Printed circuit board preparation method and printed circuit board

Abstract

The invention discloses a printed circuit board preparation method and a printed circuit board, and the method comprises the steps: providing a substrate, and forming a hole in the substrate; performing copper deposition electroplating and resin hole plugging on the hole in sequence to obtain a hole plugging plate; a groove is formed in the surface of the hole in the hole plugging plate, and the depth of the groove is smaller than that of the hole; and conducting material hole plugging is carried out on the groove. By adopting the method, the contact area of the surface copper and the hole copper can be increased, and the binding force of the POFV hole upper cap copper is increased, so that the POFV hole upper cap copper is not easy to break, and the reliability of the printed circuit board is ensured.

Description

Technical Field

[0001] The present invention relates to the field of circuit board preparation, and in particular to a method for preparing a printed circuit board and a printed circuit board. Background Art

[0002] With the development of 5G communication technology, it has driven the miniaturization trend of electronic products, and the preparation of printed circuit boards has also developed towards being thinner and lighter. Therefore, people widely adopt the POFV (Plating Over Filled Via) process. However, when using the traditional POFV process to prepare printed circuit boards, due to the too small contact area between the surface copper and the hole copper, the bonding force of the capping copper on the POFV hole is too small, and it may break in a too cold or too hot environment, thereby reducing the reliability of the printed circuit board. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, an object of the present invention is to provide a method for preparing a printed circuit board. By using this method, the contact area between the surface copper and the hole copper can be increased, the bonding force of the capping copper on the POFV hole can be increased, so that the capping copper on the POFV hole is not likely to break, thereby ensuring the reliability of the printed circuit board.

[0004] A second object of the present invention is to provide a printed circuit board.

[0005] To solve the above problems, an embodiment of the first aspect of the present invention provides a method for preparing a printed circuit board, including: providing a substrate and forming holes on the substrate; performing electroless copper plating and resin plugging on the holes in sequence to obtain a plugged hole board; forming grooves on the surface of the holes on the plugged hole board, wherein the depth of the grooves is less than the depth of the holes; and plugging the grooves with a conductive material.

[0006] According to the method for preparing a printed circuit board of the embodiment of the present invention, by processing the plugged hole board, grooves are formed on the surface of the holes on the plugged hole board, and the grooves are plugged with a conductive material, so as to increase the contact area between the surface copper and the hole copper by using the grooves, increase the bonding force of the capping copper on the POFV hole, so that the capping copper on the POFV hole is not likely to break, thereby ensuring the reliability of the printed circuit board.

[0007] In some embodiments, forming grooves on the surface of the holes on the plugged hole board includes: performing laser ablation on the surface of the holes on the plugged hole board to form grooves on the holes after plugging.

[0008] In some embodiments, the preparation method further includes: performing brownification treatment on the plugged hole board before laser ablation.

[0009] In some embodiments, laser ablation is performed on the surface of the holes in the plug-hole plate member, including: using an ultraviolet laser light source to perform laser ablation on the surface of the holes in the plug-hole plate member.

[0010] In some embodiments, after plugging the grooves with a conductive material, the preparation method further includes: heating and curing the plug-hole plate member; forming pads on the cured plug-hole plate member to obtain a printed circuit board.

[0011] In some embodiments, before heating and curing the plug-hole plate member, the preparation method further includes: performing a grinding operation on the plug-hole plate member.

[0012] In some embodiments, after forming the pads, the preparation method further includes: performing solder mask processing on the plug-hole plate member to form a solder mask protection layer on the outer surface of the plug-hole plate member.

[0013] In some embodiments, the conductive material is copper paste, conductive ink, or graphene material.

[0014] In some embodiments, the substrate is a multilayer board.

[0015] An embodiment of the second aspect of the present invention provides a printed circuit board prepared by using the printed circuit board preparation method described in the above embodiments.

[0016] For the printed circuit board according to the embodiments of the present invention, the contact area between the surface copper and the hole copper is increased, so that the bonding force of the capping copper on the POFV hole becomes larger, and the capping copper on the POFV hole is not easily broken, thereby ensuring the reliability of the printed circuit board.

[0017] The additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0019] Figure 1 is a flowchart of a printed circuit board preparation method according to an embodiment of the present invention;

[0020] Figure 2 is a schematic diagram of a printed circuit board preparation method according to an embodiment of the present invention;

[0021] Figure 3 is a schematic diagram of a printed circuit board preparation method according to another embodiment of the present invention;

[0022] Figure 4Schematic diagram of a method for manufacturing a printed circuit board according to another embodiment of the present invention;

[0023] Figure 5 Schematic diagram of a method for manufacturing a printed circuit board according to another embodiment of the present invention;

[0024] Figure 6 Schematic diagram of a method for manufacturing a printed circuit board according to another embodiment of the present invention;

[0025] Figure 7 Schematic diagram of a method for manufacturing a printed circuit board according to another embodiment of the present invention;

[0026] Figure 8 Schematic diagram of a method for manufacturing a printed circuit board according to another embodiment of the present invention.

[0027] Reference numerals:

[0028] Through-hole 101; blind hole 102;

[0029] Hole copper 20; solder mask protective layer 40. Detailed implementation manners

[0030] Embodiments of the present invention will be described in detail below. The embodiments described with reference to the drawings are exemplary. Embodiments of the present invention will be described in detail below.

[0031] When manufacturing a printed circuit board using the traditional POFV process, due to the too small contact area between the surface copper and the hole copper, the bonding force of the capping copper on the POFV hole is too small, and in a too cold or too hot environment, it may break, thereby reducing the reliability of the printed circuit board.

[0032] To solve the above problems, an embodiment of the first aspect of the present invention provides a method for manufacturing a printed circuit board. By using this method, the contact area between the surface copper and the hole copper can be increased, the bonding force of the capping copper on the POFV hole can be increased, so that the capping copper on the POFV hole is not easily broken, thereby ensuring the reliability of the printed circuit board.

[0033] The following refers to Figure 1 Describe a method for manufacturing a printed circuit board according to an embodiment of the present invention. This method for manufacturing a printed circuit board includes at least steps S1 - S4.

[0034] Step S1: Provide a substrate and form holes in the substrate.

[0035] Specifically, holes are formed in the substrate by laser drilling or mechanical drilling. Among them, the number of holes can be one or more, which can be set according to actual situations and will not be specifically limited here. The type of holes can also be set according to actual situations. For example, refer to Figure 2As shown, the holes may include through holes 101 and / or blind holes 102.

[0036] Step S2: Conduct electroless copper plating and resin plugging on the holes in sequence to obtain a hole-plugged board piece.

[0037] Specifically, referring to Figure 3 and Figure 4 As shown, electroless copper plating is performed on the surface of the holes to form a copper plating layer, i.e., hole copper 20, and resin plugging is performed after the formation of the hole copper, so that the holes are filled with resin, enhancing the stability of the holes. Among them, the resin can be a thermosetting resin, such as epoxy resin, etc.

[0038] Step S3: Form grooves 30 on the surface of the holes on the hole-plugged board piece, where the depth of the grooves is less than the depth of the holes.

[0039] Specifically, referring to Figure 5 As shown, part of the copper foil on the surface of the holes is removed by laser ablation or mechanical grinding such as drilling, and part of the resin in the holes is removed, so that the hole copper covered by this part of the resin is exposed, and the remaining resin should ensure the stability of the hole copper, thereby forming grooves 30, where the depth of the grooves 30 is less than the depth of the holes.

[0040] Exemplarily, taking drilling as an example, after resin plugging, the hole-plugged board piece is drilled, such as using a drill bit with an angle close to a flat angle for processing. Specifically, part of the copper foil on the upper and lower surfaces of the through hole 101 is removed by grinding, and then the upper and lower holes of the through hole 101 are drilled by the drill bit to remove part of the resin in the holes, so that the hole copper covered by this part of the resin is exposed, thereby forming grooves 31 and 32, and the sum of the depths of the grooves 31 and 32 is less than the depth of the through hole 101, that is, the drilling depth of the drill bit during processing is the depth that does not damage the next layer of traces. Among them, the upper and lower holes of the through hole 101 can be drilled simultaneously or separately in sequence, and no specific limitation is made here; or part of the copper foil on the surface of the blind hole 102 is removed by grinding, and then the upper and lower holes of the through hole 101 are drilled, and then the hole of the blind hole 102 is drilled by the drill bit to remove part of the resin in the holes, so that the hole copper covered by this part of the resin is exposed, thereby forming groove 33.

[0041] Among them, the drill bit should be selected according to the size of the holes, and after drilling, the inside of the grooves 30 should be cleaned to remove residues brought by drilling, etc.

[0042] Step S4: Plug the grooves with a conductive material.

[0043] Specifically, referring to Figure 6As shown, by forming a groove, part of the hole copper is exposed. After the hole is filled with a conductive material, the contact area between the formed surface copper and the hole copper increases, thereby increasing the bonding force between the capping copper on the POFV hole, making it less likely for the capping copper on the POFV hole to break, and thus ensuring the reliability of the printed circuit board.

[0044] According to the method for preparing a printed circuit board according to an embodiment of the present invention, by processing the hole-filled board member, a groove is formed on the surface of the holes on the hole-filled board member, and the groove is filled with a conductive material, thereby using the groove to increase the contact area between the surface copper and the hole copper 20, increasing the bonding force between the capping copper on the POFV hole, making it less likely for the capping copper on the POFV hole to break, and thus ensuring the reliability of the printed circuit board.

[0045] In some embodiments, forming a groove 30 on the surface of the holes on the hole-filled board member includes laser ablation of the surface of the holes on the hole-filled board member to form a groove 30 on the holes after hole filling.

[0046] Specifically, by laser ablating the periphery of the holes within a certain processing time, the copper foil on the surface of the holes and part of the resin in the holes are removed, avoiding residual resin that may affect the conductivity of the holes, and when forming the groove 30, avoiding ablation of the hole copper 20, which may cause a reduction in the thickness of the hole copper 20, and ensuring the flatness of the surface of the groove 30.

[0047] In some embodiments, the preparation method further includes subjecting the hole-filled board member to a brownification treatment before performing the laser ablation.

[0048] Specifically, through the brownification treatment, the physical and chemical properties of the copper surface around the holes are changed, facilitating the absorption of the laser light source, and being able to remove substances such as grease and debris on the surface of the substrate, ensuring the cleanliness of the substrate surface.

[0049] In some embodiments, laser ablation of the surface of the holes on the hole-filled board member includes using an ultraviolet laser light source to perform laser ablation on the surface of the holes on the hole-filled board member.

[0050] Specifically, after the brownification treatment, the physical and chemical properties of the copper surface around the holes change, and the absorption effect of the copper surface around the holes on the ultraviolet light source is enhanced. Thus, when using an ultraviolet laser for laser ablation, the laser ablation effect is better when removing the copper foil on the surface of the holes, and energy can be saved.

[0051] In some embodiments, after filling the groove 30 with a conductive material, the preparation method further includes heating and curing the hole-filled board member; forming pads on the cured hole-filled board member to obtain a printed circuit board.

[0052] Specifically, after the conductive material fills the holes, the bonding between the conductive material, the hole copper, and the resin is not tight enough. By heating and curing, the bonding between the conductive material, the hole copper 20, and the resin becomes tighter, enhancing the conductivity of the holes and ensuring that the ablated part of the resin does not reduce the stability of the holes. A solder pad is formed on the cured hole-filled board for soldering electronic components, avoiding problems such as poor soldering or de-soldering during the soldering process.

[0053] In some embodiments, before heating and curing the hole-filled board, the preparation method further includes a panel grinding operation on the hole-filled board.

[0054] Specifically, referring to Figure 6 and Figure 7 as shown, before heating and curing the hole-filled board, there is excess conductive material on the surface of the holes and the surface of the substrate. The excess conductive material can be removed by the grinding squeegee, ensuring the flatness of the substrate surface. Moreover, the substrate surface becomes rougher after grinding. If a coating or protective layer is added, the bonding force between the substrate and it can be enhanced.

[0055] In some embodiments, after forming the solder pad, the preparation method further includes a solder mask processing on the hole-filled board to form a solder mask protective layer 40 on the outer surface of the hole-filled board.

[0056] Specifically, referring to Figure 8 as shown, after forming the solder pad, a solder mask processing is performed on the hole-filled board to form a solder mask protective layer on the outer surface of the hole-filled board. When soldering electronic components, it can prevent the solder from flowing outside the solder pad, avoiding short circuits between circuit boards.

[0057] In some embodiments, the conductive material is copper paste, conductive ink, or graphene material.

[0058] In some embodiments, the substrate is a multilayer board.

[0059] Specifically, by adopting the printed circuit board preparation method, the multilayer board can reduce the wiring density of the printed multilayer board and save space.

[0060] In a second aspect embodiment of the present invention, a printed circuit board is proposed, and this printed circuit board is prepared by using the printed circuit board preparation method of the above embodiment.

[0061] For the printed circuit board according to the embodiment of the present invention, the contact area between the surface copper and the hole copper 20 increases, making the bonding force of the capping copper on the POFV hole larger, and the capping copper on the POFV hole is not easily broken, thus ensuring the reliability of the printed circuit board.

[0062] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example.

[0063] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

[0064] In the description of this specification, any process or method description shown in the flowchart or described in other ways herein can be understood as representing a module, segment, or part of code including one or more executable instructions for implementing a customized logical function or process, and the scope of the preferred embodiments of the present invention includes additional implementations, where the functions can be executed in a substantially simultaneous manner or in a reverse order according to the functions involved, rather than in the order shown or discussed, and this should be understood by those skilled in the technical field to which the embodiments of the present invention belong.

[0065] The logic and / or steps represented in the flowchart or described in other ways herein, for example, can be considered as a sequenced list of executable instructions for implementing a logical function, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or in conjunction with these instruction execution systems, apparatuses, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable media on which a program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpretation, or other suitable processing as necessary, and then stored in a computer memory.

[0066] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits with logic gate circuits for implementing logic functions on data signals, application specific integrated circuits with appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0067] Those of ordinary skill in the art can understand that all or part of the steps carried by the method of implementing the above embodiments can be completed by instructing relevant hardware through a program. The program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0068] In addition, in each embodiment of the present invention, the functional units can be integrated into a processing module, or each unit can exist physically alone, or two or more units can be integrated into one module. The above integrated module can be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0069] The above-mentioned storage medium can be a read-only memory, a magnetic disk, an optical disk, etc. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0070] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example.

[0071] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for preparing a printed circuit board, characterized in that: include: providing a substrate, and forming holes in the substrate; The holes are sequentially subjected to copper electroplating and resin plugging to obtain a plugged hole plate; A groove is formed on the surface of the hole on the plugging plate, wherein the depth of the groove is less than the depth of the hole; The groove is plugged with a conductive material.

2. The method for preparing a printed circuit board according to claim 1, characterized in that: A groove is formed on the surface of the hole on the plugging plate, comprising: Laser ablation is performed on the surface of the hole on the plugging plate to form a groove on the hole after plugging.

3. The method for preparing a printed circuit board according to claim 2, characterized in that: The preparation method further comprises: Before laser ablation, the plugging plate is subjected to browning treatment.

4. The method for preparing a printed circuit board according to claim 2, characterized in that: Laser ablation is performed on the surface of the hole on the plugging plate, comprising: An ultraviolet laser light source is used to perform laser ablation on the surface of the hole on the plugging plate.

5. The method for preparing a printed circuit board according to claim 1, characterized in that: After plugging the groove with a conductive material, the preparation method further comprises: Heating and curing the plugging plate; A pad is formed on the cured plugged plate to obtain a printed circuit board.

6. The method for preparing a printed circuit board according to claim 5, characterized in that: Before heating and curing the plugging plate, the preparation method further comprises: Perform grinding operation on the plugging plate.

7. The method for preparing a printed circuit board according to claim 5, characterized in that: After forming the pad, the preparation method further comprises: The via plugging plate is subjected to solder resist processing to form a solder resist protective layer on the outer surface of the via plugging plate.

8. The method for preparing a printed circuit board according to claim 1, characterized in that: The conductive material is copper paste, conductive ink or graphene material.

9. The method for preparing a printed circuit board according to claim 1, characterized in that: The substrate is a multi-layer board.

10. A printed circuit board, characterized in that: The printed circuit board is prepared by the method for preparing the printed circuit board according to any one of claims 1 to 9.

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