CN112996285A

CN112996285A - Glue-blocking laminating method for multi-layer rigid PCB blind groove

Info

Publication number: CN112996285A
Application number: CN202110131654.8A
Authority: CN
Inventors: 戴银海; 陈彦青; 管美章; 朱忠翰; 江菊芳; 牛顺义; 邓健
Original assignee: Anhui Sun Create Electronic Co Ltd
Current assignee: Anhui Sun Create Electronic Co Ltd
Priority date: 2021-01-30
Filing date: 2021-01-30
Publication date: 2021-06-18

Abstract

The invention discloses a method for laminating a multi-layer rigid PCB blind slot glue-blocking layer, which is characterized in that a high-temperature-resistant glue-blocking layer is attached to a pattern surface exposed at the bottom of a correspondingly formed blind slot, a prepreg and a core plate are sequentially stacked above the glue-blocking layer, the surface of a circuit pattern at the bottom of the blind slot is protected by the glue-blocking layer after lamination, and no prepreg residual glue or volatile matter is adsorbed on the surface of the circuit pattern after the glue-blocking layer is removed, so that the circuit in the blind slot is protected from being corroded by processing liquid medicine and being scratched in the processing process for a long time in the external environment.

Description

Glue-blocking laminating method for multi-layer rigid PCB blind groove

Technical Field

The invention belongs to the technical field of printed circuit board manufacturing, and particularly relates to a glue-blocking laminating method for a blind groove of a multilayer rigid PCB.

Background

As the multifunctional printed circuit board is applied more and more, the density of components mounted on the PCB substrate is higher and higher, and the application requirement of the corresponding blind slot structure design is increased. In the field of printed circuit board manufacturing, the main way of realizing the blind slot structure is to use gasket pressing to resist glue, the relation between the blind slot depth and the gasket thickness needs to be strictly controlled by the glue resisting mode, the plate thickness uniformity of the printed circuit board subjected to multiple pressing, multiple chemical copper deposition and copper electroplating is different, and the thickness of the used gasket can be controlled only according to the deepest blind slot depth when the blind slot is selected for realizing the goal of completely resisting glue of the blind slot. If the thickness of the used gasket is lower than the depth of the blind groove, an insulating glue film is formed on the surface of the circuit pattern at the bottom of the blind groove due to the inflow of prepreg glue, and subsequent product reworking and even product scrapping are caused. If the thickness of the gasket is larger than the depth of the blind groove, the plate around the gasket is pressed less during pressing, and the irreversible serious quality problems such as layering and the like occur around the blind groove. In addition, if the PCB product is designed with blind grooves with single surface or double surfaces, multiple sizes, multiple shapes and multiple depths, the control difficulty of the lamination quality is obviously improved. And the embedded adhesive tape is adopted to resist the adhesive as the adhesive layer, so that the precision requirement of depth control operation of the equipment is reduced, and the qualification rate of the multilayer board is further improved.

Disclosure of Invention

The invention aims to provide a glue-blocking laminating method for a blind groove of a multilayer rigid PCB, which aims to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme:

a glue-blocking laminating method for blind grooves of a multilayer rigid PCB comprises the following specific steps:

the method comprises the following steps: laminating a plurality of core plates, prepregs and glue blocking layers in sequence to form a PCB;

step two: and C, forming a blind groove on the PCB in the first step, wherein the bottom surface of the blind groove is the surface of the glue resisting layer.

As a still further scheme of the invention: the PCB is a multilayer rigid printed circuit board, and the PCB is more than or equal to 4 layers.

As a still further scheme of the invention: the blind groove on the PCB is a single-sided blind groove or a double-sided blind groove or a groove-in-groove, and the blind groove is square, circular or special-shaped.

As a still further scheme of the invention: the pressing temperature of the glue resisting layer in the blind groove is less than or equal to 260 ℃.

As a still further scheme of the invention: the glue resisting layer is a high-temperature-resistant PI adhesive tape.

As a still further scheme of the invention: the thickness of the glue resisting layer is 0.05mm-0.1 mm.

As a still further scheme of the invention: the ratio of the sticking size of the glue resisting layer to the size of the blind groove is 1: 1.

As a still further scheme of the invention: the prepreg is placed at the bottom of the blind groove and is positioned on the glue resisting layer.

As a still further scheme of the invention: and windowing is not adopted at the joint corresponding position of the selected prepreg and the glue blocking layer.

As a still further scheme of the invention: the core board comprises a dielectric substrate and copper foil circuits arranged on two sides of the dielectric substrate.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the invention, after the glue blocking layer is laminated on the bottom circuit pattern of the blind slot, and the prepreg is not windowed and laminated, the core plate and the prepreg above the glue blocking layer are removed by a mechanical depth control milling operation mode, the glue blocking layer is exposed, and finally the circuit pattern at the bottom of the blind slot is exposed after the glue blocking layer is removed, so that additional processing procedures such as windowing of the prepreg can be reduced, and the production efficiency is improved;

2. the method can obtain the line graph without prepreg adhesive residue at the bottom of the blind groove, and avoid the damage to the line graph in the blind groove caused by the subsequent removal of the adhesive residue in the blind groove;

3. according to the invention, the processing of small-size, special-shaped blind grooves and groove-in-groove structures can be realized, and compared with the traditional gasket glue blocking process, the scheme can remarkably reduce the quality problems of poor glue blocking effect caused by the unmatched thickness of the gasket or layering caused by poor binding force at the periphery of the blind groove of the spot gasket.

Drawings

In order to facilitate understanding for those skilled in the art, the present invention will be further described with reference to the accompanying drawings.

Fig. 1 is a schematic diagram of a blind slot glue-blocking laminating structure in a multi-layer rigid PCB blind slot glue-blocking laminating method.

Fig. 2 is a schematic structural diagram of a multi-layer rigid PCB blind groove glue-blocking laminating method after the blind groove is opened by adopting depth control.

Fig. 3 is a schematic structural diagram of a multi-layer rigid PCB with a blind groove glue-blocking lamination method after removing a glue-blocking layer at the bottom of the blind groove.

In the figure: 1. a PCB board; 101. a blind groove; 2. a core board; 201. a dielectric substrate; 202. a copper foil circuit; 3. a prepreg; 4. glue resisting layer.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 to 3, in an embodiment of the present invention, a multi-layer rigid PCB blind slot glue-blocking lamination method includes the following specific steps:

the method comprises the following steps: laminating a plurality of core plates 2, prepregs 3 and glue blocking layers 4 to form a PCB 1;

step two: a blind groove 101 is formed in the PCB 1 in the first step, and the bottom surface of the blind groove 101 is the surface of the glue blocking layer 4; (ii) a

And after lamination, removing the part of the PCB above the glue resisting layer 4 by a depth-controlled milling operation mode to expose the glue resisting layer 4, and after removing the glue resisting layer 4, realizing the processing of the PCB with the blind groove 101 structure, and realizing the circuit pattern at the bottom of the blind groove 101 without the covering of the prepreg 3 residual glue and volatile matters.

The PCB board 1 is a multilayer rigid printed circuit board.

The blind groove 101 in the PCB 1 is a single-sided blind groove or a double-sided blind groove or a groove-in-groove, and the blind groove 101 is square, circular or special-shaped, so that the flexibility is high and the application range is wide.

The pressing temperature of the glue resisting layer 4 in the blind groove 101 is less than or equal to 260 ℃, and no glue residue exists after pressing at the temperature of 235 ℃ or below.

The glue resisting layer 4 is a high-temperature-resistant PI (polyimide) adhesive tape, and the thickness of the glue resisting layer 4 is 0.05mm-0.1 mm.

The ratio of the sticking size of the glue resisting layer 4 to the size of the blind groove 101 is 1:1, so that the glue resisting layer 4 is tightly attached to the blind groove.

The prepreg 3 is placed at the bottom of the blind groove 101 and is positioned on the glue resisting layer 4.

The joint corresponding position of the selected prepreg 3 and the glue blocking layer 4 does not adopt windowing treatment, and the production efficiency is favorably improved.

The core board 2 includes a dielectric substrate 201 and copper foil circuits 202 provided on both sides of the dielectric substrate 201.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes in the embodiments and/or modifications of the invention can be made, and equivalents and modifications of some features of the invention can be made without departing from the spirit and scope of the invention.

Claims

1. A glue-blocking laminating method for a multi-layer rigid PCB blind groove is characterized by comprising the following steps: the glue-blocking laminating method for the blind groove of the multilayer rigid PCB comprises the following specific steps:

the method comprises the following steps: laminating a plurality of core plates (2), prepregs (3) and glue resisting layers (4) in sequence to form a PCB (1);

step two: and (3) forming a blind groove (101) on the PCB (1) in the first step, wherein the bottom surface of the blind groove (101) is the surface of the glue resisting layer (4).

2. The blind slot glue-blocking laminating method for the multilayer rigid PCB as claimed in claim 1, wherein the PCB (1) is a multilayer rigid printed circuit board, and the number of layers of the PCB (1) is more than or equal to 4.

3. The method for glue-blocking lamination of the blind groove of the multilayer rigid PCB as claimed in claim 1, wherein the blind groove (101) on the PCB (1) is a single-sided blind groove or a double-sided blind groove or a groove-in-groove structure, and the shape of the blind groove (101) is square, circular or irregular.

4. The blind groove glue-blocking laminating method for the multilayer rigid PCB as claimed in claim 1, wherein the laminating temperature of the glue-blocking layer (4) in the blind groove (101) is less than or equal to 260 ℃.

5. The blind groove glue-blocking laminating method for the multilayer rigid PCB as claimed in claim 1, wherein the glue-blocking layer (4) is a high temperature-resistant PI tape.

6. The blind slot resist laminating method of the multilayer rigid PCB according to claim 1, wherein the thickness of the resist layer (4) is 0.05mm-0.1 mm.

7. The method for laminating the blind grooves of the multilayer rigid PCB according to claim 1, wherein the ratio of the adhering size of the glue resisting layer (4) to the size of the blind grooves (101) is 1: 1.

8. The method for laminating the blind slot glue-blocking layer of the multilayer rigid PCB according to claim 1, wherein the prepreg (3) is placed at the bottom of the blind slot (101) and is positioned on the glue-blocking layer (4).

9. The method for laminating the blind slot glue-blocking of the multilayer rigid PCB according to claim 8, wherein the joint corresponding position of the selected prepreg (3) and the glue-blocking layer (4) does not adopt windowing treatment;

the fluidity of the prepreg (3) is more than or equal to 2%.

10. The blind slot resist laminating method of the multilayer rigid PCB as claimed in claim 1, wherein the core board (2) comprises a dielectric substrate (201) and copper foil circuits (202) arranged on both sides of the dielectric substrate (201);

the dielectric substrate (201) is a rigid microwave dielectric substrate, a high-speed dielectric substrate or a digital transmission type dielectric substrate.