A step groove and its manufacturing method

Abstract

The present invention discloses a stepped groove and a method for making the same in the field of PCB board technology. The steps include mechanically processing a set position on a circuit board having a signal layer pattern and a power layer pattern to form a stepped groove; electroplating a copper layer on the inner wall of the stepped groove; mechanically processing the electroplated copper layer on the inner wall of the stepped groove to remove the electroplated copper layer between the signal layer pattern and the power layer pattern, thereby forming a conductive surface connected to the signal layer pattern and a power surface connected to the power layer pattern. Simultaneously, the conductive surface is cut into a plurality of signal transmission surfaces according to the number of signal lines connected to the signal layer pattern; filling the stepped groove with resin; electroplating an outer layer of copper on the surface of the circuit board to cover the stepped groove, and forming an outer layer pattern on the outer layer of copper. The outer layer pattern is connected to the signal layer pattern via the signal transmission surface and to the power layer pattern via the power surface. The present invention can reduce signal loss caused by signal holes transmitting signals and reduce crosstalk between signal holes.

Description

Technical Field

[0001] The present invention belongs to the technical field of PCB boards, and particularly relates to a stepped groove and a manufacturing method thereof. Background Art

[0002] In the existing technology, PCB boards transmit signals between different functional layers through signal holes. On the one hand, circular signal holes will block signal transmission due to the formation of capacitance and inductance effects, causing signal loss and reducing signal quality. On the other hand, traditional PCB signal lines are shielded by holes, and there are gaps between holes. Signals can interfere with each other through the gaps. This method cannot provide surrounding shielding between signal holes. Summary of the Invention

[0003] In order to solve the deficiencies in the prior art, the present invention provides a stepped groove and a manufacturing method thereof, which can reduce the signal loss caused by signal holes transmitting signals and reduce the mutual crosstalk between signal holes.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] In a first aspect, a method for making a stepped groove is provided, comprising: performing mechanical processing at a set position of a circuit board having a signal layer pattern and a power layer pattern to form a stepped groove, wherein the signal layer pattern and the power layer pattern are respectively located on different bottom surfaces of the stepped groove; electroplating a copper layer on the inner wall of the stepped groove; mechanically processing the electroplated copper layer on the inner wall of the stepped groove to remove the electroplated copper layer between the signal layer pattern and the power layer pattern to form a conductive surface connected to the signal layer pattern and a power surface connected to the power layer pattern, and at the same time, cutting the conductive surface into several signal transmission surfaces according to the number of signal lines connected to the signal layer pattern; filling the stepped groove with resin; electroplating an outer layer of copper on the surface of the circuit board to cover the stepped groove, and making an outer layer pattern on the outer layer of copper, wherein the outer layer pattern is connected to the signal layer pattern through the signal transmission surface and is connected to the power layer pattern through the power surface.

[0006] Furthermore, the step groove is formed by mechanically processing the set position of the circuit board having the signal layer pattern and the power layer pattern, including: firstly making a sunken groove at the set position of the circuit board by mechanical drilling or fishing, wherein the bottom surface of the sunken groove is located between the signal layer pattern and the copper layer above the signal layer; and then continuing to process the sunken groove by laser until the signal layer pattern and the power layer pattern are formed, so that the signal layer pattern and the power layer pattern are respectively located on different bottom surfaces of the step groove.

[0007] Furthermore, after the copper layer is electroplated on the inner wall of the step groove, the non-signal layer pattern at the bottom of the step groove is burned off by laser, and then the electroplated copper layer on the inner wall of the step groove is mechanically processed.

[0008] Furthermore, the number of the signal transmission surfaces is equal to the number of the signal lines connected to the signal layer patterns.

[0009] Furthermore, the height of the resin filled in the stepped groove is equal to the height of the signal transmission surface and the height of the power supply surface.

[0010] In a second aspect, a stepped groove is provided, which is manufactured using the step groove manufacturing method described in the first aspect.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] (1) The present invention changes the traditional signal hole signal transmission to a conductive surface signal transmission. The conductive surface is approximately flat, which avoids the signal blocking caused by capacitance and inductance effects and reduces signal loss. At the same time, since a power supply surface parallel to the conductive surface for signal transmission is formed, the power supply surface can surround the signal hole, thus greatly reducing the crosstalk between the signal holes.

[0013] (2) The present invention forms a vertical power supply surface, which substantially increases the power supply area, reduces resistance, and increases current;

[0014] (3) The present invention can process micro-grooves and can be applied to inner layer interconnection, replacing the function of the central hole of the traditional circuit board through the conductive surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic longitudinal cross-sectional view of a stepped groove provided by an embodiment of the present invention;

[0016] Figure 2a yes Figure 1 Overlooking Figure 1 ;

[0017] Figure 2b yes Figure 1 Top view 2;

[0018] Figure 3 1 is a longitudinal cross-sectional diagram of a method of producing a groove on a circuit board by mechanical processing in an embodiment of the present invention;

[0019] Figure 4 Yes Figure 3 A schematic longitudinal section diagram of a stepped groove formed after the sinking groove in the embodiment is processed;

[0020] Figure 5 Yes Figure 4 Schematic diagram of the longitudinal section of the stepped groove after electroplating;

[0021] Figure 6 It will Figure 5 A longitudinal cross-sectional diagram of the step groove after the signal layer pattern is removed;

[0022] Figure 7 Yes Figure 5 A longitudinal cross-sectional diagram of the step groove in the circuit board after mechanical processing to remove the electroplated copper layer between the signal layer pattern and the power layer pattern;

[0023] Figure 8a Yes Figure 7 A top view of a schematic diagram of processing the conductive surface of the stepped groove to form several signal transmission surfaces Figure 1 ;

[0024] Figure 8b Yes Figure 7 A second top view showing a schematic diagram of processing the conductive surface of the stepped groove to form a plurality of signal transmission surfaces;

[0025] Figure 9a Yes Figure 6 The stepped grooves in the circuit are first machined to remove the electroplated copper layer between the non-signal layer pattern and the non-power layer pattern, and then the conductive surface is processed to form a schematic diagram of several signal transmission surfaces. Figure 1 ;

[0026] Figure 9b Yes Figure 6 The stepped groove is first machined to remove the electroplated copper layer between the non-signal layer pattern and the non-power layer pattern, and then the conductive surface is processed to form a plurality of signal transmission surfaces (top view 2);

[0027] Figure 10a This is a top view of the embodiment of the present invention after the outer layer pattern is completed. Figure 1 ;

[0028] Figure 10b This is a second top view of the embodiment of the present invention after the outer layer pattern is completed;

[0029] In the figure: 1. Signal layer pattern; 11. Copper layer above the signal layer pattern; 2. Power layer pattern; 3. Conductive surface; 30. Signal transmission surface; 4. Power surface; 5. Signal line; 6. Sink; 60. Step groove; 7. Hole pad; C. Area after mechanical removal. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0031] Example 1:

[0032] like Figure 1 、 Figure 2a 、 Figure 2bAs shown, a method for making a stepped groove includes: mechanical processing at a set position of a circuit board having a signal layer pattern 1 and a power layer pattern 2 to form a stepped groove 60, wherein the signal layer pattern 1 and the power layer pattern 2 are respectively located on different bottom surfaces of the stepped groove 60; electroplating a copper layer on the inner wall of the stepped groove 60; mechanical processing the electroplated copper layer on the inner wall of the stepped groove 60 to remove the electroplated copper layer between the signal layer pattern and the power layer pattern to form a conductive surface 3 connected to the signal layer pattern 1 and a power surface 4 connected to the power layer pattern 2, and at the same time, according to the number of signal lines 5 connected to the signal layer pattern 1, the conductive surface 3 is cut into several signal transmission surfaces 30; filling the stepped groove 60 with resin; electroplating an outer layer of copper on the surface of the circuit board and covering the stepped groove 60, making an outer layer pattern on the outer layer of copper, and the outer layer pattern is connected to the signal layer pattern 1 through the signal transmission surface 30 and is connected to the power layer pattern 2 through the power surface 4. Figure 2a 、 Figure 2b In the top view, the signal transmission surface 30 is located on the side wall of the stepped groove 60, so the signal transmission surface 30 is located Figure 2a 、 Figure 2b At the edge of the middle signal layer pattern 1, similarly, the power plane 4 is located at the edge of the power layer pattern 2. Figure 2a and Figure 2b The only difference is the length and width of the step groove and the form of the signal layer pattern. Figure 2a and Figure 2b C in the figure represents the area after mechanical removal, that is, the dotted line in the figure represents the position where the copper layer is removed.

[0033] The specific processing method of the stepped groove 60 in this embodiment is as follows.

[0034] Step 1: Mechanically process the circuit board having the signal layer pattern and the power layer pattern at a set position to form a stepped groove 60 , wherein the signal layer pattern and the power layer pattern are respectively located on different bottom surfaces of the stepped groove 60 .

[0035] Before machining, the inner layer pattern processing and lamination process needs to be carried out to form a circuit board with a signal layer pattern 1 and a power layer pattern 2.

[0036] 1) First, use a mechanical drill or fishing method to make a sink groove 6 at the set position of the circuit board, and process it above the signal layer pattern 1. At the same time, it must pass through the copper layer 11 of the upper layer of the signal layer pattern. The bottom surface of the sink groove 6 is located between the signal layer pattern 1 and the copper layer 11 of the upper layer of the signal layer pattern. Figure 3 shown.

[0037] 2) The laser is then used to continue processing the sink groove 6. The laser burns to the signal layer pattern 1 and the power layer pattern 2 and stops, forming a stepped groove 60 where the signal layer pattern 1 and the power layer pattern 2 are located on different bottom surfaces. Figure 4 shown.

[0038] 3) Electroplating a copper layer on the inner wall of the step groove 60; through the process of removing glue and copper plating, the inner wall of the step groove 60 is completely covered with copper (Class A, such as Figure 5 As shown); or according to the customer's needs, the signal layer pattern 1 in the step groove 60 can be selectively laser burned out (type B, such as Figure 6 As shown, Figure 6 In the figure, the copper layer above the signal layer pattern is not drawn).

[0039] 4) Resin plugging: After the resin is cured at high temperature, the electroplated copper layer on the inner wall of the stepped groove 60 is mechanically processed by mechanical fishing to remove the electroplated copper layer between the signal layer pattern 1 and the power layer pattern 2, forming a conductive surface 3 connected to the signal layer pattern 1 and a power surface 4 connected to the power layer pattern 2. At the same time, according to the number of signal lines 5 connected to the signal layer pattern 1, the conductive surface 3 is cut into several signal transmission surfaces 30; Among them, Class A, such as Figure 7 ( Figure 7 In the figure, the copper layer above the signal layer is not drawn). Figure 8a 、 Figure 8b As shown, Figure 8a and Figure 8b The only difference is the length and width of the step groove and the form of the signal layer pattern; Category B, such as Figure 9a 、 Figure 9b As shown, Figure 9a and Figure 9b The only difference is the change in the length and width of the step groove and the position of the signal line. Figure 7 、 Figure 8a 、 Figure 8b 、 Figure 9a 、 Figure 9b In the figure, C represents the area after mechanical removal, that is, the dotted line in the figure represents the position where the copper layer is removed. In this embodiment, the number of signal transmission surfaces 30 is equal to the number of signal lines 5 connected to the signal layer pattern 1.

[0040] 5) Fill the stepped groove 60 with resin, and then stuff the resin into the position where the inner wall is divided and the mechanical division of the groove bottom. After filling, solidify it, and then polish it so that the height of the resin on the surface is consistent with the copper surface. That is, the height of the resin filled in the stepped groove 60 is equal to the height of the signal transmission surface 30 and the height of the power supply surface 4.

[0041] 6) The entire surface of the circuit board is copper plated, and the resin surface is also covered with copper.

[0042] 7) After copper plating, the circuit board is patterned to form the outer layer pattern. The outer layer pattern is connected to the signal layer pattern through the signal transmission surface and signal line, and is connected to the power layer pattern through the power surface (the same for the outer layers of Class A and Class B).

[0043] 8) After subsequent printing ink and surface treatment, customers can package or test according to the hole position or hole position Pad 7, such as Figure 10a 、 Figure 10b As shown, Figure 10a and Figure 10b The only difference is the length and width of the step groove and the form of the signal layer pattern.

[0044] The present invention changes the traditional signal hole signal transmission into a conductive surface signal transmission. The conductive surface is approximately flat, avoiding the signal blocking caused by capacitance and inductance effects and reducing signal loss. At the same time, since a power supply surface parallel to the conductive surface for transmitting signals is formed, the power supply surface can surround the signal hole, thus greatly reducing the crosstalk between the signal holes. The present invention forms a vertical power supply surface, which substantially increases the power supply area, reduces the resistance and increases the current. The present invention can process tiny grooves and can be applied to inner layer interconnection, replacing the role of the hole in the traditional circuit board through the conductive surface.

[0045] Example 2:

[0046] Based on the method for manufacturing a stepped groove described in Example 1, this embodiment provides a stepped groove, which is manufactured using the method for manufacturing a stepped groove described in Example 1.

[0047] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for manufacturing a stepped groove, characterized in that: include: Mechanical processing is performed at a set position of a circuit board having a signal layer pattern (1) and a power layer pattern (2) to form a stepped groove (60), wherein the signal layer pattern (1) and the power layer pattern (2) are respectively located on different bottom surfaces of the stepped groove (60); Electroplating a copper layer on the inner wall of the step groove (60); Mechanically processing the electroplated copper layer on the inner wall of the stepped groove (60) to remove the electroplated copper layer between the signal layer pattern (1) and the power layer pattern (2) to form a conductive surface connected to the signal layer pattern (1) and a power surface (4) connected to the power layer pattern (2); at the same time, cutting the conductive surface into a plurality of signal transmission surfaces (30) according to the number of signal lines (5) connected to the signal layer pattern (1); Filling the stepped groove (60) with resin; An outer layer of copper is electroplated on the surface of the circuit board and covered with stepped grooves, and an outer layer pattern is made on the outer layer of copper. The outer layer pattern is connected to the signal layer pattern (1) through the signal transmission surface (30) and is connected to the power layer pattern (2) through the power surface (4).

2. The method for manufacturing a stepped groove according to claim 1, wherein: The method of performing mechanical processing at a set position of a circuit board having a signal layer pattern (1) and a power layer pattern (2) to form a stepped groove (60) comprises: First, a mechanical drill or a scoop is used to make a sink groove (6) at a set position of the circuit board, wherein the bottom surface of the sink groove (6) is located between the signal layer pattern (1) and the copper layer (11) above the signal layer pattern; The sink groove (6) is then processed by laser until the signal layer pattern (1) and the power layer pattern (2) are formed, thereby forming a stepped groove (60) in which the signal layer pattern (1) and the power layer pattern (2) are respectively located on different bottom surfaces.

3. The method for manufacturing a stepped groove according to claim 1, wherein: After the inner wall of the step groove (60) is electroplated with a copper layer, the non-signal layer pattern at the bottom of the step groove (60) is first burned off by laser, and then the electroplated copper layer on the inner wall of the step groove (60) is mechanically processed.

4. The method for manufacturing a stepped groove according to claim 1, wherein: The number of the signal transmission surfaces (30) is equal to the number of the signal lines (5) connected to the signal layer pattern (1).

5. The method for manufacturing a stepped groove according to claim 1, wherein: The height of the resin filled in the stepped groove (60) is equal to the height of the signal transmission surface (30) and the height of the power supply surface (4).

6. A stepped trough, characterized in that: The stepped groove is manufactured by the step groove manufacturing method according to any one of claims 1 to 5.

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