Protection device for improving yellowing of white oil plug hole of PCB (printed circuit board) after passing through IR (infrared) furnace

Abstract

The utility model relates to the technical field of PCB (printed circuit board) processing protection devices, in particular to a protection device for improving yellowing of a white oil plug hole of a PCB after passing through an IR (infrared) furnace, which comprises a circuit board. Hole structures are formed in the four corners of the circuit board correspondingly, connecting assemblies are arranged in the hole structures correspondingly, each connecting assembly comprises a connecting rod, a top rod fixed to the top end of the connecting rod and a base plate arranged at the bottom end of the connecting rod, the top ends of the four top rods are sleeved with a protection plate, and through holes are formed in the four corners of the protection plate correspondingly. The top end of the ejector rod is sleeved with a locking nut, a positioning column is fixed to the bottom end of the base plate, the positioning column structure at the bottom end of the base plate can be used for conveniently inserting and fixing a circuit board and a structure protected outside, a resistor and other structures on the circuit board can be arranged at the bottom of a protection plate, and the protection plate can be clamped to the bottom of the ejector rod through a through hole. The top end (the joint of the connecting rod and the protective plate) of the connecting rod is finally limited and fixed through a locking nut, and circuit boards with different thicknesses can be fixedly connected.

Description

Technical Field

[0001] The utility model relates to the technical field of PCB board processing protection devices, and specifically relates to a protection device for improving the yellowing of the white oil plug holes on the PCB board when passing through the IR furnace. Background Art

[0002] As is well known, resin is essential as the framework of ink, especially important for the resin used in photosensitive solder mask white oil. The resin used in photosensitive solder mask ink (such as green oil, black oil, blue oil) is mostly modified from o-cresol novolac epoxy resin or bisphenol A epoxy resin. First, acrylic acid is grafted to introduce a photosensitive group double bond, and then an anhydride is grafted to introduce an alkali-developable group carboxyl group; the photosensitive solder mask white oil on the printed circuit board belongs to the photosensitive solder mask ink on the printed circuit board and has many common points with the photosensitive solder mask ink. Both are composed of resin, monomer, initiator, diluent, filler, color powder, and additives. The main difference lies in the different raw materials used.

[0003] The resin with this structure is prone to yellowing because the main body has a benzene ring structure, and the benzene ring structure is likely to generate free radicals under ultraviolet irradiation, forming a conjugated system with a chromophore group, and finally easily turning yellow. Content of the Utility Model

[0004] Technical Problem to be Solved

[0005] Aiming at the above-mentioned disadvantages of the existing technology, the utility model provides a protection device for improving the yellowing of the white oil plug holes on the PCB board when passing through the IR furnace, which can effectively solve the problem that the resin on the PCB board in the existing technology is prone to yellowing.

[0006] Technical Solution

[0007] To achieve the above purposes, the utility model is realized through the following technical solutions:

[0008] The utility model provides a protection device for improving the yellowing of the white oil plug holes on the PCB board when passing through the IR furnace, including a circuit board; holes are provided at the four corners of the circuit board, and connection components are arranged in the holes. The connection components include connecting rods, top rods fixed at the top ends of the connecting rods, and chassis arranged at the bottom ends of the connecting rods. Protection plates are sleeved on the top ends of the four groups of top rods. Through holes are provided at the four corners of the protection plates. Locking nuts are sleeved on the top ends of the top rods. Positioning columns are fixed at the bottom ends of the chassis. The material of the protection plate is aliphatic acrylic epoxy resin.

[0009] Furthermore, the diameter of the top rod is smaller than that of the connecting rod, and the inner diameter of the through hole is adapted to the diameter of the top rod; the connection components place the protection plate on the top of the circuit board. The connecting rods in the connection components can be used to sleeve the circuit board and are fixed and limited through the chassis.

[0010] Further, the inner diameter of the connecting rod is adapted to the diameter of the connecting rod; and the top end of the connecting rod (the connection part of the two) is finally fixed by a locking nut to limit and fix the protection plate, so as to fixedly connect circuit boards with different thicknesses.

[0011] Further, convex structures are fixed on the outer side walls at both ends of the positioning post.

[0012] Further, the ejector rod is of a threaded rod structure; the positioning post structure at the bottom end can facilitate the insertion and fixation of the circuit board and the protection from external structures, and structures such as resistors on the circuit board can be arranged at the bottom of the protection plate, and the protection plate can be clamped at the bottom of the ejector rod through a through hole.

[0013] Further, the initiator in the protection plate adopts 2,4,6-trimethylbenzoyl-diphenylphosphine oxide material, and the auxiliary agent adopts amine antioxidants and phenolic antioxidants.

[0014] Beneficial effects

[0015] The technical solution provided by the present utility model has the following beneficial effects compared with the known public technology:

[0016] 1. Through the connection component and the protection plate structure provided by the present utility model, the user can place the protection plate on the top of the circuit board through the connection component. The connecting rod in the connection component can be used to sleeve the circuit board and is fixed and limited by the chassis. The positioning post structure at its bottom end can facilitate the insertion and fixation of the circuit board and the protection from external structures, and structures such as resistors on the circuit board can be arranged at the bottom of the protection plate, and the protection plate can be clamped at the bottom of the ejector rod through a through hole. The top end of the connecting rod (the connection part of the two) is finally fixed by a locking nut to limit and fix the protection plate, so as to fixedly connect circuit boards with different thicknesses.

[0017] 2. The protection plate structure in this device uses an acrylate copolymer with epoxy groups, then grafts acrylic acid to introduce a photosensitive double bond group, and finally grafts an anhydride to introduce a base-developable carboxyl group. This base-developable resin with an acrylic structure is an aliphatic acrylic epoxy resin, and it is not easy to generate chromogenic groups under ultraviolet light or high temperature, so the anti-yellowing effect is relatively excellent. Moreover, most of the initiator systems currently used in photosensitive solder mask white oil are products that are not easy to turn yellow, such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (819). Especially TPO, which is a free radical type photoinitiator, is suitable for use in low-yellowing and white systems and has a photo-bleaching effect. The working principle of amine antioxidants is to capture peroxy free radicals to prevent or inhibit chain initiation reactions and chain growth reactions, thereby terminating the free radical chain reaction and achieving the purpose of preventing oxidation. In short, it achieves an anti-aging effect, such as p-phenylenediamine and phenothiazine. However, they are easily oxidized and discolored, so it is not easy to add them to photosensitive solder mask white oil. Phenolic antioxidants have the best effect when used in combination with auxiliary antioxidants. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 Structural schematic diagram of the present invention;

[0020] Figure 2 Side view of the structure of the present invention;

[0021] Figure 3 Structural schematic diagram of the connection component and the protection plate in the present invention;

[0022] Figure 4 For Figure 3 One of the structural split diagrams;

[0023] Figure 5 For Figure 3 The second of the structural split diagrams;

[0024] Figure 6 Structural schematic diagram of the connection component in the present invention

[0025] The reference numerals in the figures respectively represent: 1, circuit board; 2, connection component; 21, connecting rod; 22, chassis; 23, ejector rod; 24, locking nut; 25, positioning post; 3, protection plate; 31, through hole. Detailed implementation manners

[0026] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0027] The present utility model will be further described below with reference to the embodiments.

[0028] Embodiment: A protection device for improving the yellowing of the white oil plug holes of a PCB board when passing through an IR furnace. Refer to the attached Figure 1 - attached Figure 6 , including a circuit board 1; holes are provided at the four corners of the circuit board 1, and connection components 2 are arranged in the hole structures. The connection components 2 include connecting rods 21, top rods 23 fixed to the tops of the connecting rods 21, and chassis 22 arranged at the bottoms of the connecting rods 21. Protective plates 3 are sleeved on the tops of the four groups of top rods 23. Through holes 31 are provided at the four corners of the protective plates 3. Locking nuts 24 are sleeved on the tops of the top rods 23. Positioning columns 25 are fixed to the bottoms of the chassis 22. The material of the protective plates 3 is aliphatic acrylic epoxy resin;

[0029] The diameter of the top rod 23 is smaller than the diameter of the connecting rod 21, and the inner diameter of the through hole 31 is adapted to the diameter of the top rod 23. Through the structures of the connection components 2 and the protective plates 3 provided, the user can place the protective plates 3 on the top of the circuit board 1 through the connection components 2. The connecting rods 21 in the connection components 2 can be used to sleeve the circuit board 1 and are fixed and limited through the chassis 22. The positioning column 25 structure at the bottom end can facilitate the insertion and fixation of the circuit board 1 and the protection to the external structure. Structures such as resistors on the circuit board 1 can be arranged at the bottom of the protective plates 3. The protective plates 3 can be clamped on the bottom of the top rods 23 through the through holes 31. Finally, the top ends (the connection parts of the two) of the connecting rods 21 are limited and fixed by the locking nuts 24, and the circuit boards 1 with different thicknesses can be fixedly connected.

[0030] The inner diameter of the connecting rod 21 is adapted to the diameter of the connecting rod 21; convex structures are fixed on the outer side walls at both ends of the positioning post 25; the ejector rod 23 is a threaded rod structure; the inducer in the protection plate 3 uses 2,4,6-trimethylbenzoyl-diphenylphosphine oxide TPO material, and the auxiliary agent uses amine antioxidants and phenolic antioxidants. Among them, the adopted protection plate structure uses an acrylate copolymer with an epoxy group, then grafts acrylic acid to introduce a photosensitive group double bond, and finally grafts anhydride to introduce an alkali-developable group carboxyl group. This alkali-developable resin with an acrylic structure is an aliphatic acrylic epoxy resin, and it is not easy to generate a chromophore group under ultraviolet light or high temperature, so the anti-yellowing effect is relatively excellent. Moreover, most of the initiator systems currently used in photosensitive solder mask white oil are products that are not easy to turn yellow, such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (819). Especially TPO, it is a free radical type photoinitiator, suitable for use in low-yellowing and white systems, and has a photo-bleaching effect. The working principle of amine antioxidants is to capture peroxy free radicals to prevent or inhibit chain initiation reactions and chain growth reactions, thereby terminating the free radical chain reaction and achieving the purpose of preventing oxidation. In short, it achieves an anti-aging effect, such as p-phenylenediamine and phenothiazine. However, it is easy to be oxidized and discolored, and it is not easy to add in photosensitive solder mask white oil. The phenolic antioxidant has the best effect when used in combination with the auxiliary antioxidant.

[0031] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A protective device for improving the yellowing of white oil plug holes in PCB boards after passing through an IR furnace, characterized in that: The invention comprises a circuit board (1); the four corners of the circuit board (1) are provided with hole structures, and a connecting assembly (2) is arranged in each hole structure, the connecting assembly (2) comprises a connecting rod (21), a top rod (23) fixed to the top end of the connecting rod (21), and a bottom plate (22) arranged at the bottom end of the connecting rod (21), the top ends of the four groups of top rods (23) are sleeved with a protective plate (3), the four corners of the protective plate (3) are provided with a through hole (31), the top ends of the top rods (23) are sleeved with a locking nut (24), the bottom end of the bottom plate (22) is fixed with a positioning column (25), and the material of the protective plate (3) is aliphatic acrylic epoxy resin.

2. The protective device for improving the yellowing of white oil plug holes in PCB boards after passing through an IR furnace according to claim 1, characterized in that: The diameter of the push rod (23) is smaller than the diameter of the connecting rod (21), and the inner diameter of the through hole (31) is matched with the diameter of the push rod (23).

3. The protective device for improving the yellowing of white oil plug holes in PCB boards after passing through an IR furnace according to claim 1, characterized in that: The inner diameter of the connecting rod (21) is adapted to the diameter of the connecting rod (21).

4. The protective device for improving the yellowing of white oil plug holes in PCB boards after passing through an IR furnace according to claim 1, characterized in that: The outer side walls at both ends of the positioning column (25) are fixed with protruding structures.

5. The protective device for improving the yellowing of white oil plug holes in PCB boards after passing through an IR furnace according to claim 4, characterized in that: The top rod (23) is a threaded rod structure.

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