TW201924497A - Radio frequency printed circuit board and method for manufacturing the same - Google Patents

Abstract

The present disclosure relates to a radio frequency printed circuit board. The radio frequency printed circuit board includes a first circuit substrate and a second circuit substrate formed on the first circuit substrate. The first circuit substrate includes a first conductive circuit layer. The first conductive circuit layer includes a first radio frequency signal circuit. The second circuit substrate includes a third conductive circuit layer. The third conductive circuit layer includes a second radio frequency signal circuit. The radio frequency printed circuit board further includes at least one grounding hole. The grounding hole is a sidewall plating hole. The first radio frequency signal circuit and the second radio frequency signal circuit avoid the grounding hole. The present disclosure further relates to a method for manufacturing the radio frequency printed circuit board.

Description

Radio frequency circuit board and manufacturing method thereof

The invention relates to a printed circuit board technology, in particular to a radio frequency circuit board and a manufacturing method thereof.

The attenuation of the signal line signal transmitted at high frequency mainly comes from the attenuation caused by the dielectric loss, wherein the dielectric loss and the dielectric loss factor are proportional to the relative dielectric constant. The common method for manufacturing the RF circuit board in the industry is to use liquid crystal polymer (LCP), Teflon or low relative dielectric constant pure glue as the substrate layer for coating the RF signal line. However, the dielectric loss of the above materials is still relatively large, resulting in a large signal attenuation of the transmission line of the circuit board made of the above materials.

In the prior art, a material with low dielectric loss is often used as a substrate layer for covering a radio frequency signal line, and a plurality of RF signal lines are arranged at a level, and a grounding hole is provided between adjacent RF signal lines to improve isolation. The thus completed RF circuit board has a thin thickness and can simultaneously complete the fabrication of a plurality of RF lines, and the manufacturing process is simple, and can be completed by using an ordinary circuit board manufacturing process.

However, since the adjacent RF signal lines are horizontally arranged and the RF signal lines are separated by a grounding hole, the width of the RF circuit board is much larger than the width of the conventional coaxial RF circuit board.

In view of this, the present invention provides a radio frequency circuit board having a small outer shape and a manufacturing method thereof.

A radio frequency circuit board comprising at least a first circuit substrate and a second circuit substrate formed on the first circuit substrate, the first circuit substrate comprising a first conductive circuit layer, the first conductive circuit The layer includes a first RF signal line, the second circuit substrate includes a third conductive circuit layer, the third conductive circuit layer includes a second RF signal line, and the RF circuit board further includes at least one grounding hole, at least one of the The grounding hole is a sidewall plating hole, and the first RF signal line and the second RF signal line are respectively curved to avoid the grounding hole of each layer.

Further, at least one of the ground holes electrically connects the first circuit substrate and the second circuit substrate.

Further, at least one of the ground holes is a part of a normal ground hole, and each of the ground holes has a smaller aperture than the normal ground hole.

Further, the RF circuit board further includes a fourth circuit substrate formed on an outer surface of the second circuit substrate, the fourth circuit substrate includes a seventh conductive circuit layer, and one end of the seventh conductive circuit layer includes at least one The first signal input terminal and a second signal input terminal, and the other end of the seventh conductive circuit layer includes at least a first signal output terminal and a second signal output terminal.

Further, the RF circuit board further includes at least a first signal input hole, a second signal input hole, a first signal output hole and a second signal output hole, wherein the first signal input hole is electrically connected to the first RF a signal line and the first signal input terminal, the first signal output hole is electrically connected to the first RF signal line and the first signal output terminal; the second signal input hole is electrically connected to the second RF signal line and the second a signal input terminal, the second signal output hole is electrically connected to the second RF signal line and the second signal output terminal.

Further, the adjacent ground holes are spaced apart on both sides of the first RF signal line and the second RF signal line.

A method for fabricating a radio frequency circuit board as described above, comprising the steps of: providing a first circuit substrate and a second circuit substrate, and forming the second circuit substrate on the first circuit substrate; the first circuit substrate comprises a a first conductive circuit layer, the first conductive circuit layer includes a first RF signal line, the second circuit substrate includes a third conductive circuit layer, the third conductive circuit layer includes a second RF signal line; The method forms at least one grounding hole, wherein the first RF signal line and the second RF signal line are respectively curved to avoid the grounding hole of each layer.

Further, the step of forming at least one of the grounding holes by using the sidewall plating method comprises: forming at least one plated through hole by electroplating, the plated through hole electrically connecting the first circuit substrate and the second circuit substrate; removing the plating pass The hole is away from the first RF signal line and a portion of the second RF signal line.

Further, the RF circuit board further includes a fourth circuit substrate formed on an outer surface of the second circuit substrate, the fourth circuit substrate includes a seventh conductive circuit layer, and one end of the seventh conductive circuit layer includes at least one end a first signal input terminal and a second signal input terminal, and the other end of the seventh conductive circuit layer includes at least a first signal output terminal and a second signal output terminal.

Further, the step of forming the plated through hole further includes the steps of: forming a first signal input hole, a second signal input hole, a first signal output hole, and a second signal output hole, the first The signal input hole is electrically connected to the first RF signal line and the first signal input terminal, the first signal output hole is electrically connected to the first RF signal line and the first signal output terminal; the second signal input hole is electrically connected to the The second RF signal line and the second signal input terminal are electrically connected to the second RF signal line and the second signal output terminal.

The radio frequency circuit board provided by the invention and the manufacturing method thereof, the arc avoidance of the radio frequency signal line and the sidewall electroplating hole having the aperture smaller than the aperture of the normal grounding hole are used as the grounding hole, thereby reducing the floor space of the grounding hole, and further Achieve the purpose of reducing the shape of the RF circuit board.

The specific embodiments, structures, and features of the radio frequency circuit board and the manufacturing method thereof provided by the present invention are further described below in conjunction with FIGS. 1-14 and the preferred embodiments in order to further explain the technical means and functions of the present invention. And its efficacy, as detailed below.

The present invention provides a radio frequency circuit board 100. The RF circuit board 100 includes at least two circuit substrates including RF signal lines and a circuit substrate that does not include RF signal lines but includes signal input terminals and signal output terminals. In order to facilitate the detailed description of the structure of the radio frequency circuit board of the present invention, the present invention is described as a specific embodiment including three circuit boards including radio frequency signal lines.

Referring to FIG. 1-3, in the embodiment, the RF circuit board 100 includes a first circuit substrate 110, a second circuit substrate 120 formed on a surface of the first circuit substrate 110, and a second circuit substrate 120 formed thereon. The third circuit substrate 130 on the surface of the circuit substrate 120 and a fourth circuit substrate 140 formed on the surface of the third circuit substrate 130.

In other embodiments, the RF circuit board 100 may further include only the first circuit substrate 110, the second circuit substrate 120, and the fourth circuit substrate 140.

In other embodiments, the RF circuit board 100 may further include a fifth circuit substrate, a sixth circuit substrate, and the like.

Specifically, the first circuit substrate 110 includes a first substrate layer 11 , a first conductive circuit layer 14 , and a second conductive circuit layer 15 . The first conductive circuit layer 14 and the second conductive circuit layer 15 are respectively formed on opposite surfaces of the first substrate layer 11.

The first substrate layer 11 has flexibility, and the material of the first substrate layer 11 may be polyimide (PI) or polyethylene terephthalate (PET). Or polyethylene naphthalate (PEN), polyethylene (PE), Teflon, liquid crystal polymer (LCP), polyvinyl chloride (polyvinyl chloride) One of materials such as polymer, PVC).

The first conductive circuit layer 14 includes at least one first RF signal line 141. In the embodiment, the first conductive circuit layer 14 includes a first RF signal line 141.

Specifically, the second circuit substrate 120 includes a second substrate layer 21, a third conductive circuit layer 24, and a fourth conductive circuit layer 25. The third conductive circuit layer 24 and the fourth conductive circuit layer 25 are respectively formed on opposite surfaces of the second substrate layer 21.

The second substrate layer 21 has flexibility. The material of the second substrate layer 21 may be polyimide (PI) or polyethylene terephthalate (PET). Or polyethylene naphthalate (PEN), polyethylene (PE), Teflon, liquid crystal polymer (LCP), polyvinyl chloride (polyvinyl chloride) One of materials such as polymer, PVC).

The third conductive circuit layer 24 includes at least one second RF signal line 241. In the embodiment, the third conductive circuit layer 24 includes a second RF signal line 241.

Specifically, the third circuit substrate 130 includes a third substrate layer 31, a fifth conductive circuit layer 34, and a sixth conductive circuit layer 35. The fifth conductive wiring layer 34 and the sixth conductive wiring layer 35 are respectively formed on opposite surfaces of the third base material layer 31.

The third substrate layer 31 has flexibility, and the material of the third substrate layer 31 may be polyimide (PI) or polyethylene terephthalate (PET). Or polyethylene naphthalate (PEN), polyethylene (PE), Teflon, liquid crystal polymer (LCP), polyvinyl chloride (polyvinyl chloride) One of materials such as polymer, PVC).

The fifth conductive circuit layer 34 includes at least one third RF signal line 341. In the embodiment, the fifth conductive circuit layer 34 includes a third RF signal line 341.

Specifically, the fourth circuit substrate 140 includes a fourth substrate layer 41 and a seventh conductive circuit layer 42 formed on a surface of the fourth substrate layer 41.

The fourth base material layer 41 has flexibility, and the material of the fourth base material layer 41 may be polyimide (PI) or polyethylene terephthalate (PET). Or polyethylene naphthalate (PEN), polyethylene (PE), Teflon, liquid crystal polymer (LCP), polyvinyl chloride (polyvinyl chloride) One of materials such as polymer, PVC).

In this embodiment, one end of the seventh conductive circuit layer 42 includes a first signal input terminal 421, a second signal input terminal 422, and a third signal input terminal 423. In this embodiment, the first signal input terminal 421, the second signal input terminal 422, and the third signal input terminal 423 are arranged in a shape of a character. The first signal input terminal 421 and the third signal input terminal 423 are located on a straight line.

In this embodiment, the other end of the seventh conductive circuit layer 42 includes a first signal output terminal 424, a second signal output terminal 425, and a third signal output terminal 426. The first signal output terminal 424, the second signal output terminal 425, and the third signal output terminal 426 are respectively coupled to the first signal input terminal 421, the second signal input terminal 422, and the third signal input terminal 423. Mirror symmetry.

In this embodiment, the RF circuit board 100 further includes a first signal input hole 62, a second signal input hole 63, a third signal input hole 64, a first signal output hole 65, a second signal output hole 66, and a third Signal output hole 67.

The first signal input hole 62, the second signal input hole 63, and the third signal input hole 64 are sequentially connected to the first signal input terminal 421, the second signal input terminal 422, and the third signal input terminal 423. The first signal output hole 65, the second signal output hole 66, and the third signal output hole 67 are respectively opposite to the first signal output terminal 424, the second signal output terminal 425, and the third signal output terminal. The 426 position is opposite.

The first signal input hole 62 is electrically connected to the second conductive circuit layer 15, the first RF signal line 141 and the first signal input terminal 421. The first signal output hole 65 is electrically connected to the second conductive circuit layer 15 , the first RF signal line 141 and the first signal output terminal 424 .

The second signal input hole 63 is electrically connected to the second RF signal line 241 and the second signal input terminal 422. The second signal output hole 66 is electrically connected to the second RF signal line 241 and the second signal output terminal 425.

The third signal input hole 64 is electrically connected to the third RF signal line 341 and the third signal output terminal 426. The third signal output hole 67 is electrically connected to the third RF signal line 341 and the third signal output terminal 426. .

In this embodiment, the RF circuit board 100 further includes three adhesive layers 50, and the three adhesive layers 50 are respectively connected to the first circuit substrate 110, the second circuit substrate 120, and the second circuit substrate 120. The third circuit substrate 130 and the third circuit substrate 130 and the fourth circuit substrate 140. Specifically, the three adhesive layers 50 face the first conductive circuit layer 14 and the fourth conductive circuit layer 25, the third conductive circuit layer 24, the sixth conductive circuit layer 35, and the fifth conductive circuit layer 34, respectively. And the fourth base material layer 41.

The RF circuit board 100 further includes at least one grounding hole 61.

At least one of the grounding holes 61 is formed by sidewall plating and is a part of a normal grounding hole. The first RF signal line 141, the second RF signal line 241 and the third RF signal line 341 are respectively curved to avoid each layer. The grounding hole 61 is configured to cover and ground the first RF signal line 141, the second RF signal line 241, and the third RF signal line 341.

The adjacent grounding holes 61 are spaced apart on both sides of each layer of the RF signal lines (the first RF signal line 141, the second RF signal line 241, and the third RF signal line 341).

The aperture of each of the grounding holes 61 is greater than 0.5 mm and smaller than the aperture of the normal grounding holes.

At least one of the grounding holes 61 electrically connects the second conductive circuit layer 15, the fourth conductive circuit layer 25, the sixth conductive circuit layer 35, and the seventh conductive circuit layer 42.

In addition, referring to FIG. 3 , the RF circuit board 100 further includes a first cover film layer 71 and a second cover film layer 72 . The first cover film layer 71 is formed on the exposed surface of the seventh conductive circuit layer 42 , and the second cover film layer 72 is formed on the exposed surface of the second conductive circuit layer 15 .

The present invention also provides a method for fabricating a radio frequency circuit board 100, comprising the following steps:

Referring to FIG. 4-12 and FIG. 1 together, a first circuit substrate 110, a second circuit substrate 120, a third circuit substrate 130, a fourth circuit substrate 140, and three adhesive layers 50 are provided. The first circuit substrate 110, the second circuit substrate 120, the third circuit substrate 130, and the fourth circuit substrate 140 are stacked by three adhesive layers 50 to form an intermediate circuit substrate 150.

The first circuit substrate 110 includes a first substrate layer 11 , a first conductive circuit layer 14 , and a second conductive circuit layer 15 . The first conductive circuit layer 14 and the second conductive circuit layer 15 are respectively formed on opposite surfaces of the first substrate layer 11. The first conductive circuit layer 14 includes at least one first RF signal line 141. In the embodiment, the first conductive circuit layer 14 includes a first RF signal line 141.

Specifically, the second circuit substrate 120 includes a second substrate layer 21, a third conductive circuit layer 24, and a fourth conductive circuit layer 25. The third conductive circuit layer 24 and the fourth conductive circuit layer 25 are respectively formed on opposite surfaces of the second substrate layer 21. The third conductive circuit layer 24 includes at least one second RF signal line 241. In the embodiment, the third conductive circuit layer 24 includes a second RF signal line 241.

Specifically, the third circuit substrate 130 includes a third substrate layer 31, a fifth conductive circuit layer 34, and a sixth conductive circuit layer 35. The fifth conductive wiring layer 34 and the sixth conductive wiring layer 35 are respectively formed on opposite surfaces of the third base material layer 31. The fifth conductive circuit layer 34 includes at least one third RF signal line 341. In the embodiment, the fifth conductive circuit layer 34 includes a third RF signal line 341.

Specifically, the fourth circuit substrate 140 includes a fourth substrate layer 41 and a seventh conductive circuit layer 42 formed on a surface of the fourth substrate layer 41.

In this embodiment, one end of the seventh conductive circuit layer 42 includes a first signal input terminal 421, a second signal input terminal 422, and a third signal input terminal 423. In this embodiment, the first signal input terminal 421, the second signal input terminal 422, and the third signal input terminal 423 are arranged in a shape of a character. The first signal input terminal 421 and the third signal input terminal 423 are located on a straight line.

In this embodiment, the other end of the seventh conductive circuit layer 42 includes a first signal output terminal 424, a second signal output terminal 425, and a third signal output terminal 426. The first signal output terminal 424, the second signal output terminal 425, and the third signal output terminal 426 are respectively coupled to the first signal input terminal 421, the second signal input terminal 422, and the third signal input terminal 423. Mirror symmetry.

The three adhesive layers 50 are respectively used to connect the first circuit substrate 110 and the second circuit substrate 120, the second circuit substrate 120 and the third circuit substrate 130, and the third circuit substrate 130 and the fourth The circuit substrate 140. Specifically, the three adhesive layers 50 face the first conductive circuit layer 14 and the fourth conductive circuit layer 25, the third conductive circuit layer 24, the sixth conductive circuit layer 35, and the fifth conductive circuit layer 34, respectively. And the fourth base material layer 41.

The method for preparing the first circuit substrate 110 includes the following steps: First, referring to FIG. 4, a first copper-clad substrate 10 is provided, wherein the first copper-clad substrate 10 includes a first a substrate layer 11 and a first copper foil layer 12 and a second copper foil layer 13 formed on opposite surfaces of the first substrate layer 11; secondly, please refer to FIG. 5, respectively, the first copper foil The layer 12 and the second copper foil layer 13 are formed to form the first conductive wiring layer 14 and the second conductive wiring layer 15 to form the first circuit substrate 110.

Referring to FIG. 6-7, the method for manufacturing the second circuit substrate 120 includes the following steps. First, referring to FIG. 6, a second copper-clad substrate 20 is provided. The second copper-clad substrate 20 includes a first a second substrate layer 21 and a third copper foil layer 22 and a fourth copper foil layer 23 formed on opposite surfaces of the second substrate layer 21; secondly, please refer to FIG. 5, respectively, the third copper foil The layer 22 and the fourth copper foil layer 23 are formed to form the third conductive wiring layer 24 and the fourth conductive wiring layer 25 to form the second circuit substrate 120.

The method for preparing the third circuit substrate 130 includes the following steps: First, referring to FIG. 8 , a third copper clad substrate 30 is provided, wherein the third copper clad substrate 30 includes a first a third base material layer 31 and a fifth copper foil layer 32 and a sixth copper foil layer 33 formed on opposite surfaces of the third base material layer 31; secondly, please refer to FIG. 5, respectively, the fifth copper foil The layer 32 and the sixth copper foil layer 33 are formed to form the fifth conductive wiring layer 34 and the sixth conductive wiring layer 35 to form the third circuit substrate 130.

The first conductive circuit layer 14, the second conductive circuit layer 15, the fifth conductive circuit layer 34, the sixth conductive circuit layer 35, and the seventh conductive circuit layer 42 are all formed by an image transfer process. of.

In the second step, referring to FIG. 13 and FIG. 1 , at least one plated through hole 60 , a first signal input hole 62 , a second signal input hole 63 , a third signal input hole 64 , and a first signal output hole are formed. 65. A second signal output hole 66 and a third signal output hole 67.

The at least one plated through hole 60 is electrically connected to the second conductive circuit layer 15, the fourth conductive circuit layer 25, the sixth conductive circuit layer 35, and the seventh conductive circuit layer 42. The first RF signal line 141, the second RF signal line 241, and the third RF signal line 341 are arcuately circumvented by the plating via 60 of each layer to the first RF signal line 141 and the second RF. The signal line 241 and the third RF signal line 341 are masked and grounded. At least one of the plated through holes 60 is disposed on both sides of each of the RF signal lines (the first RF signal line 141, the second RF signal line 241, and the third RF signal line 341).

The first signal input hole 62, the second signal input hole 63, and the third signal input hole 64 are sequentially connected to the first signal input terminal 421, the second signal input terminal 422, and the third signal input terminal 423. The first signal output hole 65, the second signal output hole 66, and the third signal output hole 67 are respectively opposite to the first signal output terminal 424, the second signal output terminal 425, and the third signal output terminal. The 426 position is opposite.

The first signal input hole 62 is electrically connected to the second conductive circuit layer 15, the first RF signal line 141 and the first signal input terminal 421. The first signal output hole 65 is electrically connected to the second conductive circuit layer 15 , the first RF signal line 141 and the first signal output terminal 424 .

The second signal input hole 63 is electrically connected to the second RF signal line 241 and the second signal input terminal 422. The second signal output hole 66 is electrically connected to the second RF signal line 241 and the second signal output terminal 425.

The third signal input hole 64 is electrically connected to the third RF signal line 341 and the third signal output terminal 426. The third signal output hole 67 is electrically connected to the third RF signal line 341 and the third signal output terminal 426. .

In the third step, referring to FIG. 14, a first cover film layer 71 is formed on the exposed surface of the seventh conductive circuit layer 42, and a second cover film layer 72 is formed on the exposed surface of the second conductive circuit layer 15. .

The fourth step, referring to FIG. 3, removes a portion of the plated through hole 60 away from the RF signal line (the first RF signal line 141, the second RF signal line 241, and the third RF signal line 341), thereby The ground hole 61 is formed to further form the radio frequency circuit board 100. Specifically, part of the plated through hole 60 away from the radio frequency signal line (the first RF signal line 141, the second RF signal line 241, and the third RF signal line 341) may be removed by mechanical cutting or laser. .

Specifically, the signal enters the radio frequency circuit board 100 from the first signal input terminal 421, and then the signal enters the first radio frequency signal line 141 through the first signal input hole 62, and then passes through the first signal output hole 65. The signal is output from the first signal output terminal 424 to the radio frequency circuit board 100.

Similarly, the signal enters the RF circuit board 100 from the second signal input terminal 422, and then the signal enters the second RF signal line 241 through the second signal input hole 63, and then passes through the second signal output hole 66. The signal outputs the RF circuit board 100 from the second signal output terminal 425.

Similarly, the signal enters the RF circuit board 100 from the third signal input terminal 423, and then the signal enters the third RF signal line 341 through the third signal input hole 64, and then passes through the third signal output hole 67. The signal outputs the RF circuit board 100 from the third signal output terminal 426.

The RF circuit board 100 and the manufacturing method thereof provide the ground avoidance through the arc avoidance of the RF signal line and the sidewall plating hole having the aperture smaller than the aperture of the normal ground hole, thereby reducing the footprint of the ground hole. In turn, the purpose of reducing the appearance of the RF circuit board is achieved.

The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, although the present invention has been described above, and is not intended to limit the present invention, any person skilled in the art. The equivalents of the above-described technical contents may be modified or modified to equivalent changes without departing from the technical scope of the present invention, and the technical essence according to the present invention is not deviated from the technical scope of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments are still within the scope of the technical solutions of the present invention.

100‧‧‧RF board

110‧‧‧First circuit board

10‧‧‧First copper-clad substrate

11‧‧‧First substrate layer

12‧‧‧First copper foil layer

13‧‧‧Second copper foil layer

14‧‧‧First conductive circuit layer

141‧‧‧First RF signal line

15‧‧‧Second conductive circuit layer

120‧‧‧Second circuit substrate

20‧‧‧second copper-clad substrate

21‧‧‧Second substrate layer

22‧‧‧ Third copper foil layer

23‧‧‧fourth copper foil layer

24‧‧‧ Third conductive circuit layer

241‧‧‧second RF signal line

25‧‧‧fourth conductive layer

130‧‧‧ Third circuit substrate

30‧‧‧ Third copper clad substrate

31‧‧‧ Third substrate layer

32‧‧‧ Fifth copper foil layer

33‧‧‧6th copper foil layer

34‧‧‧ Fifth conductive circuit layer

341‧‧‧ Third RF signal line

35‧‧‧ sixth conductive circuit layer

140‧‧‧fourth circuit substrate

41‧‧‧Four base material layer

42‧‧‧ seventh conductive circuit layer

421‧‧‧First signal input terminal

422‧‧‧Second signal input terminal

423‧‧‧ Third signal input terminal

424‧‧‧First signal output terminal

425‧‧‧Second signal output terminal

426‧‧‧ Third signal output terminal

50‧‧‧ glue layer

150‧‧‧Intermediate circuit board

60‧‧‧ plated through holes

61‧‧‧ Grounding Hole

62‧‧‧First signal input hole

63‧‧‧Second signal input hole

64‧‧‧ third signal input hole

65‧‧‧First signal output hole

66‧‧‧Second signal output hole

67‧‧‧ third signal output hole

71‧‧‧First cover layer

72‧‧‧second cover layer

FIG. 1 is a layered schematic diagram of a radio frequency circuit board provided by the present invention.

2 is a cross-sectional view of the radio frequency circuit board shown in FIG. 1 taken along II-II.

Figure 3 is a cross-sectional view along line III-III of the radio frequency circuit board shown in Figure 1.

4 is a partial cross-sectional view of a first copper clad substrate provided by the present invention (corresponding to a cross-sectional view of the radio frequency circuit board of FIG. 3).

FIG. 5 is a cross-sectional view showing the first copper-clad substrate shown in FIG. 4 formed into a first circuit board.

Figure 6 is a partial cross-sectional view showing a second copper clad substrate provided by the present invention.

Fig. 7 is a cross-sectional view showing the second copper-clad board shown in Fig. 6 formed into a second circuit board.

Figure 8 is a partial cross-sectional view showing a third copper clad substrate provided by the present invention.

Fig. 9 is a cross-sectional view showing the third copper-clad board shown in Fig. 8 in a third circuit board.

Figure 10 is a partial cross-sectional view showing a fourth circuit substrate provided by the present invention.

Figure 11 is a partial cross-sectional view of a subbing layer provided by the present invention.

12 is a view in which the first circuit board shown in FIG. 5, the second circuit board shown in FIG. 7, the third circuit board shown in FIG. 9, and the fourth circuit board shown in FIG. 10 are adhered to the adhesive layer of FIG. A cross-sectional view of the knot together.

FIG. 13 is a cross-sectional view showing a conductive via hole penetrating through the first circuit substrate, the second circuit substrate, the third circuit substrate, the fourth circuit substrate, and the adhesive layer.

Fig. 14 is a cross-sectional view showing a cover film formed on the outer surfaces of the first circuit board and the fourth circuit board shown in Fig. 13, respectively.

Claims (10)

A radio frequency circuit board comprising at least a first circuit substrate and a second circuit substrate formed on the first circuit substrate, the first circuit substrate comprising a first conductive circuit layer, the first conductive circuit The layer includes a first RF signal line, the second circuit substrate includes a third conductive circuit layer, and the third conductive circuit layer includes a second RF signal line, wherein the RF circuit board further includes at least one grounding hole, at least The grounding hole is a sidewall plating hole, and the first RF signal line and the second RF signal line are respectively curved to avoid the grounding hole of each layer. The radio frequency circuit board of claim 1, wherein at least one of the ground holes is electrically connected to the first circuit substrate and the second circuit substrate. The radio frequency circuit board of claim 1, wherein at least one of the ground holes is a part of a normal ground hole, and each of the ground holes has a smaller aperture than a normal ground hole. The radio frequency circuit board of claim 1, wherein the radio frequency circuit board further comprises a fourth circuit substrate formed on an outer surface of the second circuit substrate, the fourth circuit substrate comprising a seventh conductive circuit layer One end of the seventh conductive circuit layer includes at least a first signal input terminal and a second signal input terminal, and the other end of the seventh conductive circuit layer includes at least a first signal output terminal and a second signal output terminal. The RF circuit board of claim 4, wherein the RF circuit board further includes at least a first signal input hole, a second signal input hole, a first signal output hole, and a second signal output hole. The first signal input hole is electrically connected to the first RF signal line and the first signal input terminal, and the first signal output hole is electrically connected to the first RF signal line and the first signal output terminal; the second signal input hole The second RF signal line and the second signal input terminal are electrically connected, and the second signal output hole is electrically connected to the second RF signal line and the second signal output terminal. The radio frequency circuit board of claim 1, wherein the adjacent grounding holes are spaced apart on both sides of the first RF signal line and the second RF signal line. A method for fabricating a radio frequency circuit board according to any one of claims 1 to 6, comprising the steps of: providing a first circuit substrate and a second circuit substrate, and forming the second circuit substrate on the first circuit On the substrate, the first circuit substrate includes a first conductive circuit layer, the first conductive circuit layer includes a first RF signal line, and the second circuit substrate includes a third conductive circuit layer, the third conductive circuit layer includes a second RF signal line; forming at least one grounding hole by sidewall plating, wherein the first RF signal line and the second RF signal line are arcuately respectively avoiding the grounding hole of each layer. The method for fabricating a radio frequency circuit board according to claim 7, wherein the step of forming at least one of the ground holes by using sidewall plating comprises: forming at least one plated through hole by electroplating, the plated through hole electrically connecting the first a circuit substrate and the second circuit substrate; removing a portion of the plated through hole away from the first RF signal line and the second RF signal line. The method of manufacturing the radio frequency circuit board of claim 8, wherein the radio frequency circuit board further comprises a fourth circuit substrate formed on an outer surface of the second circuit substrate, the fourth circuit substrate comprising a first The seventh conductive circuit layer includes at least one first signal input terminal and a second signal input terminal, and the other end of the seventh conductive circuit layer includes at least one first signal output terminal and a second Signal output terminal. The method for fabricating a radio frequency circuit board according to claim 9, wherein, in the step of forming the plated through hole, the method further comprises the steps of: forming a first signal input hole, a second signal input hole, and a first a signal output hole and a second signal output hole, the first signal input hole is electrically connected to the first RF signal line and the first signal input terminal, the first signal output hole is electrically connected to the first RF signal line and the The first signal output terminal is electrically connected to the second RF signal line and the second signal input terminal, and the second signal output hole is electrically connected to the second RF signal line and the second signal output terminal.