Circuit board with waveguide and method for manufacturing the same

Abstract

A method for manufacturing a circuit board with a waveguide, comprising the following steps: forming a waveguide structure by injection molding, the waveguide structure comprising a plurality of waveguide tubes spaced apart along a first direction and a connecting portion connecting two adjacent waveguide tubes; forming a first metal layer to cover the entire outer surface of the waveguide structure; forming an insulating layer by injection molding on the waveguide structure provided with the first metal layer, so that the insulating layer and the waveguide tubes in the waveguide structure are interlocked, wherein the connecting portion is located on one side of the insulating layer; removing the connecting portion located on one side of the insulating layer to obtain an intermediate structure comprising the insulating layer and the waveguide tubes provided with the first metal layer embedded in the insulating layer; covering two opposite surfaces of the intermediate structure spaced apart along a thickness direction perpendicular to the first direction with a second metal layer respectively; and performing circuit fabrication on the intermediate structure provided with the second metal layer to form a circuit layer, wherein the circuit layer has a notch corresponding to each waveguide tube.

Description

Technical Field

[0001] The present application relates to the field of waveguides, and in particular to a circuit board with a waveguide and a manufacturing method thereof. Background Art

[0002] As PCB transmission frequencies continue to increase, traditional copper wire connections will reach their performance threshold. Rectangular waveguides, previously used in the microwave field, have the advantages of low loss, large bandwidth, and high transmission rate. If integrated into high-frequency printed circuit boards, they can well meet the development needs of microwave integrated circuits.

[0003] Substrate Integrated Waveguide (SIW) is a new type of transmission line structure that can be integrated into a dielectric substrate. SIW is usually obtained by drilling two rows of metal through holes on a dielectric substrate covered with metal on both sides of the substrate. While ensuring that energy on the transmission line does not leak, the through hole array is equivalent to a metal wall, and the transmission characteristics can be approximated by rectangular waveguide analysis. The SIW structure has the advantages of traditional waveguide and microstrip structure transmission lines, namely, low radiation, low insertion loss, high Q value, high power capacity, miniaturization, easy connection, etc., and all communication devices such as passive devices, active devices and antennas can be integrated on the same substrate. However, in the preparation of substrate integrated waveguides in the prior art, the number of metal through holes set is often very high and the precision requirements are high, which is not conducive to cost reduction and product yield improvement. Summary of the Invention

[0004] In view of this, it is necessary to provide a method for manufacturing a circuit board with a waveguide that solves the above problems.

[0005] It is also necessary to provide a circuit board with a waveguide manufactured by the above method.

[0006] A method for manufacturing a circuit board having a waveguide, comprising the following steps:

[0007] forming a waveguide structure by injection molding, wherein the waveguide structure comprises a plurality of waveguide tubes spaced apart along a first direction and a connecting portion connecting two adjacent waveguide tubes;

[0008] forming a first metal layer to cover the entire outer surface of the waveguide structure;

[0009] A plurality of receiving grooves penetrating the double-sided copper clad laminate are provided on the double-sided copper clad laminate;

[0010] Each of the waveguides in the waveguide structure provided with the first metal layer corresponds to one of the receiving grooves and is embedded in the receiving groove of the double-sided copper clad laminate, wherein the connecting portion is located on one side of the double-sided copper clad laminate;

[0011] Removing the connecting portion on one side of the double-sided copper clad laminate to obtain an intermediate structure including the double-sided copper clad laminate and a waveguide embedded in the double-sided copper clad laminate and provided with the first metal layer;

[0012] Filling a gap between the double-sided copper-clad laminate and the waveguide provided with the first metal layer in the intermediate structure with resin, and covering two opposite surfaces of the intermediate structure spaced apart in a thickness direction perpendicular to the first direction with a second metal layer respectively; and

[0013] The intermediate structure provided with the second metal layer is subjected to circuit fabrication to form a circuit layer, wherein the circuit layer is provided with a notch corresponding to each of the waveguides.

[0014] A method for manufacturing a circuit board having a waveguide, comprising the following steps:

[0015] forming a waveguide structure by injection molding, wherein the waveguide structure comprises a plurality of waveguide tubes spaced apart along a first direction and a connecting portion connecting two adjacent waveguide tubes;

[0016] forming a first metal layer to cover the entire outer surface of the waveguide structure;

[0017] forming an insulating layer on the waveguide structure provided with the first metal layer by injection molding, so that the insulating layer and the waveguide in the waveguide structure are interlocked, wherein the connecting portion is located on one side of the insulating layer;

[0018] removing the connecting portion on one side of the insulating layer to obtain an intermediate structure including the insulating layer and a waveguide embedded in the insulating layer and provided with the first metal layer;

[0019] Covering two opposite surfaces of the intermediate structure along the thickness direction perpendicular to the first direction with a second metal layer respectively;

[0020] The intermediate structure provided with the second metal layer is subjected to circuit fabrication to form a circuit layer, wherein the circuit layer is provided with a notch corresponding to each of the waveguides.

[0021] A method for manufacturing a circuit board having a waveguide, comprising the following steps:

[0022] A waveguide structure made of a thermoplastic polymer material is formed by injection molding, wherein the waveguide structure includes a plurality of spaced waveguide tubes and a connecting portion connecting two adjacent waveguide tubes, wherein each waveguide tube includes a waveguide body and at least one protrusion;

[0023] Removing the connecting portion to obtain at least two independent waveguides;

[0024] forming a first metal layer on each independent waveguide to cover the entire outer surface of the waveguide;

[0025] Providing a circuit substrate, wherein at least one receiving groove passes through the circuit substrate;

[0026] A waveguide covered by the first metal layer is embedded in each receiving groove and fixed to the waveguide and the circuit substrate; and

[0027] A portion of the first metal layer located on a surface of the protrusion facing away from the waveguide body is removed.

[0028] A circuit board with a waveguide is manufactured by the above method.

[0029] The present invention's method for manufacturing a circuit board with a waveguide first forms the waveguide structure through injection molding, resulting in a waveguide with precise dimensions and shape and a smooth surface. This smooth surface helps reduce microwave signal transmission losses. The subsequent coating of the waveguide structure with a first metal layer avoids the need for metal through-holes as in the prior art, reducing process precision requirements and costs while also improving product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figures 1-8 It is a schematic diagram of a method for manufacturing a circuit board with a waveguide according to the first embodiment provided by the present application.

[0031] Figure 9 It is a schematic diagram of forming an insulating layer by injection molding on the waveguide structure in the second embodiment of the present application.

[0032] Figure 10 It will Figure 9 Schematic diagram of the intermediate structure obtained after the connecting part in the waveguide structure is removed.

[0033] Figure 11 is Figure 10 Schematic diagram of providing a second metal layer on the intermediate structure shown.

[0034] Figure 12-17 3 is a schematic diagram of a method for manufacturing a circuit board with a waveguide according to a third embodiment of the present application.

[0035] Description of main component symbols

[0036] waveguide structure 10、10a Waveguide 11、11a Connection 13 First metal layer 21、23 Double-sided copper clad laminate 30 Storage tank 301、303 Bottom copper layer 31、35 insulation layer 33、33a Intermediate structure 40、40a Second metal layer 25、26 Conductive layer 20、20’ Circuit layer 20a gap 201 Waveguide body 111 raised part 110 circuit substrate 30a First circuit layer 31a Second circuit layer 31b

[0037] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0038] 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 the embodiments.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0040] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0041] Please refer to Figures 1 to 8 The method for manufacturing a circuit board with a waveguide according to the first embodiment of the present application comprises the following steps:

[0042] Step S1, see Figure 1 A waveguide structure 10 made of a thermoplastic polymer material is formed by injection molding. The waveguide structure 10 includes a plurality of waveguide tubes 11 arranged at intervals and a connecting portion 13 connecting two adjacent waveguide tubes 11.

[0043] The thermoplastic polymer material is preferably a material that is resistant to high temperatures, has low dielectric loss, and has a low thermal expansion coefficient. In this embodiment, the thermoplastic polymer material may be, but is not limited to, polyolefin.

[0044] The waveguide structure 10 is formed by injection molding, which is conducive to the integration of the waveguide 11 and the connecting portion 13. At the same time, it is also conducive to obtaining a waveguide 11 with precise size and shape and a smooth surface. Among them, the smooth surface of the waveguide 11 is conducive to reducing the loss of microwave signal transmission.

[0045] In this embodiment, the following description is made by taking the example that the waveguide structure 10 includes three waveguide tubes 11 spaced apart and two connecting portions 13. In some embodiments, the waveguide structure 10 is not limited to the above-mentioned case.

[0046] The three waveguides 11 are arranged at intervals along the first direction. The two ends of each connecting portion 13 are respectively connected to two adjacent waveguides 11 , and the connecting portion 13 is located on the same side of the two waveguides 11 .

[0047] Step S2, see Figure 2 , a first metal layer 21 is formed on the waveguide structure 10 to cover the entire outer surface of the waveguide structure 10 .

[0048] The first metal layer 21 may include but is not limited to copper, gold, silver, etc. The first metal layer 21 may be formed by but is not limited to electroplating, chemical vapor deposition, or printing.

[0049] Step S3, see Figure 3 A double-sided copper clad plate 30 is provided, and a plurality of receiving grooves 301 are opened through the double-sided copper clad plate 30. Among them, the plurality of receiving grooves 301 respectively correspond to the plurality of waveguides 11 in the waveguide structure 10.

[0050] In this embodiment, three receiving grooves 301 are spaced apart and distributed on the double-sided copper clad laminate 30. Each receiving groove 301 can be formed by, but not limited to, stamping, laser cutting, or etching.

[0051] Specifically, the double-sided copper clad laminate 30 includes a bottom copper layer 31, an insulating layer 33, and another bottom copper layer 35 stacked in sequence. Each receiving groove 301 sequentially penetrates the bottom copper layer 31, the insulating layer 33, and the bottom copper layer 35 along the stacking direction.

[0052] Step S4, see Figure 4 The waveguide 11 in the waveguide structure 10 provided with the first metal layer 21 is embedded in the corresponding receiving groove 301 of the double-sided copper clad laminate 30 . The connecting portion 13 is located on one side of the double-sided copper clad laminate 30 .

[0053] In this embodiment, along the stacking direction, the thickness of the waveguide 11 provided with the first metal layer 21 may be substantially equal to the thickness of the double-sided copper clad laminate 30 .

[0054] Step S5, see Figure 5 The connecting portion 13 on one side of the double-sided copper clad laminate 30 is removed to obtain an intermediate structure 40. The intermediate structure 40 includes the double-sided copper clad laminate 30 and the waveguide 11 embedded in the double-sided copper clad laminate 30 and provided with the first metal layer 21.

[0055] In this embodiment, the connecting portion 13 can be removed by, but is not limited to, mechanical cutting or laser cutting.

[0056] Step S6, see Figure 6The gap between the double-sided copper clad laminate 30 in the intermediate structure 40 and the waveguide 11 provided with the first metal layer 21 is filled with resin (not shown), and the second metal layer 25 is respectively covered on two opposing surfaces of the intermediate structure 40 spaced apart along the stacking direction. The bottom copper layer (31, 35), the second metal layer 25, and the first metal layer 21 provided on two opposing surfaces of the waveguide 11 spaced apart along the stacking direction constitute the conductive layer 20.

[0057] In this embodiment, the second metal layer 25 may be formed by, but not limited to, electroplating.

[0058] Step S7, see Figure 7 and Figure 8 , the conductive layer 20 is subjected to circuit fabrication to form a corresponding circuit layer 20a. Figure 8 As shown, the circuit layer 20 a is provided with a notch 201 corresponding to each of the waveguides 11 as a wave inlet or a wave outlet.

[0059] In the second embodiment, after step S2, steps S3 to S6 in the first embodiment can be replaced by steps S3' to S5'. Specifically:

[0060] Step S3', see Figure 9 The insulating layer 33 is directly formed by injection molding on the waveguide structure 10 provided with the first metal layer 21 , so that the insulating layer 33 and the waveguide structure 10 are interlocked. The connecting portion 13 is located on one side of the insulating layer 33 .

[0061] In this embodiment, along a thickness direction perpendicular to the first direction, the thickness of the insulating layer 33 may be substantially equal to the thickness of the waveguide 11 provided with the first metal layer 21 .

[0062] The melting point of the insulating layer 33 is preferably lower than the melting point of the waveguide structure 10 , so as to avoid affecting the waveguide structure 10 when forming the insulating layer 33 , such as changes in the structure or size of the waveguide structure 10 due to excessively high temperature.

[0063] Since the insulating layer 33 is directly formed by injection molding on the waveguide structure 10 provided with the first metal layer 21, a gap is avoided between the insulating layer 33 and the waveguide structure 10 provided with the first metal layer 21, and it is beneficial to the stability of the overall structure.

[0064] Step S4', see Figure 10The connecting portion 13 on one side of the insulating layer 33 is removed to obtain an intermediate structure 40a. The intermediate structure 40a includes the insulating layer 33 and the waveguide 11 embedded in the insulating layer 33 and provided with the first metal layer 21.

[0065] In this embodiment, the connecting portion 13 can be removed by, but is not limited to, mechanical cutting or laser cutting.

[0066] Step S5', see Figure 11 The two opposite surfaces of the intermediate structure 40a spaced apart in the thickness direction are respectively covered with a second metal layer 26. The second metal layer 26 and the first metal layer 21 disposed on the two surfaces of the waveguide 11 spaced apart in the stacking direction constitute a conductive layer 20'.

[0067] In this embodiment, the second metal layer 26 may be formed by, but not limited to, electroplating.

[0068] In some embodiments, as Figure 13 As shown, the waveguide 10 may include a waveguide body 111 and at least one protrusion 110 provided on the waveguide body 111. Each protrusion 110 is provided corresponding to one of the notches 201 as a wave inlet or a wave outlet.

[0069] The manufacturing method for the waveguide-equipped circuit board of the present application first forms the waveguide structure 10 through injection molding, which facilitates the integration of the waveguide 11 and the connecting portion 13. It also facilitates obtaining a waveguide 11 with precise size and shape and a smooth surface. The smooth surface of the waveguide 11 helps reduce microwave signal transmission losses. The subsequent coating of the waveguide structure 10 with the first metal layer 21 avoids the need for metal through-holes in the prior art, reducing process precision requirements and costs, while also improving product yield.

[0070] Please refer to the figure Figures 12 to 17 The method for manufacturing a circuit board with a waveguide according to the third embodiment of the present application comprises the following steps:

[0071] Step S1a, see Figure 12 A waveguide structure 10a made of a thermoplastic polymer material is formed by injection molding. The waveguide structure 10a includes a plurality of spaced waveguide tubes 11a and a connecting portion 13 connecting two adjacent waveguide tubes 11a. Each waveguide tube 11a includes a waveguide body 111 and at least one protrusion 110 serving as a wave inlet or a wave outlet of the waveguide tube 11a.

[0072] In this embodiment, the connecting portion 13 may be connected to the waveguide body 111 .

[0073] In some embodiments, the connecting portion 13 and the protruding portion 110 may be disposed on the same side of the waveguide body 111. In some embodiments, the connecting portion 13 and the protruding portion 110 may be disposed on opposite sides of the waveguide body 111, respectively.

[0074] Step S2a, see Figure 13 , removing the connecting portion 13 to obtain at least two independent waveguides 11 a.

[0075] Step S3a, see Figure 14 A first metal layer 23 is formed on the independent waveguide 11 a to cover the entire outer surface of the waveguide 11 a.

[0076] Step S4a, see Figure 15 , providing a circuit substrate 30a, and at least one receiving groove 303 passing through the circuit substrate 30a.

[0077] The circuit substrate 30a can be a double-layer circuit substrate or a multi-layer circuit substrate. In this embodiment, the circuit substrate 30a is a double-layer circuit substrate, including a first circuit layer 31a, an insulating layer 33a, and a second circuit layer 31b stacked in sequence. Each of the receiving grooves 303 extends through the circuit substrate 30a along the stacking direction.

[0078] Step S5a, see Figure 16 A waveguide 11 a covered by the first metal layer 23 is embedded in each receiving groove 303 to fix the waveguide 11 a and the circuit substrate 30 a.

[0079] In this embodiment, along the penetrating direction of the receiving groove 303 , the thickness of the circuit substrate 30 a may be substantially equal to the thickness of the waveguide 11 a covered by the first metal layer 23 .

[0080] Step S6a, see Figure 17 , removing a portion of the first metal layer 23 located on the surface of the protrusion 110 away from the waveguide body 111.

[0081] In this embodiment, the portion of the first metal layer 23 located on the surface of the protrusion 110 away from the waveguide body 111 may be removed by, but not limited to, grinding.

[0082] The manufacturing method for the aforementioned waveguide-equipped circuit board of the present application first forms the waveguide structure 10 through injection molding, which facilitates obtaining a waveguide 11 with precise size and shape and a smooth surface. The smooth surface of the waveguide 11 helps reduce microwave signal transmission losses. The subsequent coating of the waveguide structure 10 with a first metal layer 21 avoids the need for metal through-holes as in the prior art, reducing process precision requirements and costs while also improving product yield.

[0083] The above is only a preferred embodiment of the present application and is not intended to limit the present application in any form. Although the present application has been disclosed as a preferred embodiment as above, it is not intended to limit the present application. Any technician familiar with this profession can use the technical content disclosed above to make some changes or modify it into an equivalent embodiment with equivalent changes without departing from the scope of the technical solution of the present application. However, any simple modification, equivalent change and modification of the above embodiment made according to the technical essence of the present application without departing from the content of the technical solution of the present application still falls within the scope of the technical solution of the present application.

Claims

1. A method for manufacturing a circuit board having a waveguide, comprising the following steps: forming a waveguide structure by injection molding, wherein the waveguide structure comprises a plurality of waveguide tubes spaced apart along a first direction and a connecting portion connecting two adjacent waveguide tubes; forming a first metal layer to cover the entire outer surface of the waveguide structure; A plurality of receiving grooves penetrating the double-sided copper clad laminate are provided on the double-sided copper clad laminate; Each of the waveguides in the waveguide structure provided with the first metal layer corresponds to one of the receiving grooves and is embedded in the receiving groove of the double-sided copper clad laminate, wherein the connecting portion is located on one side of the double-sided copper clad laminate; Removing the connecting portion on one side of the double-sided copper clad laminate to obtain an intermediate structure including the double-sided copper clad laminate and a waveguide embedded in the double-sided copper clad laminate and provided with the first metal layer; Filling a gap between the double-sided copper-clad laminate and the waveguide provided with the first metal layer in the intermediate structure with resin, and covering two opposite surfaces of the intermediate structure spaced apart in a thickness direction perpendicular to the first direction with a second metal layer respectively; and The intermediate structure provided with the second metal layer is subjected to circuit fabrication to form a circuit layer, wherein the circuit layer is provided with a notch corresponding to each of the waveguides.

2. The method for manufacturing a circuit board having a waveguide according to claim 1, wherein: Along a thickness direction perpendicular to the first direction, the thickness of the waveguide provided with the first metal layer is equal to the thickness of the double-sided copper clad laminate.

3. A method for manufacturing a circuit board having a waveguide, comprising the following steps: forming a waveguide structure by injection molding, wherein the waveguide structure comprises a plurality of waveguide tubes spaced apart along a first direction and a connecting portion connecting two adjacent waveguide tubes; forming a first metal layer to cover the entire outer surface of the waveguide structure; forming an insulating layer on the waveguide structure provided with the first metal layer by injection molding, so that the insulating layer and the waveguide in the waveguide structure are interlocked, wherein the connecting portion is located on one side of the insulating layer; removing the connecting portion on one side of the insulating layer to obtain an intermediate structure including the insulating layer and a waveguide embedded in the insulating layer and provided with the first metal layer; Two opposite surfaces of the intermediate structure spaced apart along a thickness direction perpendicular to the first direction are respectively covered with a second metal layer; The intermediate structure provided with the second metal layer is subjected to circuit fabrication to form a circuit layer, wherein the circuit layer is provided with a notch corresponding to each of the waveguides.

4. The method for manufacturing a circuit board having a waveguide according to claim 3, wherein: The melting point of the insulating layer is lower than the melting point of the waveguide structure.

5. The method for manufacturing a circuit board having a waveguide according to claim 3, wherein: Along a thickness direction perpendicular to the first direction, the thickness of the waveguide provided with the first metal layer is equal to the thickness of the insulating layer.

6. The method for manufacturing a circuit board having a waveguide according to claim 3, wherein: When forming the waveguide structure, each of the waveguide tubes includes a waveguide body and at least one protrusion, the waveguide body includes two surfaces spaced apart along the thickness direction, and the protrusion protrudes from the surface of the waveguide body along the thickness direction; when forming the circuit layer, the protrusion is exposed corresponding to the notch.

7. A method for manufacturing a circuit board having a waveguide, comprising the following steps: A waveguide structure made of a thermoplastic polymer material is formed by injection molding, wherein the waveguide structure includes a plurality of spaced waveguide tubes and a connecting portion connecting two adjacent waveguide tubes, wherein each waveguide tube includes a waveguide body and at least one protrusion; Removing the connecting portion to obtain at least two independent waveguides; forming a first metal layer on each independent waveguide to cover the entire outer surface of the waveguide; Providing a circuit substrate, wherein at least one receiving groove penetrates the circuit substrate; A waveguide covered by the first metal layer is embedded in each receiving groove and fixed to the waveguide and the circuit substrate; and A portion of the first metal layer located on a surface of the protrusion facing away from the waveguide body is removed.

8. The method for manufacturing a circuit board having a waveguide according to claim 7, wherein: Along the penetrating direction of the receiving groove, the thickness of the circuit substrate is equal to the thickness of the waveguide covered by the first metal layer.

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