Circuit board and method for manufacturing the same

Abstract

The present application proposes a circuit board, including a circuit substrate, a conductive column, a filling block and an electromagnetic shielding layer. The circuit substrate includes an inner circuit layer and multiple outer circuit layers arranged on opposite sides of the inner circuit layer, the inner circuit layer includes multiple signal transmission lines arranged at a distance, and the circuit substrate is provided with through holes and slots, the through holes and slots penetrate the inner circuit layer and the outer circuit layer along the thickness direction of the circuit board, and the slots extend outward along the perpendicular thickness direction. The conductive column is filled in the through hole, and the conductive column electrically conducts multiple relatively arranged outer circuit layers, and the filling block is filled in the slot. The electromagnetic shielding layer covers the circuit substrate. The circuit board provided by the present invention can improve the pressure resistance of the circuit substrate and reduce the problem of circuit substrate fragmentation caused by processes such as pressing and heating. In addition, the present application also provides a method for manufacturing a circuit board.

Description

Technical Field

[0001] The present application relates to a circuit board and a method for manufacturing the same. Background Art

[0002] Generally speaking, an RF antenna mainly includes a signal transmission line and an electromagnetic shielding layer, which is laminated to the outside of the signal transmission line. However, there is a large hollow area near the signal transmission line, which can easily cause the RF antenna to break during the lamination process, thereby affecting the yield of the RF antenna. Summary of the invention

[0003] In view of this, the present application provides a method for manufacturing a circuit board to reduce the risk of cracking.

[0004] In addition, it is also necessary to provide a circuit board manufactured by the above manufacturing method.

[0005] A method for manufacturing a circuit board, comprising the steps of: providing a circuit substrate, the circuit substrate comprising an inner circuit layer and a plurality of outer circuit layers, the outer circuit layers being arranged on opposite sides of the inner circuit layer, the inner circuit layer comprising at least one signal transmission line. Arranging through holes and slots in the circuit substrate, the through holes and the slots penetrating the inner circuit layer and each of the outer circuit layers along the thickness direction of the circuit substrate, the slots extending to the side of the circuit substrate along another direction perpendicular to the thickness direction, the through holes and the slots avoiding the signal transmission lines. Arranging conductive columns in the through holes and filling blocks in the slots, the conductive columns and the filling blocks electrically conducting the outer circuit layers, obtaining an intermediate body, and arranging an electromagnetic shielding layer outside the intermediate body, obtaining the circuit board.

[0006] Furthermore, the manufacturing method of the circuit substrate includes: providing an inner circuit substrate, the inner circuit substrate includes the inner circuit layer and a first insulating layer arranged on one side of the inner circuit layer, providing multiple outer circuit substrates, each of the outer circuit substrates includes the outer circuit layer and a dielectric layer arranged on one side of the outer circuit layer, providing a second insulating layer, the second insulating layer is arranged between the inner circuit layer and the outer circuit substrate, the dielectric layer faces the side of the outer circuit layer away from the inner circuit layer, pressing the inner circuit substrate, the outer circuit substrate and the second insulating layer to obtain a substrate motherboard, and dividing the substrate motherboard to obtain multiple circuit substrates.

[0007] Furthermore, the step of "arranging a conductive column in the through hole and a filling block in the groove" includes: electroplating to form a seed layer on the inner wall of the through hole and the inner wall of the groove, electroplating to form the conductive column in the through hole having the seed layer, and electroplating to form the filling block in the groove having the seed layer.

[0008] Furthermore, the step of "arranging a conductive column in the through hole and a filling block in the groove" also includes: providing a jig, the jig having a chamber and an injection hole connected to the chamber. Arranging a plurality of the circuit substrates in the chamber at intervals, the injection hole connecting the through hole and the groove. Injecting a filler into the injection hole, the filler is filled into the through hole, the groove and between two adjacent circuit substrates. Opening the jig to obtain a plurality of the intermediates, two adjacent intermediates are formed with a connecting block, and the connecting block is used to connect two adjacent intermediates.

[0009] Furthermore, the substrate motherboard includes a plurality of the circuit substrates and a redundant portion connected between two adjacent circuit substrates. After the substrate motherboard is divided, the manufacturing method further includes: removing the redundant portion.

[0010] Furthermore, the method further includes the steps of: providing an opening in the redundant part, the opening communicating with the slot; providing a seed layer on the inner wall of the opening, the inner wall of the through hole and the inner wall of the slot; filling the through hole, the slot and the opening with the seed layer with a filler to form the conducting column, the filling block and the connecting block respectively, removing the redundant part to obtain a plurality of the intermediates, and the intermediates are connected by the connecting block.

[0011] Furthermore, the method further comprises the step of removing the connecting block to obtain a plurality of the circuit boards.

[0012] Furthermore, the material of the filler includes metal powder and non-metal powder, the metal powder includes at least one of copper powder, gold powder, iron powder, silver powder, cobalt powder, nickel powder, niobium powder, zirconium powder, vanadium powder and tantalum powder, and the non-metal powder includes at least one of silicon powder, boron powder and germanium powder.

[0013] A circuit board includes a circuit substrate, a conductive column, a filling block and an electromagnetic shielding layer. The circuit substrate includes an inner circuit layer and a plurality of outer circuit layers arranged on opposite sides of the inner circuit layer, the inner circuit layer includes a plurality of signal transmission lines arranged at a distance, the circuit substrate is provided with through holes and slots, the through holes and slots penetrate the inner circuit layer and the outer circuit layer along the thickness direction of the circuit board, and the slots extend outward perpendicular to the thickness direction. The conductive column is filled in the through hole, the conductive column electrically conducts the plurality of oppositely arranged outer circuit layers, and the filling block is filled in the slot. The electromagnetic shielding layer covers the circuit substrate.

[0014] Furthermore, the circuit board also includes an insulating layer, and the insulating layer is arranged between the electromagnetic shielding layer and the outer circuit layer.

[0015] The circuit board provided by the present invention improves the pressure resistance of the circuit substrate by arranging a filling block in the slot near the signal transmission line, and can effectively reduce the problem of circuit substrate fragmentation caused by processes such as pressing and heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of an inner circuit substrate provided in accordance with an embodiment of the present application.

[0017] Figure 2 for Figure 1 The schematic diagram shown is the inner circuit substrate and the outer circuit substrate before being pressed together.

[0018] Figure 3 for Figure 1 The schematic diagram shown is a schematic diagram of the inner circuit substrate and the outer circuit substrate after being pressed together.

[0019] Figure 4 A schematic diagram of a substrate motherboard provided in accordance with an embodiment of the present application.

[0020] Figure 5 A schematic diagram of a circuit substrate provided in accordance with an embodiment of the present application.

[0021] Figure 6 for Figure 5 The schematic diagram shown is a circuit substrate after the conductive pillars and the filling blocks are set.

[0022] Figure 7 for Figure 5 The schematic diagram shown is a circuit substrate after an electromagnetic shielding layer is set.

[0023] Figure 8 A schematic diagram of a circuit board provided in accordance with an embodiment of the present application.

[0024] Fig. 9A schematic diagram of a substrate motherboard retaining a redundant portion provided in yet another embodiment of the present application.

[0025] Fig.10 for Fig. 9 The schematic diagram of the substrate motherboard after being filled with filler is shown.

[0026] Main component symbols

[0027] Circuit board 100

[0028] Intermediate 101

[0029] Circuit board 1

[0030] Inner circuit layer 11

[0031] Signal transmission line 111

[0032] Dielectric layer 12

[0033] Through hole 13

[0034] Conductive column 131

[0035] Slot 14

[0036] Filling block 141

[0037] Detail 143

[0038] Upper surface 15

[0039] Lower surface 16

[0040] Side 17

[0041] Electromagnetic shielding layer 18

[0042] Inner circuit board 2

[0043] First insulating layer 21

[0044] External circuit substrate 3

[0045] Outer circuit layer 31

[0046] Adhesive layer 32

[0047] Substrate Motherboard 4

[0048] Redundant part 41

[0049] Opening 411

[0050] The second insulating layer 50

[0051] Thickness direction D

[0052] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0054] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. When an element is considered to be "set on" another element, it may be directly set on the other element or there may be a central element at the same time.

[0055] See also Figures 1 to 8 The present application embodiment provides a method for manufacturing a circuit board 100, wherein the circuit board 100 can be used to transmit high-frequency signals. The manufacturing method comprises the following steps:

[0056] S1: See Figure 5 , providing a circuit substrate 1, the circuit substrate 1 includes an inner circuit layer 11, two outer circuit layers 31, a first insulating layer 21, a second insulating layer 50 and two dielectric layers 12, the two outer circuit layers 31 are arranged on opposite sides of the inner circuit layer 11, the first insulating layer 21 is arranged between the inner circuit layer 11 and the outer circuit layer 31, the second insulating layer 50 is arranged between the inner circuit layer 11 and another outer circuit layer 31, and each dielectric layer 12 is arranged on a side of the outer circuit layer 31 away from the inner circuit layer 11.

[0057] The inner circuit layer 11 includes at least one signal transmission line 111, and the signal transmission line 111 can be used to transmit high-frequency millimeter wave signals. The circuit substrate 1 is provided with a through hole 13 and a slot 14, and the through hole 13 and the slot 14 avoid the signal transmission line 111. The through hole 13 and the slot 14 sequentially penetrate one of the dielectric layers 12, one of the outer circuit layers 31, the first insulating layer 21, the inner circuit layer 11, the second insulating layer 50, another of the outer circuit layers 31 and another of the dielectric layers 12 along the thickness direction D of the circuit substrate 1. The slot 14 extends to the side of the circuit substrate 1 along another direction perpendicular to the thickness direction D, and the slot 14 is used to enhance the flexibility of the circuit substrate 1. In other embodiments of the present application, the number of the inner circuit layer 11 can be multiple layers; the outer circuit layer 31 can also be three layers, four layers or more.

[0058] In this embodiment, the circuit substrate 1 includes an upper surface 15, a lower surface 16 opposite to the upper surface 15, and two oppositely disposed side surfaces 17 connecting the upper surface 15 and the lower surface 16, and the two outer circuit layers 31 respectively include the upper surface 15 and the lower surface 16. Each of the side surfaces 17 is recessed inward to form the groove 14, and the two grooves 14 correspond to each other, and the sum of the depths of the two grooves 14 is less than the width of the circuit substrate 1, so that a detail 143 is formed between the two grooves 14, and the detail 143 includes at least one signal transmission line 111.

[0059] See also Figures 1 to 4 In this embodiment, the manufacturing method of the circuit substrate 1 comprises the steps of:

[0060] S10: See Figure 1 , providing an inner circuit substrate 2, the inner circuit substrate 2 comprising the inner circuit layer 11 and a first insulating layer 21 disposed on one side of the inner circuit layer 11, wherein the inner circuit layer 11 comprises at least two signal transmission lines 111 disposed at a distance from each other. The material of the first insulating layer 21 is at least one of liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE) and fusible polytetrafluoroethylene (PFA).

[0061] S11: See Figure 2 , two outer circuit substrates 3 are provided, each of the outer circuit substrates 3 includes an outer circuit layer 31 and a dielectric layer 12 disposed on one side of the outer circuit layer 31. The dielectric layer 12 is made of at least one of liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE) and fusible polytetrafluoroethylene (PFA).

[0062] S12: See Figure 2 , providing a second insulating layer 50, two outer circuit substrates 3 and one inner circuit substrate 2, wherein the second insulating layer 50 is disposed between one outer circuit substrate 3 and the inner circuit substrate 2, and pressing the inner circuit substrate 2, the second insulating layer 50 and the outer circuit substrate 3 together to obtain a substrate motherboard 4 (see Figure 3 ). The first insulating layer 21 is disposed between the inner circuit layer 11 and the outer circuit layer 31 of one outer circuit substrate 3, and the second insulating layer 50 is disposed between the inner circuit layer 11 and the outer circuit layer 31 of another outer circuit substrate 3. Each dielectric layer 12 is disposed on a side of the outer circuit layer 31 away from the inner circuit layer 11. By arranging the dielectric layer 12 on the outside, the risk of the outer circuit layer 31 and the inner circuit layer 11 being damaged by pressure during the pressing process is reduced.

[0063] S13: See Figure 4 , a plurality of through holes 13 are provided on the substrate motherboard 4, the through holes 13 penetrate the inner circuit substrate 2, the two outer circuit substrates 3 and the second insulating layer 50, and a plurality of slots 14 are provided on the substrate motherboard 4 (see Figure 5 ). The substrate motherboard 4 includes a plurality of the circuit substrates 1 and a redundant portion 41 connected between two adjacent circuit substrates 1 , and each of the circuit substrates 1 includes at least one signal transmission line 111 .

[0064] S14: See Figure 5 , removing the redundant portion 41 to obtain two circuit substrates 1 .

[0065] S2: See Figure 6 , a conducting column 131 is arranged in the through hole 13, the conducting column 131 electrically conducts the two oppositely arranged outer circuit layers 31, and a filling block 141 is arranged in the slot 14, to obtain an intermediate body 101. The filling block 141 is used to enhance the structural strength of the circuit substrate 1 in the slot 14 area, thereby improving the circuit substrate 1 from being crushed by external force.

[0066] In this embodiment, step S2 includes:

[0067] S20: electroplating to form a seed layer on the inner wall of the through hole 13 and the inner wall of the groove 14 (not shown);

[0068] S21: forming the conducting pillar 131 by electroplating in the through hole 13 having the seed layer;

[0069] S23: forming the filling block 141 by electroplating in the groove 14 having the seed layer.

[0070] In another embodiment of the present application, step S2 includes:

[0071] S24: providing a jig (not shown), wherein the jig has a cavity (not shown) and an injection hole (not shown) communicating with the cavity;

[0072] S25: multiple circuit substrates 1 are arranged in the chamber at a distance, and the injection hole connects the through hole 13 and the groove 14. Finally, filler is injected into the injection hole, and the filler is filled into the through hole 13, the groove 14 and between two adjacent circuit substrates 1. After the filler is solidified, the jig is opened to obtain multiple intermediates 101. Two adjacent intermediates 101 are formed with a connecting block 142, and the connecting block 142 is used to connect two adjacent intermediates 101.

[0073] In this embodiment, in step S25, the filler includes metal powder and non-metal powder, the metal powder includes at least one of copper powder, gold powder, iron powder, silver powder, cobalt powder, nickel powder, niobium powder, zirconium powder, vanadium powder and tantalum powder, and the non-metal powder includes at least one of silicon powder, boron powder and germanium powder.

[0074] See also Figures 9 and 10 In another embodiment of the present application, step S2 may further include:

[0075] S26: See Fig. 9 , the redundant part 41 is set again between the plurality of circuit substrates 1 (i.e., the redundant part 41 is retained relative to step S13) and an opening 411 is set in the redundant part 41, and the opening 411 is connected to the slot 14. By retaining the redundant part 41, the plurality of circuit substrates 1 can be connected as one, the positioning accuracy can be improved, and the subsequent single manufacturing of a plurality of the circuit boards 100 is convenient.

[0076] In this embodiment, step S26 further includes: electroplating a seed layer (not shown) on the inner wall of the through hole 13, the slot 14 and the opening 411. The provision of the seed layer increases the bonding strength between the conductive pillar 131 and the filling block 141 and the circuit substrate 1, and reduces the risk of the conductive pillar 131 and the filling block 141 falling off.

[0077] S27: See Fig.10 , filling the filler into the through hole 13 and the slot 14;

[0078] S28: After the filler is solidified, the redundant portion 41 is removed by laser cutting or mechanical drilling to obtain a plurality of intermediate bodies 101 (see Figure 6 ), the intermediate body 101 is connected via the connecting block 142.

[0079] S3: See Figure 7 , an electromagnetic shielding layer 18 is coated on the outer side of the intermediate body 101 to obtain the circuit board 100.

[0080] In this embodiment, step S3 includes:

[0081] S30: heating the dielectric layer 12 so that the dielectric layer 12 is in a fluid state, and the electromagnetic shielding layer 18 is in close contact with the dielectric layer 12 in the fluid state, thereby achieving close connection with both sides of the intermediate body 101.

[0082] S31: See Figure 8, remove the connecting block 142 to obtain a plurality of the circuit boards 100 .

[0083] See also Figure 8 The embodiment of the present application further provides a circuit board 100, the circuit board 100 includes a circuit substrate 1, a conductive column 131, a filling block 141 and an electromagnetic shielding layer 18. The circuit substrate 1 includes an inner circuit layer 11 and an outer circuit layer 31 arranged on opposite sides of the inner circuit layer 11, and the inner circuit layer 11 includes a plurality of signal transmission lines 111 arranged at a distance. The circuit substrate 1 is provided with a through hole 13 and a slot 14, the through hole 13 and the slot 14 penetrate the inner circuit layer 11 and the outer circuit layer 31 along the thickness direction D of the circuit board 100, the slot 14 extends outward perpendicular to the thickness direction D, the conductive column 131 is filled in the through hole 13 to electrically conduct the two oppositely arranged outer circuit layers 31, and the filling block 141 is filled in the slot 14 to enhance the pressure resistance and flexibility of the circuit board 100. The electromagnetic shielding layer 18 covers the circuit substrate 1 , thereby covering the signal transmission line 111 .

[0084] Compared with the prior art, the circuit board 100 provided in the present application has the following advantages:

[0085] (i) By providing a filling block 141 in the slot 14 near the signal transmission line 111 , the problem of the circuit substrate 1 being broken due to the subsequent pressing and covering of the electromagnetic shielding layer 18 can be effectively prevented, while the flexibility of the circuit substrate 1 is not affected.

[0086] (ii) The electromagnetic shielding layer 18 covers the signal transmission line 111 to achieve all-round shielding of the signal transmission line 111 and prevent signal leakage and loss.

[0087] (iii) Covering the circuit substrate with the electromagnetic shielding layer 18 is low-cost and easy to operate.

[0088] The above description is only an optimized specific implementation of the present application, but it cannot be limited to this implementation in the actual application process. For ordinary technicians in this field, other variations and changes made according to the technical concept of the present application should all fall within the protection scope of the present application.

Claims

1. A method for manufacturing a circuit board, characterized in that: Includes steps: Providing a circuit substrate, the circuit substrate comprising an inner circuit layer and a plurality of outer circuit layers, the outer circuit layers being arranged on two opposite sides of the inner circuit layer, and the inner circuit layer comprising at least one signal transmission line; A through hole and a slot are provided on the circuit substrate, wherein the through hole and the slot penetrate the inner circuit layer and each of the outer circuit layers along the thickness direction of the circuit substrate, and the slot extends to the side of the circuit substrate along another direction perpendicular to the thickness direction, and the through hole and the slot avoid the signal transmission line; A conducting column is arranged in the through hole and a filling block is arranged in the slot, wherein the conducting column and the filling block are electrically connected to the outer circuit layer to obtain an intermediate body; and An electromagnetic shielding layer is arranged on the outer side of the intermediate body to obtain the circuit board.

2. The manufacturing method according to claim 1, characterized in that The circuit substrate further includes a dielectric layer, a first insulating layer and a second insulating layer. The manufacturing method of the circuit substrate includes: Providing an inner circuit substrate, the inner circuit substrate comprising the inner circuit layer and a first insulating layer disposed on one side of the inner circuit layer; Providing a plurality of outer circuit substrates, each of the outer circuit substrates comprising the outer circuit layer and a dielectric layer disposed on one side of the outer circuit layer; Providing a second insulating layer, wherein the second insulating layer is disposed between the inner circuit layer and the outer circuit substrate, and the dielectric layer faces a side of the outer circuit layer away from the inner circuit layer; Pressing the inner circuit substrate, the outer circuit substrate and the second insulating layer together to obtain a substrate motherboard; and The substrate motherboard is divided to obtain a plurality of the circuit substrates.

3. The manufacturing method according to claim 2, characterized in that: The step of "arranging a conductive column in the through hole and a filling block in the slot" includes: Electroplating to form a seed layer on the inner wall of the through hole and the inner wall of the groove; forming the via pillar by electroplating in the through hole having the seed layer; and, The filling block is formed by electroplating in the groove having the seed layer.

4. The manufacturing method according to claim 2, characterized in that: The step of "arranging a conductive column in the through hole and a filling block in the slot" also includes: A jig is provided, wherein the jig has a cavity and an injection hole communicating with the cavity; The plurality of circuit substrates are arranged in the chamber at intervals, and the injection holes are connected to the through holes and the slots; Injecting a filler into the injection hole, the filler is filled into the through hole, the slot and between two adjacent circuit substrates, The jig is opened to obtain a plurality of the intermediate bodies, and a connecting block is formed between two adjacent intermediate bodies, and the connecting block is used to connect the two adjacent intermediate bodies.

5. The manufacturing method according to claim 2, characterized in that: The substrate motherboard includes a plurality of the circuit substrates and a redundant portion connected between two adjacent circuit substrates. After the substrate motherboard is divided, the manufacturing method further includes: removing the redundant portion.

6. The manufacturing method according to claim 5, characterized in that: Also includes the steps: An opening is provided in the redundant portion, wherein the opening is connected to the slot; Disposing a seed layer on the inner wall of the opening, the inner wall of the through hole and the inner wall of the groove; Filling the through hole, the groove and the opening with the seed layer with a filler to form the conducting column, the filling block and the connecting block respectively; The redundant part is removed to obtain a plurality of the intermediate bodies, and the intermediate bodies are connected by the connecting blocks.

7. The manufacturing method according to claim 4 or 6, characterized in that: Also includes the steps: The connecting block is removed to obtain a plurality of the circuit boards.

8. The manufacturing method according to claim 7, characterized in that: The material of the filler includes metal powder and non-metal powder, the metal powder includes at least one of copper powder, gold powder, iron powder, silver powder, cobalt powder, nickel powder, niobium powder, zirconium powder, vanadium powder and tantalum powder, and the non-metal powder includes at least one of silicon powder, boron powder and germanium powder.

9. A circuit board, characterized in that: It includes a circuit substrate, a conductive column, a filling block and an electromagnetic shielding layer; The circuit substrate comprises an inner circuit layer and a plurality of outer circuit layers arranged on opposite sides of the inner circuit layer, the inner circuit layer comprises a plurality of signal transmission lines arranged at a distance, the circuit substrate is provided with through holes and slots, the through holes and slots penetrate the inner circuit layer and the outer circuit layer along the thickness direction of the circuit board, the slots extend outwardly perpendicular to the thickness direction, and the through holes and slots avoid the signal transmission lines; The conductive pillar is filled in the through hole, the conductive pillar electrically conducts a plurality of relatively arranged outer circuit layers, and the filling block is filled in the slot; The electromagnetic shielding layer covers the circuit substrate.

10. The circuit board according to claim 9, characterized in that: The circuit board also includes an insulating layer, and the insulating layer is arranged between the electromagnetic shielding layer and the outer circuit layer.

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