improve the efficiency and speed of the photoresist stripping process. Generally speaking, for inorganic alkali stripping liquid, increasing its concentration can increase the stripping speed, but at the same time, too high a concentration can cause problems such as discoloration of the board surface and attack on green paint. By adding this accelerator, the speed of removing photoresist from the PCB surface can be accelerated, and at the same time, the film scraps stripped by inorganic alkali can be reduced, which is suitable for higher-level processes, thereby improving production efficiency and reducing costs. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an additive for increasing the photoresist stripping speed.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solution: an additive for improving the photoresist stripping speed, comprising the following components in parts by weight: 5-15 parts of penetrating surfactant Emulsifying surfactant 10-30 parts Solvent 10-30 parts 40-70 parts of water.

[0006] Furthermore, the additive for increasing the photoresist stripping speed comprises the following components in parts by weight: 10 parts of penetrating surfactant 20 parts of emulsifying surfactant Solvent 10 parts 60 parts of water.

[0007] Adding surfactants can reduce the interfacial tension between the photoresist and the substrate, improve the permeability and wettability of the stripping solution, and thus increase the stripping speed.

[0008] Penetrating surfactants use non-ionic surfactants, such as polyoxyethylene ethers: HLB (hydrophile-lipophile balance) is 13-18.

[0009] Specifically, the penetrating surfactants are AEO, JFC, OP, NP and TX.

[0010] If too much solvent is added to a strong alkaline system, uneven dispersion may occur, so an emulsifier is added to form a more uniform environment. Its HLB value is 4-9, specifically a polyoxyethylene nonionic surfactant, whose polar group (hydrophilic part) is a hydroxyl group or ether bond, etc., and the non-polar group (lipophilic part) is a straight chain or branched alkyl group, etc.

[0011] Furthermore, the solvent is aromatic alcohol, aromatic ether or linear ether.

[0012] Adding an appropriate amount of solvent (aromatic alcohol, aromatic ethers, linear ethers, etc.) to the photoresist stripping solution can accelerate the swelling of the photoresist, improve the solubility of the photoresist, and thus accelerate the stripping process.

[0013] Specifically, it includes straight chain ethers such as diethylene glycol dimethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether and the like.

[0014] Specifically, the aromatic ether is anisole, benzyl alcohol, diphenyl ether or phenethyl ether.

[0015] The beneficial effects of the present invention are: 1) The additive of the present invention changes the microenvironment of the stripping solution, has a certain chemical dissolving effect, and more effectively destroys the photoresist structure, so that the dry film is cracked into fine insoluble particles, which are then washed off, thereby making KOH suitable for higher-order processes (finer line width and line spacing).

[0016] 2) The additive of the present invention contains an emulsifying and foam-suppressing surfactant, does not generate foam, and can suppress the foam generated during the spraying process.

[0017] 3) The main components of the product of the present invention are chain ethers: a. Its molecular structure is unique, with less steric hindrance, making it easier to penetrate into the dry film, swelling the plastic binder in the dry film components, causing the dry film to expand rapidly, and chemical reactions occur between the dry film and the copper surface, making the dry film fluffy and weakening the bonding force, and cooperating with KOH to make the dry film fall off rapidly.

[0018] 4) The penetrating surfactant contained in the present invention can further reduce the interfacial tension between the photoresist and the substrate, improve the permeability and wettability of the stripping solution, and thus increase the stripping speed; the stripping speed can be increased by about 20%. DETAILED DESCRIPTION

[0019] The technical solution of the present invention will be clearly and completely described below through specific implementation methods. Example 1

[0020] The additive for improving the photoresist stripping speed of this embodiment includes the following components in parts by weight: AEO-9 10 parts AEO-3 20 parts 10 parts of diethylene glycol propyl ether 60 parts water Example 2

[0021] The additive for improving the photoresist stripping speed of this embodiment includes the following components in parts by weight: AEO-9 10 parts JFC-3 18 servings 10 parts of benzyl alcohol 60 parts water Example

[0022] The additive for improving the photoresist stripping speed of this embodiment includes the following components in parts by weight: OP 7 copies JFC-3 19 parts Benzyl alcohol 8 parts 55 parts water Example 3

[0023] The additive for improving the photoresist stripping speed of this embodiment includes the following components in parts by weight: TX 10 copies JFC-3 16 parts 10 parts of diethylene glycol propyl ether 60 parts water Example 4

[0024] The additive for improving the photoresist stripping speed of this embodiment includes the following components in parts by weight: NP 10 parts JFC-3 18 servings 10 parts of diphenyl ether 60 parts water It can be seen from the above table that the stripping speed can be increased by about 20% by using the additive of the present invention.

[0025] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present invention, and such modifications or equivalent substitutions should also be deemed to fall within the protection scope of the technical solution of the present invention.

Claims

1. An additive for increasing the stripping speed of a photoresist, characterized in that: It includes the following components by weight: 5-15 parts of penetrating surfactant; 10-30 parts of emulsifying surfactant; 10-30 parts of solvent; 40-70 parts of water.

2. The additive for increasing the photoresist stripping speed according to claim 1, characterized in that: 10 parts of penetrating surfactant 20 parts of emulsifying surfactant Solvent 10 parts 60 parts of water.

3. The additive for improving the photoresist stripping speed according to claim 1, characterized in that: The penetrating surfactant is a nonionic surfactant.

4. The additive for increasing the photoresist stripping speed according to claim 1, characterized in that: The penetrating surfactants are AEO, JFC, OP, NP and TX.

5. The additive for increasing the photoresist stripping speed according to claim 4, characterized in that: The HLB of the penetrating surfactant is between 13 and 18.

6. The additive for increasing the photoresist stripping speed according to claim 1, characterized in that: The emulsifying surfactant is a polyoxyethylene nonionic surfactant, the polar group of which is a hydroxyl group or an ether bond, and the nonpolar group is a straight-chain or branched-chain alkyl group.

7. The additive for increasing the photoresist stripping speed according to claim 6, characterized in that: The HLB value of the emulsifying surfactant is between 4 and 9.

8. The additive for increasing the photoresist stripping speed according to claim 1, characterized in that: The solvent is aromatic alcohol, aromatic ether or linear ether.

9. The additive for increasing the photoresist stripping speed according to claim 1, characterized in that: The linear ethers include diethylene glycol dimethyl ether, diethylene glycol propyl ether or diethylene glycol butyl ether.

10. The additive for increasing the photoresist stripping speed according to claim 1, characterized in that: The aromatic ethers are anisole, benzyl alcohol, diphenyl ether or phenethyl ether.