JP2010123813A - Balun-mounted device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To electrically connect a lower transmission line and electrode pads formed on the upper side of a resin layer without forming an opening in the resin layer that provides insulation between an upper transmission line and the lower transmission line of a multilayer balun. <P>SOLUTION: A balun-mounted device includes: a balanced signal transmission line 35 (only one side is shown) that is provided on a first insulating resin layer 22 formed on a substrate 10 and includes one end functioning as a balanced signal output/input terminal 35a and the other end functioning as a grounding terminal 35b; an unbalanced signal transmission line 50 that is provided on the top surface of a resin structure 24 having a trapezoidal cross section so as to oppose to the balanced signal transmission line 35 and includes one end functioning as an unbalanced signal input/output terminal 50a and the other end that is an open end; a balanced signal output/input lead 36 that extends from the top surface of another resin structure 24 through a side surface to the balanced signal output/input terminal 35a; and a grounding lead 37 that extends from the top surface of another resin structure 24 through a side surface to the grounding terminal 35b. The unbalanced signal input/output terminal 50a and the leads 36 and 37 have electrode pads 56, 57, and 59 respectively on the top surfaces of the resin structures 24. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a balun mounting device in which a balun (balance transformer / unbalance-balance converter) used in a radio circuit or the like is mounted on a substrate.

  The balun is provided opposite to the first balanced signal transmission path, the second balanced signal transmission path provided independently of the first balanced signal transmission path, and the two balanced signal transmission paths. An unbalanced signal transmission line, one end of which is an unbalanced signal input / output end and the other end is an open end, and two balanced signal transmission lines have one end of a balanced signal input / output end and the other end. It has a structure that becomes the ground end. When a balanced signal is input from two balanced signal input / output ends, this type of balun converts the balanced signal to an unbalanced signal by electromagnetic coupling from the balanced signal transmission path to the unbalanced signal transmission path. When an unbalanced signal is output from the signal input / output end and an unbalanced signal is input from the unbalanced signal input / output end, the unbalanced signal is balanced by electromagnetic coupling from the unbalanced signal transmission path to the balanced signal transmission path. It converts into a signal and outputs a balanced signal from two balanced signal input / output terminals.

The stacked balun has a structure in which an unbalanced signal transmission line and two balanced signal transmission lines are stacked vertically (in the thickness direction of the insulating layer) via an insulating layer (dielectric layer). As a conventional laminated balun, one based on low temperature co-fired ceramics (LTCC) technology (for example, Patent Document 1) is known.
JP 2002-50910 A

  A conventional laminated balun is composed of a number of layers including an unbalanced signal transmission line layer and a balanced signal transmission line layer, a terminal layer of an input section, a ground (GND) layer, and the like, and is a terminal for mounting. It is necessary to apply the part to the side. For this reason, the production of a conventional laminated balun requires a very complicated and advanced production technique, resulting in high costs.

Further, in the balun, each of the two balanced signal transmission lines has a size of ¼ wavelength or less, and the unbalanced signal transmission line has a total size of the two balanced signal transmission lines. If the frequency of the signal is low, the wavelength of the signal becomes long, so that the length of the transmission path also becomes long.
On the other hand, in high frequency circuit design, the input / output impedance of the device is often designed to be 50Ω. Therefore, the balun is also required to make the impedance of the unbalanced input 50Ω and to reduce the insertion loss (passage loss) as much as possible. For this reason, in order to incorporate a balun into a high-frequency circuit, it is necessary to make the DC resistance value of the wiring as small as possible in order to reduce the insertion loss (passage loss) of the balun.

Currently, the design rule of the wiring used in the mass production process of LTCC is L / S = 60/60 μm (line width L = 60 μm, space S = 60 μm) and wiring thickness of about 10 μm. If wiring having such a size can be used for manufacturing a laminated balun, a low insertion loss of generally less than 1 dB can be realized.
However, when the above design rule is adopted in a semiconductor processing process using wafer level package (WLP) technology, the design rule is larger than usual for the WLP technology, so that the unbalanced input impedance is kept at 50Ω. It is necessary to secure a thickness of about several tens of μm for the insulating layer between the upper and lower transmission lines constituting the laminated balun. However, when an insulating resin layer having a thickness of about several tens of μm is formed in the WLP technique, it is not easy to form openings and vias. In general, the aspect ratio of the hole that can be opened in the insulating resin layer (ratio of the opening diameter to the thickness of the resin layer) is determined for each resin, and in order to provide an opening in a thick resin layer, it is proportional to the thickness of the resin layer. Therefore, there is a problem that the opening diameter needs to be increased and a large area is occupied by the via.

  The present invention has been made in view of the above circumstances, and an electrode formed on the lower transmission line and the upper side of the resin layer without providing an opening in the resin layer that insulates the upper and lower transmission lines of the laminated balun. It is an object of the present invention to provide a balun mounting device that can be electrically connected to a pad.

  In order to solve the above problems, the present invention provides a substrate, a first insulating resin layer formed on the substrate, and the first insulating resin layer, and has one end as a first balanced signal input / output end, A first balanced signal transmission path having the other end as a first ground terminal and the first balanced signal transmission path on the first insulating resin layer are electrically independent from each other, and one end is provided as a second balanced signal output. A second balanced signal transmission line having an input end and the other end as a second grounding end, and a top surface of a resin structure having a trapezoidal cross section formed on the two balanced signal transmission lines and the first insulating resin layer Above, formed on the first insulating resin layer, the unbalanced signal transmission line provided opposite to the two balanced signal transmission lines, having one end as an unbalanced signal input / output end and the other end as an open end. Connected to the first balanced signal input / output terminal from the top surface of the resin structure having a trapezoidal cross section, through the side surface Connected to the second balanced signal input / output terminal via the first balanced signal input / output lead wire and the top surface of the resin structure having a trapezoidal cross section formed on the first insulating resin layer. The second balanced signal input / output lead wiring and the first grounding end connected to the first grounding terminal through the side surface from the top surface of the trapezoidal resin structure formed on the first insulating resin layer. One ground lead wiring and a second ground lead wiring connected to the second ground end through the side surface from the top surface of the resin structure having a trapezoidal cross section formed on the first insulating resin layer. At least provided on the top surface of the resin structure having a trapezoidal cross section is connected to each of the unbalanced signal input / output terminal, the two balanced signal input / output lead wires, and the two ground lead wires. A rose characterized by an electrode pad being formed To provide an implementation device.

In the present invention, the electrode pad connected to the unbalanced signal input / output terminal and the electrode pad connected to the balanced signal output / input terminal via the balanced signal output input / output lead line have the same trapezoidal cross section. It is also possible to adopt a configuration provided on the resin structure.
The electrode pad connected to the unbalanced signal input / output terminal and the electrode pad connected to the ground terminal via the ground lead wiring are provided on a resin structure having the same trapezoidal cross section. It is also possible to have a configuration.
In addition, an electrode pad connected to the unbalanced signal input / output terminal, an electrode pad connected to the balanced signal output / input terminal via the balanced signal input / output lead line, and a ground terminal via the ground lead wiring It is also possible to adopt a configuration in which the connected electrode pads are provided on a resin structure having the same trapezoidal cross section.

In the unbalanced signal transmission path, a portion facing the first balanced signal transmission path and a portion facing the second balanced signal transmission path are provided on a resin structure having a trapezoidal cross section. Preferably it is.
It is preferable that bumps are mounted on the electrode pads.
It is preferable that the electrode pad is formed to be thicker than the lead wiring.

  According to the present invention, a resin structure having a trapezoidal cross section is laminated on the lower transmission line, and an upper transmission line is formed thereon to form the laminated balun on the substrate. Since the lead wiring is provided along the side surface of the resin structure, it is formed on the lower transmission line and the upper side of the resin layer without providing an opening in the resin layer that insulates the upper and lower transmission lines of the laminated balun. The electrode pad can be electrically connected.

The present invention will be described below with reference to the drawings based on the best mode.
FIG. 1 is a schematic cross-sectional view showing a main part of a balun mounting device according to a first embodiment of the present invention. FIG. 2 is a perspective view showing an overall configuration example of the balun mounting device. 3 is a partially enlarged perspective view showing a ground terminal portion and an unbalanced signal input / output terminal portion of the balun shown in FIG.
FIG. 1 is a cross-sectional view of the balun mounting device 100 shown in FIG. 2 with the II line on the left side and the cross-sectional view along the II-II line on the right side. 2 and 3 illustrate transmission paths (wirings) constituting the balun of the balun mounting device 100, and the resin structure 24 having a trapezoidal cross section is omitted.

FIG. 4 is a schematic plan view of the balun shown in FIG. FIG. 5 is a cross-sectional view taken along line AA in FIG. 6 is a cross-sectional view taken along line BB in FIG. 7 is a cross-sectional view taken along the line CC of FIG. 4 to 7, the balanced signal transmission lines 30 and 35 and the unbalanced signal transmission line 50 are illustrated in a straight line for explaining the structure of the balun.
The drawings used in the following description are schematic, and the size and aspect ratio may be different from the actual ones.

As shown in FIG. 2, the balun mounting device includes a substrate 10, a first insulating resin layer 22 formed on the substrate 10, and two balanced signal transmission paths 30 provided on the first insulating resin layer 22. , 35 and an unbalanced signal transmission path provided opposite to the two balanced signal transmission paths 30, 35 on the top surface of the resin structure 24 having a trapezoidal cross section (not shown in FIG. 2). 50.
The substrate 10 is, for example, a semiconductor substrate such as silicon (Si) or an insulating substrate such as a glass substrate.

The balanced signal transmission paths 30 and 35 include a first balanced signal transmission path 30 and a second balanced signal transmission path 35 that are provided electrically independently of each other.
The first balanced signal transmission line 30 has one end as a first balanced signal input / output end 30a and the other end as a first ground end 30b. The first balanced signal output / input terminal 30 a is connected to the first balanced signal output / input terminal section 60 via the first balanced signal output / input lead-out line 31. The first ground terminal 30 b is connected to the first ground terminal portion 70 via the first ground lead wiring 32.
Similarly, the second balanced signal transmission line 35 has one end as a second balanced signal input / output terminal 35a, the other end as a second ground terminal 35b, and the second balanced signal output / input terminal 35a is connected to the second balanced signal input / output terminal 35a. The second balanced signal input / output terminal portion 65 is connected to the second balanced signal input / output terminal portion 65 via the lead wire 36, and the second ground terminal 35 b is connected to the second ground terminal portion 75 via the second ground lead wire 37.

  The unbalanced signal transmission path 50 has one end as an unbalanced signal input / output end 50a and the other end as an open end 50b. The unbalanced signal transmission path 50 includes a portion 50c facing the first balanced signal transmission path 30 and a portion 50d facing the second balanced signal transmission path 35 between the unbalanced signal input / output end 50a and the open end 50b. And have. The unbalanced signal input / output terminal 50 a is connected to the unbalanced signal input / output terminal unit 90.

In this embodiment, as shown in FIGS. 1 and 2, the portion 50c of the unbalanced signal transmission path 50 facing the first balanced signal transmission path 30 and the first balanced signal transmission path 30 have a space E1 on the inner periphery. The portion 50d of the unbalanced signal transmission path 50 facing the second balanced signal transmission path 35 and the second balanced signal transmission path 35 have a space E2 on the inner periphery. Are arranged in a plane spiral type.
As shown in FIGS. 2, 4, and 5, between the portion 50 c of the unbalanced signal transmission path 50 facing the first balanced signal transmission path 30 and the section 50 d facing the second balanced signal transmission path 35. Are connected by an intermediate portion 50e.
In this embodiment, the winding direction of the planar spiral (winding direction from the inner periphery to the outer periphery) is opposite to each other in the first balanced signal transmission path 30 and the second balanced signal transmission path 35, and unbalanced signal transmission is performed. The two planar spiral portions 50c and 50d of the path 50 are opposite to each other. In the unbalanced signal transmission line 50, the direction in which the wiring is wound along the direction of the current flowing from the unbalanced signal input / output end 50a to the open end 50b (or vice versa) is two planar spiral shapes. The portions 50c and 50d of FIG.
By providing the transmission lines 30, 35, and 50 in a spiral shape, a long transmission line can be arranged in a narrow space such as a square or an ellipse. For this reason, by using a spiral type, it is possible to reduce the space occupied by the balun and realize a balun having a long transmission path.
In the present invention, the shape of the transmission line may be a meander shape, a straight line shape, etc. in addition to a planar spiral.

In this planar spiral, the unbalanced signal input / output end 50a and the open end 50b of the unbalanced signal transmission path 50 and the ground ends 30b, 35b of the balanced signal transmission paths 30, 35 are arranged on the inner peripheral side, and are unbalanced. An intermediate portion 50e of the signal transmission path 50 and balanced signal input / output ends 30a and 35a of the balanced signal transmission paths 30 and 35 are arranged on the outer peripheral side.
The first ground terminal portion 70 is disposed in the first space E1 on the inner periphery of the planar spiral, and the second ground terminal portion 75 and the unbalanced signal input / output terminal portion 90 are in the second space E2 on the inner periphery of the planar spiral. Is placed inside. The two balanced signal input / output terminal portions 60 and 65 are disposed outside the planar spiral.

  The two balanced signal transmission paths 30 and 35 can be made of, for example, a plating metal such as copper plating. The two balanced signal transmission lines 30 and 35 are formed of the same conductor material so that the transmission line length L1 of the first balanced signal transmission line 30 and the transmission line length L2 of the second balanced signal transmission line 35 are equal. preferable. Here, the transmission path lengths L1 and L2 are the lengths of the transmission paths along the spiral. The width W and the thickness T of the two balanced signal transmission lines 30 and 35 are preferably formed such that the width W and the thickness T are equal to each other.

As shown in FIGS. 5 to 7, the thickness h <b> 1 of the first insulating resin layer 22 is preferably as uniform as possible over the entire surface of the substrate 10. The thickness h1 of the first insulating resin layer 22 corresponds to the distance between the upper surface of the substrate 10 and the lower surfaces of the balanced signal transmission lines 30 and 35.
Examples of the resin constituting the first insulating resin layer 22 include a polyimide resin and an epoxy resin. Of these, photosensitive resins such as a photosensitive polyimide resin and a photosensitive epoxy resin are preferable because they can be patterned by photolithography. Since the first insulating resin layer 22 is applied to the entire surface of the substrate 10, a thermosetting resin or the like may be used.

As shown in FIGS. 1 and 5 to 7, the unbalanced signal transmission path 50 is a resin structure having a trapezoidal cross section formed on the two balanced signal transmission paths 30 and 35 and the first insulating resin layer 22. 24 is formed on the top surface. The resin structure 24 provided under the unbalanced signal transmission path 50 is formed in an annular shape (around the spaces E1 and E2) along the respective balanced signal transmission paths 30 and 35, for example.
The “cross-sectional trapezoidal shape” means that the side surfaces on both sides are inclined slopes toward the top surface so that the top surface of the resin structure 24 is narrower than the bottom surface. This slope serves as a base when lead wires 31, 32, 36, and 37 to be described later are formed along the side surface of the resin structure 24.

  The unbalanced signal transmission path 50 includes two spiral portions 50c and 50d connected by an intermediate portion 50e, and is connected at least in a range from the unbalanced signal input / output end 50a at one end to the open end 50b at the other end. It is a transmission line of a book. The intermediate portion 50e of the unbalanced signal transmission path 50 is provided at a position where the outer peripheral ends of the planar spiral are connected to each other.

  The unbalanced signal transmission path 50 can be composed of, for example, a plating metal such as copper plating. The unbalanced signal transmission line 50 is preferably formed of the same conductor material as the two balanced signal transmission lines 30 and 35. Further, the width W and the thickness T of the unbalanced signal transmission path 50 are formed so that the width W and the thickness T of the two balanced signal transmission paths 30 and 35 are equal to each other. It is preferred that

The intermediate portion 50e has a length corresponding to the interval g between the two planar spiral portions 50c and 50d. The lengths L1 and L2 of the two spiral portions 50c and 50d are equal to the transmission line lengths L1 and L2 of the balanced signal transmission lines 30 and 35, respectively.
The length L from the unbalanced signal input / output end 50a to the open end 50b of the unbalanced signal transmission path 50 is the lengths L1 and L2 of the two spiral portions 50c and 50d, and the length g of the intermediate portion 50e. (L = L1 + g + L2).
Note that the transmission line lengths L1 and L2 shown in FIG. 4 are such that the balanced signal transmission lines 30 and 35 and the unbalanced signal transmission line 50 are vertically moved through the second insulating resin layer made of the resin structure 24 having a trapezoidal cross section. This represents the length of the portion facing the.

  As shown in FIGS. 5 to 7, the thickness d of the resin structure 24 on the balanced signal transmission paths 30 and 35 is preferably made as uniform as possible along the entire length along the balanced signal transmission paths 30 and 35. The thickness d of the resin structure 24 corresponds to the distance between the upper surfaces of the balanced signal transmission paths 30 and 35 and the lower surface of the unbalanced signal transmission path 50. The thickness of the resin structure 24 on the first insulating resin layer 22 is calculated in terms of the thickness T of the balanced signal transmission paths 30 and 35 and the thickness of the resin structure 24 on the balanced signal transmission paths 30 and 35. It corresponds to the sum (T + d) with d. However, since the resin structure 24 is formed on the uneven surface by the first insulating resin layer 22 and the balanced signal transmission lines 30 and 35 formed thereon, at a place away from the balanced signal transmission lines 30 and 35. The thickness of the resin structure 24 is not necessarily uniform.

The distance d between the upper surfaces of the balanced signal transmission lines 30 and 35 and the lower surface of the unbalanced signal transmission path 50 is not particularly limited, but may be d = 5 to 40 μm.
Examples of the resin constituting the resin structure 24 having a trapezoidal cross section include a polyimide resin and an epoxy resin. Of these, photosensitive resins such as a photosensitive polyimide resin and a photosensitive epoxy resin are preferable because they can be patterned by photolithography.

On the unbalanced signal transmission line 50, a sealing resin layer 26 can be provided as a third insulating resin layer. The thickness h 2 of the sealing resin layer 26 on the unbalanced signal transmission path 50 corresponds to the distance between the upper surface of the unbalanced signal transmission path 50 and the upper surface of the sealing resin layer 26.
Examples of the resin constituting the sealing resin layer 26 include a polyimide resin and an epoxy resin. Of these, photosensitive resins such as a photosensitive polyimide resin and a photosensitive epoxy resin are preferable because they can be patterned by photolithography. Since the sealing resin layer 26 is applied to the entire surface of the device, a thermosetting resin or the like may be used.

As shown in FIGS. 1, 2, 4, and 6, the balanced signal input / output lead wires 31 and 36 are on the top surface of the resin structure 24 having a trapezoidal cross section formed on the first insulating resin layer 22. Are connected to the respective balanced signal output / input electrode pads 51 and 56 (the first balanced signal output / input electrode pad 51 and the second balanced signal output / input electrode pad 56). The balanced signal input / output lead wires 31 and 36 are connected to the balanced signal output / input ends 30a and 35a from the top surface of the resin structure 24 through the side surfaces. The balanced signal output / input electrode pads 51 and 56 are electrode pads for inputting and outputting a balanced signal at the balanced signal output / input terminal portions 60 and 65.
The sealing resin layer 26 has openings 26 a and 26 c for exposing at least a part of the balanced signal input / output electrode pads 51 and 56. 1 shows a cross-sectional structure of the second balanced signal input / output terminal portion 65, the same applies to the first balanced signal input / output terminal portion 60. FIG.
The length L1a (the length from the first balanced signal output / input terminal 30a to the first balanced signal output / input electrode pad 51) of the first balanced signal input / output lead line 31 and the second balanced signal output / input lead line 36 are shown. Length L2a (the length from the second balanced signal input / output terminal 35a to the second balanced signal output / input electrode pad 56) is equal to each other in order to improve the amplitude balance characteristic and the phase balance characteristic (L1a = L2a). Is preferred.

As shown in FIGS. 1, 2, 3, and 4, the ground lead wires 32 and 37 are respectively formed on the top surface of the resin structure 24 having a trapezoidal cross section formed on the first insulating resin layer 22. It is connected to the formed ground electrode pads 52, 57 (first ground electrode pad 52 and second ground electrode pad 57). The ground lead wires 32 and 37 are connected to the ground ends 30b and 35b from the top surface of the resin structure 24 through the side surfaces. The ground electrode pads 52 and 57 are electrode pads for grounding the other ends of the balun balanced signal transmission lines 30 and 35 at the ground terminal portions 70 and 75.
The sealing resin layer 26 has openings 26 b and 26 d for exposing at least a part of the ground electrode pads 52 and 57. Although FIG. 1 shows a cross-sectional structure of the second ground terminal portion 75, the same applies to the first ground terminal portion 70.
Note that the length L1b of the first ground lead wiring 32 (the length from the first ground end 30b to the first ground electrode pad 52) and the length L2b of the second ground lead wiring 37 (the second ground end 35b to the first length). The length of the two ground electrode pads 57) is preferably equal to each other (L1b = L2b) in order to improve the amplitude balance characteristic and the phase balance characteristic.

As shown in FIGS. 1, 2, 3, 4, and 7, the unbalanced signal input / output end 50 a of the unbalanced signal transmission path 50 has a trapezoidal cross section formed on the first insulating resin layer 22. It is connected to an unbalanced signal input / output electrode pad 59 provided on the top surface of the resin structure 24. The unbalanced signal input / output electrode pad 59 is an electrode pad for inputting / outputting an unbalanced signal at the unbalanced signal input / output terminal unit 90.
The sealing resin layer 26 has an opening 26 e for exposing at least a part of the unbalanced signal input / output electrode pad 59.

  As described above, in the balun mounting device of this embodiment, the balanced signal output / input electrode pads 51 and 56 connected to the balanced signal output / input terminals 30a and 35a and the ground electrode pad 52 connected to the ground terminals 30b and 35b. , 57 and an electrode pad 59 connected to the unbalanced signal input / output terminal 50a are provided on the top surface of the resin structure 24 having a trapezoidal cross section, and the balanced signal input / output terminals 30a, 35a and the balanced signal output / input electrode Lead wires (balanced signal input / output) in which the connection between the pads 51 and 56 and the connection between the ground ends 30b and 35b and the ground electrode pads 52 and 57 are arranged from the top surface of the resin structure 24 through the side surfaces. The lead wires 31 and 36 and the ground lead wires 32 and 37) are used. As a result, even if the resin structure 24 is thick, the balanced signal transmission paths 30 and 35 under the resin structure 24 can be connected to the electrode pads 51, 52, 56, and over the resin structure 24 without providing openings and vias. 57 can be connected.

  Furthermore, in the balun mounting device of the present embodiment, each of the lead wires 31, 32, 36, and 37 is connected to the balanced signal input / output ends 30a and 35a of the balanced signal transmission lines 30 and 35 on the first insulating resin layer 22. Balanced signal transmission line extensions 31a, 32a, 36a, 37a arranged between the grounding ends 30b, 35b and the vicinity of the side surface of the resin structure 24 having the trapezoidal cross section having the electrode pads 51, 52, 56, 57. And resin structure side surface connecting portions 31b, 32b, 36b, and 37b disposed between the side surface and the top surface of the resin structure 24 having a trapezoidal cross section.

The balanced signal transmission line extensions 31a, 32a, 36a, and 37a are formed integrally with the balanced signal transmission lines 30 and 35 (in the same process as the balanced signal transmission lines 30 and 35), and then the resin structure having a trapezoidal cross section. After the object 24 is formed and the balanced signal input / output ends 30a and 35a and the ground ends 30b and 35b are covered with the resin structure 24, they are exposed to the outside of the resin structure 24. Therefore, after the resin structure 24 is formed, the resin structure side surface connecting portions 31b, 32b, and 36b are connected to the balanced signal transmission line extensions 31a, 32a, 36a, and 37a exposed to the outside. , 37b and electrode pads 51, 52, 56, 57 can be formed. In this case, in the step of forming the resin structure 24, the resin structure 24 on which the unbalanced signal transmission path 50 is formed, and the resin structure 24 on which the electrode pads 51, 52, 56, 57 are formed. Even if the balanced signal transmission lines 30 and 35 are covered with the resin structure 24, the formation of the lead wires 31, 32, 36 and 37 is not hindered.
The balanced signal transmission line extension portions 31a, 32a, 36a, and 37a may be at least partially exposed to the outside of the resin structure 24 in which the unbalanced signal transmission path 50 is formed on the top surface. The balanced signal transmission line extension portions 31a, 32a, 36a, and 37a do not necessarily need to be in contact with the side surface of the resin structure 24 on which the resin structure side surface connecting portions 31b, 32b, 36b, and 37b are formed. . That is, in the case of manufacturing by the method described later, in FIG. 15, the left end of the balanced signal transmission path extension 37a is in contact with the side surface of the resin structure 24 on the left side. The right end of the resin structure side surface connecting portion 37b may be extended on the first insulating resin layer 22 until the resin structure side surface connecting portion 37b is electrically connected to the balanced signal transmission line extension portion 37a.

  In the case of this embodiment, as shown in FIGS. 1 and 2, solder bumps (first balanced signal output / input bump 81, first ground bump) are formed on the electrode pads 51, 52, 56, 57, 59, respectively. 82, a second balanced signal output / input bump 86, a second ground bump 87, and an unbalanced signal input / output bump 89) are mounted. These bumps 81, 82, 86, 87, and 89 are arranged inside the openings 26 a, 26 b, 26 c, 26 d, and 26 e of the sealing resin layer 26 and protrude upward from the upper surface of the sealing resin layer 26. . By using these bumps 81, 82, 86, 87, 89, the balun mounting device 100 can be flip-chip mounted on another mounting substrate. In order to improve the stability of flip chip mounting, dummy bumps are appropriately provided in addition to the bumps 81, 82, 86, 87, 89 connected to the transmission paths 30, 35, 50 of the balun, and other mounting boards are provided. It is desirable to support the balun mounting device 100 in a balanced manner.

When the balun mounting device 100 is flip-chip mounted on another mounting substrate, the electrode pads 51, 52, 56, 57, 59 are formed to be thicker than the lead-out wirings 31, 32, 36, 37. It is preferable. Accordingly, when the balun mounting device 100 is flip-chip mounted on another mounting substrate via the bumps 81, 82, 86, 87, 89 provided on the electrode pads 51, 52, 56, 57, 59, the other The distance between the wiring circuit on the mounting substrate and the transmission paths 30, 35, 50 of the balun mounting device 100 can be further increased, and the interaction between the wiring circuit and the transmission paths 30, 35, 50 can be suppressed.
As a method of forming the electrode pads 51, 52, 56, 57, 59 thicker than the lead wires 31, 32, 36, 37, plating is selectively grown on the electrode pads 51, 52, 56, 57, 59. A method is mentioned.
The electrode pad 59 is not connected to the lead wires 31, 32, 36, and 37, but preferably has the same thickness as the other electrode pads 51, 52, 56, and 57.

The multilayer resin body 20 has a laminated structure composed of a first insulating resin layer 22, a second insulating resin layer made of a resin structure 24 having a trapezoidal cross section, and a third insulating resin layer made of a sealing resin layer 26. It is. The first insulating resin layer 22 is formed on the substrate 10.
These resin layers 22, 24, and 26 may have the same relative dielectric constant by being formed by the same method using the same resin.
In particular, the resin structure 24 having a trapezoidal cross section interposed between the upper and lower balanced signal transmission paths 30 and 35 and the unbalanced signal transmission path 50 includes the balanced signal transmission paths 30 and 35 and the unbalanced signal transmission path 50. In order to control the electromagnetic coupling between the other resin layers 22 and 26, the resin layers 22 and 26 may be made of a resin having a different dielectric constant.

FIG. 8 shows a schematic circuit diagram of the balun shown in FIG.
In the balun 110 of FIG. 8, when an unbalanced signal (single signal) SS is input to the unbalanced signal input / output terminal 50a of the unbalanced signal transmission path 50, the unbalanced signal transmission path 50 and the balanced signal transmission path 30, Electromagnetic coupling with 35 occurs. At this time, if the wavelength of the signal to be transmitted is λ, the transmission line length L1 of the first balanced signal transmission line 30 and the transmission line length L2 of the second balanced signal transmission line 35 are each λ / 4 (below). Thus, balanced signals (differential signals) SD1 and SD2 are output from the balanced signal input / output ends 30a and 35a of the balanced signal transmission lines 30 and 35, respectively.
Similarly, when balanced signals (differential signals) SD1 and SD2 are input from the balanced signal input / output terminals 30a and 35a of the balanced signal transmission paths 30 and 35, the balanced signal transmission paths 30 and 35 and the unbalanced signal transmission path 50 are connected. Due to the electromagnetic coupling, an unbalanced signal (single signal) SS is output from the unbalanced signal input / output terminal 50a of the unbalanced signal transmission path 50.

  Such a balun 110 converts the unbalanced signal into a balanced signal when demodulating the unbalanced signal received by the antenna, or conversely unbalances the balanced signal when transmitting the modulated signal as a balanced signal from the antenna. In order to convert it into a signal, it is used in a wireless communication device such as a mobile phone.

  Further, the balun 110 in FIG. 8 also has a function as a transformer for converting impedance. In the impedance conversion, the input / output impedance ZS of the unbalanced signal transmission path 50 and the input / output impedances ZD1, ZD2 of the balanced signal transmission paths 30, 35 are required to be impedances of design specifications. For example, ZS = 50Ω, ZD1 + ZD2 = 100Ω, 150Ω, 200Ω, and the like.

In the balun mounting device of this embodiment, the number of resin structures 24 having a trapezoidal cross section is not particularly limited.
9 to 11 are sectional views in which the II line of the balun mounting device 100 shown in FIG. 2 is arranged on the left side and the sectional view along the line II-II is arranged on the right side, like FIG. .
For example, as shown in FIG. 9, an electrode pad 59 connected to the unbalanced signal input / output terminal 50a and an electrode pad 56 connected to the balanced signal output / input terminal 35a via the balanced signal output / input lead line 36 are provided. The resin structure 24 having the same trapezoidal cross section may be provided.
Further, as shown in FIG. 10, the electrode pad 59 connected to the unbalanced signal input / output terminal 50a and the electrode pad 57 connected to the ground terminal 35b through the ground lead wiring 37 have the same trapezoidal cross section. The resin structure 24 may be provided.
Further, as shown in FIG. 11, an electrode pad 59 connected to the unbalanced signal input / output terminal 50a, an electrode pad 56 connected to the balanced signal output / input terminal 35a via the balanced signal output / input lead wiring 36, The electrode pad 57 connected to the ground end 35b via the ground lead wiring 37 may be provided on the resin structure 24 having the same trapezoidal cross section.
The electrode pad 59 connected to the unbalanced signal input / output terminal 50a and the portion of the unbalanced signal transmission path 50 facing the second balanced signal transmission path 35 (the side having the unbalanced signal input / output terminal 50a on the inner periphery). The spiral portion) 50d is preferably provided on the resin structure 24 having the same trapezoidal cross section.

9 to 11 show the spiral portion 50d on the side having the unbalanced signal input / output end 50a on the inner periphery, but the same applies to the spiral portion 50c on the side having the open end 50b on the inner periphery. It is.
For example, the open end 50b and the electrode pad 51 connected to the balanced signal input / output end 30a via the balanced signal input / output lead line 31 are provided on the resin structure 24 having the same trapezoidal cross section. Also good.
Further, the open end 50 b and the electrode pad 52 connected to the ground end 30 b via the ground lead wiring 32 may be provided on the resin structure 24 having the same trapezoidal cross section.
Also, an open end 50b, an electrode pad 51 connected to the balanced signal input / output terminal 30a via the balanced signal input / output lead line 31, and an electrode pad 52 connected to the ground end 30b via the ground lead line 32 However, it may be provided on the resin structure 24 having the same trapezoidal cross section.
Note that the open end 50b and the portion of the unbalanced signal transmission line 50 facing the first balanced signal transmission line 30 (the spiral part on the side having the open end 50b on the inner periphery) 50c have the same trapezoidal cross section. It is preferable to be provided on the resin structure 24.

As shown in FIG. 12, the unbalanced signal transmission path 50 has a portion 50c facing the first balanced signal transmission path 30 and a section 50d facing the second balanced signal transmission path 35 having the same trapezoidal cross section. It is preferably provided on the resin structure 24.
The intermediate portion 50e is also provided on the resin structure 24 having the same trapezoidal cross section as the portion 50c facing the first balanced signal transmission path 30 and the portion 50d facing the second balanced signal transmission path 35. Preferably it is.
As shown in FIG. 13, the balun mounting device of this embodiment has openings 26a, 26b, 26c, 26d, and 26e that expose the electrode pads 51, 52, 56, 57, and 59 in the sealing resin layer 26. The electrode pads 51, 52, 56, 57, 59 may be configured to be mounted on a mounting substrate (not shown) by wire bonding.

The balun mounting device of this embodiment can be manufactured by a manufacturing method applying WLP technology. 14 to 16 show a manufacturing process of the balun mounting device of the first embodiment shown in FIG.
As shown in FIG. 14, after forming the first insulating resin layer 22 on the substrate 10 such as a silicon (Si) wafer, the balanced signal transmission path 35 is formed on the first insulating resin layer 22. When the balanced signal transmission path 35 is formed, balanced signal transmission path extensions 36 a and 37 a respectively extended from the balanced signal input / output terminal 35 a and the ground terminal 35 b are formed together with the balanced signal transmission path 35.
Although not shown in FIG. 14, the balanced signal transmission path 30 and the balanced signal transmission path extensions 31a and 32a are formed at the same time as the balanced signal transmission path 35 and the balanced signal transmission path extensions 36a and 37a. The

Next, as shown in FIG. 15, a resin structure 24 having a trapezoidal cross section is formed on the balanced signal transmission path 35 and the first insulating resin layer 22. The resin structure 24 having the trapezoidal cross section on the balanced signal transmission path 35 is not limited to the balanced signal transmission line extension 36a, even if the balanced signal input / output end 35a and the ground end 35b are covered with the resin structure 24 having the trapezoidal cross section. At least a part of 37a is formed to be exposed to the outside of the resin structure 24.
Although not shown in FIG. 15, the resin structure 24 having a trapezoidal cross section on the balanced signal transmission line 30 similarly has a resin structure 24 having a balanced signal input / output end 30a and a grounding end 30b having a trapezoidal cross section. Even when covered, the balanced signal transmission line extension portions 31 a and 32 a are formed so as to be exposed to the outside of the resin structure 24.

Next, as shown in FIG. 16, the unbalanced signal transmission path 50 and the electrode pads 56, 57, 59 are formed on the resin structure 24 having a trapezoidal cross section, and the balanced signal transmission path extension portions 36a, 37a are connected to the electrodes. Resin structure side surface connecting portions 36 b and 37 b that communicate with the pads 56 and 57 are formed from the top surface to the side surface of the resin structure 24.
Although not shown in FIG. 16, the unbalanced signal transmission line 50 is an entire structure from the unbalanced signal input / output end 50a to the open end 50b (the portion 50c facing the first balanced signal transmission line, the second balanced signal). A part 50d and an intermediate part 50e) facing the transmission line are formed simultaneously. Similarly to the electrode pads 56, 57, and 59 and the resin structure side surface connecting portions 36b and 37b, the electrode pads 51 and 52 and the resin structure side surface connecting portions 31b and 32b are formed at the same time.

Next, when the sealing resin layer 26 having openings 26c, 26d, and 26e exposing at least a part of the electrode pads 56, 57, and 59 is formed, the unbalanced signal transmission path 50 is sealed as shown in FIG. A balun mounting device that is covered with the stop resin layer 26 is obtained.
Although not shown in FIG. 13, openings 26 a and 26 b that expose at least part of the electrode pads 51 and 52 are formed in the sealing resin layer 26 in the same manner.

Further, as shown in FIG. 1, bumps 86, 87, 89 are formed on the electrode pads 56, 57, 59 exposed in the openings 26c, 26d, 26e.
Although not shown in FIG. 1, bumps 81 and 82 on the electrode pads 51 and 52 are formed in the same manner.
In the case where the substrate 10 is a wafer, dicing is performed to obtain a balun mounting device chip.
The transmission lines 30, 35, 50, the lead wires 31, 32, 36, 37 and the electrode pads 51, 52, 56, 57, 59 are preferably formed using metal plating such as copper (Cu) plating.
In order to form a resin structure 24 having a trapezoidal cross section or to form an opening in the third insulating resin layer 26, a photosensitive resin layer is formed on the entire surface by spin coating, electrodeposition, dry film adhesion, etc. Examples include a patterning method by a lithography process.
As described above, according to the manufacturing method applying the wafer level package (WLP) technology, the process temperature when manufacturing the balun mounting device 100 can be less than 300 ° C. at the maximum.

In the balun mounting device of this embodiment, the resin structure 24 having a trapezoidal cross section is formed on the lower transmission lines 30 and 35, and the upper transmission line 50 is formed thereon to form the laminated balun on the substrate 10. Since it is configured above, the lead wires 31, 32, 36, 37 are provided along the side surface of the resin structure 24 having the trapezoidal cross section, and the electrode pads 51, formed on the top surface of the resin structure 24 having the trapezoidal cross section. 52, 56, 57 can be connected.
Accordingly, a resin structure having a trapezoidal cross section in the same layer as the upper transmission line 50 without forming an opening or a via in the dielectric layer between the lower transmission lines 30 and 35 and the upper transmission line 50. It is possible to easily connect the electrode pads 51, 52, 56, 57 formed on the top surface of 24 and the lower transmission lines 30, 35. That is, the WLP technology can be applied to a balun transmission line having a design rule larger than that of a semiconductor processing process. Furthermore, it is possible to provide a low-loss and low-cost balun mounting device that realizes an unbalanced input of 50Ω and a manufacturing method thereof.
Further, not only the characteristics of the device but also stress relaxation during mounting can be realized, and the reliability can be improved.

The balun mounting device of the present embodiment is provided with balanced signal transmission lines 30 and 35 on the lower side (side closer to the substrate 10) of the resin structure 24 having the trapezoidal cross section, and the resin structure 24 having the trapezoidal cross section. The unbalanced signal transmission path 50 is provided on the upper side (the side far from the substrate 10).
In the idea of the present invention, an unbalanced signal transmission path 50 is provided on the lower side (side closer to the substrate 10) of the resin structure 24 having a trapezoidal cross section, and the upper side (from the substrate 10) of the resin structure 24 having a trapezoidal section. It is also possible to realize a balun mounting device in which balanced signal transmission lines 30 and 35 are provided on the far side. However, in this case, the two balanced signal input / output terminals 30a and 35a and the two ground terminals 30b and 35b are formed on the resin structure 24, and when connecting them to the electrode pads on the resin structure 24, It is not necessary to go through the side surface of the resin structure 24. Instead, from the top surface of the resin structure 24 having a trapezoidal cross section formed on the first insulating resin layer 22 in order to connect the unbalanced signal input / output end 50a of the unbalanced signal transmission line 50 to the electrode pad. A lead-out wiring for connecting the unbalanced signal input / output end 50a to the electrode pad on the top surface of the resin structure 24 having a trapezoidal cross section is provided via the side surface.

Hereinafter, the present invention will be specifically described with reference to examples.
In FIG. 1, the width W1 of a portion where three balanced signal transmission lines 30, 35 are arranged in parallel in a spiral shape is 300 μm, and the height of the resin structure 24 having a trapezoidal cross section (corresponding to T + d in FIG. 6) is T1. The balun mounting device 100 shown in FIGS. 1 and 2 was simulated assuming that the width of the lower surface of the resin structure 24 having a trapezoidal cross section of W = 40 μm and W3 = 450 μm.
An insulating resin such as a photosensitive resin was used to form the first insulating resin layer 22, the resin structure 24 having a trapezoidal cross section, and the sealing resin layer 26.
The transmission lines 30, 35, 50, the lead wires 31, 32, 36, 37 and the electrode pads 51, 52, 56, 57, 59 were formed by using metal plating such as copper (Cu) plating, for example.

  The substrate 10 is a silicon (Si) substrate or a glass substrate. After the first insulating resin layer 22 is applied on the substrate 10, the balanced signal transmission paths 30, 35 and the balanced signal transmission path extensions 31a, 32a are formed by electroplating or the like. , 36a, 37a (see FIG. 14).

Next, a dielectric layer was provided by spin coating, electrodeposition, dry film bonding, etc., and patterned by a photolithography process to form a resin structure 24 having a trapezoidal cross section (see FIG. 15).
Next, the unbalanced signal transmission path 50, the electrode pads 51, 52, 56, 57, and 59, and the resin structure side surface connecting portions 31b, 32b, 36b, and 37b were formed by electroplating or the like. (See Figure 16)

Next, a sealing resin layer 26 is provided by spin coating, electrodeposition, dry film bonding, etc., and patterned by a photolithography process to expose at least a part of the electrode pads 51, 52, 56, 57, 59. Openings 26a, 26b, 26c, 26d, and 26e were formed. (See Figure 13)
Next, bumps 81, 82, 86, 87, and 89 are formed on the electrode pads 51, 52, 56, 57, and 59 exposed from the openings 26a, 26b, 26c, 26d, and 26e. The balun mounting device 100 shown in FIG.

  The present invention can be used for various high-frequency circuits. For example, it can be suitably used for a circuit constituting a wireless communication device such as a mobile phone, a wireless LAN, Bluetooth (registered trademark), WiMAX (registered trademark).

It is typical sectional drawing which shows the principal part of the balun mounting device of the 1st example of this invention. It is a perspective view which shows the example of whole structure of a balun mounting device. FIG. 3 is a partially enlarged perspective view showing a ground terminal part and an unbalanced signal input / output terminal part of FIG. 2. FIG. 3 is a schematic plan view of the balun shown in FIG. 2. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which follows the BB line of FIG. It is sectional drawing which follows the CC line of FIG. FIG. 3 is a schematic circuit diagram of the balun shown in FIG. 2. It is typical sectional drawing which shows the principal part of the balun mounting device of the 2nd form example of this invention. It is typical sectional drawing which shows the principal part of the balun mounting device of the 3rd example of this invention. It is typical sectional drawing which shows the principal part of the balun mounting device of the 4th example of this invention. It is typical sectional drawing which shows the principal part of the balun mounting device of the 5th example of this invention. It is typical sectional drawing which shows the principal part of the balun mounting device of the 6th example of this invention. It is typical sectional drawing which shows the manufacturing process of the balun mounting device of a 1st form example. It is typical sectional drawing which shows the manufacturing process of the balun mounting device of a 1st form example. It is typical sectional drawing which shows the manufacturing process of the balun mounting device of a 1st form example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Board | substrate, 22 ... 1st insulating resin layer, 24 ... Resin structure of cross-sectional trapezoid shape,
30 ... 1st balanced signal transmission path, 30a ... 1st balanced signal input / output terminal, 30b ... 1st grounding terminal,
31... First balanced signal input / output lead wiring, 32... First ground lead wiring,
35 ... 2nd balanced signal transmission path, 35a ... 2nd balanced signal input / output end, 35b ... 2nd grounding end,
36: second balanced signal input / output lead wiring, 37: second ground lead wiring,
50 ... an unbalanced signal transmission path, 50a ... an unbalanced signal input / output end, 50b ... an open end, 50c ... a portion facing the first balanced signal transmission path, 50d ... a portion facing the second balanced signal transmission path,
51, 52, 56, 57, 59 ... electrode pads, 81, 82, 86, 87, 89 ... bumps,
100: Balun mounting device, 110: Balun.

Claims (7)

A substrate,
A first insulating resin layer formed on the substrate;
A first balanced signal transmission line provided on the first insulating resin layer, having one end as a first balanced signal input / output end and the other end as a first ground end;
A second balanced signal provided on the first insulating resin layer electrically independent from the first balanced signal transmission line, having one end as a second balanced signal input / output end and the other end as a second ground end. A transmission line;
On the top surface of the trapezoidal resin structure formed on the two balanced signal transmission lines and on the first insulating resin layer, the two balanced signal transmission lines are provided opposite to each other, and one end is unbalanced. An unbalanced signal transmission line having a signal input / output end and the other end being an open end;
A first balanced signal input / output lead line connected to the first balanced signal input / output terminal via a side surface from a top surface of the resin structure having a trapezoidal cross section formed on the first insulating resin layer;
A second balanced signal input / output lead line connected to the second balanced signal input / output end via a side surface from the top surface of the resin structure having a trapezoidal cross section formed on the first insulating resin layer;
A first ground lead wiring connected to the first ground end via a side surface from a top surface of the resin structure having a trapezoidal cross section formed on the first insulating resin layer;
At least a second ground lead wiring connected to the second ground end via a side surface from a top surface of the resin structure having a trapezoidal cross section formed on the first insulating resin layer,
On the top surface of the trapezoidal resin structure, there are electrode pads connected to the unbalanced signal input / output terminal, the two balanced signal input / output lead wires, and the two ground lead wires, respectively. A balun mounting device characterized by being formed.   The electrode pad connected to the unbalanced signal input / output terminal and the electrode pad connected to the balanced signal output / input terminal via the balanced signal input / output lead line are formed on the resin structure having the same trapezoidal cross section. The balun mounting device according to claim 1, wherein the balun mounting device is provided.   The electrode pad connected to the unbalanced signal input / output end and the electrode pad connected to the ground end via the ground lead wiring are provided on a resin structure having the same trapezoidal cross section. The balun mounting device according to claim 1.   An electrode pad connected to the unbalanced signal input / output terminal, an electrode pad connected to the balanced signal output / input terminal via the balanced signal input / output lead line, and a ground terminal via the ground lead wiring The balun mounting device according to claim 1, wherein the electrode pads are provided on a resin structure having the same trapezoidal cross section.   In the unbalanced signal transmission path, a portion facing the first balanced signal transmission path and a portion facing the second balanced signal transmission path are provided on a resin structure having a trapezoidal cross section. The balun mounting device according to any one of claims 1 to 4, wherein:   The balun mounting device according to claim 1, wherein bumps are mounted on the electrode pads.   The balun mounting device according to claim 6, wherein the electrode pad is formed to be thicker than the lead wiring.

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