阅读说明：本技术 抗电磁干扰电路板及其制作方法 (Anti-electromagnetic interference circuit board and manufacturing method thereof ) 是由 李卫祥 于 2019-10-10 设计创作，主要内容包括：本发明涉及一种抗电磁干扰电路板,其包括：电路基板、形成在电路基板表面的绝缘胶层及形成在绝缘胶层表面的电磁屏蔽层,所述电路基板包括基材层及至少位于基材层其中一个表面的导电线路层；所述基材层表面形成有凹部；所述绝缘胶层填充所述凹部及包覆所述导电线路层,且所述绝缘胶层的厚度不大于所述凹部的深度,以使所述电磁屏蔽层覆盖所述导电线路层的与所述绝缘胶层接触的端缘。本发明还涉及一种抗电磁干扰电路板的制作方法。(The invention relates to an anti-electromagnetic interference circuit board, which comprises: the electromagnetic shielding circuit comprises a circuit substrate, an insulating glue layer formed on the surface of the circuit substrate and an electromagnetic shielding layer formed on the surface of the insulating glue layer, wherein the circuit substrate comprises a base material layer and a conductive circuit layer at least positioned on one surface of the base material layer; a concave part is formed on the surface of the base material layer; the insulating glue layer fills the concave part and coats the conducting circuit layer, and the thickness of the insulating glue layer is not larger than the depth of the concave part, so that the electromagnetic shielding layer covers the end edge of the conducting circuit layer, which is in contact with the insulating glue layer. The invention also relates to a manufacturing method of the anti-electromagnetic interference circuit board.)

1. A manufacturing method of an anti-electromagnetic interference circuit board is characterized by comprising the following steps:

providing a circuit substrate, wherein the circuit substrate comprises a substrate layer and a conductive circuit layer at least positioned on one surface of the substrate layer, and the conductive circuit layer comprises a plurality of conductive circuit patterns which are spaced from each other;

forming a plurality of concave parts on the surface of the base material layer;

forming an insulating glue layer on the surfaces of the substrate layer and the conductive circuit layer, wherein the insulating glue layer fills the plurality of concave parts and wraps the conductive circuit layer, and the thickness of the insulating glue layer is not more than the depth of the concave parts; and

and forming an electromagnetic shielding layer on the surface of the insulating adhesive layer, wherein the electromagnetic shielding layer covers the periphery of the bottom end of the conductive circuit layer, which is in contact with the insulating adhesive layer.

2. The method of claim 1, further comprising forming a protective layer on the surface of the electromagnetic shielding layer.

3. The method of claim 1, wherein the depth of the recess is between 0.1 microns and 3 microns.

4. The method for manufacturing an anti-electromagnetic interference circuit board of claim 1, wherein the insulating glue layer is formed by coating liquid ink or epoxy resin on the surfaces of the substrate layer and the conductive circuit layer and then curing the liquid ink or epoxy resin.

5. The method for manufacturing an anti-electromagnetic interference circuit board of claim 1, wherein the electromagnetic shielding layer is a copper foil or a copper layer formed by sputtering or chemical deposition or a coated conductive adhesive.

6. The method for manufacturing an anti-electromagnetic interference circuit board of claim 2, wherein the passivation layer is a prepreg laminated on the surface of the electromagnetic shielding layer or a solder mask layer formed by coating.

7. An anti-electromagnetic interference circuit board, comprising: the electromagnetic shielding circuit comprises a circuit substrate, an insulating glue layer formed on the surface of the circuit substrate and an electromagnetic shielding layer formed on the surface of the insulating glue layer, wherein the circuit substrate comprises a base material layer and a conductive circuit layer at least positioned on one surface of the base material layer; the method is characterized in that: a concave part is formed on the surface of the base material layer; the insulating glue layer fills the concave part and coats the conducting circuit layer, and the thickness of the insulating glue layer is not larger than the depth of the concave part, so that the electromagnetic shielding layer covers the bottom end periphery of the conducting circuit layer, which is in contact with the insulating glue layer.

8. The EMI resistant circuit board of claim 7 wherein said recess has a depth of between 0.1 and 3 microns.

9. The anti-electromagnetic interference circuit board of claim 8, wherein the insulating glue layer is ink or epoxy resin.

10. The anti-electromagnetic interference circuit board of claim 9, wherein the electromagnetic shielding layer is a copper layer or a conductive adhesive or an aluminum layer.

Technical Field

The invention relates to the technical field of circuit boards, in particular to an anti-electromagnetic interference circuit board and an anti-electromagnetic interference circuit board manufactured by the method.

Background

When a common electronic device works, because of intermittent or continuous changes of operating voltage and current, an internal electronic component of the electronic device often generates electromagnetic radiation energy with a certain frequency, and the electromagnetic radiation energy is radiated to the surrounding environment, so that interference is caused to an adjacent electronic component, and even the adjacent electronic component cannot work normally. Furthermore, as the quality of the middle and high-order consumer electronic products is higher, the electromagnetic shielding requirement is higher and higher.

An Electromagnetic Shielding Film (ESF) used in the prior art can only protect the noise between the PCB and external electronic components, but the noise between the conductive traces inside the PCB cannot be isolated.

Disclosure of Invention

In view of the above, it is desirable to provide an emi circuit board and an emi circuit board manufactured by the method.

A manufacturing method of an anti-electromagnetic interference circuit board comprises the following steps:

providing a circuit substrate, wherein the circuit substrate comprises a base material layer and a conductive circuit layer which is at least positioned on one surface of the base material layer;

forming a plurality of concave parts on the surface of the base material layer;

forming an insulating glue layer on the surfaces of the substrate layer and the conductive circuit layer, wherein the insulating glue layer fills the concave part and wraps the conductive circuit layer, and the thickness of the insulating glue layer is not more than the depth of the concave part; and

and forming an electromagnetic shielding layer on the surface of the insulating adhesive layer, wherein the electromagnetic shielding layer covers the end edge of the conductive circuit layer, which is in contact with the insulating adhesive layer.

In a preferred embodiment, the method further comprises forming a protective layer on the surface of the electromagnetic shielding layer.

In a preferred embodiment, the depth of the recess is between 0.1 and 3 microns.

In a preferred embodiment, the insulating glue layer is formed by coating liquid ink or epoxy resin on the surfaces of the substrate layer and the conductive circuit layer and then curing the liquid ink or epoxy resin.

In a preferred embodiment, the electromagnetic shielding layer is a pasted copper foil or a metal copper layer formed by sputtering or chemical deposition or a coated conductive adhesive.

In a preferred embodiment, the protective layer is a prepreg laminated on the surface of the electromagnetic shielding layer or a solder mask formed by coating.

The invention also relates to an anti-electromagnetic interference circuit board, comprising:

an anti-electromagnetic interference circuit board, comprising: the electromagnetic shielding circuit comprises a circuit substrate, an insulating glue layer formed on the surface of the circuit substrate and an electromagnetic shielding layer formed on the surface of the insulating glue layer, wherein the circuit substrate comprises a base material layer and a conductive circuit layer at least positioned on one surface of the base material layer; a concave part is formed on the surface of the base material layer; the insulating glue layer fills the concave part and coats the conducting circuit layer, and the thickness of the insulating glue layer is not larger than the depth of the concave part, so that the electromagnetic shielding layer covers the end edge of the conducting circuit layer, which is in contact with the insulating glue layer.

In a preferred embodiment, a protective layer is formed on a surface of the electromagnetic shielding layer.

In a preferred embodiment, the depth of the recess is between 0.1 and 3 microns.

In a preferred embodiment, the insulating glue layer is ink or epoxy.

In a preferred embodiment, the electromagnetic shielding layer is a copper layer or a conductive glue or an aluminum layer.

Compared with the prior art, the manufacturing method of the anti-electromagnetic interference circuit board and the anti-electromagnetic interference circuit board manufactured by the method provided by the invention have the advantages that the concave part is formed in the substrate layer, the insulating adhesive layer is filled on the surfaces of the concave part and the conductive circuit layer, and when the electromagnetic shielding layer is formed on the surface of the insulating adhesive layer, the side surface of the conductive circuit included in the conductive circuit layer is completely covered by the electromagnetic shielding layer, so that the electromagnetic interference generated among the conductive circuits included in the circuit board is avoided, and the quality of the transmission signals of the circuit board is improved.

Drawings

Fig. 1 is a cross-sectional view of a circuit board according to the present invention.

Fig. 2 is a sectional view of a recessed portion formed on the surface of a base material layer included in a circuit board.

Fig. 3 is a cross-sectional view of an insulating glue layer formed on the surface of the substrate layer and the conductive circuit layer.

Fig. 4 is a cross-sectional view of the electromagnetic shielding layer formed on the basis of fig. 3.

Fig. 5 is a cross-sectional view of the anti-electromagnetic interference circuit board obtained after a protective layer is formed on the surface of the electromagnetic shielding layer.

Description of the main elements

Anti-electromagnetic interference circuit board	100
		Circuit board	10
Insulating glue layer	20
		Electromagnetic shielding layer	30
Protective layer	40
		Substrate layer	11
Conductive circuit layer	12
		Concave part	110
Conductive circuit pattern	120
		First surface	32
Second surface	122
		Upper surface of	101
Lower surface	102

The following detailed description will further illustrate the invention in conjunction with the above-described figures.

Detailed Description

The following will explain the anti-electromagnetic interference circuit board and the manufacturing method thereof provided by the present invention in detail with reference to the drawings and the embodiments.

The invention relates to a method for manufacturing an anti-electromagnetic interference circuit board 100, which comprises the following steps:

the first step is as follows: referring to fig. 1, a circuit board 10 is provided, where the circuit board 10 includes a substrate layer 11 and a conductive circuit layer 12 located on at least one surface of the substrate layer 11. Of course, the circuit substrate 10 may also be a multilayer substrate, and the multilayer substrate may include a plurality of resin layers and a plurality of conductive trace layers 12 alternately arranged.

In this embodiment, the circuit board 10 includes a substrate layer 11 and a conductive circuit layer 12 located on two opposite surfaces of the substrate layer 11. The conductive line layer 12 includes a plurality of conductive line patterns 120 spaced apart from each other.

The material of the substrate layer 11 may be Polyimide (PI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or the like. The substrate layer 11 may be a flexible substrate layer formed of the above-described material. The conductive circuit layers 12 on the two opposite surfaces of the substrate layer 11 are electrically connected to each other through conductive holes (not shown). The conductive line layer 12 is formed by the steps of: pasting a dry film → exposing → developing → etching → removing the film. Since the manufacturing process of the circuit substrate 10 is conventional for those skilled in the art, the detailed operation thereof will not be described in detail.

The second step is that: referring to fig. 2, a plurality of concave portions 110 are formed on the surface of the substrate layer 11. The depth of the recess 110 is between 0.1 micron and 3 microns. The method for forming the recess 110 includes plasma etching, Desmear (Desmear) method after laser etching, and the like. Each of the recesses 110 extends to a bottom edge of each of the conductive trace patterns 120 near one end of the conductive trace pattern 120. That is, the concave portions 110 may be formed only at both ends of each of the conductive trace patterns 120, and one end of the concave portion 110 near each of the conductive trace patterns 120 may extend to a side directly below a bottom edge of the conductive trace pattern 120. In the present embodiment, the substrate layer 11 not covered by the conductive trace layer 12 is thinned by 0.1 to 3 microns to form the concave portion 110, that is, the depth of the concave portion 110 is between 0.1 to 3 microns.

The third step: referring to fig. 3, an insulating adhesive layer 20 is formed on the surfaces of the substrate layer 11 and the conductive circuit layer 12, the insulating adhesive layer 20 fills the concave portion 110 and wraps the conductive circuit layer 12, and the thickness of the insulating adhesive layer 20 is not greater than the depth of the concave portion 110. The insulating glue layer 20 is formed by coating liquid ink or epoxy resin on the surfaces of the substrate layer 11 and the conductive circuit layer 12 and then curing the liquid ink or epoxy resin.

The fourth step: referring to fig. 4, an electromagnetic shielding layer 30 is formed on the surface of the insulating adhesive layer 20, and the electromagnetic shielding layer 30 covers the end edge of the conductive circuit layer 12 contacting the insulating adhesive layer 20. The thickness of the electromagnetic shielding layer is between 10 and 100 nanometers. Taking the conductive circuit layer 12 on the upper surface 101 of the substrate layer 11 as an example, a surface of the electromagnetic shielding layer 30 contacting the substrate layer 11 is a first surface 32, and a surface of the conductive circuit layer 12 contacting the substrate layer 11 is a second surface 122. The first surface 32 is closer to the lower surface 102 of the substrate layer 11 than the second surface 122, so that the bottom periphery of the conductive circuit layer 12 can be completely shielded by the electromagnetic shielding layer 30 to realize signal interference between the conductive circuit patterns 120.

The electromagnetic shielding layer 30 is a copper foil attached to the substrate, a copper layer formed by electroplating, sputtering or chemical deposition, or a conductive adhesive coated on the copper layer.

The conductive adhesive can be conductive silver adhesive, conductive gold adhesive, conductive copper adhesive or conductive carbon adhesive.

The electromagnetic shielding layer 30 can play an electromagnetic shielding role on the signal line, so that electromagnetic interference generated by the outside world on the signal line can be prevented, and the electromagnetic shielding layer 30 covers the bottom end periphery of the conductive circuit layer 12 in contact with the insulating adhesive layer 20, so that interference generated by signal coupling among a plurality of circuit patterns included in the conductive circuit layer 12 is shielded by the electromagnetic shielding layer 30, and signal interference among the conductive circuit patterns 120 can be prevented.

The fifth step: referring to fig. 5, a protection layer 40 is formed on the surface of the electromagnetic shielding layer 30 to obtain the anti-electromagnetic interference circuit board 100.

The protection layer 40 is a solder mask or a prepreg.

The solder mask layer may be formed by printing ink.

In this embodiment, the protection layer 40 is a prepreg, and the prepreg can be filled between the recesses formed by the adjacent conductive circuit patterns 120 after being pressed.

Referring to fig. 5 again, the present invention further relates to an anti-electromagnetic interference circuit board 100 formed by the above-mentioned method for manufacturing a rigid-flex board.

The anti-electromagnetic interference circuit board 100 includes: the electromagnetic shielding layer comprises a circuit substrate 10, an insulating adhesive layer 20 formed on the surface of the circuit substrate 10, an electromagnetic shielding layer 30 formed on the surface of the insulating adhesive layer 20, and a protective layer 40 formed on the surface of the electromagnetic shielding layer 30.

The circuit board 10 includes a substrate layer 11 and a conductive circuit layer 12 located on at least one surface of the substrate layer 11. The material of the substrate layer 11 may be PI or PET.

The circuit substrate 10 may also be a multilayer substrate including a plurality of resin layers and a plurality of conductive trace layers 12 alternately arranged.

In this embodiment, the circuit board 10 includes a substrate layer 11 and a conductive circuit layer 12 located on two opposite surfaces of the substrate layer 11. The conductive line layer 12 includes a plurality of conductive line patterns 120 spaced apart from each other.

A concave part 110 is formed on the surface of the substrate layer 11; the insulating adhesive layer 20 fills the concave portion 110 and covers the conductive circuit layer 12, and the thickness of the insulating adhesive layer 20 is not greater than the depth of the concave portion 110, so that the electromagnetic shielding layer 30 covers the end edge of the conductive circuit layer 12 contacting the insulating adhesive layer 20.

The depth of the recess 110 is between 0.1 micron and 3 microns. One end of the concave portion 110 near the conductive trace pattern 120 extends to the bottom edge of the conductive trace. In the present embodiment, the base material layer 11 not covered by the conductive line layer 12 is thinned by 0.1 to 3 micrometers to form the concave portion 110.

The insulating glue layer 20 is formed by coating liquid ink or epoxy resin on the surfaces of the substrate layer 11 and the conductive circuit layer 12 and then curing the liquid ink or epoxy resin.

The electromagnetic shielding layer 30 is a copper foil attached to the substrate, a copper layer formed by electroplating, sputtering or chemical deposition, or a conductive adhesive coated on the copper layer.

The conductive adhesive can be conductive silver adhesive, conductive gold adhesive, conductive copper adhesive or conductive carbon adhesive.

In summary, according to the manufacturing method of the anti-electromagnetic interference circuit board 100 and the anti-electromagnetic interference circuit board 100 manufactured and formed thereby provided by the present invention, the concave portion 110 is formed in the substrate layer 11, so that the insulating adhesive layer 20 is filled on the surfaces of the plurality of concave portions 110 and the conductive circuit layer 12, and then when the electromagnetic shielding layer 30 is formed on the surface of the insulating adhesive layer 20, the side surface of the conductive circuit pattern 120 included in the conductive circuit layer 12 is completely covered by the electromagnetic shielding layer 30, thereby preventing electromagnetic interference from being generated between conductive circuits included in the circuit board, and improving the quality of signal transmission of the circuit board.

It should be understood that the above examples are only for illustrating the present invention and are not to be construed as limiting the present invention. It will be apparent to those skilled in the art that various other changes and modifications can be made in the technical spirit of the present invention within the scope of the appended claims.