Amplifying device and matching circuit substrate

Abstract

An amplification device includes a base substrate, an amplification element, and a matching circuit substrate. The amplification element is mounted on the base substrate. The matching circuit substrate is mounted on the base substrate and has a circuit pattern electrically connected to the amplification element. The matching circuit substrate has a first side surface and a second side surface each extending in a long dimension direction of the matching circuit substrate. A first recess is provided on the first side surface. A second recess is provided on the second side surface opposite the first recess.

Description

Technical Field

[0001] This disclosure relates to amplification devices and matching circuit boards.

[0002] This application claims priority based on Japanese Application No. 2020-060465, filed on March 30, 2020, and invokes the entire contents of the stated Japanese application. Background Technology

[0003] As a high-frequency amplification device, for example, Patent Document 1 discloses a technology involving an internally matched high-output field-effect transistor. This internally matched high-output field-effect transistor includes: a package; an amplifying element for amplifying high-frequency (RF) signals on the package; an input-side matching circuit connected between the input terminal of the amplifying element and the input terminal of the package for impedance transformation; and an output-side matching circuit connected between the output terminal of the amplifying element and the output terminal of the package for impedance transformation.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 63-86904 Summary of the Invention

[0007] One aspect of this disclosure relates to an amplification device. The amplification device includes a substrate, an amplifying element, and a matching circuit board. The amplifying element is mounted on the substrate. The matching circuit board is mounted on the substrate and has a circuit pattern electrically connected to the amplifying element. The matching circuit board has a first side surface and a second side surface extending in the longitudinal direction of the matching circuit board. A first recess is provided on the first side surface. A second recess is provided on the second side surface opposite to the first recess.

[0008] Another aspect of this disclosure relates to a matching circuit substrate. This matching circuit substrate can be mounted on a substrate and has a circuit pattern for impedance transformation. The matching circuit substrate has a first side surface and a second side surface extending in the longitudinal direction of the matching circuit substrate. A first recess is provided on the first side surface. A second recess is provided on the second side surface opposite to the first recess. Attached Figure Description

[0009] Figure 1 This is a top view showing the internal structure of a high-frequency amplification device according to one embodiment.

[0010] Figure 2 It is along Figure 1 A cross-sectional view of the high-frequency amplification device of line II-II.

[0011] Figure 3A It means Figure 1 The top view of the matching circuit on the input side is shown.

[0012] Figure 3B It means Figure 1 The top view of the matching circuit on the output side is shown.

[0013] Figure 4 This is a perspective view showing a portion of the high-frequency amplification device of the comparative example.

[0014] Figure 5A It is along Figure 4 A cross-sectional view of the high-frequency amplification device of the VA-VA line.

[0015] Figure 5B It is used for Figure 5A The diagram illustrates the effect of temperature changes on the matching circuit.

[0016] Figure 6 This is a diagram showing the stress distribution of the dielectric substrate of the comparative example.

[0017] Figure 7 This is a diagram showing the stress distribution state of the dielectric substrate in this embodiment.

[0018] Figure 8 This is a top view showing the matching circuit of a modified example.

[0019] Figure 9 This is a diagram showing the stress distribution of the dielectric substrate in the modified example.

[0020] Figure 10A This is a diagram showing the concave portion of a modified example.

[0021] Figure 10B This is a diagram showing the concave portion of a modified example.

[0022] Figure 10C This is a diagram showing the concave portion of a modified example. Detailed Implementation

[0023] [The problem this disclosure aims to solve]

[0024] The matching circuit board used to construct the input-side matching circuit or output-side matching circuit described in Patent Document 1 is primarily used to form a capacitive circuit in impedance transformation. Therefore, from the viewpoint of obtaining the desired capacitance, the thickness of the matching circuit board is sometimes specified. Furthermore, the thickness of the matching circuit board is sometimes limited by the dimensions of other electronic components mounted in a package shared with the matching circuit board (such as the thickness of a different substrate or the height of a cavity). In these cases, it is conceivable to use a component with a relatively thin thickness (e.g., 0.1 mm to 0.5 mm) as the matching circuit board.

[0025] Furthermore, it is conceivable that high-frequency amplification devices are used in the market under a wide temperature range (e.g., -65°C to 150°C). When temperature changes occur within this range, if the coefficient of linear expansion of the material constituting the package on which the matching circuit board is mounted differs from that of the material constituting the matching circuit board, the matching circuit board will be subjected to tensile or compressive stresses. As mentioned above, the matching circuit board has a relatively thin thickness, so it is conceivable that cracks may occur in the matching circuit board unspecified due to these stresses. In such cases, depending on the location of the cracks, the circuit function of the matching circuit board may be impaired.

[0026] However, when measures are taken to avoid the formation of cracks in the mating circuit board (e.g., the thickness of the mating circuit board, the external dimensions of the mating circuit board, the mounting position of the mating circuit board on the package, and the type of substrate of the package), it is time-consuming and laborious to conduct tests whenever the configuration is changed.

[0027] [The Effects of This Disclosure]

[0028] According to this disclosure, the degree of loss of circuit function of the matching circuit board can be reduced.

[0029] [Description of embodiments of this disclosure]

[0030] First, embodiments of the present disclosure will be described. One embodiment of the amplification device includes a substrate, an amplifying element, and a matching circuit board. The amplifying element is mounted on the substrate. The matching circuit board is mounted on the substrate and has a circuit pattern electrically connected to the amplifying element. The matching circuit board has a first side surface and a second side surface extending in the longitudinal direction of the matching circuit board. A first recess is provided on the first side surface. A second recess is provided on the second side surface opposite to the first recess.

[0031] In this amplification device, a first recess and a second recess, facing each other, are respectively provided on the first and second sides of the matching circuit substrate. When stress arises in such a matching circuit substrate that could cause cracks, the first or second recess preferentially becomes the starting point of the crack. Furthermore, cracks tend to form along the line connecting the first and second recesses. Therefore, the location of crack formation in the matching circuit substrate can be controlled by the first and second recesses. Thus, by arranging the first and second recesses at a position where the line connecting them is positioned to mitigate the loss of circuit function (e.g., a position where the matching circuit will not be electrically disconnected), even if cracks occur in the matching circuit substrate, the degree of loss of circuit function can be mitigated. With this configuration, even when the coefficients of linear expansion of the materials constituting the base substrate and the matching circuit substrate differ, the degree of loss of circuit function caused by temperature changes in the matching circuit substrate can be mitigated.

[0032] In one embodiment of the amplification device, the top ends of the first recess and the second recess may be located on the same straight line extending in a direction orthogonal to the longitudinal direction. In this case, the positional relationship between the first recess and the second recess is a shortest distance relationship.

[0033] In one embodiment of the amplification device, the first recess and the second recess may be located approximately at the center of the matching circuit board in the longitudinal direction.

[0034] In one embodiment of the amplification device, the line connecting the first and second recesses may be separated from the circuit pattern. In this case, even if a crack occurs in the mating circuit board, the crack can be prevented from spreading to the circuit pattern. Therefore, the degree of loss of circuit function in the circuit pattern can be reduced, and circuit function can be maintained.

[0035] In one embodiment of the amplification device, the matching circuit board may also have a resistor pattern. Alternatively, the line connecting the first and second recesses may be separated from the resistor pattern. In this case, even if a crack occurs in the matching circuit board, the crack can be prevented from spreading to the resistor pattern. Therefore, the degree of loss of function obtained through the resistor pattern can be reduced, and the function obtained through the resistor pattern can be maintained.

[0036] In one embodiment of the amplification device, the matching circuit board may have a dielectric substrate for setting circuit patterns. Alternatively, a first recess and a second recess may be provided on the dielectric substrate. The material constituting the substrate may include a copper alloy. Alternatively, the dielectric substrate may contain barium titanate. A dielectric substrate containing barium titanate (BaTiO3) is a plastic body, therefore it is conceivable that cracks may easily form in the dielectric substrate under tensile stress. Furthermore, the coefficient of linear expansion of copper (Cu) is approximately 16.7 × 10⁻⁶. －6 / K, the coefficient of linear expansion of barium titanate is approximately 9.6 × 10⁻⁶. －6 / K. In this case, the coefficient of linear expansion of the material constituting the substrate is greater than that of the material constituting the dielectric substrate. Therefore, when the temperature increases (e.g., from 25°C to 150°C), the thermal expansion of the substrate is greater than that of the dielectric substrate. Consequently, tensile stress is easily generated in the dielectric substrate, leading to cracks. On the other hand, according to this amplification device, the location of crack formation in the dielectric substrate can be controlled by the first and second recesses. Therefore, even if cracks occur, the loss of circuit function of the matching circuit board can be suppressed. Therefore, the amplification device of this disclosure is advantageous in configurations where cracks are easily generated in the dielectric substrate.

[0037] In one embodiment of the amplification device, the thickness of the substrate may be 1 mm or more and 3 mm or less, and the thickness of the dielectric substrate may be 0.1 mm or more and 0.5 mm or less. In this case, the dielectric substrate is relatively thin, and therefore it is prone to cracking due to temperature changes affecting the matching circuit substrate. On the other hand, according to this high-frequency amplification device, the location of crack formation in the dielectric substrate can be controlled by the first and second recesses, so even if cracks occur, the loss of circuit function of the matching circuit substrate can be suppressed. Therefore, the amplification device of this disclosure is advantageous in configurations where cracks are easily formed in the dielectric substrate.

[0038] One embodiment of the matching circuit board can be mounted on a substrate and has a circuit pattern for impedance transformation. The matching circuit board has a pair of side surfaces extending along its longitudinal direction. On each side surface, a first recess and a second recess are respectively provided at positions opposite to each other. According to this matching circuit board, similarly as described above, the first or second recess preferentially becomes the starting point of a crack, and the crack easily forms along the line connecting the first and second recesses. Therefore, by controlling the location of crack formation in the matching circuit board using the first and second recesses, the degree of loss of circuit function can be reduced.

[0039] In one embodiment of the matching circuit substrate, the top ends of the first recess and the second recess may be located on the same straight line extending in a direction orthogonal to the longitudinal direction. In this case, the positional relationship between the first recess and the second recess is a shortest distance relationship.

[0040] In one embodiment of the matching circuit substrate, the first recess and the second recess may be located approximately at the center of the matching circuit substrate in the longitudinal direction.

[0041] In one embodiment of the matching circuit board, the line connecting the first recess and the second recess may be separated from the circuit pattern.

[0042] In one embodiment of the matching circuit substrate, the matching circuit substrate may also have a resistor pattern. Alternatively, the line connecting the first recess and the second recess may be separated from the resistor pattern.

[0043] In one embodiment of the matching circuit substrate, the matching circuit substrate may also have a dielectric substrate for setting the circuit pattern. Alternatively, the first recess and the second recess may be provided on the dielectric substrate. Alternatively, the dielectric substrate may comprise barium titanate.

[0044] In one embodiment of the matching circuit substrate, the thickness of the dielectric substrate may be 0.1 mm or more and 0.5 mm or less.

[0045] [Details of the embodiments of this disclosure]

[0046] Hereinafter, a specific example of a high-frequency amplification device according to one embodiment of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to these examples, but is illustrated by the claims, which are intended to include all modifications within the meaning and scope equivalent to the claims. In the following description, the same reference numerals are sometimes used to denote the same elements or elements having the same function, and repeated descriptions are omitted. In the description, the XYZ orthogonal coordinate system shown in the accompanying drawings is sometimes referred to.

[0047] Figure 1 This is a top view showing the internal configuration of a high-frequency amplification device 1 according to one embodiment of the present disclosure. Figure 2 It is along Figure 1 A cross-sectional view of the high-frequency amplification device 1 of line II-II. (See attached image.) Figure 1As shown, the high-frequency amplification device 1 includes an input terminal 2, an output terminal 3, an amplifying element section 10, a branch circuit board 20, a combining circuit board 30, a matching circuit 40, and a matching circuit 50. In this embodiment, as an example, the high-frequency amplification device 1 includes two matching circuits 40 and two matching circuits 50. Furthermore, the amplifying element section 10 includes two amplifying elements 11. The output of each amplifying element 11 is, for example, 30W, and the output of the entire amplifying element section 10 is, for example, 60W. The high-frequency amplification device 1 includes: a package 4 that houses the amplifying element section 10, the branch circuit board 20, the combining circuit board 30, and the matching circuits 40 and 50; and a housing 5 that houses the package 4.

[0048] Package 4 is made of metal and is connected to a reference potential. An example of a metal material constituting package 4 is an alloy of copper (Cu). The coefficient of linear expansion of this Cu alloy is, for example, approximately 16.7 × 10⁻⁶. －6 / K. The package 4 has a generally rectangular shape in top view. The package 4 has end walls 4a, 4b opposite each other in a first direction and side walls 4c, 4d opposite each other in a second direction. The first direction and the second direction intersect each other, and in one example, they are orthogonal to each other. In this embodiment, the first direction is the Y-axis direction and the second direction is the X-axis direction.

[0049] The package 4 has a rectangular, flat base plate 4e (base substrate). The base plate 4e extends along a plane defined by the Y-axis and X-axis directions. The thickness D1 of the base plate 4e (here, the length along the Z-axis) is, for example, more than 1 mm and less than 3 mm. End walls 4a and 4b are erected along one pair of sides of the base plate 4e (sides extending along the X-axis direction), and side walls 4c and 4d are erected along the other pair of sides of the base plate 4e (sides extending along the Y-axis direction). It should be noted that the package 4 also has a cover (not shown). The cover seals the upper opening formed by the end walls 4a and 4b and the side walls 4c and 4d.

[0050] The housing 5 is made of metal. The coefficient of linear expansion of the metal material constituting the housing 5 is, for example, greater than that of the metal material constituting the package 4. An example of a metal material constituting the housing 5 is aluminum (Al). The coefficient of linear expansion of Al is, for example, approximately 23.7 × 10⁻⁶. －6 / K. The top view of the housing 5 is generally rectangular. The housing 5 has a rectangular, flat base plate 5a. The encapsulation member 4 is disposed on the base plate 5a. The base plate 5a extends along a plane defined by the Y-axis and X-axis directions. The thickness D2 of the base plate 5a (here, the length along the Z-axis direction) is, for example, greater than the thickness D1. The thickness D2 is, for example, more than 5 mm and less than 20 mm. The housing 5 may also have sidewalls (not shown) and covers (not shown) extending along each side of the base plate 5a.

[0051] Input terminal 2 is a metal wiring pattern that receives a high-frequency signal from the outside of the high-frequency amplifier 1. The high-frequency signal is a multi-carrier transmission signal, which is formed by superimposing multiple signals with different carrier frequencies. The frequency band of the carrier signal is, for example, 500MHz or less. Input terminal 2 is located at the center of the end wall 4a in the X-axis direction and extends from the outside of the package 4 inward.

[0052] The amplifying element section 10 is disposed on the base plate 4e of the package 4 and is located approximately at the center of the package 4 in the Y-axis direction. Each amplifying element 11 of the amplifying element section 10 incorporates a transistor. The transistor is, for example, a field-effect transistor (FET), and in one embodiment, a high-electron-mobility transistor (HEMT). Each amplifying element 11 has multiple gate fingers, multiple source fingers, and multiple drain fingers. In the Y-axis direction, the source fingers and drain fingers are arranged alternately, and the gate fingers are disposed between each source finger and drain finger. Gate pads (signal input terminals) and source pads are arranged alternately on the edge of the input terminal 2 side of each amplifying element 11, and drain pads (signal output terminals) are arranged on the edge of the output terminal 3 side of each amplifying element 11. Each source pad is electrically connected to the base plate 4e of the package 4 via a via hole that penetrates the amplifying element 11 in the thickness direction (here, the Z-axis direction) and is set to a reference potential. Each amplifying element 11 amplifies the high-frequency signal input to each gate pad and outputs the amplified high-frequency signal from each drain pad.

[0053] A branch circuit board 20 is disposed on the base plate 4e of the package 4. The branch circuit board 20 is arranged side-by-side with the input terminal 2 and the amplification element section 10 along the Y-axis direction, located between the input terminal 2 and the amplification element section 10. The branch circuit board 20 has a ceramic substrate 21 and branch circuits 22 disposed on the main surface of the substrate 21. The top view shape of the substrate 21 is, for example, rectangular, with one long side 21a facing the input terminal 2 and the other long side 21b facing the amplification element section 10 across the matching circuit 40. The back side of the substrate 21 faces the base plate 4e of the package 4. One short side 21c of the substrate 21 is located near the side wall 4c of the package 4, and the other short side 21d of the substrate 21 is located near the side wall 4d of the package 4. That is, the substrate 21 extends from near one end of the package 4 to near the other end in the X-axis direction.

[0054] Branch circuit 22 includes a wiring pattern 23 disposed on the main surface of substrate 21. Wiring pattern 23 is electrically connected to input terminal 2 via bonding line 9a. High-frequency signals are input to wiring pattern 23 from the center of substrate 21 in the X-axis direction. Wiring pattern 23 has a shape that is linearly symmetrical about the centerline of substrate 21 along the Y-axis direction. Wiring pattern 23 repeatedly branches from the connection point with bonding line 9a, eventually reaching eight metal pads 23a. The eight metal pads 23a are arranged side by side along the long side 21b. Adjacent metal pads 23a are connected to each other via film resistors, forming Wilkinson couplers. This ensures isolation between the multiple gate pads of amplifying element section 10 and achieves matching of the input impedance of amplifying element section 10 as observed from input terminal 2. It should be noted that only one film resistor 23b is shown in the figure as an example. The eight metal pads 23a are electrically connected to matching circuit 40 via bonding line 9b.

[0055] Matching circuit 40 (matching circuit substrate) is disposed on the base plate 4e of package 4, and is disposed between branch circuit substrate 20 and amplifying element section 10 in the Y-axis direction. Two matching circuits 40 are arranged along the X-axis direction between branch circuit substrate 20 and amplifying element section 10. Figure 3A It means Figure 1 A top view of the matching circuit 40. The matching circuit 40 is, for example, a die-capacitor. Figure 3A As shown, the matching circuit 40 has a dielectric substrate 41 and a plurality of metal pads 42.

[0056] The dielectric substrate 41 is, for example, a plastic body. The coefficient of linear expansion of the dielectric material constituting the dielectric substrate 41 is, for example, less than the coefficient of linear expansion of the metal material constituting the package 4. Examples of dielectric materials constituting the dielectric substrate 41 include materials containing barium (Ba) and titanium (Ti). As an example, the dielectric material constituting the dielectric substrate 41 is barium titanate (BaTiO3). The coefficient of linear expansion of this barium titanate is, for example, approximately 9.6 × 10⁻⁶. －6 / K. The dielectric substrate 41 has a generally rectangular shape in top view. The dielectric substrate 41 extends along a plane defined by the Y-axis and X-axis directions. The thickness D3 of the dielectric substrate 41 (here, the length along the Z-axis) is, for example, 0.1 mm or more and 0.5 mm or less. The dielectric substrate 41 has: a main surface 41a (first main surface) fixed to the base plate 4e; a main surface 41b (second main surface) opposite to the main surface 41a; side surfaces 41c and 41d connected to the main surfaces 41a and 41b, respectively; and end surfaces 41e and 41f (see also). Figure 2The main surface 41a is opposite to the base plate 4e. Side surfaces 41c (first side surface) and 41d (second side surface) extend in a direction along which they are aligned (in this case, the X-axis direction). End surfaces 41e and 41f extend in a direction along which they are aligned (in this case, the Y-axis direction). Side surfaces 41c and 41d are the long sides of the dielectric substrate 41, and end surfaces 41e and 41f are the short sides of the dielectric substrate 41. In this example, the long dimension direction of the dielectric substrate 41 and the matching circuit 40 (matching circuit substrate) is along the X-axis direction. The short dimension direction of the dielectric substrate 41 and the matching circuit 40 (matching circuit substrate) is along the Y-axis direction.

[0057] A recess 41g (first recess) is provided on side 41c, recessed toward side 41d, and a recess 41h (second recess) is provided on side 41d, recessed toward side 41c. The recesses 41g and 41h are positioned opposite each other. In other words, recesses 41g and 41h are respectively provided on a pair of long sides of the dielectric substrate 41, facing each other. Specifically, the recesses 41g and 41h face each other along the direction in which a crack is desired to be created in the dielectric substrate 41. In this embodiment, as an example, the recesses 41g and 41h face each other in a direction orthogonal to the extending direction of sides 41c and 41d (in this case, the Y-axis direction). It should be noted that the recesses 41g and 41h may also face each other in a direction inclined relative to the extending direction of sides 41c and 41d. As an example, the recesses 41g and 41h are positioned approximately at the center of the dielectric substrate 41 and the matching circuit 40 (matching circuit substrate) in the X-axis direction. The approximate central portion refers, for example, to a position within ±5% of the length along the X-axis from the center of the length along the X-axis. The top view shape of the recesses 41g and 41h is, for example, semi-circular. In this example, the tops of the recesses 41g and 41h are located on the same straight line extending in the Y-axis direction orthogonal to the X-axis direction.

[0058] The metal pad 42 is an example of the circuit pattern in this embodiment. The metal pad 42 is, for example, gold-plated (Au). Each metal pad 42 is provided on the main surface 41b of the dielectric substrate 41. The line N1 connecting the aforementioned recesses 41g and 41h on the main surface 41b is separated from the metal pad 42. That is, the line N1 does not intersect with the metal pad 42. In this example, the line N1 extends in the Y-axis direction. The number of metal pads 42 is, for example, the same as the number of metal pads 23a in the two matching circuits 40 (eight in this case), and is evenly distributed among the matching circuits 40. The plurality of metal pads 42 are arranged in a row along the X-axis direction. Each metal pad 42 is electrically connected to the corresponding metal pad 23a via a bonding line 9b, and is electrically connected to the corresponding gate pad of the amplifying element section 10 via a bonding line 9c.

[0059] In the matching circuit 40, a T-type filter circuit (matching circuit) is constructed using the inductive components based on the bonding lines 9b and 9c and the capacitance of the metal pad 42 connecting the nodes between these inductive components and the reference potential (base plate 4e). The matching circuit 40 performs impedance transformation using this T-type filter circuit, thereby achieving impedance matching for the amplifying element section 10. Typically, the impedance in the amplifying element section 10 viewed from the gate pad towards the inside of the transistor differs from the characteristic impedance of the transmission line (e.g., 50Ω). The matching circuit 40 transforms this impedance to 50Ω as seen from the input terminal 2 towards the inside of the package 4 using the T-type filter circuit.

[0060] Matching circuit 50 (matching circuit substrate) is disposed on the base plate 4e of package 4, and is positioned between amplifying element section 10 and combining circuit substrate 30 in the Y-axis direction. Two matching circuits 50 are arranged along the X-axis direction between amplifying element section 10 and combining circuit substrate 30. Figure 3B It means Figure 1 A top view of the matching circuit 50. Matching circuit 50, like matching circuit 40, is, for example, a parallel plate capacitor (core capacitor). Figure 3B As shown, the matching circuit 50 has a dielectric substrate 51 and a plurality of metal pads 52.

[0061] The dielectric substrate 51 is, for example, a plastic body. The coefficient of linear expansion of the dielectric material constituting the dielectric substrate 51 is, for example, the same as the coefficient of linear expansion of the dielectric material constituting the dielectric substrate 41, and less than the coefficient of linear expansion of the metal material constituting the package 4. The dielectric material constituting the dielectric substrate 51 is, for example, the same as the dielectric material constituting the dielectric substrate 41. The top view of the dielectric substrate 51 is approximately rectangular. The dielectric substrate 51 extends along a plane defined by the Y-axis and X-axis directions. The thickness D4 of the dielectric substrate 51 (here, the length along the Z-axis) is, for example, 0.1 mm or more and 0.5 mm or less. The dielectric substrate 51 has: a main surface 51a (first main surface), fixed to the base plate 4e; a main surface 51b (second main surface) opposite to the main surface 51a; side surfaces 51c and 51d, respectively connected to the main surfaces 51a and 51b; and end surfaces 51e and 51f (to be seen together). Figure 2 The main surface 51a is opposite to the base plate 4e. Side surfaces 51c (first side surface) and 51d (second side surface) extend in a direction along each other (here, the X-axis direction). End surfaces 51e and 51f extend in a direction along each other (here, the Y-axis direction). Side surfaces 51c and 51d are the long sides of the dielectric substrate 51, and end surfaces 51e and 51f are the short sides of the dielectric substrate 51. In this example, the long dimension direction of the dielectric substrate 51 and the matching circuit 50 (matching circuit substrate) is along the X-axis direction. The short dimension direction of the dielectric substrate 51 and the matching circuit 50 (matching circuit substrate) is along the Y-axis direction.

[0062] A recess 51g (first recess) is provided on side 51c, recessed toward side 51d, and a recess 51h (second recess) is provided on side 51d, recessed toward side 51c. The recesses 51g and 51h are positioned opposite each other. In other words, recesses 51g and 51h are respectively provided on a pair of long sides of the dielectric substrate 51, facing each other. Specifically, the recesses 51g and 51h face each other along the direction in which a crack is desired to be created in the dielectric substrate 51. In this embodiment, as an example, the recesses 51g and 51h face each other in a direction orthogonal to the extending direction of sides 51c and 51d (in this case, the Y-axis direction). It should be noted that the recesses 51g and 51h may also face each other in a direction inclined relative to the extending direction of sides 51c and 51d. As an example, the recesses 51g and 51h are positioned approximately at the center of the dielectric substrate 51 and the matching circuit 50 (matching circuit substrate) in the X-axis direction. The approximate central portion refers, for example, to a position within ±5% of the length along the X-axis from the center of the length along the X-axis. The top view shape of the recesses 51g and 51h is, for example, semi-circular. It should be noted that the dielectric substrate 51 can also be configured to be the same as the dielectric substrate 41. In this example, the top ends of the recesses 51g and 51h are located on the same straight line extending in the Y-axis direction orthogonal to the X-axis direction.

[0063] The metal pads 52 are an example of the circuit pattern in this embodiment. Each metal pad 52 is provided on the main surface 51b of the dielectric substrate 51. The line N2 connecting the recesses 51g and 51h mentioned above is separated from the metal pads 52 on the main surface 51b. That is, the line N2 does not intersect with the metal pads 52. In this example, the line N2 extends in the Y-axis direction. The number of metal pads 52 is, for example, the same as the number of metal pads 23a in the two matching circuits 50 (eight in this case), and is evenly distributed among the matching circuits 50. The plurality of metal pads 52 are arranged in a row along the X-axis direction. Each metal pad 52 is electrically connected to the corresponding drain pad of the amplifying element section 10 via bonding line 9d, and is electrically connected to the corresponding metal pad 33a (described later) of the synthesis circuit substrate 30 via bonding line 9e.

[0064] In the matching circuit 50, a T-type filter circuit (matching circuit) is also constructed based on the inductive components of the bonding lines 9d and 9e and the capacitance of the metal pad 52 connecting the nodes between these inductive components and the reference potential (base plate 4e). The matching circuit 50 performs impedance transformation through this T-type filter circuit, thereby achieving impedance matching for the amplifying element section 10. Typically, the impedance in the amplifying element section 10 viewed from the drain pad towards the inside of the transistor is different from the characteristic impedance of the transmission line (e.g., 50Ω), and is approximately a value smaller than 50Ω. The matching circuit 50 matches this impedance to 50Ω as seen from the output terminal 3 towards the inside of the package 4 through the T-type filter circuit.

[0065] A composite circuit board 30 is disposed on the base plate 4e of the package 4. The composite circuit board 30 is arranged side-by-side with the amplifying element section 10 and the output terminal 3 along the Y-axis direction, located between the amplifying element section 10 and the output terminal 3. The composite circuit board 30 has a ceramic substrate 31 and a composite circuit 32 disposed on the main surface of the substrate 31. The top view shape of the substrate 31 is, for example, rectangular, with one long side 31a facing the amplifying element section 10 across the matching circuit 50, and the other long side 31b facing the output terminal 3. The back side of the substrate 31 faces the base plate 4e of the package 4. One short side 31c of the substrate 31 is located near the side wall 4c of the package 4, and the other short side 31d of the substrate 31 is located near the side wall 4d of the package 4. That is, the substrate 31 extends from near one end of the package 4 to near the other end in the X-axis direction.

[0066] The combining circuit 32 combines the signals output from the multiple drain pads of the amplifying element section 10 into a single output signal. The combining circuit 32 includes a wiring pattern 33 disposed on the main surface of the substrate 31. The wiring pattern 33 has a shape that is linearly symmetrical about the centerline of the substrate 31 along the Y-axis. The wiring pattern 33 includes four metal pads 33a. The four metal pads 33a are arranged side-by-side along the long side 31a. Adjacent metal pads 33a are connected to each other via film resistors, forming Wilkinson couplers. This ensures isolation between the multiple drain pads of the amplifying element section 10 and achieves matching of the output impedance of the amplifying element section 10 as observed from the output terminal 3. It should be noted that only one film resistor 33b is illustrated in the figure for representative purposes. Each metal pad 33a is electrically connected to two corresponding metal pads 52 of the matching circuit 50 via bonding lines 9e. The wiring pattern 33 repeatedly couples from the four metal pads 33a and finally reaches the connection point with the bonding line 9f. Wiring pattern 33 is electrically connected to output terminal 3 via bonding line 9f. The amplified high-frequency signal is output from the center of substrate 31 in the X-axis direction to output terminal 3.

[0067] Output terminal 3 is a metal wiring pattern that outputs the amplified high-frequency signal to the outside of the high-frequency amplifier 1. Output terminal 3 is located at the center of the end wall 4b in the X-axis direction and extends from the inside of the package 4 to the outside.

[0068] The effects of the high-frequency amplification device 1 described above will be explained. First, a comparative example will be explained. Figure 4 This is a perspective view showing a portion of the high-frequency amplification device 1X, a comparative example. Figure 5A It is along Figure 4 A cross-sectional view of the high-frequency amplification device 1X for the VA-VA line. The high-frequency amplification device 1X differs from the high-frequency amplification device 1 in that it has a matching circuit 40X instead of the matching circuit 40 and a matching circuit 50X instead of the matching circuit 50. The other components of the high-frequency amplification device 1X are the same as those of the high-frequency amplification device 1, and are shown schematically in the figure.

[0069] The matching circuit 40X differs from the matching circuit 40 in that it has a dielectric substrate 41X instead of the dielectric substrate 41; otherwise, its configuration is the same as that of the matching circuit 40. The dielectric substrate 41X differs from the dielectric substrate 41 in that it does not have recesses 41g and 41h. It should be noted that the other configurations of the dielectric substrate 41X are the same as those of the dielectric substrate 41.

[0070] It is conceivable that a high-frequency amplification device 1X with such a configuration can be used under a wide range of temperature conditions (e.g., above -65°C and below 150°C). When temperature changes occur within this temperature range, the coefficient of linear expansion of the material constituting the package 4 is different from the coefficient of linear expansion of the material constituting the dielectric substrate 41X of the matching circuit 40X. Therefore, the dielectric substrate 41X will be subjected to stresses such as tensile stress or compressive stress. Figure 5B It is used for Figure 5A The diagram illustrates the effect of temperature changes on the matching circuit 40X.

[0071] Figure 5B This shows the temperature environment at room temperature (e.g., 25°C). Figure 5A The high-frequency amplifier 1X shown is placed in a higher temperature environment (e.g., 150°C).

[0072] In the high-frequency amplification device 1X, similar to the high-frequency amplification device 1, the material constituting the package 4 includes an alloy of Cu, and the dielectric substrate 41X contains Ba and Ti. For example, the dielectric material constituting the dielectric substrate 41X is barium titanate (BaTiO3). The dielectric substrate 41X containing barium titanate is a plastic body, so it is conceivable that cracks are easily generated in the dielectric substrate 41X when tensile stress is generated. Furthermore, the coefficient of linear expansion of the material constituting the package 4 is greater than that of the material constituting the dielectric substrate 41X, therefore, at higher temperatures (i.e., ... Figure 5B In the case shown, the thermal expansion of package 4 is greater than that of dielectric substrate 41X. Therefore, the thermal expansion of dielectric substrate 41X cannot keep up with the thermal expansion of package 4, resulting in tensile stress across almost the entire dielectric substrate 41X. Specifically, as... Figure 5B As shown, stress is generated that causes the dielectric substrate 41X to warp toward the package 4 side.

[0073] Figure 6 This is a diagram showing the stress distribution of the dielectric substrate 41X of the comparative example. Figure 7 This is a diagram showing the stress distribution state of the dielectric substrate 41 in this embodiment. Figure 6 and Figure 7 The stress distribution of dielectric substrates 41 and 41X under the influence of a temperature change from 25°C to 125°C is shown (simulation results). It should be noted that... Figure 6 and Figure 7 The illustrations of other components have been omitted. Figure 6 and Figure 7 In the diagram, contour lines represent stress, with darker colors indicating greater stress. According to... Figure 6 It can be seen that a stress of 70 MPa or more but less than 80 MPa was generated on the dielectric substrate 41X. Furthermore, according to... Figure 6 It can be seen that the stress distribution along the long side of the dielectric substrate 41X is gentle, and no large stress or rapid stress change occurs in a specific location. It can be said that cracks can easily occur in non-specific locations in the dielectric substrate 41X due to deviations in the mounting position of the dielectric substrate 41X on the base plate 4e of the package 4.

[0074] In contrast, in the high-frequency amplification device 1, recesses 41g and 41h, respectively, are provided on the sides 41c and 41d of the dielectric substrate 41 of the matching circuit 40. In cases where stresses may occur in such a dielectric substrate 41, leading to cracks, such as... Figure 7 As shown, particularly large stresses are generated at recesses 41g and 41h (in Figure 7In the example, the stress is 120 MPa or more but less than 130 MPa. Thus, large stresses are generated locally, and the recess 41g or recess 41h preferentially becomes the starting point of the crack. Furthermore, the crack tends to originate in a direction perpendicular to the stress direction, and tends to originate along the line N1 connecting the recesses 41g and 41h. Therefore, the location of crack formation in the dielectric substrate 41 can be controlled by the recesses 41g and 41h. Therefore, by arranging the recesses 41g and 41h such that the line N1 connecting the recesses 41g and 41h is located at a position where the matching circuit 40 will not be electrically disconnected, the degree of loss of circuit function in the matching circuit 40 can be mitigated even if a crack occurs in the dielectric substrate 41. According to this configuration, even when the coefficient of linear expansion of the material constituting the package 4 is different from the coefficient of linear expansion of the material constituting the dielectric substrate 41 of the matching circuit 40, the degree of loss of circuit function in the matching circuit 40 caused by temperature changes can be mitigated. It should be noted that the same applies to the matching circuit 50.

[0075] In the high-frequency amplification device 1, the line N1 connecting the recesses 41g and 41h is separated from the metal pad 42. This configuration prevents the crack from spreading to the metal pad 42 even if a crack develops in the dielectric substrate 41 of the matching circuit 40. Therefore, the degree of loss of circuit function in the metal pad 42 can be reduced, and circuit function can be maintained. The same applies to the matching circuit 50.

[0076] In the high-frequency amplification device 1, the material constituting the package 4 includes a copper alloy, and the dielectric substrate 41 contains barium titanate. Therefore, as described above, when tensile stress is applied to the dielectric substrate 41, cracks are easily generated. In response, according to the high-frequency amplification device 1, the location of crack formation in the dielectric substrate 41 can be controlled by the recesses 41g and 41h. Therefore, even if cracks occur, the degree of loss of circuit function in the matching circuit 40 can be mitigated. Thus, the high-frequency amplification device 1 is advantageous in a configuration where cracks are easily generated in the dielectric substrate 41. The same applies to the matching circuit 50.

[0077] In the high-frequency amplification device 1, the thickness D1 of the base plate 4e of the package 4 is 1 mm or more and 3 mm or less, and the thickness D3 of the dielectric substrate 41 is 0.1 mm or more and 0.5 mm or less. The thickness D3 of the dielectric substrate 41 is relatively thin, making it prone to cracking due to temperature variations. However, according to this high-frequency amplification device 1, the location of crack formation in the dielectric substrate 41 can be controlled by the recesses 41g and 41h. Therefore, even if cracks occur, the degree of loss of circuit function in the matching circuit 40 can be reduced. Thus, the high-frequency amplification device 1 is advantageous in a configuration where cracks are easily generated in the dielectric substrate 41. The same applies to the matching circuit 50.

[0078] The above embodiments are one example of the high-frequency amplification device of this disclosure. The high-frequency amplification device of this disclosure can be configured as a high-frequency amplification device with arbitrary modifications to the above embodiments.

[0079] For example, the high-frequency amplification device 1 of the above embodiment includes two matching circuits 40 and 50, and the amplification element section 10 includes two amplification elements 11, but is not limited to this configuration. The high-frequency amplification device 1 may also include one matching circuit 40 and one matching circuit 50, or it may include three or more matching circuits 40 and 50. The amplification element section 10 may also include a single amplification element 11, or it may include three or more amplification elements 11.

[0080] In addition, the high-frequency amplification device 1 may also have Figure 8 The matching circuit 60 shown is used to replace the matching circuit 40. Figure 8 This is a top view showing a modified matching circuit 60. Matching circuit 60 differs from matching circuit 40 in that it has a dielectric substrate 61 instead of dielectric substrate 41, metal pads 62 instead of metal pads 42, and a resistive film 63 (resistive pattern). The other configurations of matching circuit 60 are the same as matching circuit 40. Dielectric substrate 61 differs from dielectric substrate 41 in that it has sides 61c and 61d instead of sides 41c and 41d, but is otherwise the same as dielectric substrate 41. Sides 61c and 61d are, like sides 41c and 41d, the long sides of dielectric substrate 61. Sides 61c (first side) and 61d (second side) extend in a direction along each other (here, the X-axis direction). In this example, the long dimension direction of dielectric substrate 61 and matching circuit 60 (matching circuit substrate) is along the X-axis direction. The short dimension direction of dielectric substrate 61 and matching circuit 60 (matching circuit substrate) is along the Y-axis direction.

[0081] Two recesses 61g (first recesses) recessed toward side 61d are provided on side 61c, and two recesses 61h (second recesses) recessed toward side 61c are provided on side 61d. The recesses 61g and 61h are positioned opposite each other. In other words, two opposite recesses 61g and 61h are provided on a pair of long sides of the dielectric substrate 61. The recesses 61g and 61h are located at both ends of the dielectric substrate 61 in the X-axis direction. The top view shape of the recesses 61g and 61h is, for example, semi-circular. In this example, the top ends of the recesses 61g and 61h are located on the same straight line extending in the Y-axis direction, which is orthogonal to the X-axis direction. The metal pad 62 differs from the metal pad 42 in that it has a greater thickness (length along the Z-axis direction) than the metal pad 42, but is otherwise identical to the metal pad 42. A resistive film 63 is disposed between two adjacent metal pads 62 along the X-axis direction and is electrically connected to these two metal pads 62. The line N3 connecting the aforementioned recesses 61g and 61h is separated from the resistive film 63. That is, line N3 does not intersect with the resistive film 63. In this example, line N3 extends in the Y-axis direction.

[0082] Figure 9 This is a diagram showing the stress distribution of the dielectric substrate 61 in the modified example. Figure 9 The stress distribution of the dielectric substrate 61 under the influence of a temperature change from 25°C to 125°C is shown (simulation results). It should be noted that... Figure 9 The illustrations of other components have been omitted. Figure 9 In, also with Figure 6 and Figure 7 Similarly, contour lines represent stress, with darker colors indicating greater stress.

[0083] In the event that the dielectric substrate 61 is subjected to stress that could potentially cause cracks, such as Figure 9 As shown, particularly large stresses are generated at recesses 61g and 61h (in Figure 9In the example, the stress is above 120 MPa and below 130 MPa. Thus, large stresses are generated locally, and therefore, recesses 61g or 61h preferentially become the starting point of the crack. Therefore, in the matching circuit 60, the location of crack generation in the dielectric substrate 61 can be controlled by recesses 61g and 61h. Therefore, even if a crack occurs in the dielectric substrate 61, the crack can be prevented from spreading to the resistive film 63, thus mitigating the degree of functional loss obtained through the resistive film 63. As a result, the function obtained through the resistive film 63 can be maintained. It should be noted that in the matching circuit 60, it is also conceivable that if a crack occurs in the dielectric substrate 61, the crack will spread to the metal pad 62. In this regard, the metal pad 62 has a greater thickness than the metal pad 42; therefore, even if it is desired to prevent cracks from forming on the metal pad 62, the adhesion of Au can suppress the formation of cracks on the metal pad 62.

[0084] It should be noted that the high-frequency amplification device 1 may also have a matching circuit 60 instead of the matching circuit 50. Alternatively, it may have a matching circuit 60 instead of each of the matching circuits 40 and 50.

[0085] Furthermore, in the above embodiments and variations, the top view shape of each of the recesses 41g, 41h, 51g, 51h, 61g, and 61h is semi-circular, but the top view shape of each of the recesses (the first recess and the second recess) is not limited to this configuration. Figure 10A , Figure 10B as well as Figure 10C These are diagrams showing the recesses 41i, 41j, and 41k of the modified examples, respectively. Hereinafter, a modified example of recess 41g will be described, but it may also be a modified example of any one of recesses 41g, 41h, 51g, 51h, 61g, and 61h.

[0086] like Figure 10A As shown, a recess 41i (first recess) can also be provided on the side 41c, which, when viewed from above, has a shape that divides the ellipse in two along its major axis, as shown in the figure. Figure 10B As shown, the top view shape can also be configured as a concave portion 41j (first concave portion) that divides the ellipse in two along its minor axis. Alternatively, as... Figure 10CAs shown, a recess 41k (first recess) with a triangular shape when viewed from above can also be provided on the side 41c. In the recesses 41g, 41i, 41j, and 41k, at the top of the direction U in which a crack is to be generated in the dielectric substrate 41 (e.g., a direction orthogonal to the principal direction V that generates tensile stress), the greater the curvature of the vertex P, which is linearly symmetrical with respect to direction U, the greater the stress generated at that vertex. That is, the stress that can be locally generated in the dielectric substrate 41 where the recess is provided tends to increase. The curvature of the vertex P of recess 41i is less than the curvature of the vertex P of recess 41g. Furthermore, the curvature of the vertex P of recess 41j is greater than the curvature of the vertex P of recess 41g. Moreover, the curvature of the vertex P of recess 41k is greater than the curvature of the vertex P of recess 41j. Therefore, recesses 41k, 41j, 41g, and 41i tend to preferentially become the starting point of the crack in that order.

[0087] Alternatively, recesses 41i, 41j, and 41k can be used to replace recesses 41g, 41h, 51g, 51h, 61g, and 61h.

[0088] Explanation of reference numerals in the attached figures

[0089] 1. 1X: High-frequency amplification device

[0090] 2: Input terminals

[0091] 3: Output terminals

[0092] 4: Package

[0093] 4a, 4b: end wall

[0094] 4c, 4d: Sidewall

[0095] 4e: Base plate (substrate)

[0096] 5: Casing

[0097] 5a: Base plate

[0098] 9a~9f: Joint lines

[0099] 10: Amplifying element section

[0100] 11: Amplifying element

[0101] 20: Branch circuit board

[0102] 21: Substrate

[0103] 21a, 21b: Long side

[0104] 21c, 21d: Short side

[0105] 22: Branch circuit

[0106] 23: Wiring pattern

[0107] 23a: Metal pad

[0108] 23b: Membrane resistance

[0109] 30: Composite circuit board

[0110] 31: Substrate

[0111] 31a, 31b: Long side

[0112] 31c, 31d: Short side

[0113] 32: Synthetic Circuit

[0114] 33: Wiring pattern

[0115] 33a: Metal pad

[0116] 33b: Membrane resistance

[0117] 40, 40X: Matching circuit (matching circuit board)

[0118] 41, 41X: Dielectric substrate

[0119] 41a: Main face (first main face)

[0120] 41b: Main face (second main face)

[0121] 41c: Side view (first side view)

[0122] 41d: Side view (second side view)

[0123] 41e: End face

[0124] 41f: End face

[0125] 41g, 41i, 41j, 41k: concave portion (first concave portion)

[0126] 41h: Recessed portion (second recessed portion)

[0127] 42: Metal pads (circuit pattern)

[0128] 50, 50X: Matching circuit (matching circuit board)

[0129] 51: Dielectric substrate

[0130] 51a: Main face (first main face)

[0131] 51b: Main face (second main face)

[0132] 51c: Side view (first side view)

[0133] 51d: Side view (second side view)

[0134] 51e: End face

[0135] 51f: End face

[0136] 51g: concave part (first concave part)

[0137] 51h: Recessed portion (second recessed portion)

[0138] 52: Metal pads (circuit pattern)

[0139] 60: Matching circuit

[0140] 61: Dielectric substrate

[0141] 61c: Side view (first side view)

[0142] 61d: Side view (second side view)

[0143] 61g: concave part (first concave part)

[0144] 61h: Recessed portion (second recessed portion)

[0145] 62: Metal pads (circuit pattern)

[0146] 63: Resistive film (resistor pattern)

[0147] D1~D4: Thickness

[0148] P: Vertex

[0149] U: Direction

[0150] V: Main direction

[0151] N1~N3: Lines.

Claims

1. An amplification device comprising: Substrate; Amplifying elements are mounted on the substrate; and A matching circuit board, mounted on the substrate, has a circuit pattern electrically connected to the amplifying element. The matching circuit substrate has a first side and a second side extending in the long dimension direction of the matching circuit substrate, respectively. The matching circuit board also has a resistor pattern. A first recess is provided on the first side. A second recess is provided on the second side, which is opposite to the first recess. The top ends of the first recess and the second recess are located on the same straight line extending in a direction orthogonal to the longitudinal direction. The line connecting the first recess and the second recess is separated from the resistor pattern, and the connecting line is located on the circuit pattern.

2. The amplification device according to claim 1, wherein, The matching circuit board has a dielectric substrate for setting the circuit pattern and the resistor pattern. The first recess and the second recess are provided on the dielectric substrate. The material constituting the substrate includes copper. The dielectric substrate contains barium titanate.

3. The amplification device according to claim 2, wherein, The thickness of the substrate is more than 1 mm and less than 3 mm. The thickness of the dielectric substrate is 0.1 mm or more and 0.5 mm or less.

4. A matching circuit board, mountable on a substrate, and having resistive patterns and circuit patterns for impedance transformation, wherein, The matching circuit substrate has a first side surface and a second side surface extending in the long dimension direction of the matching circuit substrate, respectively. A first recess is provided on the first side. A second recess is provided on the second side, which is opposite to the first recess. The top ends of the first recess and the second recess are located on the same straight line extending in a direction orthogonal to the longitudinal direction. The line connecting the first recess and the second recess is separated from the resistor pattern, and the connecting line is located on the circuit pattern.

5. The matching circuit substrate according to claim 4, It also includes a dielectric substrate for setting the circuit pattern and the resistor pattern. The first recess and the second recess are provided on the dielectric substrate. The dielectric substrate contains barium titanate.

6. The matching circuit substrate according to claim 5, wherein, The thickness of the dielectric substrate is 0.1 mm or more and 0.5 mm or less.

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