JP4646699B2 - High frequency transmission circuit board and high frequency circuit board - Google Patents

Description

  The present invention relates to a high-frequency transmission circuit board for mounting electronic components that operate with a high-frequency signal such as a semiconductor element, and a high-frequency circuit board in which this high-frequency transmission circuit board is connected to an electric circuit board. The present invention relates to a high-frequency transmission circuit board capable of accurately and easily positioning and connecting a high-frequency line conductor of a circuit board and a high-frequency line wiring of an electric circuit board, and a high-frequency circuit board to which the circuit board is connected.

  Conventionally, a high-frequency transmission circuit board for transmitting a high-frequency signal by connecting to an electronic component such as a semiconductor element that operates with a high-frequency signal such as a microwave band or a millimeter-wave band is used as a high-frequency line wiring such as an external electric circuit board. When a high-frequency transmission circuit board is surface-mounted on an electric circuit board, the capacitance component existing between the high-frequency transmission circuit board and the electric circuit board does not increase, and high-frequency signals are transmitted well. In order to achieve this, a high frequency transmission circuit board in which a dielectric is removed from the high frequency transmission circuit board in the vicinity of the high frequency transmission line to form a groove has been used. FIG. 6 shows such a high-frequency transmission circuit board having grooves.

  In FIG. 6, the circuit board for high-frequency transmission includes a dielectric substrate 21, a first line conductor 22a whose one end is connected to the upper main surface of the dielectric substrate 21, and the first line conductor 22a. And a first ground conductor 23a formed at a predetermined interval around the dielectric substrate 21 and from the position facing the other end of the first line conductor 22a on the lower main surface of the dielectric substrate 21. The second line conductor 22b is formed up to the end of the lower main surface and forms a connection portion with the electric circuit board 31, and the second line conductor 22b is formed at a predetermined interval around the second line conductor 22b. Two ground conductors 23b are formed, a line connecting conductor 22c is formed from the other end of the first line conductor 22a to one end of the second line conductor 22b facing the first line conductor 22a, and a dielectric substrate A ground connection conductor 23c is formed on the end face of 21 from the first ground conductor 23a to the second ground conductor 23b. Is made in the lower surface of the dielectric substrate 21 located between the second line conductor 22b and the second ground conductor 23b, a groove 24 is provided.

  The dielectric substrate 21 is made of an inorganic dielectric material such as alumina ceramics or glass ceramics having a placement portion 21a on which an electronic component 26 such as a semiconductor element that operates by a high frequency signal is placed on the upper surface, polyimide, glass epoxy, etc. A dielectric substrate composed of a composite dielectric material or the like formed by bonding an organic dielectric material or an inorganic dielectric powder such as ceramic powder with a thermosetting resin such as an epoxy resin. As a result, a high-frequency transmission circuit board is formed.

  Also, a first line conductor 22a is formed on the upper main surface of the dielectric substrate 21 and one end thereof is connected to the electronic component 26, and is formed on the lower main surface from the one end to the lower end of the dielectric substrate 21. A line is formed from a second line conductor 22b formed by connecting to the electric circuit board 31, and a line connection conductor 22c formed from the other end of the first line conductor 22a to one end of the second line conductor 22b. Conductor 22 is formed.

  A first ground conductor 23a formed at a predetermined interval around the first line conductor 22a on the upper main surface of the dielectric substrate 21, and a second line conductor 22b on the lower main surface of the dielectric substrate 21. From the second ground conductor 23b formed at a predetermined interval around the ground and the ground connection conductor 23c formed from the first ground conductor 23a to the second ground conductor 23b on the end face of the dielectric substrate 21. Conductor 23 is formed.

  The line conductor 22 and the ground conductor 23 are formed using a metallized conductor, a metal thin film, a metal foil, a metal plate, or the like by a thick film printing method, various thin film forming methods, a plating method, or the like. The thickness, shape, line width, distance between the line conductor 22 and the ground conductor 23, and the like are appropriately set according to the frequency of the high-frequency input / output signal transmitted through the line conductor 22, the characteristic impedance, and the like.

  In the circuit board for high frequency transmission shown in FIG. 6, a groove 24 is provided on the lower surface of the dielectric substrate 21 located between the second line conductor 22b and the second ground conductor 23b. In this way, the mounting portion 21a for mounting the electronic component 26 such as a semiconductor element is formed on the upper main surface of the dielectric substrate 21, and the lower main surface of the dielectric substrate 21 from the periphery of the mounting portion 21a. A line conductor 22 is formed to electrically connect the electronic component 26 and the high-frequency line wiring 32 of the electric circuit board 31 to the end of the mounting portion 21a and from the periphery of the mounting portion 21a so as to be parallel to the line conductor 22. By forming the ground conductor 23 over the end of the lower main surface of the dielectric substrate 21, a circuit board for high-frequency transmission is obtained (see, for example, Patent Document 1).

  The electronic component 26 is placed and fixed on the placement portion 21a, and the electronic component 26 is attached to one end of the first line conductor 22a and the first ground conductor 23a via an electrical connection means 27 such as a bonding wire. One end of the second line conductor 22b is connected to the high-frequency line wiring 32 of the electric circuit board 31 through the conductive adhesive 25, and the second ground conductor 23b is connected through the conductive adhesive 25. By connecting to the ground wiring 33 of the electric circuit board 31, the electronic component 26 is connected to the electric circuit board 31, and a high frequency signal is input to and output from the electronic component 26.

By providing the groove 24, the capacitance component generated between the dielectric substrate 21 constituting the high-frequency transmission circuit board and the electric circuit board 31 on which the high-frequency transmission circuit board is mounted can be reduced. In addition, since the electric field concentration between the dielectric substrate 21 and the electric circuit board 31 is relaxed, the high frequency impedance for the high frequency signal at the input / output part when the circuit board for high frequency transmission is surface-mounted on the electric circuit board 31 Inconsistency is suppressed and loss of the high-frequency signal is kept low, and as a result, the high-frequency signal can be transmitted satisfactorily.
JP 2003-152124 A

  However, in recent years, the operating frequency of the electronic component 26 mounted on the high frequency transmission circuit board has become higher, and the first line conductor 22a and the second line conductor 22b of the high frequency transmission circuit board are transmitted. In order to effectively reduce the dielectric loss generated in the high-frequency signal, the dielectric substrate 21 itself constituting the high-frequency transmission circuit substrate tends to be thinned. When the groove 24 is provided in the thin dielectric substrate 21 as described above, the dielectric substrate 21 becomes very thin at a location above the groove 24.

  For this reason, it becomes difficult to manufacture the dielectric substrate 21 in a predetermined shape, making it unsuitable for mass production, and the mechanical strength of the dielectric substrate 21 is reduced at a location above the groove 24. Damage such as cracks was likely to occur in the body substrate 21 part. Further, when the dielectric substrate 21 is damaged such as a crack, the line conductor 22 is disconnected, and a high-frequency signal cannot be transmitted. This problem has occurred remarkably when the dielectric substrate 21 is made of an inorganic dielectric material such as alumina ceramics or glass ceramics.

  Accordingly, the present invention has been completed in view of the above-described conventional problems, and the object thereof is to reliably transmit a high-frequency signal between two substrates and reduce transmission loss of the high-frequency signal. Another object of the present invention is to provide a high-frequency transmission circuit board that can be efficiently manufactured without causing breakage such as cracks, and a high-frequency circuit board using the same.

The circuit board for high-frequency transmission of the present invention includes a dielectric substrate, a first line conductor formed on an upper main surface of the dielectric substrate, one end connected to an electronic component, and the periphery of the first line conductor Formed on the lower main surface of the dielectric substrate from the position facing the other end of the first line conductor to the end of the lower main surface. A second line conductor, a second ground conductor formed at a predetermined interval around the second line conductor, and the other end of the first line conductor inside the dielectric substrate. A line connecting conductor formed over one end of the second line conductor facing each other through the dielectric substrate; and formed from the first ground conductor to the second ground conductor adjacent to the line connecting conductor. A circuit board for high-frequency transmission having a ground connection conductor. On one side of the dielectric substrate at the other end of the pair of grooves at the site where the lower end while being positioned vertically adjacent to and on both sides of the other end of the second line conductor reaches the lower major surface The dielectric substrate is characterized in that a stepped portion is formed on the one side surface by removing the upper main surface side from a portion located between the pair of grooves .

The circuit board for high frequency transmission according to the present invention includes a dielectric substrate, a first line conductor formed on an upper main surface of the dielectric substrate, one end connected to an electronic component, and a lower side of the dielectric substrate. A second line conductor formed on the main surface from a position facing the other end of the first line conductor to an end of the lower main surface; and the other end of the first line conductor in the dielectric substrate A line connection conductor formed from one end of the second line conductor facing each other through the dielectric substrate, and a predetermined distance from the line connection conductor in the inner layer of the dielectric substrate and the first line A high frequency transmission circuit board comprising a conductor and an inner ground conductor layer formed in parallel with the second line conductor, on one side of the dielectric substrate on the other end side of the second line conductor , the lower end while being positioned vertically the second At a site adjacent to both sides of the other end of the road conductors are a pair of grooves is provided to reach the lower major surface, said dielectric substrate, said one side surface, from sites located between the pair of grooves Has a stepped portion formed by removing the upper main surface side .

  The high-frequency circuit board according to the present invention has the lower main surface of the high-frequency transmission circuit board having the above-described configuration placed on the upper surface of the electric circuit board having the high-frequency line wiring formed on the upper surface, and the second line conductor. The other end of is electrically connected to the high-frequency line wiring.

The circuit board for high-frequency transmission of the present invention includes a dielectric substrate, a first line conductor formed on an upper main surface of the dielectric substrate, one end connected to an electronic component, and the periphery of the first line conductor Formed on the lower main surface of the dielectric substrate from the position facing the other end of the first line conductor to the end of the lower main surface. A second line conductor, a second ground conductor formed at a predetermined interval around the second line conductor, and the other end of the first line conductor inside the dielectric substrate. A line connecting conductor formed over one end of the second line conductor facing each other through the dielectric substrate; and formed from the first ground conductor to the second ground conductor adjacent to the line connecting conductor. A circuit board for high-frequency transmission having a ground connection conductor. On one side of the dielectric substrate at the other end of the pair of grooves at the site where the lower end while being positioned vertically adjacent to and on both sides of the other end of the second line conductor reaches the lower major surface Since the dielectric substrate has a step portion formed by removing the upper main surface side from the portion located between the pair of grooves on the one side surface , The dielectric on both the left and right sides of the other end of the line conductor is completely removed between the upper and lower main surfaces, and between the dielectric substrate constituting the high-frequency transmission circuit board and the electric circuit board on which this high-frequency transmission circuit board is mounted The capacitance component generated at the same time can be reduced, and a high-frequency signal can be transmitted satisfactorily. Further, since no groove is formed between the second line conductor and the second ground conductor on the lower main surface of the circuit board for high-frequency transmission, the dielectric substrate is partially extremely thin. Part does not occur.

  In addition, since the pair of grooves penetrating between the upper and lower main surfaces can be formed by punching between the upper and lower main surfaces of the dielectric substrate, the processing for providing the grooves is easy even when the dielectric substrate is thinned. Since it is not necessary to use a dielectric substrate having an extremely thin thickness, the dielectric substrate can be handled easily and is suitable for mass production. And it can be set as the circuit board for high frequency transmission which can transmit a high frequency signal satisfactorily, and a line conductor is hard to disconnect.

The circuit board for high-frequency transmission according to the present invention includes a dielectric substrate, a first line conductor formed on an upper main surface of the dielectric substrate, one end connected to an electronic component, and a bottom of the dielectric substrate. A second line conductor formed on the side main surface from a position facing the other end of the first line conductor to an end of the lower main surface; and the first line conductor in the dielectric substrate. A line connecting conductor formed from one end to one end of the second line conductor facing each other through the dielectric substrate, and providing a predetermined distance from the line connecting conductor in an inner layer of the dielectric substrate and the first One side surface of the dielectric substrate on the other end side of the second line conductor in a circuit board for high frequency transmission comprising a line conductor and an inner ground conductor layer formed in parallel with the second line conductor the lower end while being positioned vertically the second At a site adjacent to both sides of the other end of the line conductor has a pair of grooves is provided to reach the lower major surface, said dielectric substrate, said one side surface, from sites located between the pair of grooves Also has a step portion formed by removing the upper main surface side, so that the left and right dielectrics at the other end of the second line conductor are completely removed between the upper and lower main surfaces, and the circuit board for high frequency transmission The capacitance component generated between the dielectric substrate constituting the circuit board and the electric circuit board on which the high frequency transmission circuit board is mounted can be reduced, and high frequency signals can be transmitted satisfactorily. Further, since no groove is formed between the second line conductor and the second ground conductor on the lower main surface of the circuit board for high-frequency transmission, the dielectric substrate is partially extremely thin. Part does not occur.

  In addition, since the pair of grooves penetrating between the upper and lower main surfaces can be formed by punching between the upper and lower main surfaces of the dielectric substrate, the processing for providing the grooves is easy even when the dielectric substrate is thinned. Since it is not necessary to use a dielectric substrate having an extremely thin thickness, the dielectric substrate can be handled easily and is suitable for mass production. And it can be set as the circuit board for high frequency transmission which can transmit a high frequency signal satisfactorily, and a line conductor is hard to disconnect.

  The high frequency transmission circuit board of the present invention is preferably formed with the step portion formed by removing the dielectric substrate on the upper principal surface side located between the pair of grooves. The capacitance component generated in the vicinity of the connection between the dielectric substrate constituting the circuit board and the electric circuit board on which the high-frequency transmission circuit board is mounted can be further reduced, and the high-frequency transmission circuit board is surface-mounted on the electric circuit board. In this case, high frequency impedance mismatch with respect to the high frequency signal in the input / output unit can be suppressed, and the high frequency signal can be transmitted satisfactorily.

  In addition, the dielectric substrate is thin at the stepped portion, but the stepped portion is only on the upper main surface side located between the pair of grooves, and the dielectric at the stepped portion. The mechanical strength of the body substrate is not significantly reduced.

  The high-frequency circuit board according to the present invention has the lower main surface of the high-frequency transmission circuit board having the above-described configuration placed on the upper surface of the electric circuit board having the high-frequency line wiring formed on the upper surface, and the second line conductor. Since the other end is electrically connected to the high-frequency line wiring, the second line conductor and the second ground conductor formed on the lower main surface of the high-frequency transmission circuit board are respectively connected to the upper surface of the electric circuit board. This is electrically connected to the high-frequency line wiring and ground wiring, and the dielectric on both the left and right sides of the other end of the second line conductor is completely removed between the upper and lower main surfaces, thus constituting a circuit board for high-frequency transmission The capacitance component generated between the dielectric substrate and the electric circuit board on which the high-frequency transmission circuit board is mounted can be reduced. As a result, the high-frequency transmission circuit board is connected to the electric circuit board. High on circuit board Wave signal is satisfactorily transmitted.

  In addition, a pair of grooves are provided on the left and right sides of the second line conductor so as to contact the other end of the second line conductor, and the dielectric is completely removed between the upper and lower main surfaces by the grooves. Therefore, when the high frequency transmission circuit board is mounted on the electric circuit board, the position of the second line conductor and the line width are determined by observing the pair of grooves from the upper main surface side of the high frequency transmission circuit board. As can be seen, alignment of the electric circuit board with the high-frequency line wiring can be performed accurately and efficiently. Thereby, the second line conductor can be accurately aligned and connected to a predetermined position of the high-frequency line wiring. Therefore, the impedance value at the connection portion between the second line conductor and the high-frequency line wiring is matched within a predetermined value, and reflection loss and transmission loss generated in the high-frequency signal transmitted through the connection portion can be reduced. The transmission efficiency can be improved. In addition, since the alignment operation is easy, the high-frequency circuit board with extremely high productivity is obtained.

  Furthermore, it is possible to confirm the flow of the conductive adhesive that connects the second line conductor of the high frequency transmission circuit board and the high frequency line wiring of the electric circuit board from above the high frequency transmission circuit board. And the presence or absence of an electrical short circuit between the second line conductor or the high-frequency line wiring and the second ground conductor or the ground wiring as well as the confirmation of the presence or absence of adhesion failure between the second line conductor and the high-frequency line wiring Can also be confirmed. As a result, it is possible to provide a high-frequency circuit board that can reliably transmit a high-frequency signal between the two boards.

The circuit board for high frequency transmission and the high frequency circuit board of the present invention will be described in detail below. 1 (a) is a perspective view showing a reference example of the high-frequency circuit board connected to the circuit board for high frequency transmission in the electric circuit board, FIG. 1 (b) the lower surface of the high-frequency transmission circuit board used in FIGS. 1 (a) FIG, cross-sectional view of a central portion of FIG. 1 (c) first and second line conductor and the high-frequency line wire of FIG. 1 (a), a perspective view showing an embodiment of a high-frequency circuit board of FIG. 2 is the invention 3 is a perspective view showing a reference example of the high-frequency circuit board, FIG. 4 is a perspective view showing another example of the embodiment of the high-frequency circuit board of the present invention, and FIGS. 5A to 5C are for high-frequency transmission. The other example of embodiment of a circuit board is shown and it is a waist expansion plan view of the circumference of a slot.

  In these drawings, 1 is a dielectric substrate, 2 is a line conductor (2a is a first line conductor, 2b is a second line conductor, 2c is a line connection conductor), 3 is a ground conductor (3a is a first ground conductor) Conductor, 3b is a second ground conductor, 3c is a ground connection conductor, 3d is an inner ground conductor layer), 4 is a groove, 5 is a conductive adhesive, 6 is an electronic component, 7 is an electrical connection means, and 11 is an electrical connection. A circuit board, 12 is a high-frequency line wiring, and 13 is a ground wiring. The line conductor 2 includes a first line conductor 2a, a second line conductor 2b, and a line connection conductor 2c, and the ground conductor 3 includes the first ground conductor 3a, the second ground conductor 3b, and the ground connection conductor. 3c or an inner ground conductor layer 3d. 1 (a), FIG. 1 (b), FIG. 2, FIG. 3, FIG. 4, FIG. 5 (b), and FIG. 5 (c), the substrate surface portion on which the conductor is formed is conveniently shown. Cross hatching is attached. Therefore, these cross hatched portions do not show a cross section.

As shown in FIG. 1, the high-frequency transmission circuit board includes a dielectric substrate 1, a first line conductor 2 a formed on the upper main surface of the dielectric substrate 1 and having one end connected to the electronic component 6, A first ground conductor 3a formed at a predetermined interval around the first line conductor 2a and a lower main surface of the dielectric substrate 1 from a position facing the other end of the first line conductor 2a. The second line conductor 2b formed up to the end of the lower main surface, the second ground conductor 3b formed at a predetermined interval around the second line conductor 2b, and the inside of the dielectric substrate 1 A line connecting conductor 2c formed by a through conductor extending from the other end of the first line conductor 2a to one end of the second line conductor 2b opposed via the dielectric substrate 1, and adjacent to the line connecting conductor 2c. Formed on the side surface of the dielectric substrate 1 from one ground conductor 3a to the second ground conductor 3b. A pair of grooves 4 in contact with the other end of the second line conductor 2b on one side surface of the dielectric substrate 1 on the other end side of the second line conductor 2b. It is provided on both sides of the conductor 2b.

As shown in FIG. 3, the high-frequency transmission circuit board includes a dielectric substrate 1, a first line conductor 2 a formed on the upper main surface of the dielectric substrate 1, and having one end connected to the electronic component 6. A second line conductor 2b formed on a lower main surface of the dielectric substrate 1 from a position facing the other end of the first line conductor 2a to an end of the lower main surface; A line connecting conductor 2c formed by a through conductor from the other end of the first line conductor 2a to one end of the second line conductor 2b opposed via the dielectric substrate 1, and a line connecting conductor on the inner layer of the dielectric substrate 1 2c and an inner ground conductor layer 3d formed to be parallel to the first line conductor 2a and the second line conductor 2b while providing a predetermined interval, and on the other end side of the second line conductor 2b One side in contact with the other end of the second line conductor 2b on one side of the dielectric substrate 1 In which grooves 4 are provided on both sides of the second line conductor 2b.

As shown in FIGS. 2 and 4 , the high frequency transmission circuit board of the present invention is formed with the stepped portion 8 by removing the dielectric substrate 11 on the upper main surface side located between the pair of grooves 4. Is what

In the high frequency circuit board, the lower main surface of the high frequency transmission circuit board having the above-described configuration is placed on the upper surface of the electric circuit board 11 having the high frequency line wiring 12 formed on the upper surface, and the second line conductor 2b. The other end is electrically connected to the high-frequency line wiring 12. When the second ground conductor 3 b is provided on the high-frequency transmission circuit board, the second ground conductor 3 b is electrically connected to the ground wiring 13 of the electric circuit board 11.

  1 to 5, the connection of the high-frequency transmission line between the high-frequency transmission circuit board and the electric circuit board 11 is shown using a conductive adhesive 5. Also, at one end of the first line conductor 2a, there are an electrode of an electronic component 6 such as a high-frequency semiconductor element mounted and fixed on the upper surface of the mounting portion 1a, a first line conductor, and a first ground conductor. The form which is electrically connected using the bonding wire as the electrical connection means 7 is shown.

  In addition, a conductor layer (not shown) for attaching and fixing the electronic component 6 is formed on the mounting portion 1a. The electronic component 6 is bonded to the conductor layer through a conductive bonding material such as silver (Ag) solder, gold (Au) -tin (Sn) solder, or Ag epoxy (an epoxy resin containing Ag metal powder). The

The dielectric substrate 1 is made of an alumina sintered body, an aluminum nitride sintered body, a mullite sintered body, ceramics such as glass ceramics, or a resin such as an epoxy resin.

  As shown in FIGS. 1 and 2, the dielectric substrate 1 has a placement portion 1 a for placing the electronic component 6 on the upper principal surface, and one end of the dielectric substrate 1 is disposed on the upper principal surface of the dielectric substrate 1. The first line conductor 2a connected to the first line conductor 2 and the first ground conductor 3a formed at a predetermined interval around the first line conductor 2a are formed, and the lower main surface of the dielectric substrate 1 is formed. Further, one end of the first line conductor 2a is opposed to the other end of the first line conductor 2a, the other end is formed up to the end of the lower main surface of the dielectric substrate 1, and the other end is the high-frequency line wiring of the electric circuit board 11. A second line conductor 2b connected to 12 and a second ground conductor 3b formed at a predetermined interval around the second line conductor 2b, and the other end of the first line conductor 2a. A line connection conductor 2c is formed from one end of the second line conductor 2b to the second line conductor 2b, and the second grounding is performed from the first grounding conductor 3a. A ground connection conductor 3c is formed over the conductor 3b. A high-frequency signal is transmitted between the upper and lower main surfaces of the dielectric substrate 1 by the line connection conductor 2c and the ground connection conductor 3c. That is, the line conductor 2 includes a first line conductor 2a, a second line conductor 2b, and a line connection conductor 2c, and the ground conductor 3 includes the first ground conductor 3a, the second ground conductor 3b, and the ground connection conductor. The high-frequency signal is transmitted by being composed of 3c.

  In addition, a pair of grooves 4 penetrating between the upper and lower main surfaces on both sides in the width direction of the connecting portion between the second line conductor 2b at the end of the dielectric substrate 1 and the high-frequency line wiring 12 are the second line conductor 2b. The side surface on the side is formed so as to be in contact with the second line conductor 2b.

  Alternatively, as shown in FIG. 3 and FIG. 4, the grounding conductor 3 of the dielectric substrate 1 is not provided with the first grounding conductor 3a, the second grounding conductor 3b, and the grounding connection conductor 3c. The conductor layer 3d may be formed to be parallel to the first line conductor 2a and the second line conductor 2b while providing a predetermined interval so that the conductor layer 3d is not connected to the line connection conductor 2c in the inner layer of the dielectric substrate 1. .

  The electric circuit board 11 is made of a resin such as an epoxy resin, or a ceramic such as an alumina sintered body, an aluminum nitride sintered body, a mullite sintered body, or a glass ceramic. And a ground wiring 13 formed at predetermined intervals on both sides of the high-frequency line wiring 12.

  When the dielectric substrate 1 is made of ceramics, the line conductor 2 and the ground conductor 3 are preferably formed by a metallization method.

  First, as shown in FIGS. 1 and 2, when the ground conductor 3 is composed of the first ground conductor 3a, the second ground conductor 3b, and the ground connection conductor 3c, the ceramic green sheet that forms the dielectric substrate 1 is used. A metal paste made of tungsten (W), molybdenum (Mo), manganese (Mn), or the like, which becomes the first line conductor 2a and the first ground conductor 3a, is printed on the upper main surface by screen printing, and the lower side thereof A metal paste made of W, Mo, Mn, or the like that becomes the second line conductor 2b and the second ground conductor 3b is printed and applied to the main surface by a screen printing method. Furthermore, a through-hole penetrating between the upper and lower main surfaces of the dielectric substrate 1 is formed so as to connect the other end of the first line conductor 2a of the dielectric substrate 1 and one end of the second line conductor 2b, In this through hole, a metal paste made of W, Mo, Mn, or the like that becomes the line connecting conductor 2c is formed by a suction method or the like. The line connecting conductor 2c in the through hole may be formed so that the metal conductor fills the inside of the through hole, or may be formed so as to cover the inner wall of the through hole and be formed in a hollow shape inside.

  Further, a metal paste made of W, Mo, Mn or the like serving as the ground connection conductor 3c is formed on the side surface of the dielectric substrate 1 so as to connect the first ground conductor 3a and the second ground conductor 3b. The printing is applied by the printing method. Alternatively, a castellation (notch) is provided on the side surface of the dielectric substrate 1, and a metal paste made of W, Mo, Mn, or the like that serves as the ground connection conductor 3c is applied to the inner surface of the castellation. Alternatively, a through hole penetrating between the upper and lower main surfaces of the dielectric substrate 1 is formed so as to connect the first ground conductor 3a and the second ground conductor 3b, and the ground connection conductor 3c is formed in the through hole. A metal paste made of W, Mo, Mn, or the like is filled by a suction method or the like or formed so as to cover the inner wall. In the case where the dielectric substrate 1 is formed by laminating a plurality of ceramic green sheets, a ceramic green laminate to be the dielectric substrate 1 is formed by laminating the plurality of ceramic green sheets.

  As described above, the metal paste forming the first line conductor 2a and the first ground conductor 3a is formed on the upper main surface of the ceramic green sheet serving as the dielectric substrate 1, and the second line conductor 2b is formed on the lower main surface. After the metal paste that becomes the second ground conductor 3b is applied between the upper and lower main surfaces, and the metal paste that becomes the line connection conductor 2c and the ground connection conductor 3c, the dielectric substrate 1 is put into a high temperature furnace. The ceramic green sheet to be the dielectric substrate 1 is fired to become a ceramic substrate, and these metal pastes are fired to become a metallized conductor.

  Next, as shown in FIGS. 3 and 4, when the ground conductor 3 is composed of the inner ground conductor layer 3d, the first line conductor is formed on the upper main surface of the ceramic green sheet serving as the upper main surface of the dielectric substrate 1. A metal paste made of W, Mo, Mn or the like that becomes 2a is printed and applied by a screen printing method, and W, Mo, which becomes the second line conductor 2b on the lower main surface of the ceramic green sheet that becomes the lower main surface. A metal paste made of Mn or the like is printed by a screen printing method. Furthermore, screen printing is performed except for the periphery where the metal connecting paste 3c forming the inner ground conductor layer 3d is formed on one main surface of the ceramic green sheet serving as the inner layer of the dielectric substrate 1 and the line connecting conductor 3c is formed. Printing is applied by the method. Furthermore, a through-hole penetrating between the upper and lower main surfaces of the dielectric substrate 1 is formed so as to connect the other end of the first line conductor 2a of the dielectric substrate 1 and the other end of the second line conductor 2b. The through hole is filled with a metal paste made of W, Mo, Mn, or the like that becomes the line connecting conductor 2c by a suction method or the like. Thereafter, a plurality of ceramic green sheets are laminated to form a ceramic green laminate that becomes the dielectric substrate 1.

  As described above, the metal paste to be the first line conductor 2a is formed on the upper main surface of the ceramic green sheet to be the dielectric substrate 1, and the metal paste to be the second line conductor 2b is formed on the lower main surface. After the metal paste that forms the inner ground conductor layer 3d is applied to one main surface of the ceramic green sheet that forms the inner layer of the body substrate 1, and the metal paste that forms the line connection conductor 2c between the upper and lower main surfaces, the dielectric substrate 1 When the ceramic raw laminate is placed in a high-temperature furnace, the ceramic green sheet serving as the dielectric substrate 1 is fired to become a ceramic substrate, and these metal pastes are fired to become a metallized conductor.

  Although not shown, the ground conductor 3 is a combination of the form shown in FIGS. 1 and 2 and the form shown in FIGS. 3 and 4, and the first ground conductor 3a and the second ground conductor 3b are grounded. The connection conductor 3c and the inner ground conductor layer 3d may be used. With this configuration, the ground potential for the line conductor 2 can be strengthened, and high-frequency signals can be transmitted efficiently.

  3 and 4, the electric circuit board 11 may be a coplanar type in which the ground wiring 13 is formed with a predetermined interval around the high-frequency line wiring 12 as shown in FIGS. In this case, the inner layer ground conductor 3d is connected to the ground wiring 13 by the ground connection conductor 3c or the like. When the electric circuit board 11 is a microstrip type as shown in FIG. 4, the inner layer ground conductor 3 d is connected to a ground wiring (not shown) provided on the lower main surface of the electric circuit board 11.

The first line conductor 2a, the first ground conductor 3a, the second line conductor 2b, and the second ground conductor 3b may be formed by a thin film forming method. In this case, the first line conductor 2a Is formed of tantalum nitride (Ta ₂ N), nichrome (Ni—Cr alloy), titanium (Ti), palladium (Pd), platinum (Pt), etc., and after firing a ceramic green sheet serving as the dielectric substrate 1, sputtering is performed. It is formed by a thin film forming method such as.

  Further, on one side surface of the dielectric substrate 1 where the second line conductor 2b and the high-frequency line wiring 12 are connected, on both sides in the width direction of the second line conductor 2b, FIG. As shown in FIG. 2, a pair of grooves 4 penetrating between the upper and lower main surfaces are formed so as to contact both ends of the second line conductor 2b in the width direction. When the dielectric substrate 1 is made of ceramic, the groove 4 is formed by punching a through hole penetrating between the upper and lower main surfaces at a predetermined position of the ceramic green sheet to be the dielectric substrate 1, and then placing the ceramic green sheet at the center of the through hole. It is formed by firing after dividing so as to be divided.

  As described above, the circuit board for high frequency transmission capable of transmitting a high frequency signal between the upper and lower main surfaces of the dielectric substrate 1 is obtained.

When the electric circuit board 11 is made of ceramics, like the circuit board for high-frequency transmission, the high-frequency line wiring 12 and the ground wiring 13 are formed on the upper surface by baking a metal paste made of W, Mo, Mn, etc. at a high temperature. . Alternatively, the high-frequency line wiring 12 and the ground wiring 13 are made of Ta ₂ N, Ni—Cr alloy, Ti, Pd, Pt or the like, and formed by a thin film forming method such as sputtering after firing the ceramic green sheet.

  The lower main surface of the circuit board for high frequency transmission is placed on the upper surface of the electric circuit board 11, and then the other end of the second line conductor 2b formed on the lower main surface of the circuit board for high frequency transmission. And the second ground conductor 3b are electrically connected to the high-frequency line wiring 12 and the ground wiring 13, respectively, to form a high-frequency circuit board capable of transmitting a high-frequency signal.

  The high-frequency transmission circuit board has a configuration in which a pair of grooves 4 penetrating between the upper and lower main surfaces are formed so as to be in contact with both ends in the width direction of the second line conductor 2b on one side surface of the dielectric substrate 1. Thus, no groove is formed between the second line conductor 22b and the second ground conductor 23b on the lower main surface of the high-frequency transmission circuit board. There is no occurrence of a thinned portion. Further, the dielectrics on both the left and right sides of the second line conductor 2b are completely removed between the upper and lower main surfaces, and the upper surfaces of the high-frequency line wiring 12 and the ground wiring 13 are located on the dielectric substrate from one side to the back of the dielectric substrate 1. The capacitance component generated by being sandwiched by 1 does not change abruptly when the high-frequency line wiring 12 and the ground wiring 13 are arranged with the groove 4 sandwiched therebetween, and the first high-frequency transmission circuit board has the first component. The capacitance component generated between the ground conductor 3a and the high-frequency line wiring 12 of the electric circuit board on which the high-frequency transmission circuit board is mounted can be alleviated, and high-frequency signals can be transmitted satisfactorily. Can be made.

  Further, since the pair of grooves 4 penetrating between the upper and lower main surfaces can be formed by punching between the upper and lower main surfaces of the dielectric substrate 1, processing for providing the grooves 4 even if the dielectric substrate 1 is thinned. Since it is not necessary to make the dielectric substrate 21 partly extremely thin as in the prior art, the dielectric substrate 1 is easy to handle and is suitable for mass production. It can be.

  Also, the pair of grooves 4 are provided on the left and right sides of the second line conductor 2b so as to contact the other end of the second line conductor 2b, and the dielectric is completely removed between the upper and lower main surfaces. Therefore, when the high frequency transmission circuit board is mounted on the electric circuit board 11, the position of the second line conductor 2b and the second line conductor 2b are determined by observing the pair of grooves 4 from the upper main surface side of the high frequency transmission circuit board. The size of the line width is known, and alignment with the high-frequency line wiring 12 can be performed accurately and efficiently. In particular, when the width of the second line conductor 2b of the high frequency transmission circuit board and the high frequency line wiring 12 of the electric circuit board 11 are substantially the same line width, the high frequency line wiring 12 cannot be seen inside the grooves 4 on both sides. By placing the high-frequency transmission circuit board at the position, the high-frequency transmission circuit board and the electric circuit board 11 can be aligned extremely accurately.

  Accordingly, the second line conductor 2b can be accurately aligned and connected to a predetermined position of the high-frequency line wiring 12. Therefore, the impedance value at the connection portion between the second line conductor 2b and the high-frequency line wiring 12 is matched within a predetermined value, and reflection loss and transmission loss generated in the high-frequency signal transmitted through the connection portion can be reduced. The signal transmission efficiency can be improved. In addition, since the alignment operation is easy, a high-frequency circuit board with high productivity can be obtained.

  Further, it is possible to confirm the flow of the conductive adhesive 5 that connects the second line conductor 2b of the high frequency transmission circuit board and the high frequency line wiring 12 of the electric circuit board 11 from the upper side of the high frequency transmission circuit board. it can. And between the 2nd line conductor 2b or the high frequency line wiring 12, and the 2nd ground conductor 3b or the ground wiring 13 while confirming the presence or absence of the adhesion defect of the 2nd line conductor 2b and the high frequency line wiring 12 The presence or absence of an electrical short circuit can also be confirmed. As a result, it is possible to realize a high-frequency circuit board that can reliably transmit a high-frequency signal between the two boards.

As shown in FIGS. 2 and 4 , the high-frequency transmission circuit board has a stepped portion 8 formed by removing the dielectric substrate 1 on the upper main surface side located between the pair of grooves 4. Good. With this configuration, a sudden change in capacitance component between the high-frequency line wiring 12 and the ground wiring 13 on one side of the dielectric substrate 1, the first ground conductor 3a of the high-frequency transmission circuit board, and the high-frequency transmission circuit The rapid change of the capacitance component generated near the connection portion of the electric circuit board 11 on which the board is mounted with the high frequency line wiring 12 can be further mitigated, and the circuit board for high frequency transmission is surface-mounted on the electric circuit board 11 The high-frequency circuit board can moderate the high-frequency impedance mismatch with respect to the high-frequency signal and can transmit the high-frequency signal satisfactorily.

  In addition, the dielectric substrate 1 becomes thin at the portion where the step portion 8 is formed, but the portion which is the step portion 8 is only on the upper main surface side located between the pair of grooves 4, The mechanical strength of the dielectric substrate 1 at the stepped portion 8 is not significantly reduced. As shown in FIGS. 2 and 3, the upper surface and the side surface of the stepped portion 8 may be an inclined surface that can alleviate a rapid change in the capacitance component, or may be mechanical strength.

  In addition, the planar view shape of the groove | channel 4 can be made into various shapes. In addition to the semicircular shape as shown in FIG. 1A, FIG. 1B, FIG. 2, FIG. 3, and FIG. 4, a rectangular shape as shown in FIG. If the semicircular shape as shown in FIG. 1A, FIG. 1B, FIG. 2, FIG. 3 or FIG. 4 is used, the shape of the groove 4 in a plan view is curved. The stress concentration point is eliminated, and cracks and the like are less likely to occur in the dielectric substrate 1 starting from the groove 4, and a sudden change in capacitance component is easily mitigated. 5A makes it easy to align the side surface of the groove 4 and the side surface of the high-frequency line wiring 12, and the circuit board for high-frequency transmission with respect to the electric circuit board 11. It becomes possible to align accurately and efficiently.

The planar view shape of the groove 4 may be an inverted L shape as shown in FIG. 5B or a trapezoidal shape as shown in FIG. In the case of the inverted L shape as shown in FIG. 5B, the width of the dielectric substrate 1 positioned between the pair of grooves 4 is set on the front end side of the second line conductor 2b where the width of the grooves 4 is narrow. The width of the dielectric substrate 1 positioned between the pair of grooves 4 is made narrower than that of the high-frequency line wiring 12 on the bottom side of the groove 4 having the same width as the high-frequency line wiring 12 and the width of the groove 4 being wide. With this configuration, when the high frequency transmission circuit board is mounted on the electric circuit board 11, the tip of the second line conductor 1b having the narrow width of the groove 4 is observed by observing the groove 4 from the upper side of the high frequency transmission circuit board. When the alignment is performed so that the high-frequency line wiring 12 is completely covered by the dielectric substrate 1 positioned between the pair of grooves 4 on the side, the high-frequency line wiring 12 extends from the groove 4 on the wide bottom side of the groove 4. Since the left and right sides are evenly exposed, the flow of the conductive adhesive 5 for connecting the second line conductor 2b of the circuit board for high frequency transmission and the high frequency line wiring 12 of the electric circuit board 11 can be easily confirmed. It is possible to easily confirm that the mechanical connection between the second line conductor 2b of the high frequency transmission circuit board and the high frequency line wiring 12 of the electric circuit board 11 is firmly performed. Therefore, it can be immediately confirmed that the second line conductor 2b and the high-frequency line wiring 12 are normally connected.

  Further, in the case of the trapezoidal groove 4 as shown in FIG. 5C, the dielectric located between the pair of grooves 4 on the distal end side of the second line conductor 2 b of the dielectric substrate 1 of the groove 4. The width of the substrate 1 is the same as that of the high-frequency line wiring 12, and the width of the dielectric substrate 1 positioned between the pair of grooves 4 is wider than that of the high-frequency line wiring 12 on the bottom side of the groove 4 where the width of the groove 4 is wide. Narrow. With this configuration, when the high frequency transmission circuit board is mounted on the electric circuit board 11, the groove 4 is observed from the upper side of the high frequency transmission circuit board, whereby the end of the second line conductor 1b having the narrow width of the groove 4 is observed. In FIG. 2, when the alignment is performed so that the high frequency line wiring 12 is completely covered by the dielectric substrate 1 positioned between the pair of grooves 4, the high frequency line wiring 12 is left and right from the groove 4 on the wide bottom side of the groove 4. Since it will be exposed evenly, the flow of the conductive adhesive 5 for connecting the second line conductor 2b of the circuit board for high frequency transmission and the high frequency line wiring 12 of the electric circuit board 11 is easily confirmed. It is possible to easily confirm that the mechanical connection between the second line conductor 2b of the circuit board for high frequency transmission and the high frequency line wiring 12 of the electric circuit board 11 is firmly performed. Therefore, it can be immediately confirmed that the second line conductor 2b and the high-frequency line wiring 12 are normally connected.

  Other shapes of the groove 4 may be an arc shape larger than a semicircle, a shape in which the hypotenuse of the trapezoidal shape shown in FIG. 5C is an arc shape, or the like, and may be various other shapes. For example, the bottom side width of the pair of grooves 4 is narrow and the groove 4 is in contact with both sides of the second line conductor 2b on the bottom side, and the width of the groove 4 is widened on the tip side of the second line conductor 2b. Alternatively, the width of the dielectric substrate 1 between the grooves 4 may be narrow, and the tip of the second line conductor 2b may be trapezoidal so that the width gradually decreases. Further, if this trapezoidal hypotenuse has a staircase shape and the width of each step is a predetermined size, the number of steps on the left and right sides from the tip of the second line conductor 2b is the high frequency line wiring. By observing whether it overlaps with the 12 edges, it is possible to immediately calculate how much the position is shifted in the left-right direction, and to speed up the alignment work.

  The width of the groove 4 may be narrower than that between the high-frequency line wiring 12 and the ground wiring 13 as shown in FIGS. When emphasizing the transmission characteristics of the high-frequency signal transmitted through the high-frequency line wiring 12, it is preferable that the width of the groove 4 is the same as that between the high-frequency line wiring 12 and the ground wiring 13, and the change in the capacitance component is changed. Can be effectively mitigated. However, since the size of the groove 4 is increased and the dielectric substrate 1 is likely to be damaged such as a crack starting from the groove 4, care must be taken when the dielectric substrate 1 is thin.

  Further, the depth of the groove 4 is preferably a dimension equal to or smaller than the width of the groove 4. Thereby, it is possible to prevent the size of the groove 4 from becoming too large and to prevent the dielectric substrate 1 from being easily damaged such as a crack starting from the groove 4. Further, the depth of the groove 4 may be an integral multiple of 1/4 of the wavelength of the high-frequency signal transmitted to the high-frequency line wiring 12.

  The exposed surfaces of the first line conductor 2a and the second line conductor 2b, the first ground conductor 3a and the second ground conductor 3b and the ground connection conductor 3c, the high-frequency line wiring 12 and the ground wiring 13 are It is preferable to deposit a metal having excellent corrosion resistance such as nickel (Ni) or gold (Au) with a thickness of about 1 to 20 μm, and can effectively prevent oxidative corrosion of the line conductor 2 and the ground conductor 3. The connection between the line conductor 2 and the high-frequency line wiring 12, the connection between the ground conductor 3 and the ground wiring 13, and the electrical connection means 7 such as a bonding wire between the electronic component 6 and the first line conductor 2. The connection can be strengthened. Therefore, for example, a Ni plating layer having a thickness of about 1 to 10 μm and an Au plating layer having a thickness of about 0.1 to 3 μm are sequentially coated on the exposed surface of the first line conductor 2 by an electrolytic plating method or an electroless plating method. More preferably it is worn.

  Then, an electronic component 6 such as a semiconductor element is placed and fixed on the upper surface of the placement portion 1a, and a bonding wire or the like is attached to one end of the first line conductor 2a (end on the placement portion 1a side) and the first ground conductor 3a. The other end of the second line conductor 2b (one side surface of the dielectric substrate 1) is connected via a conductive adhesive 5 such as Ag solder, Au-Sn solder, Ag epoxy, or the like. The second ground conductor 3b is mechanically and electrically connected to the ground wiring 13 via the conductive adhesive 5 such as Ag solder, Au-Sn solder, Ag epoxy or the like. The electronic component 6 is connected to the high-frequency line wiring of the electric circuit board 11, and the line conductor 2 composed of the first line conductor 2a, the second line conductor 2b, and the line connection conductor 2c is High frequency between the electronic component 6 and the electric circuit board 11 It serves as a high frequency transmission line for inputting and outputting signals.

Further, in the embodiment of the high-frequency circuit substrate shown in FIG. 4, the connecting portion between the high-frequency line wiring 12 of the second line conductor 2b, than the line width second line conductor 2b is made with a predetermined characteristic impedance value Is also narrow (not shown) . With this configuration, when the second line conductor 2b is placed on and connected to the high-frequency line wiring 12 having the characteristic impedance value, the impedance value is reduced by the capacitance component added to the high-frequency line wiring 12. Can be minimized. As a result, it is possible to prevent the impedance value at the connection portion between the second line conductor 2b and the high-frequency line wiring 12 from being significantly lowered from the predetermined characteristic impedance value and the high-frequency signal cannot be efficiently transmitted.

  In addition, this invention is not limited to the example of the above embodiment, If it is in the range which does not deviate from the summary of this invention, it will not interfere at all. For example, the dielectric substrate 1 may be used for a substrate disposed in an electronic component storage package.

(A) is a perspective view which shows the reference example of a high frequency circuit board, (b) is a bottom view of the circuit board for high frequency transmission used by (a), (c) is sectional drawing of (a). It is a perspective view which shows embodiment of the high frequency circuit board of this invention. It is a perspective view which shows the reference example of a high frequency circuit board . It is a perspective view which shows the other example of embodiment of the high frequency circuit board of this invention. (A)-(c) shows the other example of embodiment of the circuit board for high frequency transmission, and is the principal part enlarged plan view of a groove periphery. It is a top view which shows the example of the connection structure of the conventional high frequency transmission line.

Explanation of symbols

1: Dielectric substrate 2: Line conductor 2a: First line conductor 2b: Second line conductor 2c: Line connection conductor 3: Ground conductor 3a: First ground conductor 3b: Second ground conductor 3c: Ground connection Conductor 3d: Inner layer ground conductor 4: Groove 6: Electronic component 8: Stepped portion
11: Electric circuit board
12: High frequency line wiring
13: Ground wiring

Claims (3)

A dielectric substrate;
A first line conductor formed on the upper main surface of the dielectric substrate and having one end connected to an electronic component;
A first ground conductor formed at a predetermined interval around the first line conductor;
A second line conductor formed on a lower main surface of the dielectric substrate from a position facing the other end of the first line conductor to an end of the lower main surface;
A second ground conductor formed at a predetermined interval around the second line conductor;
Inside the dielectric substrate, a line connecting conductor formed from the other end of the first line conductor to one end of the second line conductor facing the dielectric substrate,
In a circuit board for high frequency transmission comprising a ground connection conductor formed from the first ground conductor to the second ground conductor adjacent to the line connection conductor,
The lower main surface at a part of the dielectric substrate on the other end side of the second line conductor that is arranged in the vertical direction and whose lower end is adjacent to both sides of the other end of the second line conductor. A pair of grooves reaching the
The circuit board for high frequency transmission , wherein the dielectric substrate has a stepped portion formed by removing an upper main surface side from a portion located between the pair of grooves on the one side surface . A dielectric substrate;
A first line conductor formed on the upper main surface of the dielectric substrate and having one end connected to an electronic component;
A second line conductor formed on a lower main surface of the dielectric substrate from a position facing the other end of the first line conductor to an end of the lower main surface;
A line connection conductor formed from the other end of the first line conductor to the one end of the second line conductor facing the dielectric substrate inside the dielectric substrate;
An inner layer ground conductor layer formed on the inner layer of the dielectric substrate so as to have a predetermined distance from the line connecting conductor and to be parallel to the first line conductor and the second line conductor. In the circuit board,
The lower main surface at a part of the dielectric substrate on the other end side of the second line conductor that is arranged in the vertical direction and whose lower end is adjacent to both sides of the other end of the second line conductor. A pair of grooves reaching the
The circuit board for high frequency transmission , wherein the dielectric substrate has a stepped portion formed by removing an upper main surface side from a portion located between the pair of grooves on the one side surface . The lower main surface of the circuit board for high-frequency transmission according to claim 1 or 2 is placed on the upper surface of the electric circuit board on which the high-frequency line wiring is formed. A high-frequency circuit board, wherein the other end is electrically connected to the high-frequency line wiring.

Images