Circuit board and processing method thereof

Abstract

The present invention discloses a circuit board and a processing method thereof, the processing method comprising: providing at least a first laminate, an adhesive layer, a gasket and a second laminate, wherein the first laminate is provided with an annular ring, and the adhesive layer is provided with a receiving hole; forming at least the first laminate, the adhesive layer, the gasket and the second laminate into a stacking assembly for lamination, wherein the adhesive layer and the second laminate are sequentially located on the side of the first laminate provided with the annular ring, the gasket is located in the receiving hole, and the projection of the annular ring on the gasket is located around the gasket; a groove is opened on the side of the stacking assembly away from the first laminate to expose the gasket, and a circuit board with a step groove is formed after the gasket is removed. By arranging the annular ring at a position corresponding to the gasket on the first laminate, when lamination is performed, the force of the annular ring on the gasket prevents the molten adhesive layer from entering the position corresponding to the area enclosed by the gasket and the annular ring, thereby protecting the bottom surface of the step groove and improving the quality of the product.

Description

Technical Field

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

[0002] Printed Circuit Board (PCB) is an important electronic component and one of the important components of the electronics industry. Almost every electronic device, from electronic watches and calculators to computers, communication electronic equipment, and military weapon systems, as long as there are electronic components such as integrated circuits, must use printed circuit boards to achieve electrical interconnection between them. Therefore, the role played by printed circuit boards in the field of circuit technology is becoming more and more important.

[0003] At present, circuit boards with step grooves are increasingly used. One method of forming a step groove is to embed a gasket in the circuit board, and then remove the gasket and the substrate on the gasket by controlled depth milling. The step groove obtained by this method has a high precision of the margin corresponding to the step groove on the circuit board. However, when embedding a gasket of larger size, the melted prepreg will enter the gap between the gasket and the substrate, so that the bottom surface of the step groove has adhesive material, which affects the quality of the product. Summary of the invention

[0004] The invention provides a circuit board and a processing method thereof, so as to solve the technical problem that adhesive material exists on the bottom surface of a step groove.

[0005] In order to solve the above technical problems, a technical solution adopted by the present invention is: to provide a processing method for a circuit board with a step groove, comprising: providing at least a first laminate, an adhesive layer, a gasket and a second laminate, wherein an annular ring is arranged on the first laminate, and a receiving hole is opened on the adhesive layer; at least the first laminate, the adhesive layer, the gasket and the second laminate are formed into a stacking assembly for pressing, wherein the adhesive layer and the second laminate are sequentially located on the side of the first laminate provided with the annular ring, the gasket is located in the receiving hole, the gasket and the annular ring are stacked, and the projection of the annular ring on the gasket is located around the gasket; a groove is opened on the side of the stacking assembly away from the first laminate to expose the gasket, and the circuit board with the step groove is formed after removing the gasket.

[0006] Optionally, the step of providing the first laminate includes: providing a substrate, the substrate including a dielectric layer and a metal layer located on at least one side of the dielectric layer; etching the metal layer to form a circuit pattern and / or a toroidal coil on the dielectric layer, the toroidal coil forming the annular ring.

[0007] Optionally, the stacking assembly has an end face away from the first laminate, and a method for opening a groove on a side of the stacking assembly away from the first laminate to expose the gasket is: using a controlled depth milling process to open a groove surrounding the gasket on the end face, wherein the depth of the groove is greater than or equal to the distance between the surface of the gasket away from the first laminate and the end face, and is less than or equal to the distance between the surface of the gasket close to the first laminate and the end face.

[0008] Optionally, the number of the annular rings is at least two, and the width of each of the annular rings along a direction perpendicular to the stacking direction of the first laminate and the second laminate is 0.1-2.0 mm.

[0009] Optionally, the shape of the accommodating hole formed on the adhesive layer is matched with the shape of the gasket, and the thickness of the gasket is less than or equal to the thickness of the adhesive layer.

[0010] Optionally, the thickness of the gasket is greater than the thickness of the adhesive layer. Before the first laminate, the adhesive layer, the gasket and the second laminate are assembled into a stacked assembly for lamination, the method further includes: opening an avoidance groove on the side of the second laminate close to the adhesive layer, and the depth of the avoidance groove is equal to the height of the gasket above the adhesive layer.

[0011] Optionally, the gasket is made of Teflon, plasticized glue or curing resin.

[0012] In order to solve the above technical problems, another technical solution adopted by the present invention is: providing a circuit board with a step groove, the circuit board comprising: a first laminate, an adhesive layer and a second laminate, the adhesive layer is arranged between the first laminate and the second laminate, and is used to bond the first laminate and the second laminate, the step groove passes through the second laminate and ends at the first laminate, and an annular ring is arranged on the bottom surface of the step groove, and the area enclosed by the annular ring is smaller than the bottom area of ​​the step groove.

[0013] Optionally, a width of the annular ring along a direction perpendicular to a stacking direction of the first laminate and the second laminate is 0.1-2.0 mm.

[0014] Optionally, the distance between the outer periphery of the annular ring and the side wall of the step groove is greater than or equal to 0.1 mm.

[0015] The beneficial effects of the above-mentioned embodiments are as follows: in the embodiments of the present invention, an annular ring is arranged at a position corresponding to the gasket on the first laminate, and after the first laminate, the adhesive layer, the gasket and the second laminate are stacked, the annular ring and the gasket are stacked in the pressing direction. During pressing, the force exerted by the annular ring on the gasket prevents the adhesive layer in a molten state from entering the position corresponding to the area enclosed by the gasket and the annular ring, that is, the adhesive layer in a molten state cannot flow to the bottom surface of the step groove, thereby protecting the bottom surface of the step groove and improving the quality of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0017] Figure 1 is a schematic flow chart of a method for processing a circuit board in one embodiment of the present invention;

[0018] Figure 2 It is a schematic diagram of the top view of the structure when the annular ring and the gasket are matched;

[0019] Figure 3 yes Figure 1 A schematic diagram of a specific flow chart of an embodiment of step S10 in FIG. 1 ;

[0020] Figure 4 is with Figure 1 A schematic diagram of a process flow of an embodiment corresponding to the steps in;

[0021] Figure 5 yes Figure 1 A schematic diagram of a specific flow chart of another embodiment of step S10;

[0022] Figure 6 is with Figure 1 A schematic diagram of a process flow of another embodiment corresponding to the steps in;

[0023] Figure 7 yes Figure 6 A schematic cross-sectional view of a stacked assembly after the components are stacked and pressed;

[0024] Figure 8 It is a schematic diagram of the process flow of slotting on a stacked component;

[0025] Fig. 9 is a schematic cross-sectional structural diagram of a stacked assembly formed in another embodiment of the present invention;

[0026] Fig.10is a schematic flow chart of a method for processing a circuit board in another embodiment of the present invention;

[0027] Fig.11 is a schematic cross-sectional structural diagram of a circuit board in one embodiment of the present invention;

[0028] Fig.12 is a schematic flow chart of a method for processing a circuit board in another embodiment of the present invention;

[0029] Fig.13 yes Fig.12 A specific flow chart of step M10 in FIG.

[0030] Fig.14 is with Fig.12 Schematic diagram of the process flow corresponding to the steps in;

[0031] Fig.15 It is a schematic cross-sectional structural diagram of a circuit board in another embodiment of the present invention. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] See also Figure 1 , Figure 1 FIG. 1 is a flow chart of a method for processing a circuit board in an embodiment of the present invention. The present invention provides a method for processing a circuit board, comprising:

[0034] S10: Provide at least a first laminate, an adhesive layer, a gasket and a second laminate, wherein the second laminate is provided with an annular ring and the adhesive layer is provided with a receiving hole.

[0035] S20: At least a first laminate, an adhesive layer, a gasket and a second laminate are formed into a stacking assembly for lamination, wherein the adhesive layer and the second laminate are sequentially located on one side of the first laminate, the gasket is located in the receiving hole, and the projection of the annular ring on the gasket is located around the gasket.

[0036] S30: Grooving a side of the stacked assembly away from the first laminate to expose the gasket, and removing the gasket to form a circuit board with a step groove.

[0037] In the embodiment of the present invention, an annular ring is arranged at a position on the second laminate corresponding to the gasket. After the first laminate, the adhesive layer, the gasket and the second laminate are stacked, the annular ring and the gasket are stacked in the pressing direction. During pressing, the force exerted by the annular ring on the gasket prevents the adhesive layer in a molten state from entering the position corresponding to the area enclosed by the gasket and the annular ring, that is, the adhesive layer in a molten state cannot flow to the bottom surface of the step groove, thereby protecting the bottom surface of the step groove and improving the quality of the product.

[0038] The annular ring is a hollow annular part, and the adhesive layer can be made of a viscous material, and specifically a thermosetting material. A thermosetting material means that the material can soften and flow when heated for the first time, and when heated to a certain temperature, a chemical reaction occurs, causing the cross-linking to solidify and harden; this change is irreversible, and thereafter, when heated again, the material can no longer soften and flow. In this embodiment, a prepreg is used to make the adhesive layer, and the adhesive layer is formed by the prepreg being melted and solidified.

[0039] In other embodiments, the adhesive layer can also be made of thermoplastic materials. Among them, thermoplastic materials refer to: plastics with the characteristics of softening when heated and hardening when cooled. When heated, it softens and flows, and when cooled, it hardens. This process is reversible and can be repeated. Common thermoplastic materials include but are not limited to polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyoxymethylene, polycarbonate, polyamide, acrylic plastics, other polyolefins and their copolymers, polysulfones, polyphenylene ethers, chlorinated polyethers, etc. The resin molecular chains in thermoplastic plastics are all linear or branched structures. There are no chemical bonds between the molecular chains. The process of softening and flowing when heated and hardening when cooled is a physical change.

[0040] In one example, the thermoplastic material may include polyketone, polyaramid, polyimide, polyetherimide, polyamideimide, polyphenylene sulfide, polyphenylene sulfone, fluoropolymer, polybenzimidazole, derivatives thereof, or combinations thereof.

[0041] Among them, Figure 2 As shown, Figure 2 1 is a schematic diagram of the top view of the structure when the annular ring and the gasket are matched. The projection of the annular ring 10 on the gasket 20 is located around the gasket 20, which means that the positive projection of the annular ring 10 on the gasket 20 is close to the periphery of the gasket 20 and is spaced from the periphery of the gasket 20. The size of the spacing can be flexibly set as needed, and the embodiment of the present invention does not specifically limit it. The hardness coefficients of the annular ring 10 and the gasket 20 are both large, so that when laminating, the force of the annular ring 10 on the gasket 20 can extend to the other opposite side of the gasket 20.

[0042] Among them, see Figure 3 , Figure 3 yes Figure 1A specific flow chart of step S10 in an embodiment of the present invention is shown in FIG. In step S10, the step of providing a second laminate comprises:

[0043] S101: providing a substrate, wherein the substrate comprises a dielectric layer and a metal layer located on at least one side of the dielectric layer.

[0044] S102: etching the metal layer to form a circuit pattern and / or a toroidal coil on the dielectric layer, wherein the toroidal coil forms an annular ring.

[0045] Specifically, the substrate can be a commonly used copper clad laminate, and can be a single-sided copper clad laminate or a double-sided copper clad laminate. The single-sided copper clad laminate includes a dielectric layer and a metal layer located on one side of the dielectric layer, and the double-sided copper clad laminate includes a dielectric layer and metal layers located on opposite sides of the dielectric layer. The use of a single-sided copper clad laminate or a double-sided copper clad laminate can be determined according to the number of circuit patterns formed on the substrate as needed, and the embodiment of the present invention does not make specific limitations.

[0046] In other embodiments, other metals may be used to make the metal layer located on the surface of the dielectric layer, which is not specifically limited in the embodiments of the present application.

[0047] Among them, see Figure 4 , Figure 4 is with Figure 1 . In this embodiment, the number of substrates 32 used to form the second laminate 30 can be one, and the substrate 32 is a double-sided copper-clad plate, including a dielectric layer 321 and metal layers 323 located on opposite sides of the dielectric layer 321. When forming a circuit pattern 325 and a toroidal coil on the dielectric layer 321, a conventional etching process can be used to etch the metal layer 323 to simultaneously form the circuit pattern 325 and / or the toroidal coil located on the dielectric layer 321.

[0048] In this embodiment, when etching the substrate 32 , the circuit pattern 325 and the annular coil are respectively formed on the two metal layers 323 to increase the number of the annular coils and enhance the force of the annular coils on the gasket 20 .

[0049] In another embodiment, when etching the substrate 32 , the circuit pattern 325 and the toroidal coil may be simultaneously formed on one of the metal layers 323 , and the circuit pattern 325 or the toroidal coil may be formed on the other metal layer 323 .

[0050] In another embodiment, the substrate 32 may also be a single-sided copper-clad board. When etching the substrate 32 , the circuit pattern 325 and the annular coil may be simultaneously formed on the metal layer 323 , or only the annular coil may be formed on the metal layer 323 .

[0051] In another embodiment, the number of the substrate 32 can be more than one. Figure 5 , Figure 5 yes Figure 1 A specific flow chart of another embodiment of step S10 in FIG. 1 is shown in FIG. 1. In step S10, the step of providing a second laminate comprises:

[0052] S110: providing a plurality of substrates, each substrate comprising a dielectric layer and a metal layer located on at least one side of the dielectric layer.

[0053] S120: etching a metal layer on at least one substrate to form a circuit pattern and / or a toroidal coil on the dielectric layer, wherein the toroidal coil forms an annular ring.

[0054] S130: stacking a plurality of substrates, sandwiching an adhesive layer between adjacent substrates, and pressing them together to form a second laminate.

[0055] Among them, the structure of the substrate in this embodiment is the same as the structure of the substrate in the above embodiment, and the method of forming a circuit pattern and a ring coil on the substrate is also the same as that in the above embodiment. The difference between this embodiment and the above embodiment is that the number of substrates in this embodiment is multiple, and after etching the multiple substrates, the multiple substrates need to be pressed together to form a second laminate.

[0056] Specifically, see Figure 6 , Figure 6 is with Figure 1 Schematic diagram of a process flow of another embodiment corresponding to the steps in . In this embodiment, there are two substrates 32, each substrate 32 includes a dielectric layer 321 and metal layers 323 located on opposite sides of the dielectric layer 321, and the number of the annular coils formed on the dielectric layer 321 can be one or more.

[0057] For example, in one embodiment, a toroidal coil may be formed on one of the two substrates 32 , and the toroidal coil may be located on one side of the substrate 32 or on both opposite sides of the substrate 32 , while no toroidal coil is formed on the other substrate 32 .

[0058] In another embodiment, an annular coil may be formed on both substrates 32 , and the annular coil on each substrate 32 may be located on one side of the substrate 32 or on two opposite sides of the substrate 32 at the same time.

[0059] Among them, the number of substrates 32 can be determined according to the number of circuit layers required for the circuit board, and the embodiment of the present invention does not make specific limitations. When the number of substrates 32 is greater than two, a ring coil can be formed on one of the multiple substrates 32, or on part of the multiple substrates 32. Of course, ring coils can also be formed on all substrates 32, and the embodiment of the present invention does not make specific limitations. When multiple ring coils are formed, the multiple ring coils have the same size, and when multiple substrates 32 are stacked, the multiple ring coils are aligned with each other to abut against the same position of the gasket 20 together, thereby increasing the abutting force of the ring coils on the gasket 20.

[0060] By configuring the annular ring 10 as an annular coil formed by etching, the embodiment of the present invention can simultaneously etch and form the circuit pattern 325 on the second laminate 30 and form the annular ring 10 at the same time, thereby simplifying the processing technology and improving the production efficiency of the second laminate 30.

[0061] In another embodiment, the annular ring 10 can also be set as an annular gasket, which can be fixed on the second laminate 30 by welding or bonding. The embodiment of the present invention does not specifically limit the form of the annular ring 10 and its connection method with the second laminate 30.

[0062] Among them, Figure 4 and Figure 6 As shown, the first laminate 40 may be a double-sided copper clad laminate, and a circuit pattern 325 is formed on one side of the first laminate 40 close to the second laminate 30 .

[0063] Optionally, the number of the annular rings 10 is at least two, and the width of the two annular rings 10 along the stacking direction perpendicular to the first laminate 40 and the second laminate 30 may be 0.1-2.0 mm. Figure 4 As shown, the width of the annular ring 10 along the stacking direction perpendicular to the first laminate 40 and the second laminate 30 is L, and the size of L can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm or 2.0mm, etc., which is not specifically limited in the embodiment of the present invention. By setting the width of the annular ring 10 along the stacking direction perpendicular to the first laminate 40 and the second laminate 30 to 0.1-2.0mm, not only can the problem of the inability of multiple annular coils to be stacked in the stacking direction of the first laminate 40 and the second laminate 30 due to the alignment accuracy error of the substrate 32 be overcome, but also the overflow of glue can be effectively prevented.

[0064] Furthermore, if Figure 7 As shown, Figure 7 yes Figure 6 The cross-sectional structure diagram of the stacked assembly after the elements are stacked and pressed. The stacked assembly 50 formed by step S20 has an end face 52 away from the first laminate 40. In step S30, the specific method of making a groove on the side of the stacked assembly 50 away from the first laminate 40 to expose the gasket 20 is: using a controlled depth milling process, a groove surrounding the gasket 20 is opened on the end face 52, and the depth of the groove is greater than or equal to the distance between the surface 21 of the gasket 20 away from the first laminate 40 and the end face 52, and less than or equal to the distance between the surface 23 of the gasket 20 close to the first laminate 40 and the end face 52.

[0065] Specifically, Figure 8 As shown, Figure 8 Schematic diagram of the process flow of slotting on a stacked assembly. A drill bit 60 is inserted into the stacked assembly 50 from the side of the second laminate 30 away from the first laminate 40 to slot on the end surface 52. The travel path of the drill bit 60 surrounds the circumference of the gasket 20 to cut off the connection between the gasket 20 and the circumferential adhesive layer 70, so as to facilitate the removal of the gasket 20.

[0066] Among them, Figure 8 As shown, the distance between the surface 21 of the gasket 20 away from the first laminate 40 and the end face 52 is A, the distance between the surface 23 of the gasket 20 close to the first laminate 40 and the end face 52 is B, and the drilling depth of the drill bit 60 is H. By setting the drilling depth H of the drill bit 60 to be greater than or equal to the distance A between the surface 21 of the gasket 20 away from the first laminate 40 and the end face 52, and less than or equal to the distance B between the surface 23 of the gasket 20 close to the first laminate 40 and the end face 52, that is, setting A≤H≤B, on the one hand, it is convenient to remove the gasket 20, and on the other hand, it can also avoid interference with the circuit pattern 325 on the first laminate 40, thereby protecting the circuit pattern 325 located at the bottom of the step groove.

[0067] In one embodiment, the shape of the receiving hole 72 formed on the adhesive layer 70 matches the shape of the gasket 20, and the thickness of the gasket 20 is less than or equal to the thickness of the adhesive layer 70. Figure 4 and Figure 6 As shown, the thickness of the gasket 20 is set to be equal to the thickness of the adhesive layer 70 so that the gasket 20 completely fills the gap between the first laminate 40 and the second laminate 30, reducing the flow of the adhesive layer 70 in a molten state.

[0068] Specifically, the shape of the receiving hole 72 is adapted to the shape of the gasket 20 , which means that the shape of the receiving hole 72 is the same as the shape of the gasket 20 , and the size of the receiving hole 72 is the same as the size of the gasket 20 , and the gasket 20 can just be completely filled in the receiving hole 72 .

[0069] like Fig. 9 As shown, Fig. 9 2 is a schematic diagram of a cross-sectional structure of a stacked assembly formed in another embodiment of the present invention. In another embodiment, the thickness of the gasket 20 can be set to be greater than the thickness of the adhesive layer 70. In this case, before the first laminate 40, the adhesive layer 70, the gasket 20 and the second laminate 30 are assembled into a stacked assembly 50 for lamination, the method further includes: a relief groove 34 is opened on one side of the second laminate 30 close to the adhesive layer 70, and the depth of the relief groove 34 is equal to the height of the gasket 20 above the adhesive layer 70.

[0070] Specifically, in the step of providing the second laminate 30, after laminating a plurality of substrates 32 to obtain the second laminate 30, the step further includes opening an avoidance groove 34 on the surface of the second laminate 30 facing the first laminate 40. The depth of the avoidance groove 34 is equal to the height of the gasket 20 above the adhesive layer 70, and the shape of the avoidance groove 34 is adapted to the shape of the gasket 20, so that when the first laminate 40, the adhesive layer 70, the gasket 20 and the second laminate 30 are stacked, part of the gasket 20 is located in the receiving hole 72 on the adhesive layer 70, and the other part of the gasket 20 is located in the avoidance groove 34 on the second laminate 30.

[0071] The material of the gasket 20 may be Teflon, plasticized glue or cured resin, etc. Specifically, in this embodiment, since the Teflon gasket 20 has strong anti-adhesion and anti-plating properties, it is convenient for subsequent removal and is not easily electroplated, so the Teflon material is used to make the gasket 20. In addition, by providing the gasket 20, the processing accuracy of the step groove can be improved in this embodiment.

[0072] In another embodiment, if Fig.10 As shown, Fig.10 FIG. 1 is a flow chart of a method for processing a circuit board in another embodiment of the present invention. Specifically, the method for processing a circuit board includes:

[0073] S100: Provide at least a first laminate, an adhesive layer, a gasket and a second laminate, wherein the second laminate is provided with an annular ring and the adhesive layer is provided with a receiving hole.

[0074] S200: At least a first laminate, an adhesive layer, a gasket and a second laminate are formed into a stacking assembly for lamination, wherein the adhesive layer and the second laminate are sequentially located on one side of the first laminate, the gasket is located in the receiving hole, and the projection of the annular ring on the gasket is located around the gasket.

[0075] S300: Drill holes in the non-step groove area of ​​the stacked component, and perform copper deposition and electroplating.

[0076] S400: Etching to form a circuit pattern on a surface of the stacked component away from the first laminate.

[0077] S500: forming a solder resist layer on the circuit pattern.

[0078] S600: A groove is formed on a side of the stacked assembly away from the first laminate to expose the gasket, and a circuit board with a step groove is formed after the gasket is removed.

[0079] Among them, step S100 in this embodiment is the same as step S10 in the above embodiment, step S200 is the same as step S20 in the above embodiment, and step S600 is the same as step S30 in the above embodiment. For details, please refer to the description in the above embodiment. The difference between this embodiment and the above embodiment is that before the groove is formed on the side of the stacked assembly away from the first laminate, it also includes: forming a circuit pattern in the non-step groove area of ​​the stacked assembly, and electrically connecting the circuit pattern with the circuit pattern inside the stacked assembly, and then insulating the circuit pattern on the surface of the circuit board.

[0080] Specifically, after the laminated assembly is obtained, a hole can be drilled in the non-step groove area of ​​the laminated assembly obtained by lamination, for example, a through hole outside the step groove area can be made, and then, the through hole can be copper plated and electroplated to metalize the processed through hole. Then, a conventional etching process can be used to form a circuit pattern on the end face of the second laminate. The metalized through hole electrically connects the circuit pattern on the end face of the second laminate with the circuit pattern inside the laminated assembly. Finally, a solder mask is formed on the circuit pattern to protect the circuit pattern on the surface and to insulate the circuit pattern.

[0081] Furthermore, if Fig.11 As shown, Fig.11 It is a schematic diagram of the cross-sectional structure of a circuit board in an embodiment of the present invention. On the other hand, the present invention also provides a circuit board 100 having a step groove 110, and the circuit board 100 can be manufactured by the processing method in the above embodiment. The circuit board 100 can specifically include a first laminate 40, a second laminate 30 and an adhesive layer 70, the adhesive layer 70 is arranged between the first laminate 40 and the second laminate 30, and is used to bond the first laminate 40 and the second laminate 30, the step groove 110 passes through the second laminate 30 and ends at the first laminate 40, and an annular indentation is formed on the bottom surface of the step groove 110, and the outer contour of the annular indentation is spaced apart from the side wall of the step groove 110. Please refer to the description in the above embodiment for the method of making the circuit board 100, which will not be repeated here. Among them, the annular indentation on the bottom surface of the step groove 110 is formed due to the abutment of the annular ring 10 on the gasket 20.

[0082] In the above embodiment, the annular ring 10 is formed on the second laminate 30, and the abutting force of the annular ring 10 on the gasket 20 during lamination is utilized to prevent the molten adhesive layer 70 from entering the bottom surface of the step groove.

[0083] In another embodiment, see Fig.12 , Fig.12 FIG. 1 is a flow chart of a method for processing a circuit board in another embodiment of the present invention. In this embodiment, the method for processing a circuit board includes:

[0084] M10: At least a first laminate, an adhesive layer, a gasket and a second laminate are provided, the first laminate is provided with an annular ring, and the adhesive layer is provided with a receiving hole.

[0085] M20: At least a first laminate, an adhesive layer, a gasket and a second laminate are formed into a stacking assembly for lamination, wherein the adhesive layer and the second laminate are sequentially located on one side of the first laminate provided with an annular ring, the gasket is located in the receiving hole, the gasket and the annular ring are stacked, and the projection of the annular ring on the gasket is located at the periphery of the gasket.

[0086] M30: A groove is made on the side of the stacked assembly away from the first laminate to expose the gasket, and a circuit board with a step groove is formed after the gasket is removed.

[0087] The processing method of the circuit board in this embodiment is roughly the same as the processing method of the circuit board in the above embodiment, with the difference being that in this embodiment, an annular ring is arranged at a position corresponding to the gasket on the first laminate, and after the first laminate, the adhesive layer, the gasket and the second laminate are stacked, the annular ring and the gasket are stacked in the pressing direction. During pressing, the force exerted by the annular ring on the gasket prevents the adhesive layer in a molten state from entering the position corresponding to the area enclosed by the gasket and the annular ring, that is, the adhesive layer in a molten state cannot flow to the bottom surface of the step groove, thereby protecting the bottom surface of the step groove and improving the quality of the product.

[0088] The differences between this embodiment and the above embodiment will be described below. For the description of the same parts, please refer to the description in the above embodiment, which will not be repeated here.

[0089] like Fig.13 and Fig.14 As shown, Fig.13 yes Fig.12 The specific flow chart of step M10 in FIG. Fig.14 is with Fig.12 Schematic diagram of the process flow corresponding to the steps in step M10. In step M10, the step of providing a first laminate 40 includes:

[0090] M110: Provide a substrate 32 , wherein the substrate 32 includes a dielectric layer 321 and a metal layer 323 located on at least one side of the dielectric layer 321 .

[0091] M120 : etching the metal layer 323 to form a circuit pattern 325 and / or a toroidal coil on the dielectric layer 321 , and the toroidal coil forms an annular ring 10 .

[0092] Specifically, in this embodiment, the steps of forming the first laminate 40 are the same as the steps of forming the second laminate 30 in the above embodiment, and please refer to the description in the above embodiment. Fig.14 In the illustrated embodiment, there is one substrate 32, which includes a dielectric layer 321 and a metal layer 323 located on opposite sides of the dielectric layer 321. Two annular coils are formed on the first laminate 40, and the two annular coils are stacked in the stacking direction of the stacking assembly.

[0093] like Fig.15 As shown, Fig.15 2 is a schematic diagram of a cross-sectional structure of a circuit board in another embodiment of the present invention. The present invention also provides a circuit board 200 with a step groove, the circuit board 200 comprises: a first laminate 240, an adhesive layer 270 and a second laminate 230, the adhesive layer 270 is arranged between the first laminate 240 and the second laminate 230, and is used to bond the first laminate 240 and the second laminate 230, the step groove 210 passes through the second laminate 230 and ends at the first laminate 240, and an annular ring 220 is arranged on the bottom surface of the step groove 210, and the area enclosed by the annular ring 220 is smaller than the bottom area of ​​the step groove 210.

[0094] The annular ring 220 is an annular member with a hollow interior, and the width of the annular ring 220 along the stacking direction perpendicular to the first laminate 240 and the second laminate 230 is 0.1-2.0 mm. For example, the width of the annular ring 220 can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm or 2.0 mm, etc., which is not specifically limited in the embodiment of the present invention.

[0095] Furthermore, the distance between the outer periphery of the annular ring 220 and the side wall of the step groove 210 is greater than or equal to 0.1 mm. Fig.15As shown, the distance between the outer periphery of the annular ring 220 and the side wall of the step groove 210 is S. By setting S≥0.1mm, the drill bit can be prevented from interfering with the annular ring 220 during the process of opening the step groove 210, thereby protecting the bottom surface of the step groove 210 and improving the quality of the product.

[0096] In this embodiment, the first laminate 240 includes a dielectric layer 242 and a circuit pattern 246, and the circuit pattern 246 is located on at least one surface of the dielectric layer 242. Specifically, the first laminate 240 can be a double-sided copper clad plate, including a dielectric layer 242 and a metal layer 244 located on opposite sides of the dielectric layer 242, and the circuit pattern 246 can be obtained by etching the metal layer on the dielectric layer 242. The preparation method of the circuit pattern 246 is referred to the prior art, and will not be repeated here.

[0097] In this embodiment, the annular ring 220 is an annular coil surrounded by a portion of the line pattern 246. Specifically, a portion of the line pattern 246 is surrounded to form a closed annular structure, thereby forming an annular coil. By setting the annular ring 220 as a portion of the line pattern 246, the manufacturing process of the annular ring 220 can be simplified.

[0098] Further, in one embodiment, the annular coil and another part of the line pattern 246 are arranged in the same layer. Alternatively, in another embodiment, the annular coil and the line pattern 246 are respectively located on opposite sides of the dielectric layer 242. Among them, the other part of the line pattern 246 refers to other line patterns 246 except for forming the annular coil, and the part of the line pattern 246 is mainly used to form a transmission loop. Please refer to the description of the above embodiment for the arrangement structure and formation method of the annular coil and the line pattern 246, which will not be repeated here.

[0099] Optionally, the number of the annular coils is at least two, and the at least two annular coils are stacked in a stacking direction of the circuit board 200 .

[0100] Specifically, in some embodiments, when the first laminate 240 includes only one dielectric layer 242 , the number of the annular coils may be one or two.

[0101] For example, in one embodiment, when only one annular coil is provided, the one annular coil is located on the surface of the dielectric layer 242 facing the second laminate 230. In another embodiment, when two annular coils are provided, the two annular coils are respectively located on opposite sides of the dielectric layer 242, and the two annular coils are stacked in the stacking direction of the circuit board 200.

[0102] In other embodiments, when the first laminate 240 includes at least two dielectric layers 242, the number of the annular coils may be one, two, or more. The plurality of annular coils may be formed on the surface of any dielectric layer 242, and the embodiment of the present invention does not limit the dielectric layer 242 on which the annular coils are specifically disposed.

[0103] Furthermore, if Fig.15 As shown, a through hole 250 is opened in the non-step groove area of ​​the circuit board 200, and a conductive layer 260 is formed on the side wall of the through hole 250. A circuit pattern is formed on the surface of the second laminate 230 away from the first laminate 240, and the conductive layer 260 electrically connects the circuit pattern on the surface of the second laminate 240 away from the first laminate 240 with the circuit pattern located inside the circuit board 200.

[0104] The structure and formation method of the through hole 250 and the conductive layer 260 in this embodiment refer to step S300 and step S400 in the above embodiment, which will not be described again.

[0105] Furthermore, the circuit board 200 further includes a solder resist layer 280, which covers the circuit pattern on the surface of the second laminate 240 away from the first laminate 240. By forming the solder resist layer 280 on the circuit pattern, the circuit pattern on the surface can be protected and insulated.

[0106] The above description is only an implementation mode of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for processing a circuit board having a step groove, characterized in that: include: At least a first laminate, an adhesive layer, a gasket and a second laminate are provided, the first laminate is provided with an annular ring, and the adhesive layer is provided with a receiving hole; At least the first laminate, the adhesive layer, the gasket and the second laminate form a stacked assembly for lamination, wherein the adhesive layer and the second laminate are sequentially located on one side of the first laminate provided with the annular ring, the gasket is located in the receiving hole, the gasket and the annular ring are stacked, and the projection of the annular ring on the gasket is located at the periphery of the gasket; A groove is formed on a side of the stacked assembly away from the first laminate to expose the gasket, and the circuit board with the step groove is formed after the gasket is removed.

2. The processing method according to claim 1, characterized in that: The step of providing the first laminate comprises: Providing a substrate, the substrate comprising a dielectric layer and a metal layer located on at least one side of the dielectric layer; The metal layer is etched to form a circuit pattern and / or a toroidal coil on the dielectric layer, and the toroidal coil forms the annular ring.

3. The processing method according to claim 1, characterized in that: The stacked assembly has an end surface away from the first laminate, and a method for making a groove on a side of the stacked assembly away from the first laminate to expose the gasket is: A controlled depth milling process is used to open the groove surrounding the gasket on the end face, and the depth of the groove is greater than or equal to the distance between the surface of the gasket away from the first laminate and the end face, and less than or equal to the distance between the surface of the gasket close to the first laminate and the end face.

4. The processing method according to claim 1, characterized in that: The number of the annular rings is at least two, and the width of each of the annular rings along a direction perpendicular to the stacking direction of the first laminate and the second laminate is 0.1-2.0 mm.

5. The processing method according to claim 1, characterized in that: The shape of the receiving hole formed on the adhesive layer is matched with the shape of the gasket, and the thickness of the gasket is less than or equal to the thickness of the adhesive layer.

6. The processing method according to claim 1, characterized in that: The thickness of the gasket is greater than the thickness of the adhesive layer. Before the first laminate, the adhesive layer, the gasket and the second laminate are formed into a stacking assembly for lamination, the method further includes: An avoidance groove is provided on one side of the second laminate close to the adhesive layer, and the depth of the avoidance groove is equal to the height of the gasket above the adhesive layer.

7. The processing method according to claim 1, characterized in that: The material of the gasket is Teflon, plasticized glue or cured resin.

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