JP4448461B2 - Manufacturing method of semiconductor package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling structure, using a simple constitution optimum for a three-dimensional high density mounting structure. <P>SOLUTION: In the semiconductor package mounting high-frequency semiconductor elements (15) on both surfaces of a circuit substrate (11), the circuit substrate is provided with a coaxial wiring (12), penetrating the circuit substrate in the thickness direction thereof. The connecting unit (19) of the first semiconductor element (15a), positioned on one side of the circuit substrate and the connecting unit (19) of the second semiconductor element (15b), is connected to the central conductors (31) of the coaxial wiring, which are exposed on both surfaces of the circuit substrate. According to this method, a plurality of semiconductor elements are connected mutually by the shortest passages. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to a semiconductor package on which a high-frequency semiconductor element is mounted, and more particularly to a high-frequency semiconductor package that enables transmission of a low-loss high-frequency signal and a manufacturing method thereof.

  In the information communication field in recent years, high speed and large capacity are important issues, and a microwave band having a relatively large amount of information transmission and a millimeter wave band of 30 GHz or more have been actively used. A microwave package or a millimeter wave package in which a high frequency IC is mounted is used in a radio base station or a radio terminal that performs communication at such a high frequency.

  In fields other than information communication, the millimeter wave band is used for in-vehicle radar (millimeter wave radar), measurement, sensors, and the like for the purpose of collision prevention.

  Under such circumstances, there is a demand for an IC package having high mass productivity and low cost in addition to maintaining electrical characteristics at high frequencies.

  A millimeter-wave package on which a semiconductor element (IC chip) in the millimeter-wave band is mounted requires a low-loss transmission line for connecting the semiconductor elements or connecting the semiconductor package and the antenna.

  Conventionally, the connection of a microstrip line and a waveguide is mainly used for the signal line of a high-frequency signal, and a semiconductor element is mounted on one end of the microstrip line on the same plane of the circuit board, and the other end is connected to the microstrip line. Stripline and waveguide conversion were performed. The signal propagates through the waveguide and is radiated from an antenna connected to the waveguide.

  FIG. 1 is a diagram showing an example of a high-frequency semiconductor package 100 according to the prior art. An oscillation circuit (VCO) 102 is mounted on one surface side of the circuit board 101 and is electrically connected by an Au wire 105. Further, a microwave integrated circuit (MMIC) 103 is mounted on the same plane via Au bumps 106. Further, a waveguide 109 provided on the same plane is connected to the antenna 104, and the whole is sealed with a CAN seal 110 by a hermetic seal or the like.

  In this example, the signal is transmitted from the VCO 102 → Au wire 105 → transmission line 108 → Au bump 106 → MMIC 103 → Au bump 106 → transmission line 108 → via 107 → transmission line 108 → waveguide conversion (via) 110 → antenna. The order is 104.

  In the microwave band and the millimeter wave band, it is desirable to shorten the transmission line length as much as possible in order to reduce transmission loss. However, in the high-frequency semiconductor package in which the circuit element is mounted on the microstrip line as shown in FIG. 1, the characteristics are shown in the portion where the cross-sectional shape of the transmission line conductor is discontinuous, that is, the arrow (→) in the transmission order. Impedance shifts and causes transmission loss. The deviation of the characteristic impedance is caused by, for example, signal reflection at a discontinuous portion and an increase in inductance component at the Au wire 105 or via 107.

  In addition, it is easily affected by electromagnetic interference such as electromagnetic interference and electromagnetic susceptibility due to the structure of planar mounting using a microstrip line. Furthermore, there is a limit to downsizing of the package in order to ensure isolation between semiconductor elements.

  By the way, the structure which shortens wiring length by the through-hole connection of a coaxial structure is known in a multilayer wiring board (for example, refer patent document 1). A double-cylindrical coaxial through-hole composed of an outer layer through-hole and an inner layer through-hole filled with metal is formed on the multilayer wiring board, and a filled via is disposed immediately above the inner layer through-hole to shorten the wiring length.

  In this configuration, a semiconductor element (IC chip) mounted on one side of a multilayer wiring board and a daughter board connected to the other side of the multilayer wiring board are electrically connected via a coaxial through hole. The purpose is not related to the double-sided mounting semiconductor package. Further, no consideration is given to transmission loss in high-frequency transmission.

  On the other hand, in a high-frequency circuit module in which RF circuit components are mounted on both surfaces of a multilayer dielectric substrate, loss in the millimeter-wave transmission line can be reduced by using a coaxial via hole extending in the vertical direction of the substrate as a part of the transmission line. The structure which reduces is proposed (for example, refer patent document 2).

This configuration uses a vertical coaxial via that penetrates the substrate as part of the transmission path, but uses a microstrip for transmission from the coaxial via to another RF circuit element located on the opposite side of the substrate. Yes. Therefore, as in the prior art of FIG. 1, eventually, the cross-sectional shape of the conductor becomes discontinuous between the via and the microstrip, resulting in a deviation in characteristic impedance.
JP 2002-305377 A JP 2003-133801 A

  In order to solve the above-described problems in the prior art, the present invention has a low transmission loss and is compatible with the electromagnetic environment without using a configuration of microstrip line or microstrip line-waveguide conversion ( It is an object to provide a small high-frequency semiconductor package having EMC (Electoro-Magnetic Compatibiity).

  In order to solve the above-described problems, in the present invention, high-frequency semiconductor elements are mounted on both sides of a circuit board so as to face each other with the circuit board interposed therebetween, and bonding portions (bumps) of the respective high-frequency semiconductor elements are attached to the substrate. Connect by vertical coaxial wiring.

As a technique related to the present invention , a semiconductor package in which high-frequency semiconductor elements are mounted on both sides of a circuit board is provided. In this semiconductor package,
(A) The circuit board has coaxial wiring penetrating in the thickness direction of the circuit board,
(B) A joint portion of the first semiconductor element located on one surface of the circuit board and a joint portion of the second semiconductor element located on the other surface of the circuit board are formed on both surfaces of the circuit board. It is characterized by being joined to the exposed central conductor of the coaxial wiring.

  With this configuration, the high-frequency semiconductor elements can be connected in the shortest distance by the coaxial wiring that penetrates the circuit board, the transmission loss can be reduced, and the electromagnetic environment compatibility (EMC) can be maintained well.

In an example of a preferred implementation, the circuit board further comprises a waveguide that penetrates the branch board,
The first semiconductor element is, for example, a monolithic microwave integrated circuit, and the second semiconductor element is, for example, an oscillation circuit.

  Thereby, a semiconductor package for communication excellent in high frequency characteristics is realized.

In one aspect of the present invention, a method for manufacturing a high-frequency compatible semiconductor package is provided. The manufacturing method of the semiconductor package is as follows:
(A) forming a first laminated portion having a sidewall conductor, a bottom conductor, and a center conductor at a predetermined position of the insulating layer;
(B) forming a second laminated portion having a sidewall conductor and an upper conductor at a predetermined position of the insulating layer;
(C) producing a laminated substrate by superimposing the first laminated portion and the second laminated portion so that the respective side wall conductors are connected;
(D) cutting the circuit board of the semiconductor package by cutting the stacked board in a stacking direction with a predetermined thickness.

  By this method, circuit boards having coaxial wiring penetrating the board can be mass-produced easily and inexpensively.

In an example of a good implementation, the cutout circuit board has the center conductor exposed on both sides,
Mounting the first semiconductor element on one surface of the circuit board so that the junction of the first semiconductor element is bonded to the exposed central conductor;
Mounting the second semiconductor element on the other surface of the circuit board so that the joint portion of the second semiconductor element is bonded to the exposed central conductor.

  As a result, a plurality of semiconductor elements are connected in the shortest distance through the coaxial wiring, so that transmission loss can be prevented in high frequency transmission and EMC performance can be maintained.

  High-frequency semiconductor elements bonded on both sides of the circuit board can be shield-connected on the same axis at the shortest distance, resulting in a small high-frequency semiconductor package with low transmission loss and electromagnetic compatibility (EMC) Is done.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings.

  2A is a schematic cross-sectional view of a multi-chip mounted high-frequency semiconductor package 10A according to an embodiment of the present invention, and FIG. 2B is a schematic cross-sectional view of a CAN-sealed multi-chip mounted high-frequency semiconductor package 10B. FIG.

  In FIG. 2A and FIG. 2B, the circuit board 11 has a coaxial wiring 12 extending perpendicularly to the substrate surface. The coaxial wiring 12 extends perpendicularly to the substrate surface over the entire thickness of the circuit board 11, and the center conductor 31 appears on the front surface and the back surface of the substrate 11. And the electrode pad 17 formed, for example by the plating method is arrange | positioned on the center conductor 31 exposed to the surface of the board | substrate 11, and a back surface.

  A plurality of semiconductor elements 15 a, 15 b, 15 c are arranged opposite to each other on both surfaces of the circuit board 11, and bumps (joined portions) 19 of these semiconductor elements 15 a, 15 b, 15 c are connected to the central conductor 31 of the coaxial wiring 12. Connect directly. The semiconductor element 15 c faces the coaxial connector 13 as a circuit component formed on the opposite surface of the circuit board 11, and is electrically connected by joining the bumps 19 and the coaxial wiring 12. The bumps 19 are columnar bumps having a height of about 20 μm, for example.

  In the configuration of FIG. 2B, the entire high-frequency semiconductor package 10 is CAN-sealed 16 in addition to the configuration of FIG.

  2A and 2B, each semiconductor element and circuit component are electrically connected in the shortest way by the coaxial wiring 12 that penetrates the circuit board 11 without using a microstrip. The Thereby, it is possible to prevent the deviation of the characteristic impedance caused by the discontinuity of the cross-sectional shape of the conductor.

  The arrangement configuration of the coaxial wiring and the semiconductor element is not limited to the example in FIG. 2 and is appropriately changed depending on the number of semiconductor elements (or electronic devices). Also in this case, the elements (devices) located at positions facing each other across the circuit board 11 are directly bump-connected to the central conductor 31 of the coaxial wiring 12 penetrating the circuit board 11.

  The high-frequency semiconductor packages 10A and 10B in FIG. 2 are suitably used for signal transmission of microwaves of 1 GHz or higher, particularly millimeter waves of 30 GHz or higher.

  Next, another configuration example of the high-frequency semiconductor package is shown.

  FIG. 3A is a schematic cross-sectional view of a high-frequency semiconductor package 20A mounted with a multichip waveguide antenna according to an embodiment of the present invention, and FIG. It is a schematic sectional drawing of the high frequency semiconductor package 20B mounted with a waveguide antenna.

  In FIG. 3A and FIG. 3B, the circuit board 21 includes a coaxial wiring 21 that penetrates the board 21 and a waveguide 24. An oscillation circuit (VCO) 26 and an antenna substrate 23 are arranged on one side of the circuit board 21. The oscillation circuit (VCO) 26 is joined to the central conductor 41 of the coaxial wiring 22 by the bump 29 and the electrode pad 17, and the antenna substrate 23 is coaxially aligned with the waveguide 24.

  A monolithic microwave integrated circuit (MMIC) 27 is bonded to the other surface of the circuit board so as to face the oscillation circuit (VCO) 26 and the antenna board 23. The MMIC 27 is joined to the central conductor 41 of the coaxial wiring 22 by the bump 29 and the electrode pad 17. As a result, the VCO 26 and the MMIC 27 as high-frequency semiconductor elements are connected to each other through the coaxial wiring 22 penetrating the circuit board 21 without using a microstrip. The MMIC 27 is connected to the waveguide 24 by the waveguide conversion unit 25.

  In the example of FIG. 3B, in addition to the configuration of FIG. In any configuration, the discontinuous portion of the cross-sectional shape of the conductor is reduced as much as possible, and the shortest high-frequency transmission path is formed from the VCO 26 to the coaxial wiring 22, the MMIC 27, the waveguide conversion 25, the waveguide 24, and the antenna substrate 23. Is done.

  The arrangement configuration of the coaxial wiring, the waveguide, and the semiconductor element is not limited to the example of FIG. 3 and can be changed as appropriate depending on the number of semiconductor elements (or electronic devices) and antennas. The high-frequency semiconductor packages 20A and 20B of FIG. 3 are also preferably used for signal transmission of microwaves of 1 GHz or higher, particularly millimeter waves of 30 GHz or higher.

  FIG. 4 is a diagram showing a method for producing the circuit board 11 used in the multi-chip high-frequency semiconductor package 10 shown in FIG. In the example of FIG. 4, the coaxial wiring laminated substrate 30 that constitutes the coaxial wiring 12 is sliced in the direction perpendicular to the lamination, and a large number of circuit boards 11 of FIG. 2 are cut out. 4A is a cross-sectional view along the longitudinal direction (lateral direction) of the coaxial wiring multilayer substrate 30, and FIG. 4B is a cross-sectional view along the width direction (vertical direction) of the coaxial wiring multilayer substrate 30. .

  Assuming that the width direction of the coaxial wiring laminated substrate 30 is the X direction, the longitudinal direction is the Y direction, and the lamination direction is the Z direction, FIG. 4A is a YZ sectional view and FIG. 4B is an XZ sectional view. The coaxial wiring multilayer substrate 30 is obtained by laminating the insulating layer 51 in which the predetermined conductor patterns 31 and 32 are formed in the Z direction. In FIG. 4A, the conductor pattern 31 becomes the center conductor 31 of the coaxial wiring 12, and the conductor patterns 32 positioned above and below the central conductor 31 become the outer conductor 32 of the coaxial wiring 12.

  The circuit board 11 of FIG. 2 is obtained by slicing the coaxial wiring laminated board 30 to a thickness t. The cut-out thickness t is the thickness of the circuit board 11 of the high-frequency semiconductor package 10 as it is, and is several mm, for example. The cross-sectional view of FIG. 4B corresponds to the state where the circuit board 11 shown in FIG. 2 is viewed from directly above or directly below. The semiconductor element 15 is mounted by bonding the bump 19 (see FIG. 2) to the central conductor 31 exposed at the cut end.

  FIG. 5 is a diagram showing a method of creating the circuit board 21 used in the multi-chip / waveguide-mounted high-frequency semiconductor package 20 of FIG. In the example of FIG. 5, the coaxial wiring / waveguide laminated substrate 40 that forms the coaxial wiring 22 and the waveguide section 24 inside is sliced in the direction perpendicular to the lamination, and a large number of circuit boards 21 of FIG. 3 are cut out. The slice thickness t is the same as the thickness of the circuit board 21 in FIG. In the example of FIG. 5A, the conductor pattern 41 becomes the center conductor 41 of the coaxial wiring 22, and the conductor pattern 42 positioned above and below becomes the outer conductor 42.

  The cross-sectional view of FIG. 5B corresponds to the state where the circuit board 21 shown in FIG. 3 is viewed from directly above or directly below. A bump 29 is joined to the central conductor 41 exposed at the cut end, and for example, an oscillation circuit (VCO) 26 is mounted, and the antenna substrate 23 is disposed on the waveguide 24. The MMIC 27 is mounted on the central conductor 41 and the waveguide 24 that are also exposed on the back surface of the circuit board 21 by bonding the bumps 29 and the waveguide converter 25.

  FIG. 6 is a view showing a manufacturing process of the high-frequency semiconductor package 10 of FIG. A lower half part A and an upper half part B are separately formed with the lower half portion of the outer conductor 32 surrounding the central conductor 31 of the coaxial wiring 12 as A and the upper half portion as B.

  First, as shown in FIG. 6A, an insulating layer 51 constituting the coaxial wiring laminated substrate 30 is prepared. The insulating layer 51 may be a single layer or a laminate of a plurality of layers, and has a thickness of about 1 mm, for example. As a material of the insulating layer 51, a thermoplastic resin material such as an epoxy resin or a PEEK (polyether ether ketone) resin, or a ceramic material such as glass ceramics, alumina, or aluminum nitride can be used.

  Next, as shown in FIG. 6B, a groove (or long hole) 52 is formed in the insulating layer 51 by a laser drill or the like, and a conductor layer 53 is formed on the side wall of the groove 52 in FIG. . This conductor layer becomes a side wall conductor 53 surrounding the central wiring 31 of the coaxial wiring. The conductor layer 53 can be formed by a printing method in which, for example, a conductive paste is filled and sucked.

  Next, as shown in FIG. 6D, a conductor 54 is formed at a predetermined position on another insulating layer 51, that is, at a position corresponding to the side wall conductor 53 and the groove (long hole) 52. The conductor 54 formed in the lower laminate A serves as the bottom conductor 54 a of the outer conductor 32 of the coaxial wiring 12, and the conductor 54 formed in the upper laminate B serves as the upper conductor 54 b of the outer conductor 32 of the coaxial wiring 12. It becomes. The bottom conductor 54a and the top conductor 54b can also be formed by a printing method using a conductive paste, for example.

  The other insulating layer 51 and the insulating layer 51 on which the side wall conductor 53 has been formed are aligned, and the bottom (or upper) conductor 54 is laminated so that the side wall conductor 53 and the groove 52 are closed. As a result, a U-shaped shield wall is formed. The steps so far are the same for the lower laminate A and the upper laminate B of the coaxial wiring 12.

  Next, as shown in FIG. 6E, the central conductor 31 is formed on the laminated insulating layer 51 so as to be positioned at the center of the sidewall conductor 53. The center conductor 31 is formed by printing directly on the upper surface of the insulating layer 51.

  Next, as shown in FIG. 6 (f), the separately prepared upper laminate B is rotated 180 ° and turned upside down so that the side wall conductors 53 are connected to each other. Laminate. Thereby, the laminated part which has the coaxial wiring 12 is completed. By further stacking another laminated portion formed of the lower laminate A and the upper laminate B formed in the same manner, the coaxial wiring laminate substrate 30 having the cross-sectional shape of FIG. 6F is completed. The circuit board 11 shown in FIG. 2 is manufactured by slicing this in a direction perpendicular to the stack with a predetermined thickness t.

  Although not shown, in order to form the electrode pad 17 (see FIGS. 2 and 3) on the central conductor 31 exposed on the front and back surfaces of the circuit board 11, for example, electroless plating is directly deposited on the substrate. It can be formed by an additive method. Specifically, the surface of the circuit board 11 is subjected to a roughening process for improving the adhesion of plating. Next, after patterning with a plating resist on the substrate, a method of forming a conductor pattern by electroless copper plating (full additive method), or by depositing electroless plating on the entire surface of the substrate, The electrode pad 17 is formed by applying a method (semi-additive method) using resist peeling and etching after electrolytic copper plating only on the pattern portion.

  For example, the bump 19 of the semiconductor element 15a is bonded to the electrode pad 17 on the central conductor 31 exposed on one surface of the circuit board 11, and the electrode pad 17 on the central conductor 31 exposed on the other surface is bonded. The bumps of the semiconductor element 15b are bonded. Thus, the plurality of semiconductor elements are connected in the shortest distance by the coaxial wiring 12.

  By adopting the production method shown in FIG. 6, circuit boards having coaxial wiring penetrating the board can be mass-produced easily and inexpensively.

  FIG. 7 is a first modification of the manufacturing process of the circuit board shown in FIG. Only the step (e) of FIG. 7 is different from the step of FIG. 6 (e), and the subsequent steps are the same as those of FIGS. 6 (a) to 6 (d) and FIG. 6 (f).

  In FIG. 7E, an insulating layer 51a is separately prepared instead of directly printing paste on the upper surface of the insulating layer 51 on which the sidewall conductor 53 is formed. 7A to 7C, a groove is formed in a predetermined portion of the insulating layer 51a, and the groove is filled with a conductive paste, so that the side wall conductor 53a and the central conductor 31 are connected at a time. Form. The lower layer A is completed by pasting the insulating layer 51a on the layered portion having the U-shaped shield previously stacked. The upper laminated layer B produced in the steps of FIGS. 7A to 7D is overlapped in the opposite direction to complete the laminated portion having the coaxial wiring 12.

  6 and 7, when a ceramic material is used as the material of the insulating layer 51, a conductor portion is formed on the green sheet before firing, laminated in the above procedure, and then fired simultaneously. For example, when alumina or aluminum nitride is used, tungsten (W) or molybdenum (Mo) is used, and when glass ceramics is used, a conductor material capable of simultaneous firing such as copper or gold is used.

  In the case where a resin material is used for the insulating layer 51, the insulating layer 51 is laminated by the above procedure, and then heat treated and cured at once. The conductor layers 53 and 54 are formed not only by a printing method using a conductive paste but also by a plating method.

  FIG. 8 is a diagram illustrating a manufacturing process of the modified example 2 of the coaxial wiring laminated substrate 30. In Modification 2, instead of embedding the periphery of the center conductor 31 with the insulating layer 51, the hollow coaxial wiring 12 is formed.

  First, as shown in FIG. 8A, an insulating layer 51 constituting the coaxial wiring laminated substrate 30 is prepared. The insulating layer 51 may be a single layer or a laminate of a plurality of layers, and a thermoplastic resin, a ceramic material, or the like is used as a material.

  Next, as shown in FIG. 8B, a groove (or long hole) 62 having a size corresponding to the width of the coaxial wiring 12 is formed, and a conductor layer 53 is formed on the side wall of the groove 62 in FIG. To do. The conductor layer 53 becomes a side wall conductor 53 surrounding the central wiring 31 of the coaxial wiring, and the inside of the groove surrounded by the conductor 53 becomes a hollow portion 63.

  Next, as shown in FIG. 8D, a conductor 54 is formed at a predetermined position on another insulating layer 51, that is, at a position corresponding to the side wall conductor 53 and the groove (long hole) 52. The conductor 54 formed in the lower laminate A serves as the bottom conductor 54 a of the outer conductor 32 of the coaxial wiring 12, and the conductor 54 formed in the upper laminate B serves as the upper conductor 54 b of the outer conductor 32 of the coaxial wiring 12. It becomes.

  Next, as shown in FIG. 8E, another insulating layer 61 is prepared, and a groove formed at a predetermined location is filled with a conductive material to form the center conductor 31 and the sidewall conductor 53a. Then, as shown in FIG. 8 (f), the insulating layer 61 is aligned so that the side wall conductor 53a of the insulating layer 61 coincides with the side wall conductor 53 of the insulating layer 51 previously formed, and the insulating layer 61 is formed in a U-shape. Overlay the laminated part with the shield. As a result, the lower laminate A having the cavity 63 between the bottom conductor 54a and the center conductor 31 is completed.

  Next, as shown in FIG. 8 (g), the upper laminate B separately formed in the procedure of FIGS. 8 (a) to 8 (d) is rotated 180 ° and turned upside down to be superimposed on the lower laminate A. Thus, the laminated substrate 30 having the coaxial wiring 12 of the cavity 63 is completed.

  Although not shown, the periphery of the central conductor 31 may be embedded with another dielectric material having a different dielectric constant instead of the insulating layer 51 and the cavity 63. In this case, the cavity 63 formed in FIG. 8D is filled with a dielectric material, and the central conductor 31 is formed directly on the upper surface of the dielectric material layer.

  By setting the dielectric constant of the dielectric material filling the cavity 63 to be lower than the dielectric constant of the insulating layer 51 constituting the wiring board, dielectric loss can be reduced and the coaxial size can be reduced. .

  FIG. 9 is a manufacturing process diagram of the circuit board 21 used in the multi-chip / waveguide-mounted high-frequency semiconductor package 20 shown in FIG.

  First, as shown in FIG. 9A, an insulating layer 51 constituting the coaxial wiring / waveguide laminated substrate 40 is prepared. The insulating layer 51 may be a single layer or a laminate of a plurality of layers, and a thermoplastic resin, a ceramic material, or the like is used as a material.

  Next, as shown in FIG. 9B, grooves (or long holes) 52 and grooves (or long holes) 62 having a size corresponding to the width of the waveguide 24 are formed in the insulating layer 51. In FIG. 9C, the conductor layer 73 is formed on the side walls of the grooves 52 and 62. The conductor layer 73 formed inside the groove 52 becomes the side wall conductor 73 of the coaxial wiring 22. On the other hand, the inside of the groove 62 serves as a cavity 63 constituting a part of the waveguide 24.

  Next, as shown in FIG. 9D, a conductor 74 is formed at a predetermined position on another insulating layer 51, that is, a position corresponding to the side wall conductor 73 and the grooves (long holes) 52 and 62. The conductor 74 formed in the lower laminate A becomes the bottom conductor 74 a of the outer conductor 42 of the coaxial wiring 22 and the bottom conductor 74 a constituting the waveguide 24. The conductor 74 formed in the upper laminate B becomes the upper conductor 74 b of the outer conductor 42 of the coaxial wiring 22 and the upper conductor 74 b constituting the waveguide 24. The steps so far are the same for the lower laminate A and the upper laminate B.

  Next, as shown in FIG. 9E, the central conductor 41 is formed at a predetermined position on the insulating layer 51 of the lower laminate A. Further, as shown in FIG. 9 (f), the upper laminate B is overlapped on the lower laminate A on which the central conductor 41 is formed so that the respective side wall conductors 73 coincide with each other. By further overlapping another laminated portion produced in the same procedure, the laminated substrate 40 having the coaxial wiring 22 and the waveguide 24 is completed. By slicing the coaxial wiring / waveguide laminated substrate 40 with a predetermined thickness t perpendicular to the lamination direction, the circuit substrate 21 used in the high-frequency semiconductor package 20 of FIG. 3 is formed.

  The electrode pads 17 are formed by the above-described method on the central conductor exposed on both surfaces of the circuit board 21 thus manufactured. The bumps 29 of the VCO 21 are joined to the central conductor 41 exposed on one surface of the substrate 21 via the electrode pad 17, and the central conductor 41 exposed on the other surface is interposed via the electrode pad 17. By joining the bumps 27 of the MMIC 27, the high-frequency semiconductor elements are shortest connected by coaxial wiring.

  FIG. 10 is a manufacturing process diagram of Modification 1 of the coaxial wiring / waveguide laminated substrate 40 of FIG. In FIG. 10, instead of the hollow waveguide 24, the inside of the waveguide 24 is filled with a dielectric material having a dielectric constant larger than that of the insulating material 51 of the wiring board 40, so that the dielectric waveguide 84. With this configuration, the size of the waveguide 84 can be reduced.

  In FIG. 10, the steps of FIGS. 10A to 10D are the same as those of FIGS. 9A to 9D, and the description thereof is omitted. In FIG. 10 (e), the cavity 63 is filled with a dielectric material 75. In FIG. 10F, the central conductor 41 is formed at a predetermined position on the insulating layer 51 where the side wall body 73 is formed. On the lower stack A thus formed, a separately prepared upper stack B is inverted and overlapped. Further, the coaxial wiring / waveguide laminated substrate 40 having the coaxial wiring 22 and the dielectric waveguide 84 is completed by stacking the laminated portions composed of the lower lamination A and the upper lamination B formed in the same procedure. To do.

  The filling of the cavity 63 in FIG. 10 (e) can employ any method such as a method of pouring a liquid material or a method of fitting a solid dielectric having a matching shape of the groove 62. As the dielectric material, the dielectric waveguide 84 is formed by firing or curing using a known compound such as barium titanate or magnesium titanate or a composite material of these compounds and a resin material.

  As described above, joints (bumps) are shield-connected at the shortest distance on the same axis using coaxial wiring that penetrates the circuit board without using a microstrip in the transmission path connecting the high-frequency semiconductor elements. can do. Therefore, a miniaturized high-frequency semiconductor package with low transmission loss, electromagnetic compatibility (EMC), and a small size is realized.

  The above-described high-frequency semiconductor package can be applied to mobile communication, satellite communication, in-vehicle radar of 30 GHz or more using a frequency band of 1 GHz or more.

Finally, the following notes are disclosed regarding the above description.
(Additional remark 1) In the semiconductor package which mounts a high frequency semiconductor element on both surfaces of a circuit board,
The circuit board has coaxial wiring penetrating in the thickness direction of the circuit board,
The junction of the first semiconductor element located on one side of the circuit board and the junction of the second semiconductor element located on the other side of the circuit board are exposed on both sides of the circuit board. A semiconductor package characterized by being joined to a central conductor of coaxial wiring.
(Additional remark 2) The said circuit board further has a waveguide which penetrates the said circuit board,
The first semiconductor element is a monolithic microwave integrated circuit;
The semiconductor package according to appendix 1, wherein the second semiconductor element is an oscillation circuit.
(Additional remark 3) The said waveguide is located directly under the junction part of the said monolithic microwave integrated circuit, and an antenna is connected to the said waveguide, The semiconductor package of Additional remark 2 characterized by the above-mentioned.
(Supplementary note 4) The semiconductor package according to supplementary note 3, wherein the monolithic microwave integrated circuit, the waveguide, and the antenna are connected coaxially.
(Supplementary note 5) The semiconductor package according to supplementary note 1, wherein the coaxial wiring penetrating the circuit board in the thickness direction includes an outer conductor having a rectangular cross section surrounding the central conductor.
(Additional remark 6) The step which forms the 1st lamination | stacking part which has a side wall conductor, a bottom part conductor, and a center conductor in the predetermined position of an insulating layer;
Forming a second laminated portion having a sidewall conductor and an upper conductor at a predetermined position of the insulating layer;
Stacking the first laminated portion and the second laminated portion so that the respective side wall conductors are connected to produce a laminated substrate;
Cutting the circuit board of the semiconductor package by cutting the stacked board in a stacking direction with a predetermined thickness.
(Supplementary Note 7) The cutout circuit board has the central conductor exposed on both sides,
Mounting the first semiconductor element on one surface of the circuit board so that the junction of the first semiconductor element is bonded to the exposed central conductor;
And an additional step of mounting the second semiconductor element on the other surface of the circuit board so that the junction of the second semiconductor element is bonded to the exposed central conductor. A manufacturing method of the semiconductor package described in 1.
(Appendix 8) Forming a first cavity in the first stacked portion;
Forming a second cavity in the second laminated portion, and superimposing the first laminated portion and the second laminated portion to produce a laminated substrate including a waveguide inside. The manufacturing method of the semiconductor package according to appendix 6, further comprising:

It is a schematic sectional drawing of the high frequency semiconductor package by a prior art. 1 is a schematic configuration diagram of a multichip mounting type high-frequency semiconductor package according to an embodiment of the present invention. It is a schematic block diagram of the high frequency semiconductor package which mounted the multichip and waveguide antenna concerning one Embodiment of this invention. It is a figure for demonstrating the formation method of the circuit board used with the high frequency semiconductor package of FIG. It is a figure for demonstrating the formation method of the circuit board used with the high frequency semiconductor package of FIG. FIG. 3 is a production process diagram of a coaxial wiring laminated substrate for a circuit board used in the high-frequency semiconductor package of FIG. 2. It is the modification 1 of the manufacturing process of the coaxial wiring laminated substrate of FIG. It is the modification 2 of the manufacturing process of the coaxial wiring laminated substrate of FIG. FIG. 4 is a manufacturing process diagram of a coaxial wiring / waveguide laminated substrate for a circuit board used in the high-frequency semiconductor package of FIG. 3. 10 is a first modification of the manufacturing process of the coaxial wiring / waveguide laminated substrate of FIG. 9.

Explanation of symbols

10A, 10B, 20A, 20B High frequency semiconductor package 11, 21 Circuit board 12, 22 Coaxial wiring 15a, 15b, 15c Semiconductor element (high frequency semiconductor element)
19, 29 Bump (joint)
23 Antenna substrate 24 Waveguide 25 Waveguide converter 26 VCO (Oscillation circuit or high-frequency semiconductor element)
27 MMIC (monolithic microwave integrated circuit or high frequency semiconductor device)
30 Coaxial wiring laminated substrate 40 Coaxial wiring / waveguide laminated substrate 31, 41 Center conductor 32, 42 External conductor

Claims (3)

Forming a first laminated portion having a sidewall conductor, a bottom conductor, and a center conductor at a predetermined position of the insulating layer;
Forming a second laminated portion having a sidewall conductor and an upper conductor at a predetermined position of the insulating layer;
Stacking the first laminated portion and the second laminated portion so that the respective side wall conductors are connected to produce a laminated substrate;
Cutting the circuit board of the semiconductor package by cutting the stacked substrate in a stacking direction with a predetermined thickness. The cut out circuit board has the center conductor exposed on both sides,
Mounting the first semiconductor element on one surface of the circuit board so that the junction of the first semiconductor element is bonded to the exposed central conductor;
And mounting the second semiconductor element so that a joint portion of the second semiconductor element is bonded to the exposed central conductor on the other surface of the circuit board. A method for manufacturing a semiconductor package according to 1 . Forming a first cavity in the first laminated portion;
Forming a second cavity in the second laminated portion, and stacking the first laminated portion and the second laminated portion to produce a laminated substrate including a waveguide inside The method for manufacturing a semiconductor package according to claim 1 , further comprising the step of:

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