Method for manufacturing a PCB board with stepped slots

Abstract

The application discloses a preparation method of a PCB (Printed Circuit Board) with a stepped groove, which comprises the following steps: pressing a plurality of core plates with inner layer patterns and a plurality of base layer sheets according to a preset stacking sequence to form a laminated plate, wherein the laminated plate comprises a laser window layer, a signal layer and a power supply layer arranged in sequence; a first groove is formed above the laser window layer by milling; the base layer sheet remaining above the laser window layer is removed by laser, and a part of the copper layer of the signal layer and a part of the copper layer of the power supply layer are exposed through each laser window of the laser window layer to form a stepped groove; the inner wall of the stepped groove is plated with copper to obtain a copper wall; the connection between the copper layer and the copper wall between the signal layer and the power supply layer is disconnected to avoid the electrical connection between the signal layer and the power supply layer; after the holes and grooves of the laminated plate are filled with resin, the outer surface of the laminated plate is plated with copper, and outer layer circuit etching is performed to obtain the PCB with the stepped groove. The application can obtain the PCB with the stepped groove.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of a PCB board with a stepped groove and belongs to the technical field of PCB board preparation. BACKGROUND

[0002] With the development of electronic product technology and the demand for multifunction, stepped PCBs emerge as the times require, and the main functions are as follows: improving the overall performance of products, increasing the assembly density of products, reducing the volume and weight of products, increasing the heat dissipation area, strengthening the safety of surface components, and meeting the demand for high speed and high information quantity of communication products.

[0003] The stepped PCB can improve the overall performance of products, increase the assembly density of products, reduce the volume and weight of products, increase the heat dissipation area, strengthen the safety of surface components, and meet the demand for high speed and high information quantity of communication products.

[0004] The stepped PCB can improve the overall performance of products, increase the assembly density of products, reduce the volume and weight of products, increase the heat dissipation area, strengthen the safety of surface components, and meet the demand for high speed and high information quantity of communication products.

[0005] Chinese patent document CN113411977A discloses a manufacturing method of a stepped groove, which is to first make a groove, then make a groove again at the position of one side of the groove after metalization, so as to widen and deepen one side of the groove and realize the stepped groove, and then metalize again to make the side wall of the new groove have metal. This method needs twice electroplating, and the inner wall of the first metalization needs to be covered by a dry film before the second metalization can be performed. This step is difficult to realize.

[0006] Therefore, the application provides a preparation method of a PCB board with a stepped groove. SUMMARY

[0007] The application aims to overcome the defects in the prior art, provide a preparation method of a PCB board with a stepped groove, and obtain a PCB board with a stepped groove.

[0008] To achieve the above-mentioned purpose, the application is implemented by using the following technical scheme:

[0009] On one hand, the application provides a preparation method of a PCB board with a stepped groove, which comprises the following steps:

[0010] A plurality of core plates with inner layer patterns and a plurality of base layer sheets are pressed to form a laminated plate according to a preset stacking order, and the laminated plate comprises a laser window layer, a signal layer and a power supply layer arranged in sequence;

[0011] A first groove is made above the laser window layer by milling;

[0012] The base layer sheet remaining above the laser window layer is removed by laser, and the partial copper layer of the signal layer and the partial copper layer of the power supply layer are exposed through each laser window of the laser window layer to form a stepped groove;

[0013] Copper is plated on the inner wall of the stepped groove to obtain a copper wall;

[0014] Disconnect the connection between the copper layer and the copper wall between the signal layer and the power supply layer to avoid electrical connection between the signal layer and the power supply layer.

[0015] After filling the holes and grooves of the laminated plate with resin, the outer surface of the laminated plate is plated with copper, and outer layer circuit etching is performed to obtain a PCB plate with stepped grooves.

[0016] Further, the signal layer includes signal blocks and signal lines.

[0017] Further, the copper layer of the power supply layer is in a sheet structure.

[0018] Further, the signal blocks of the signal layer can all be mapped onto the copper layer of the power supply layer.

[0019] Further, the outer layer circuit includes outer layer signal PAD and outer layer power supply PAD.

[0020] The signal layer is connected to the outer layer signal PAD through the copper layer and the copper wall.

[0021] The power supply layer is connected to the outer layer power supply PAD through the copper layer and the copper wall.

[0022] In a second aspect, the present application provides a PCB plate with stepped grooves, comprising the following steps:

[0023] A plurality of core plates with inner layer patterns and a plurality of base layers are pressed to form a laminated plate according to a predetermined stacking order, and the laminated plate includes a signal layer and a power supply layer.

[0024] A first groove is made above the signal layer by milling;

[0025] Part of the copper layer of the signal layer and part of the copper layer of the power supply layer are exposed by laser to form a stepped groove.

[0026] The inner wall of the stepped groove is plated with copper to obtain a copper wall.

[0027] Disconnect the connection between the copper layer and the copper wall between the signal layer and the power supply layer to avoid electrical connection between the signal layer and the power supply layer.

[0028] After filling the holes and grooves of the laminated plate with resin, the outer surface of the laminated plate is plated with copper, and outer layer circuit etching is performed to obtain a PCB plate with stepped grooves.

[0029] Further, the signal layer includes signal blocks and signal lines.

[0030] Further, the copper layer of the power supply layer is in a sheet structure.

[0031] Further, the signal blocks of the signal layer can all be mapped onto the copper layer of the power supply layer.

[0032] Further, the outer layer circuit includes an outer layer signal PAD and an outer layer power PAD;

[0033] The signal layer is connected with the outer layer signal PAD through a copper layer and a copper wall;

[0034] The power layer is connected with the outer layer power PAD through a copper layer and a copper wall.

[0035] Compared with the prior art, the present application has the following beneficial effects:

[0036] The present application has the following beneficial effects: BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 (a) is a top view of one embodiment of the inner layer pattern of the laser window layer of the present application;

[0038] Figure 1 (b) is a top view of one embodiment of the inner layer pattern of the signal layer of the present application;

[0039] Figure 1 (c) is a top view of one embodiment of the inner layer pattern of the power layer of the present application;

[0040] Figure 2 (a) is a top view of one embodiment of the inner layer pattern of the laser window layer of the present application;

[0041] Figure 3 (b) is a top view of one embodiment of the inner layer pattern of the signal layer of the present application;

[0042] Figure 4 (a) is a top view of one embodiment of the inner layer pattern of the laser window layer of the present application;

[0043] Figure 4 (b) is a top view of one embodiment of the inner layer pattern of the signal layer of the present application;

[0044] Figure 5 (a) is a top view of one embodiment of the inner layer pattern of the laser window layer of the present application;

[0045] Figure 6 (b) is a top view of one embodiment of the inner layer pattern of the signal layer of the present application;

[0046] In the figure, the black area is the copper layer, the white area is the laser area, and the diagonal area is the base material. DETAILED DESCRIPTION

[0047] The application will be further described below with reference to the drawings. The following examples are only used to more clearly illustrate the technical solutions of the application, and cannot be used to limit the protection scope of the application.

[0048] In the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application. In addition, the terms "first", "second" and the like are only used for description purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" and the like can be explicitly or implicitly included one or more. In the description of the application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0049] In the description of the application, it should be noted that unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0050] The two preparation methods of the PCB board with stepped slots of the application are as follows:

[0051] The first method is:

[0052] A plurality of core boards with inner layer patterns and a plurality of base layer sheets are pressed to form a laminated board according to a predetermined stacking order, the laminated board comprising a laser window layer, a signal layer and a power layer arranged in sequence;

[0053] A first slot is made above the laser window layer by milling;

[0054] The residual base layer sheet above the laser window layer is removed by laser, and part of the copper layer of the signal layer and part of the copper layer of the power layer are exposed through the laser windows of the laser window layer, forming a stepped slot;

[0055] Copper is plated on the inner wall of the stepped groove to obtain a copper wall;

[0056] The connection between the copper layer and the copper wall between the signal layer and the power supply layer is disconnected to avoid electrical connection between the signal layer and the power supply layer;

[0057] After filling the holes and grooves of the laminated board with resin, the outer surface of the laminated board is plated with copper, and outer layer circuit etching is performed to obtain a PCB board with a stepped groove.

[0058] Secondly:

[0059] A plurality of core boards with inner layer patterns and a plurality of base layer sheets are laminated according to a preset stacking order to form a laminated board, which includes a signal layer and a power supply layer;

[0060] A first groove is formed above the signal layer by milling;

[0061] Part of the copper layer of the signal layer and part of the copper layer of the power supply layer are exposed by laser to form a stepped groove;

[0062] Copper is plated on the inner wall of the stepped groove to obtain a copper wall;

[0063] The connection between the copper layer and the copper wall between the signal layer and the power supply layer is disconnected to avoid electrical connection between the signal layer and the power supply layer;

[0064] After filling the holes and grooves of the laminated board with resin, the outer surface of the laminated board is plated with copper, and outer layer circuit etching is performed to obtain a PCB board with a stepped groove.

[0065] Embodiment 1

[0066] This embodiment details the preparation method of a PCB board with a stepped groove.

[0067] The preparation method of the PCB board of this embodiment includes the following steps:

[0068] S11 A plurality of core boards with inner layer patterns and a plurality of base layer sheets are laminated according to a preset stacking order to form a laminated board, which includes a laser window layer, a signal layer and a power supply layer arranged in sequence.

[0069] Reference Figure 1 The laser window layer includes a laser window, the signal layer includes a signal block and a signal line, the signal block and the signal line are arranged perpendicular to each other and are connected to each other; in addition, the copper layer of the power supply layer is in a sheet structure.

[0070] The existing PCB includes a plurality of circular through-copper, and the circular through-copper of different frequencies will generate a capacitance that has an influence on signal transmission. The signal block and the signal line of the signal layer of this embodiment are in communication, forming a complete plane, so that no capacitance and inductance are derived to affect signal transmission.

[0071] In addition, the signal blocks of the signal layer can be mapped to the copper layer of the power layer, so that the power layer can surround the signal blocks of the signal layer, and the crosstalk between the signal blocks is greatly reduced.

[0072] S12 refers to Figure 2 (a) A first groove is formed above the laser window layer by milling.

[0073] In application, the laser window layer above is processed by mechanical drilling or milling without touching the laser window layer, the width of the first groove is not limited, and the length of the first groove is not limited. The top view shape of the first groove of the embodiment is the same as the inner layer pattern shape of the power layer, and reference is made to Figure 3 (a).

[0074] S13 refers to Figure 2 (b) The residual base layer sheet above the laser window layer is removed by laser, and part of the copper layer of the signal layer and part of the copper layer of the power layer are exposed through the laser windows of the laser window layer to form a stepped groove.

[0075] In application, the laser window layer is stopped from being burned when the signal layer and the power layer are burned through the laser windows of the laser window layer. At this time, the copper layer of the area burned by the laser window layer, the signal layer and the power layer is exposed, and reference is made to Figure 3 (b).

[0076] The top view of the first groove of the embodiment is the same as the top view of the stepped groove.

[0077] S14 refers to Figure 2 (c) Copper is plated on the inner wall of the stepped groove to obtain a copper wall.

[0078] In application, the inner wall of the first groove and the inner wall of each laser window are formed into a copper wall by chemical copper deposition and electroplating, and reference is made to Figure 3 (c). At this time, the area of the power layer includes not only the original inner layer pattern but also the power copper wall perpendicular to the inner layer pattern. Therefore, the area of the power layer is expanded, and the current speed is increased.

[0079] In the traditional PCB, the signal hole is surrounded by a shielding hole. Due to the gap between the holes, the signal of one signal line will affect the signal transmission of other signal lines during transmission. In the embodiment, the signal line of the signal layer is surrounded by a copper wall, and the signal cannot overflow, so that the signal line is prevented from being disturbed by the outside world.

[0080] S15 disconnects the connection between the copper layer and the copper wall between the signal layer and the power layer to avoid electrical connection between the signal layer and the power layer.

[0081] In application, the connection between the signal lines and the signal lines is disconnected by mechanical or chemical method, and the connection between the signal lines and the power wall is disconnected.

[0082] S16 refers to Figure 2 (d), after the holes and grooves of the laminated plate are blocked by resin, the outer surface of the laminated plate is plated with copper, and outer layer circuit etching is performed to obtain a PCB plate with stepped grooves, refer to Figure 3 (d).

[0083] In actual application, the holes and grooves are blocked by resin and baked and cured to prevent the subsequent process from entering the holes and grooves.

[0084] The outer layer circuit of the embodiment includes an outer layer signal PAD and an outer layer power PAD. Moreover, the signal layer is in communication with the outer layer signal PAD through the copper layer and the copper wall, and the power layer is in communication with the outer layer power PAD through the copper layer and the copper wall.

[0085] The existing PCB relies on electroplated holes or laser holes for interlayer conduction. The laser hole needs to be pressed multiple times to achieve cross-layer connection, and the residues generated when the electroplated hole is opened increase the loss of the signal during signal transmission. The present application only needs to be pressed once and does not generate residues that lose the signal. In addition, the preparation process of the PCB plate with stepped grooves of the present application only needs to be plated with copper once. Therefore, the present application can obtain a PCB plate with better signal transmission through a simple preparation process.

[0086] Embodiment 2

[0087] The embodiment details a preparation method of a PCB plate with stepped grooves.

[0088] The preparation method of the PCB plate of the embodiment includes the following steps:

[0089] S21 laminates a plurality of core plates with inner layer patterns and a plurality of base layer sheets according to a predetermined stacking order to form a laminated plate, and the laminated plate includes a signal layer and a power layer.

[0090] Referring to Figure 4 , the signal layer includes a signal block and a signal line, and the copper layer of the power layer is in a sheet structure.

[0091] The existing PCB includes a plurality of circular conductive copper, and the circular conductive copper of different frequencies will generate a capacitance that affects signal transmission. The signal block of the signal layer of the embodiment is in communication with the signal line, forming a complete plane, so that no capacitance and inductance are derived to affect signal transmission.

[0092] In addition, the signal block of the signal layer of the embodiment can be mapped onto the copper layer of the power layer, so that the power layer can surround the signal block of the signal layer, greatly reducing the crosstalk between the signal blocks.

[0093] S22 refers to Figure 5 (a), a first groove is made above the signal layer by milling.

[0094] In application, the signal layer above is processed by mechanical drilling or milling, etc. without touching the signal layer. The width of the first groove is not limited, and the length is not limited. The top view shape of the first groove of the embodiment is the same as the inner layer pattern shape of the power layer, as shown in Figure 6 (a).

[0095] S23, as shown in Figure 5 (b), the part of the copper layer of the signal layer and the part of the copper layer of the power layer are exposed by laser to form a stepped groove.

[0096] In application, when the signal layer and the power layer are burned by the first groove, the laser is stopped, that is, the substrate on all the copper layers mapped by the first groove is burned. At this time, the copper layer of the area where the signal layer and the power layer are burned is exposed, as shown in Figure 6 (b).

[0097] The top view of the first groove of the embodiment is the same as the top view of the stepped groove.

[0098] S24, as shown in Figure 5 (c), copper is plated on the inner wall of the stepped groove to obtain a copper wall.

[0099] In application, the copper wall is formed on the inner wall of the groove and the inner wall of the laser area by chemical copper deposition and electroplating, as shown in Figure 6 (c). At this time, the area of the power layer includes the original inner layer pattern and the power copper wall perpendicular to the inner layer pattern. Therefore, the area of the power layer is expanded, and the current speed is increased.

[0100] The traditional PCB signal hole is surrounded by a shielding hole. Due to the gap between the holes, the signal of the signal line will pass through the gap and affect the signal transmission of other signal lines in the transmission process. The signal line of the signal layer of the embodiment is surrounded by a copper wall, and the signal cannot overflow, which can avoid interference between the signal line and the outside world.

[0101] S25, the connection between the copper layer and the copper wall between the signal layer and the power layer is disconnected to avoid the electrical connection between the signal layer and the power layer

[0102] In application, the connection between the signal line and the signal line is disconnected by mechanical or chemical method, and the connection between the signal line and the power wall is disconnected.

[0103] S26, as shown in Figure 5 (d), after filling the holes and grooves of the laminated board with resin, the outer surface of the laminated board is plated with copper, and the outer layer circuit is etched to obtain a PCB board with a stepped groove, as shown in Figure 6 (d).

[0104] In practical application, the resin is blocked in the holes and grooves, and is baked and solidified to prevent the chemical solution from entering the holes and grooves in the subsequent process.

[0105] The outer layer circuit of the embodiment includes an outer layer signal PAD and an outer layer power PAD, which are connected to the signal layer and the power layer respectively. Figure 5 (e) and Figure 6 (e). Furthermore, the signal layer is connected to the outer layer signal PAD through the copper layer and the copper wall, and the power layer is connected to the outer layer power PAD through the copper layer and the copper wall.

[0106] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and modifications without departing from the technical principles of the present application, and these improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. A method of manufacturing a PCB board having a stepped groove, characterized by, The method comprises the following steps: a plurality of core boards with inner layer patterns and a plurality of base layer sheets are pressed to form a laminated board according to a preset stacking sequence, the laminated board comprises a laser window layer, a signal layer and a power supply layer arranged in sequence; a first groove is formed above the laser window layer by milling; the residual base layer sheet above the laser window layer is removed by laser, and part of the copper layer of the signal layer and part of the copper layer of the power supply layer are exposed through the laser windows of the laser window layer to form a stepped groove; a copper wall is plated on the inner wall of the stepped groove; the connection between the copper layer and the copper wall between the signal layer and the power supply layer is disconnected to avoid electrical connection between the signal layer and the power supply layer; after filling the holes and grooves of the laminated board with resin, the outer surface of the laminated board is plated with copper, and outer layer circuit etching is performed to obtain a PCB board with a stepped groove; the signal layer comprises signal blocks and signal lines; the copper layer of the power supply layer is in a sheet structure; the signal blocks of the signal layer can be mapped onto the copper layer of the power supply layer; the outer layer circuit comprises outer layer signal PADs and outer layer power supply PADs; the signal layer is connected with the outer layer signal PADs through the copper layer and the copper wall; the power supply layer is connected with the outer layer power supply PADs through the copper layer and the copper wall.

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