Method for processing circuit board and circuit board

Abstract

The present invention relates to a circuit board processing method and a circuit board, the processing method comprising: providing an inner substrate, the inner substrate comprising an inner dielectric layer, a circuit layer located between the inner dielectric layers, and a copper layer located on an outer surface of the inner dielectric layer corresponding to the circuit layer area; reducing copper and patterning the copper layer to form a blank pattern area corresponding to the circuit layer on the copper layer; mixing epoxy resin conductive silver paste with photosensitive ink to form a coating; applying the coating to the copper layer to form a coating; performing pre-baking; after the pre-baking is completed, forming a coating pattern; laminating an outer dielectric layer on each side of the inner substrate; attaching a reinforcement sheet to the outer dielectric layer, and then laminating to form the desired circuit board. The present invention has a reasonable overall structural design and a simple and convenient processing method, and can effectively improve the shielding and high heat dissipation properties of circuit board products in precision fields such as medical treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit boards, and in particular to a processing method of a circuit board and the circuit board. Background Art

[0002] A circuit board, also known as a printed circuit board or PCB, is a support for electronic components and a carrier for electrical connections.

[0003] Circuit boards used in precision fields such as medical equipment are required to have high shielding properties to prevent interference from other electronic components during internal electrical signal transmission. At the same time, large amounts of heat will be generated locally during the operation of the equipment, so the circuit boards are also required to have strong heat dissipation performance.

[0004] At present, the requirement for high shielding performance is generally achieved by sticking electromagnetic film on the circuit, that is, in the area where high shielding properties are required, electromagnetic film with insulating colloid is stuck to achieve high shielding performance of the circuit in this area; but due to the limited bonding force of the electromagnetic film, problems such as electromagnetic film sliding and falling off are prone to occur during subsequent processing, and the sticking of electromagnetic film relies on the alignment bonding method, and the bonding accuracy is limited, which makes it difficult to meet the high-precision circuit board processing requirements. In addition, the electromagnetic film is easily affected by the processing during subsequent processing, resulting in unstable expansion and contraction, etc., causing the electromagnetic film to fail.

[0005] There are many ways to design and process high-heat dissipation circuit boards, such as increasing the copper thickness of the circuit, adding a heat dissipation module in the area where heat dissipation is required, or adding a heat dissipation device to the outside of the circuit board. However, all of these methods require increasing the volume of the circuit module in the equipment or changing the original circuit design, which will lead to changes in the design of other modules, increase the overall design cost, and complicate the design and manufacturing.

[0006] Based on the above problems, it is necessary to design and produce a circuit board and processing method that has both high shielding and high heat dissipation characteristics to meet the circuit board needs of precision fields such as medical care. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a circuit board processing method and a circuit board, which can have both high shielding and high heat dissipation properties and meet the circuit board needs in the precision field.

[0008] The first aspect of the present invention provides a method for processing a circuit board, comprising: providing an inner substrate, the inner substrate comprising an inner dielectric layer, a circuit layer located between the inner dielectric layers, and a copper layer located on an outer surface of the inner dielectric layer corresponding to an area of ​​the circuit layer, the area of ​​the copper layer being larger than the area of ​​the circuit layer; performing copper reduction and patterning on the copper layer to form a blank pattern area corresponding to the circuit layer on the copper layer; mixing epoxy resin conductive silver paste with photosensitive ink to form a coating; disposing the coating on the copper layer to form a coating layer, the coating layer filling the blank pattern area, the area of ​​the coating layer being larger than the area of ​​the copper layer and completely covering the copper layer area; performing pre-baking; after the pre-baking is completed, forming a coating pattern by exposure, development, and post-baking, the coating pattern completely covering the blank pattern area; laminating an outer dielectric layer on each side of the inner substrate; attaching a reinforcing sheet to the outer dielectric layer, and then laminating to form the desired circuit board.

[0009] Optionally, the area of ​​the coating pattern is smaller than the area of ​​the copper layer.

[0010] Optionally, the reinforcing sheet includes a stainless steel sheet, a nickel layer and an adhesive layer, and the reinforcing sheet is attached to the area of ​​the outer dielectric layer corresponding to the circuit layer through the adhesive layer.

[0011] Optionally, the copper layer is subjected to copper reduction and patterning operations, which specifically include forming a blank pattern area corresponding to the circuit layer on the copper layer by laminating, exposing, developing, and etching.

[0012] Optionally, the volume ratio of epoxy resin conductive silver paste to photosensitive ink in the coating is 10:1 to 20:1.

[0013] Optionally, a single side of the copper layer is 1 to 5 mm larger than a single side of the circuit layer.

[0014] Optionally, the baking parameters for the pre-baking are 75° C.×20 to 30 min.

[0015] Optionally, disposing the coating paste on the copper layer includes screen printing the coating paste on the copper layer.

[0016] A second aspect of the present invention provides a circuit board, which is manufactured using the above-mentioned processing method and includes: an inner substrate, wherein the inner substrate has an inner dielectric layer, a circuit layer located between the inner dielectric layers, and a copper layer located on the outer surface of the inner dielectric layer corresponding to the circuit layer area, and a blank pattern area corresponding to the circuit layer is provided on the copper layer; a coating pattern is provided on the copper layer and covers the blank pattern area; an outer dielectric layer is pressed onto both sides of the inner substrate; and a reinforcing sheet is attached to the outer dielectric layer.

[0017] Optionally, the reinforcing sheet includes a stainless steel sheet, a nickel layer and an adhesive layer, and the reinforcing sheet is attached to the area of ​​the outer dielectric layer corresponding to the circuit layer through the adhesive layer.

[0018] By adopting the above technical solution, epoxy resin conductive silver paste is mixed with photosensitive ink to form a coating, which is screen-printed on the area that needs to have high shielding properties, that is, the area on the copper layer corresponding to the circuit layer, to form a coating. Since the epoxy resin conductive silver paste has good metal layer properties and good thermal conductivity, the coating can achieve high shielding and high heat dissipation effects. At the same time, by attaching a reinforcing sheet to the area, on the one hand, it forms a strengthening support for the area, and on the other hand, it further enhances the shielding performance from the outer surface. The overall structural design of the circuit board is reasonable, and the processing method is simple and convenient, which can effectively improve the shielding and high heat dissipation of circuit board products in fine fields such as medical care. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 is a schematic diagram of a method for processing a circuit board according to an embodiment of the present invention;

[0021] Figure 2 Schematic diagram of the structure of the inner substrate in an embodiment of the present invention;

[0022] Figure 3 Schematic diagram of the structure after copper reduction and patterning of the copper layer in an embodiment of the present invention;

[0023] Figure 4 This is a schematic structural diagram of the embodiment of the present invention after the coating is formed by screen printing the coating on the copper layer;

[0024] Figure 5This is a schematic diagram of the structure after the coating pattern is produced in an embodiment of the present invention;

[0025] Figure 6 Schematic diagram of the structure of the circuit board in an embodiment of the present invention.

[0026] The reference numerals are as follows:

[0027] 101-inner dielectric layer, 102-circuit layer, 103-copper layer, 104-blank pattern area, 105-coating, 106-coating pattern, 107-outer dielectric layer, 108-reinforcement sheet, 1081-stainless steel sheet, 1082-nickel layer, 1083-glue layer. DETAILED DESCRIPTION

[0028] The following is a further description of specific embodiments of the present invention in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is intended to facilitate understanding of the present invention and does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0029] Example 1:

[0030] Please refer to Figure 1 , an embodiment of the present invention provides a method for processing a circuit board, comprising:

[0031] S1: Provide an inner substrate, wherein the inner substrate comprises an inner dielectric layer, a circuit layer located between the inner dielectric layers, and a copper layer located on an outer surface of the inner dielectric layer corresponding to the circuit layer area, wherein the area of ​​the copper layer is larger than the area of ​​the circuit layer.

[0032] Please refer to the following for details Figure 2 , take an inner substrate, the inner substrate has an inner dielectric layer 101 and a circuit layer 102 located between the dielectric layer 101, the area where the circuit layer 102 is located and the corresponding area of ​​the inner substrate are both areas where high shielding performance and high heat dissipation performance need to be produced, and a copper layer 103 is provided on the outer surface of the inner dielectric layer 101. The area of ​​the copper layer 103 is larger than the area of ​​the circuit layer 102. Optionally, a single side of the copper layer 103 is 1 to 5 mm larger than a single side of the circuit layer 102.

[0033] S2: performing copper reduction and patterning on the copper layer to form a blank pattern area corresponding to the circuit layer on the copper layer.

[0034] Please refer to Figure 3, the copper 103 is subjected to copper reduction and pattern production, and a blank pattern area 104 corresponding to the circuit layer 102 is etched on the copper layer 103 by means of film lamination, exposure, development, and etching, so as to reserve a position for the subsequent coating production and provide a bonding strength basis for the edge copper layer.

[0035] S3: Mix the epoxy resin conductive silver paste with the photosensitive ink to form a coating paste.

[0036] It should be further explained that this step can also be performed before step S1, and the coating paste is prepared for use. Optionally, the volume ratio of epoxy resin conductive silver paste to photosensitive ink in the coating paste is 10:1 to 20:1.

[0037] S4: placing the coating paste on the copper layer to form a coating layer, wherein the coating layer fills the blank pattern area, and the area of ​​the coating layer is larger than the area of ​​the copper layer, and completely covers the copper layer area.

[0038] Please continue reading Figure 4 The prepared coating slurry is applied on the copper layer 103 to form a coating 105. The coating 105 fills the blank graphic area 104. The area of ​​the coating 105 is larger than the area of ​​the copper layer 103 and completely covers the copper layer 103 area. The epoxy resin conductive silver paste in the coating slurry has good metal layer properties and good thermal conductivity. Therefore, the coating 105 can achieve high shielding and high heat dissipation effects.

[0039] Optionally, setting the coating on the copper layer 103 includes: screen printing the coating on the copper layer 103. It should be noted that screen printing is not the only method to set a coating on the copper layer, and is not specifically limited here.

[0040] S5: Pre-bake.

[0041] The coating layer 105 is cured by pre-baking.

[0042] Optionally, the coating 105 may be cured by baking at 75° C. for 20 to 30 minutes.

[0043] S6: After the pre-baking is completed, a coating pattern is produced by exposure, development, and post-baking, and the coating pattern completely covers the blank pattern area.

[0044] Please refer to Figure 5 Since the coating contains a photosensitive ink component, the coating 105 has photosensitive properties. After pre-baking, the coating pattern 106 is produced by exposure, development, and post-baking. The coating pattern 106 completely covers the blank pattern area 104.

[0045] Optionally, in order to make the bonding force of the coating pattern 106 stronger, after development and etching, the area of ​​the coating pattern 106 is made smaller than the area of ​​the copper layer 103, that is, the coating outside the copper layer 103 area is etched away, and the coating in the blank pattern area 104 and part of the coating on the copper layer 103 are retained.

[0046] It is understandable that the purpose of this step is to further process the coating 105 , remove unnecessary parts, obtain the coating pattern 106 , and ensure the flatness and regularity of the coating pattern 106 .

[0047] S7: stacking an outer dielectric layer on both sides of the inner substrate.

[0048] Please refer to Figure 6 After the coating pattern 106 is produced, an outer dielectric layer 107 is stacked on both sides of the inner substrate. The outer dielectric layer 107 protects the coating pattern 106 and the copper layer 103 and has an insulating effect.

[0049] S8: attaching a reinforcing sheet to the outer dielectric layer, and then laminating the layers to form a desired circuit board.

[0050] Please continue reading Figure 6 A reinforcing sheet 108 is attached to the outer dielectric layer 107 and then pressed to form the desired circuit board.

[0051] Optionally, the reinforcing sheet 108 includes a stainless steel sheet 1081 , a nickel layer 1082 and an adhesive layer 1083 , and the reinforcing sheet 108 is attached to the area of ​​the outer dielectric layer 107 corresponding to the circuit layer 102 through the adhesive layer 1083 .

[0052] Optionally, the pressing may be performed at a temperature of 180° C. for 2 to 5 minutes.

[0053] It can be understood that attaching the reinforcing sheet 108 not only forms a reinforcing support function for this area, but also further enhances the shielding performance from the outer surface.

[0054] The size of the reinforcing sheet 108 is larger than that of the copper layer 103. The reinforcing sheet 108 can be manufactured in the following manner: take a stainless steel sheet, apply an anti-corrosion film to one side of the stainless steel sheet, and then nickel-plate the other side of the stainless steel sheet. After the nickel plating is completed, make a glue layer on the nickel layer, and remove the anti-corrosion film to obtain the completed reinforcing sheet 108.

[0055] It should be noted that the above-mentioned method for preparing the reinforcing sheet is not the only method, and other methods can also be used to obtain the reinforcing sheet, which is not specifically limited here.

[0056] Example 2:

[0057] Please refer to Figure 6 , an embodiment of the present invention provides a circuit board, comprising:

[0058] An inner substrate, the inner substrate comprising an inner dielectric layer 101, a circuit layer 102 located between the inner dielectric layers 101, and a copper layer 103 located on an outer surface of the inner dielectric layer 101 corresponding to the circuit layer 102, wherein the copper layer 103 is provided with a blank pattern area corresponding to the circuit layer 102;

[0059] A coating pattern 106 is provided on the copper layer 102 and covers the blank pattern area;

[0060] An outer dielectric layer 107 is pressed onto both sides of the inner substrate;

[0061] The reinforcing sheet 108 is attached to the outer dielectric layer 107 .

[0062] Optionally, the reinforcing sheet 108 includes a stainless steel sheet 1081 , a nickel layer 1082 and an adhesive layer 1083 , and the reinforcing sheet 108 is attached to the area of ​​the outer dielectric layer 107 corresponding to the circuit layer 102 through the adhesive layer 1083 .

[0063] Optionally, the inner dielectric layer 101 and the outer dielectric layer 107 are made of polyimide, epoxy resin-glass fiber, or polytetrafluoroethylene.

[0064] The circuit board provided in the embodiment of the present invention can be manufactured using the method of Example 1. Please refer to Example 1 for a more detailed description.

[0065] A processing method for a circuit board and a circuit board in an embodiment of the present invention mix epoxy resin conductive silver paste with photosensitive ink to form a coating, which is screen-printed on an area that needs to have high shielding properties, that is, an area on the copper layer corresponding to the circuit layer, to form a coating. Since the epoxy resin conductive silver paste has good metal layer properties and good thermal conductivity, the coating can achieve high shielding and high heat dissipation effects. At the same time, by attaching a reinforcing sheet to the area, on the one hand, it forms a reinforced support for the area, and on the other hand, it further enhances the shielding performance from the outer surface. The overall structural design of the circuit board is reasonable, the processing method is simple and convenient, and it can effectively improve the shielding and high heat dissipation properties of circuit board products in precision fields such as medical care.

[0066] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It is apparent to those skilled in the art that various changes, modifications, substitutions, and variations to these embodiments may be made without departing from the principles and spirit of the present invention, and these changes and modifications still fall within the scope of protection of the present invention.

[0067] In the description of the patent of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", "row", "column", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the patent of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation to the patent of the present invention.

[0068] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention patent, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0069] In invention patents, unless otherwise expressly specified or limited, terms such as "install," "connect," "connect," "fix," and "fixed" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components, unless otherwise expressly limited. A person of ordinary skill in the art can understand the specific meanings of the above terms in invention patents based on the specific circumstances.

[0070] In the present invention, unless otherwise expressly specified or limited, a first feature "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature.

Claims

1. A method for processing a circuit board, characterized in that: include: Providing an inner substrate, the inner substrate comprising an inner dielectric layer, a circuit layer located between the inner dielectric layers, and a copper layer located on an outer surface of the inner dielectric layer corresponding to an area of ​​the circuit layer, wherein an area of ​​the copper layer is larger than an area of ​​the circuit layer; performing copper reduction and patterning on the copper layer to form a blank pattern area corresponding to the circuit layer on the copper layer; Mixing epoxy resin conductive silver paste with photosensitive ink to form a coating paste; Disposing the coating paste on the copper layer to form a coating layer, wherein the coating layer fills the blank pattern area, the area of ​​the coating layer is larger than the area of ​​the copper layer, and the coating layer completely covers the copper layer area; Pre-bake; After the pre-baking is completed, a coating pattern is produced by exposure, development, and post-baking, wherein the coating pattern completely covers the blank pattern area; and the area of ​​the coating pattern is smaller than the area of ​​the copper layer; An outer dielectric layer is stacked on both sides of the inner substrate; A reinforcing sheet is attached to the outer dielectric layer, and then pressed together to form the required circuit board.

2. A method for processing a circuit board according to claim 1, characterized in that: The reinforcing sheet includes a stainless steel sheet, a nickel layer and an adhesive layer. The reinforcing sheet is attached to the area of ​​the outer dielectric layer corresponding to the circuit layer through the adhesive layer.

3. The method for processing a circuit board according to claim 1, wherein: The specific operations of copper reduction and pattern production on the copper layer are to form a blank pattern area corresponding to the circuit layer on the copper layer through film lamination, exposure, development, and etching.

4. The method for processing a circuit board according to claim 1, wherein: The volume ratio of the epoxy resin conductive silver paste to the photosensitive ink in the coating is 10:1 to 20:

1.

5. The method for processing a circuit board according to claim 1, wherein: A single side of the copper layer is 1 to 5 mm larger than a single side of the circuit layer.

6. A method for processing a circuit board according to claim 1, characterized in that: The baking parameters for the pre-baking are 75° C.×20 to 30 minutes.

7. A method for processing a circuit board according to claim 1, characterized in that: The step of disposing the coating paste on the copper layer comprises screen printing the coating paste on the copper layer.

8. A circuit board, characterized in that: The circuit board is manufactured by the processing method according to any one of claims 1 to 6, comprising: An inner substrate, the inner substrate comprising an inner dielectric layer, a circuit layer located between the inner dielectric layers, and a copper layer located on an outer surface of the inner dielectric layer corresponding to the circuit layer area, wherein the copper layer is provided with a blank pattern area corresponding to the circuit layer; A coating pattern is provided on the copper layer and covers the blank pattern area; an outer dielectric layer, pressed onto both sides of the inner substrate; The reinforcing sheet is attached to the outer dielectric layer.

9. The circuit board according to claim 8, characterized in that: The reinforcing sheet includes a stainless steel sheet, a nickel layer and an adhesive layer. The reinforcing sheet is attached to the area of ​​the outer dielectric layer corresponding to the circuit layer through the adhesive layer.

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