TWI428068B - Printed circuit board and method for manufacturing same - Google Patents

Description

Circuit board and manufacturing method thereof

The invention relates to the field of printed circuit board manufacturing, in particular to a circuit board having an electromagnetic shielding layer and a manufacturing method thereof.

Printed circuit boards are widely used due to their high assembly density. For application of the circuit board, please refer to the literature Takahashi, A. Ooki, N. Nagai, A. Akahoshi, H. Mukoh, A. Wajima, M. Res. Lab, High density multilayer printed circuit board for HITAC M-880, IEEE Trans On Components, Packaging, and Manufacturing Technology, 1992, 15(4): 418-425.

When the circuit board is working, electromagnetic interference between the electrical signals transmitted in the conductive lines in the circuit board and other electronic components in the electronic device is likely to cause electromagnetic interference, thereby affecting the normal operation of the electronic device. Therefore, in the manufacturing process of the circuit board, it is usually required to make an electromagnetic mask layer on the surface of the outer circuit of the circuit board to shield the electromagnetic interference between the conductive lines in the circuit board and other electronic components. In the prior art, the electromagnetic mask layer in the circuit board is usually formed by laminating an electromagnetic mask film. That is, the electromagnetic shielding film is first punched according to the shape of the conductive circuit pattern of the electromagnetic shielding portion, and then the electromagnetic shielding film corresponding to the conductive circuit pattern obtained by punching is attached to the circuit by hand. The surface of the board. However, since the bonding of a single circuit board is required manually in the laminating process, the production efficiency of the circuit board is low, and the problem of inaccurate alignment accuracy is easily generated, which affects the performance of the obtained circuit board.

In view of the above, it is necessary to provide a circuit board capable of improving the fabrication speed and accuracy of an electromagnetic mask layer in a circuit board and a method of fabricating the same.

A circuit board and a method of fabricating the same will be described below by way of embodiments.

A method for manufacturing a circuit board, comprising the steps of: providing a circuit substrate having a circuit pattern, the circuit pattern comprising a plurality of ground pads and a plurality of conductive lines, the circuit substrate further comprising a cover layer formed on the line pattern, a plurality of openings corresponding to the plurality of ground pads are formed in the cover layer, and each of the ground pads is correspondingly exposed from an opening; a blocking pattern is formed on a surface of the cover layer, the plurality of ground pads and a portion of the cover layer is exposed from the gap in the barrier pattern; an electromagnetic mask layer is formed on a surface of the plurality of ground pads exposed from the barrier pattern and a portion of the cover layer by sputtering metal; and the barrier pattern is formed The surface of the plurality of ground pads and the surface of the partial cover layer are exposed to form an electromagnetic shielding layer surface to form an insulating layer.

A method of manufacturing a circuit board, comprising the steps of: providing a circuit substrate comprising a plurality of sequentially connected substrate units, each of the circuit substrate units being formed with a circuit pattern, the circuit pattern comprising a plurality of ground pads and a plurality of conductive lines The substrate unit further includes a cover layer formed on the circuit pattern, wherein the cover layer is formed with a plurality of openings corresponding to the plurality of ground pads in a one-to-one manner, and each of the ground pads is correspondingly exposed from one opening; Forming a barrier pattern on a surface of the cover layer on each substrate unit, the plurality of ground pads and a portion of the cover layer being exposed from a gap in the barrier pattern; by means of sputtering metal, sequentially in the The barrier pattern on the substrate unit exposes a surface of the plurality of ground pads and a surface of the partial cover layer to form an electromagnetic mask layer; and electromagnetic shielding is formed on the surface of the plurality of ground pads exposed from the barrier pattern and a portion of the cover layer. Forming an insulating layer on the surface of the cover layer, thereby forming a circuit substrate including a plurality of sequentially connected substrate units into a plurality of circuit board units including a plurality of sequentially connected circuit board units Board; and a circuit board unit along the boundary of each of the cutting board, the circuit board unit to obtain a plurality of separation.

A circuit board comprising a substrate layer, a wiring pattern, a cover layer and an electromagnetic shielding layer, the circuit pattern being formed on the substrate layer and comprising a plurality of conductive lines and a plurality of grounding for grounding a solder pad, the cover layer covers the circuit pattern, and the cover layer is formed with a plurality of openings corresponding to the plurality of ground pads in a one-to-one manner, such that each of the ground pads is exposed from a corresponding one of the cover openings The electromagnetic shielding layer is formed on a surface of the grounding pad and the partial covering layer, and the electromagnetic shielding layer is formed by sputtering metal.

The manufacturing method of the circuit board provided by the technical solution forms a blocking pattern on the substrate before forming the electromagnetic shielding layer, and after the electromagnetic shielding layer is formed, removes the blocking pattern, thereby causing electromagnetic in the circuit board unit The mask layer is complementary to the blocking pattern. In this way, the position at which the electromagnetic mask layer is formed in the circuit board is defined by the blocking pattern, and the alignment accuracy of the formed electromagnetic mask layer can be ensured. Secondly, since the electromagnetic mask layer is formed by sputtering, it has better thickness uniformity.

The circuit board provided by the technical solution and the manufacturing method thereof are further described below with reference to the accompanying drawings and embodiments.

The manufacturing method of the circuit board provided by the technical solution includes the following steps:

In a first step, referring to FIG. 1, a circuit substrate 10 is provided. The circuit substrate 10 includes a plurality of substrate units 100 connected in series.

The circuit substrate 10 is a flexible substrate, and the circuit substrate 10 can be wound on a reel. All steps in the technical solution can be applied to a Roll-to-Roll Process. Each of the substrate units 100 includes a substrate layer 120, a wiring pattern 110, and a cover layer 130. The line pattern 110 is formed on the substrate layer 120. The line pattern 110 includes a plurality of conductive lines 111 and a plurality of ground pads 112 for grounding. A surface of each of the ground pads 112 is formed with a plating layer 113 including a copper plating layer 114 and a nickel gold plating layer 115 formed on the copper plating layer 114. The thickness of the plating layer 113 is approximately 15 microns to 20 microns. The cover layer 130 covers the circuit pattern 110, and a plurality of openings 131 corresponding to the plurality of ground pads 112 are formed in the cover layer 130 such that each of the ground pads 112 is exposed from the cover layer 130. The cover layer 130 is used to cover the conductive line 111. The cover layer 130 may be composed of a glue layer and an insulation layer, wherein the glue layer is adhered between the insulation layer and the conductive line 111. The cover layer 130 has a thickness of approximately 25 microns to 30 microns. The surface of the plating layer 113 is lower than the surface of the cover layer 130.

The substrate unit 100 may be a single-sided circuit board, or may be a double-sided circuit board or a multi-layer circuit board, that is, the base material layer 120 may be an insulating layer, or may include alternating conductive layers and insulating layers. In this embodiment, the substrate unit 100 is a single-sided circuit board, and the substrate layer 120 is an insulating layer.

It can be understood that when the substrate unit 100 is a double-sided circuit board, a circuit pattern is formed on opposite sides of the substrate. When the substrate unit 100 is a multilayer circuit board, a circuit pattern is formed on opposite sides of the substrate. In addition, the circuit substrate 10 may also include only one substrate unit 100, that is, only one substrate unit is operated in each step.

In the second step, referring to FIG. 2, a blocking pattern 140 is sequentially formed on the surface of each substrate unit 100 such that a portion of the surface of each substrate unit 100 that does not need to form an electromagnetic mask layer is shielded by the blocking pattern 140, the ground pad 112 and The surface of the partial cover layer 130 is exposed from the gap in the barrier pattern 140.

The barrier pattern 140 may be formed by first forming a barrier layer 141 covering the entire surface of the circuit substrate 10 on the surface of each substrate unit 100. The barrier layer 141 can be formed by pressing a dry film. The barrier layer 141 can also be formed by printing a liquid photosensitive ink. Then, the barrier layer 141 is subjected to exposure and development to form the barrier pattern 140 such that a portion of the surface of the circuit substrate 10 where the electromagnetic mask layer needs to be formed is exposed from the slit in the barrier pattern 140. The barrier pattern 140 has a thickness of approximately 40 microns to 100 microns. In this step, the surfaces of the ground pad 112 and the partial cover layer 130 are exposed from the gaps in the barrier pattern 140. This step can be performed by a roll-to-roll process, in which the surface of each substrate unit 100 is sequentially formed into a blocking pattern.

In the third step, please refer to FIG. 3 and FIG. 4 together, and the surface of the barrier pattern 140 of each substrate unit 100 and the ground pad 112 and partial coverage exposed from the gap in the barrier pattern 140 are sputtered by metal. The surface of layer 130 forms an electromagnetic mask layer 150.

The electromagnetic mask layer 150 may be formed by chemical vapor deposition (CVD) or physical vapor deposition (PVD). The sputtered metal may be zinc, nickel, silver, copper or an alloy of the above metals. The electromagnetic shielding layer 150 is formed to have a thickness of from 1 micrometer to 50 micrometers, preferably from 1 micrometer to 25 micrometers. When the electromagnetic mask layer 150 is formed by chemical vapor deposition, the temperature in the coating chamber is controlled to be 20 degrees Celsius to 2000 degrees Celsius. When the physical vapor deposition method is used for sputtering, the vacuum in the coating chamber is controlled to be 0.001 Pa to 10 Pa, the voltage is 200 V to 1000 V, the sputtering duration is 5 minutes to 30 minutes, and the temperature in the coating chamber is 50 degrees Celsius to 500 degrees Celsius.

In this step, it is also possible to shield the area where each of the substrate units 100 does not need to form the electromagnetic mask layer 150 (ie, the area blocked by the blocking pattern 140) during sputtering, so that the electromagnetic mask layer 150 is formed only on The surface of the ground pad 112 and the partial cover layer 130 exposed from the gap in the blocking pattern 140.

In the fourth step, referring to FIG. 5, an insulating layer 160 is formed on the surface of the electromagnetic mask layer 150 on each of the substrate units 100, and the insulating layer 160 covers only the ground pads 112 exposed from the gaps in the barrier pattern 140. And a portion of the cover layer 130 corresponding to the surface of the electromagnetic mask layer 150.

The insulating layer 160 is formed only on the surface of the portion of the electromagnetic mask layer 150 corresponding to the ground pad 112 and the partial cover layer 130 exposed from the gap in the barrier pattern 140, and the portion of the electromagnetic mask layer 150 corresponding to the barrier pattern 140 The surface is not formed with an insulating layer. The insulating layer 160 can be formed by coating or spraying a liquid insulating material. Specifically, the insulating layer 160 may be formed by screen printing or inkjet printing or the like.

In the fifth step, referring to FIG. 6, the blocking pattern 140 on each substrate unit 100 and the electromagnetic mask layer 150 formed on the blocking pattern 140 are sequentially removed to obtain a circuit board 101, and each substrate unit 100 is formed into a circuit board correspondingly. Unit 170.

The barrier pattern 140 can be removed by stripping. The thickness of the design barrier pattern 140 is greater than the thickness of the electromagnetic mask layer 150, and portions of the side of the barrier pattern 140 are exposed. The blocking pattern 140 is reacted with its corresponding chemical reagent such that the blocking pattern 140 is dissolved by the chemical agent to be detached from the surface of the circuit substrate 10. When the electromagnetic mask layer 150 is formed on the surface of the barrier pattern 140, the electromagnetic mask layer 150 on the surface of the barrier pattern 140 is also removed.

The barrier pattern 140 can also be removed from the surface of each substrate unit 100 by mechanical peeling.

In a sixth step, referring to FIG. 7, the circuit board 101 is cut along the boundary of each of the board units 170 to obtain a plurality of separate board units 170.

The technical solution also provides a circuit board which is manufactured by the above-mentioned circuit board manufacturing method, and the circuit board is each circuit board unit 170, which comprises a substrate layer 120, a circuit pattern 110, a cover layer 130, and an electromagnetic mask layer 150. And an insulating layer 160. The line pattern 110 is formed on the substrate layer 120. The line pattern 110 includes a plurality of conductive lines 111 and a plurality of ground pads 112 for grounding. A surface of each of the ground pads 112 is formed with a plating layer 113 including a copper plating layer 114 and a nickel gold plating layer 115 formed on the copper plating layer 114. The thickness of the plating layer 113 is approximately 15 microns to 20 microns. The cover layer 130 covers the circuit pattern 110, and a plurality of openings 131 corresponding to the plurality of ground pads 112 are formed in the cover layer 130 such that each of the ground pads 112 is exposed from the cover layer 130. The electromagnetic mask layer 150 is formed on the surface of the ground pad 112 and the partial cover layer 130, and the insulating layer 160 is formed on the electromagnetic mask layer 150.

In the present technical solution, the barrier pattern 140 is formed on each of the substrate units 100 before the electromagnetic mask layer 150 is formed, and after the electromagnetic mask layer 150 is formed, the barrier pattern 140 is removed. The electromagnetic mask layer 150 in the circuit board unit 170 is thus made complementary to the blocking pattern 140. Thus, the position at which the electromagnetic mask layer 150 in each of the circuit board units 170 is formed is defined by the blocking pattern 140, and the alignment accuracy of the formed electromagnetic mask layer 150 can be ensured. Secondly, since the electromagnetic mask layer 150 is formed by sputtering, it has better thickness uniformity. Finally, the circuit board manufacturing method provided by the technical solution can be operated by a roll-to-roll process, which can greatly improve the efficiency of circuit board fabrication.

However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

10‧‧‧ circuit board

101‧‧‧ boards

100‧‧‧Substrate unit

110‧‧‧ line graphics

111‧‧‧Electrical circuit

112‧‧‧Ground pad

113‧‧‧ plating

114‧‧‧copper plating

115‧‧‧ Nickel gold plating

120‧‧‧Substrate layer

130‧‧‧ Coverage

131‧‧‧ openings

140‧‧‧block graphics

141‧‧‧Block

150‧‧‧Electromagnetic mask layer

160‧‧‧Insulation

170‧‧‧Circuit unit

FIG. 1 is a cross-sectional view of a substrate provided by the technical solution.

2 is a cross-sectional view showing the surface of the substrate of FIG. 1 after forming a barrier layer.

3 is a cross-sectional view of the barrier layer of FIG. 2 after exposure and development to form a barrier pattern.

4 is a cross-sectional view showing the barrier pattern surface of FIG. 3 and the electromagnetic mask layer formed on the surface of the substrate from which the barrier pattern is exposed.

Figure 5 is a cross-sectional view showing the insulating layer formed on the electromagnetic mask layer of Figure 4.

Figure 6 is a cross-sectional view of Figure 5 with the barrier pattern removed.

Figure 7 is a cross-sectional view of the circuit board unit obtained after cutting in Figure 6.

111‧‧‧Electrical circuit

112‧‧‧Ground pad

120‧‧‧Substrate layer

130‧‧‧ Coverage

150‧‧‧Electromagnetic mask layer

160‧‧‧Insulation

170‧‧‧Circuit unit

Claims (10)

A method for manufacturing a circuit board, comprising the steps of:
Providing a circuit substrate having a circuit pattern, the circuit pattern comprising a plurality of ground pads and a plurality of conductive lines, the circuit substrate further comprising a cover layer formed on the circuit pattern, wherein the cover layer is formed with a plurality of grounds The solder pads correspond to the plurality of openings one by one, and each of the ground pads is correspondingly exposed from one opening;
Forming a barrier pattern on a surface of the cover layer, the plurality of ground pads and a portion of the cover layer being exposed from a gap in the barrier pattern;
Forming an electromagnetic mask layer on a surface of the plurality of ground pads exposed from the barrier pattern and a surface of the partial cover layer by sputtering metal; and surface and partial coverage of the plurality of ground pads exposed from the barrier pattern The surface of the layer forms an electromagnetic shielding layer surface to form an insulating layer. The method of manufacturing a circuit board according to the first aspect of the invention, wherein after the forming the insulating layer, the step of removing the blocking pattern from the surface of the circuit substrate is further included. The method of manufacturing the circuit board of claim 2, wherein the electromagnetic shielding layer is further formed on a surface of the blocking pattern when the metal is sputtered, and the blocking is removed when the blocking pattern is removed. When the pattern is formed, the electromagnetic mask layer formed on the surface of the barrier pattern is removed together. The method for fabricating a circuit board according to claim 1, wherein the material for forming the electromagnetic shielding layer is zinc, nickel, silver, copper or an alloy of the above metals. The method of fabricating a circuit board according to the fourth aspect of the invention, wherein the electromagnetic mask layer is formed by a chemical vapor deposition method or a physical vapor deposition method. The method of fabricating a circuit board according to claim 1, wherein the electromagnetic shielding layer has a thickness of 1 micrometer to 25 micrometers. The method for manufacturing a circuit board according to claim 1, wherein the forming of the blocking pattern comprises the following steps:
Forming a barrier layer covering the entire surface of the circuit substrate on the surface of the circuit substrate; and exposing and developing the barrier layer to form a barrier pattern. A method for manufacturing a circuit board, comprising the steps of:
Providing a circuit substrate including a plurality of sequentially connected substrate units, each of the circuit substrate units being formed with a line pattern, the circuit pattern comprising a plurality of ground pads and a plurality of conductive lines, the substrate unit further comprising a line formed a cover layer on the pattern, wherein the cover layer is formed with a plurality of openings corresponding to the plurality of ground pads in a one-to-one manner, and each of the ground pads is correspondingly exposed from the one opening;
Forming a barrier pattern on the surface of the cover layer on each of the substrate units, the plurality of ground pads and a portion of the cover layer being exposed from a gap in the barrier pattern;
Forming an electromagnetic shielding layer on the surface of the plurality of grounding pads and the surface of the partial covering layer by sequentially exposing the blocking pattern on each of the substrate units by means of sputtering metal;
Forming an insulating layer on the surface of the surface of the plurality of grounding pads and the surface of the partial covering layer from the blocking pattern to form an insulating layer, thereby forming the circuit substrate including the plurality of sequentially connected substrate units into a plurality of a circuit board of the connected circuit board unit; and cutting the circuit board along the boundary of each circuit board unit to obtain a plurality of separate circuit board units. The method for fabricating a circuit board according to claim 8, wherein the method of manufacturing the circuit board is performed by a roll-to-roll process. A circuit board comprising a substrate layer, a wiring pattern, a cover layer and an electromagnetic shielding layer, the circuit pattern being formed on the substrate layer and comprising a plurality of conductive lines and a plurality of grounding for grounding a solder pad, the cover layer covers the circuit pattern, and the cover layer is formed with a plurality of openings corresponding to the plurality of ground pads in a one-to-one manner, such that each of the ground pads is exposed from a corresponding one of the cover openings The electromagnetic shielding layer is formed on a surface of the grounding pad and the partial covering layer, and the electromagnetic shielding layer is formed by sputtering metal.