JP2004172247A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable semiconductor device having an electromagnetic shielding performance and an excellent airtightness. <P>SOLUTION: On a surface (a first main surface) of a multilayer substrate 1 laminated by insulation substrates comprising alumina which includes ferrite, a plurality of passive element comprising a semiconductor element 21, a chip resistor 22, a chip capacitor 23, an inductor 24, or the like are electrically and mechanically fixed by alloy material 25. Both the ends of the surface (the first main surface) of the multilayer substrate 1 and an insulation cap 32 comprising alumina which includes ferrite are firmly fixed by an adhesive agent 31, and these mounted components 21, 22, 23, 24, the alloy material 5, and a bonding wire 27 are hermetically sealed by the multilayer substrate 1 and the insulation cap 32. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a semiconductor device typified by a high-frequency module used for an electronic device such as a portable radio telephone or a car telephone, and more particularly to a semiconductor device which suppresses electromagnetic wave disturbance in a high-frequency region and has excellent reliability.
[0002]
[Prior art]
In recent years, high-frequency modules have become smaller, thinner, and more sophisticated, while preventing electromagnetic waves generated in the high-frequency module from being emitted to the outside of the module and preventing electromagnetic wave disturbances such as preventing electromagnetic waves from entering from outside. Is required to do so. As this type of high-frequency module, the one shown in FIG. 3 is known (for example, see Patent Document 1). FIG. 3 is a sectional view showing the high-frequency module.
[0003]
In the high-frequency module 140 disclosed in this patent document, as shown in FIG. 3, a wiring layer 105 is selectively formed on a surface of a metal substrate 101 with an insulating layer 102 interposed therebetween. In addition, a semiconductor element 121, a plurality of passive elements including a chip resistor 122 and a chip capacitor 123, and an external terminal 128 are electrically and mechanically fixed by an alloy material 125.
[0004]
The electrode 126 of the semiconductor element 121 and the wiring layer 105 are electrically connected by a bonding wire 127. These mounted components 121, 122, 123, external terminals 128, alloy material 125, bonding wires 127, and metal substrate 101 are hermetically sealed with mold resin 130 containing ferrite.
[0005]
[Patent Document 1]
JP-A-11-40708 (page 11, FIG. 1)
[0006]
[Problems to be solved by the invention]
In the above-described conventional high-frequency module, the mounted components and the like are covered with the mold resin 130 containing ferrite in order to prevent interference of electromagnetic waves, so that electromagnetic waves generated inside the high-frequency module are emitted to the outside and electromagnetic waves from outside the high-frequency module are And the thermal expansion coefficient of the mold resin 130 is made closer to the thermal expansion coefficient of the metal substrate 101, thereby preventing separation of the bonding interface between the metal substrate 101 and the mold resin 130.
[0007]
However, high-frequency modules used in recent mobile radiotelephones and automobile telephones are required to have even higher functions and more functions. For this reason, substrates used in high-frequency modules are ceramic substrates having a wiring layer on the surface. Have been adopted.
[0008]
However, the coefficient of thermal expansion of such a multilayer ceramic substrate is smaller than the coefficient of thermal expansion of the mold resin by half to one-sixth. The module has a problem that the bonding interface between the multilayer ceramic substrate and the mold resin is peeled off, and the reliability is reduced due to the entry of moisture and the like.
[0009]
The present invention has been made to solve the above problems, and an object of the present invention is to provide a highly reliable semiconductor device having an electromagnetic shielding function and excellent in confidentiality.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a semiconductor device according to the present invention includes an insulating substrate having a wiring layer on a main surface thereof laminated, and a first wiring layer on a first main surface of the insulating substrate having the laminated structure. Is provided, a second wiring layer is provided between the insulating substrates of the laminated structure, and a third wiring layer is provided on a second main surface opposite to the first main surface, and 3 is electrically connected through vias, and the insulating substrate contains ferrite, and the first wiring layer is provided on a first main surface of the multilayer substrate. A semiconductor element and a passive element that are electrically connected to the semiconductor element and a passive element, and an insulating cap that covers the semiconductor element and the passive element, is sealed on the first main surface of the multilayer substrate, and includes ferrite. Features.
[0011]
According to the present invention, since the ferrite is contained in the multilayer substrate and the insulating cap, emission of electromagnetic waves to the outside and entry from the outside are prevented, and the coefficient of thermal expansion between the multilayer substrate and the insulating cap is reduced. Has an approximate value, so that the sealed portions of the two maintain airtightness.
[0012]
Therefore, it is possible to provide a semiconductor device including a high-reliability high-frequency module having an electromagnetic shielding function and excellent airtightness.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
(First Embodiment)
First, a high-frequency module as a semiconductor device according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a sectional view showing the high-frequency module.
[0015]
As shown in FIG. 1, a high-frequency module 40 according to the present embodiment has a multilayer substrate 1 made of alumina having a cavity (recess) 2 formed on the surface (first main surface), and a semiconductor element 21 in the cavity 2. And a plurality of passive elements such as a chip resistor 22, a capacitor 23, and an inductor 24, and an insulating cap 32 for hermetically sealing the semiconductor element 21 and the passive elements.
[0016]
The multilayer substrate 1 has an insulating substrate 3a, 3b, 3c, 3d made of alumina containing a ferrite, a wiring layer 4 formed on a surface thereof, a ferrite, and a cavity 2 on the surface. A wiring layer 6 is formed in a predetermined pattern, and an insulating substrate 3e made of alumina containing ferrite is laminated in this order and sintered. A wiring layer 5 as a ground is formed on the entire back surface (second main surface) of the multilayer substrate 1.
[0017]
The wiring layers 4, 5, and 6 are made of, for example, Cu, and the wiring layer (first wiring layer) 6 in the cavity is used for mounting the semiconductor element 21 and the chip resistor 22, the capacitor 23, the inductor 24, and the like. The first wiring layer 6, the wiring layers (second wiring layers) 4a, 4b, 4c, 4d between the insulating substrate 3 and the third wiring layer 5 are formed corresponding to the arrangement of the electrodes. Are electrically connected by vias 7 provided through the insulating substrates 3a, 3b, 3c, 3d, and 3e. Further, via holes are provided through the insulating substrate from the mounting surface on the bottom surface of the cavity 2 to the back surface of the insulating substrate 3a, and a thermal via 8 having excellent thermal conductivity in which a metal is embedded is formed. I have.
[0018]
Then, for example, a semiconductor element 21 made of GaAsHBT having a power amplifier function is fixed to a predetermined first wiring layer 6 in the cavity 2 on the surface of the multilayer substrate 1 by an alloy material 25 made of Sn-Sb, and the thermal via 8 is formed. The electrode 26 and the first wiring layer 6 are electrically connected to the third wiring layer 5 serving as ground via a bonding wire 27. In addition, a plurality of passive elements including the chip resistor 22, the chip capacitor 23, the inductor 24, and the like are electrically and mechanically fixed to the other predetermined first wiring layer 6 by the alloy material 25.
[0019]
Further, an insulating cap 32 made of alumina containing ferrite is provided on the cavity 2 on the surface of the multilayer substrate 1 and sealed around the periphery of the cavity 2 with an adhesive 31, and these mounted components 21, 22, 23, 24 The alloy material 5 and the bonding wire 27 are hermetically sealed with the multilayer substrate 1 and the insulating cap 32.
[0020]
The ferrite used here is composed of a metal and an iron oxide, specifically, NiFe2O4, ZnFe2O4, CdFe2O4, CoFe2O4, CuFe2O4, MgFe2O4, MnFe2O4, BaFe2O4, SrFe2O4, PbFe2O4, and a mixture thereof.
[0021]
The thermal expansion coefficients of the multilayer substrate 1 made of alumina containing ferrite and the insulating cap 32 made of alumina containing ferrite have values close to the thermal expansion coefficient of GaAs of 5.7 ppm / K.
[0022]
In the high-frequency module of the present embodiment as described above, since the multilayer substrate 1 and the insulating cap 32 contain ferrite, the electromagnetic waves generated in the high-frequency module 40 are emitted to the outside and emitted from the outside. Electromagnetic waves can be prevented from entering, and since the multilayer substrate 1 and the insulating cap 32 have substantially the same coefficient of thermal expansion, there is almost no peeling of the adhesive 31, and the entry of moisture and the like into the high-frequency module 40 causes high-frequency waves. There is no problem that the reliability of the module 40 is reduced.
[0023]
Further, since the coefficient of thermal expansion of the multilayer substrate 1 and the coefficient of thermal expansion of the semiconductor element 21 are close to each other, there is no problem that the semiconductor element 21 is separated from the multilayer substrate 1 due to a thermal cycle.
[0024]
(Second embodiment)
Next, a high-frequency module as a semiconductor device according to a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a sectional view showing the high-frequency module. In the drawings, the same components as those in the first embodiment are denoted by the same reference numerals.
[0025]
As shown in FIG. 2, a high-frequency module 40a according to the present embodiment includes a multilayer substrate 1 made of aluminum nitride (AlN) having a cavity 2 formed on a surface thereof, a first semiconductor element 21 and a second An insulating cap 32 for hermetically sealing a plurality of passive elements such as the semiconductor element 21a and the chip resistor 22, the capacitor 23, and the inductor 24 is provided.
[0026]
This multilayer substrate 1 is provided with insulating substrates 3a, 3b, 3c, 3d made of aluminum nitride (AlN) containing ferrite having a wiring layer 4 formed in a predetermined pattern on the surface and a cavity 2 on the surface. A wiring layer 6 is formed in a predetermined pattern on the bottom surface of the substrate 2, and an insulating substrate 3e made of aluminum nitride (AlN) containing ferrite is laminated in this order and sintered. A wiring layer 5 as a ground is formed on the entire back surface (second main surface) of the multilayer substrate 1.
[0027]
The wiring layers 4, 5, and 6 are made of, for example, Cu, and the wiring layer (first wiring layer) 6 in the cavity 2 includes first and second semiconductor elements 21, 21a and a chip resistor 22 to be mounted. , The capacitor 23, the inductor 24, and the like, and are formed corresponding to the arrangement of the electrodes of the passive elements, and the wiring layers (second wiring layers) 4a, 4b, 4c, 4d between the first wiring layer 6 and the insulating substrate 3 are formed. The third wiring layer 5 on the back surface is electrically connected to via holes 7 provided through predetermined insulating substrates 3a, 3b, 3c, 3c and 3e. Further, via holes are provided through the insulating substrate from the mounting surface on the bottom surface of the cavity 2 to the back surface of the insulating substrate 3a, and a thermal via 8 having excellent thermal conductivity in which a metal is embedded is formed. I have.
[0028]
A first silicon semiconductor element 21 composed of, for example, a power amplifier is provided face-down in the cavity 2 on the surface of the multilayer substrate 1, and is fixed to a predetermined first wiring layer 6 by a bump 33. . Further, for example, a second silicon semiconductor element 21 a having an input control function is fixed to another first wiring layer 6 by an alloy material 25 made of Sn—Pb, and the third wiring layer The electrode 26 and the first wiring layer 6 are electrically connected to each other by a bonding wire 27. Further, a plurality of passive elements including a chip resistor 22, a chip capacitor 23, an inductor 24, and the like are electrically and mechanically fixed to the other first wiring layer 6 by an alloy material 25.
[0029]
The insulating cap 32 is made of aluminum nitride (AlN) containing ferrite. The alloy material 25 is provided on the inner surface, and a heat radiating plate 34 made of, for example, Cu is provided on the outer surface. Are formed in a structure connected to each other via a via 9.
[0030]
The insulating cap 32 is disposed on the cavity 2 on the surface of the multilayer substrate 1 and is fixed to the back surface of the first silicon semiconductor element 21 via the alloy material 25 and adheres to the peripheral edge of the cavity 2. The components 31, 21a, 22, 23, and 24, the alloy material 5, the bumps 33, and the bonding wires 27 are hermetically sealed with an agent 31.
[0031]
The thermal expansion coefficients of the multilayer substrate 1 made of aluminum nitride (AlN) containing ferrite and the insulating cap 32 made of aluminum nitride (AlN) containing ferrite are close to the thermal expansion coefficient of silicon, 3.5 ppm / K. Has a value.
[0032]
In the high-frequency module of the present embodiment as described above, similarly to the first embodiment, it is possible to prevent the electromagnetic waves generated in the high-frequency module 40a from being released to the outside and from entering the electromagnetic waves from the outside. There is no problem that the reliability of the high-frequency module 40a is reduced due to the entry of moisture or the like into the high-frequency module 40a. Further, there is no problem of peeling of the semiconductor element 21a from the multilayer substrate 1 and peeling of the semiconductor element 21 from the insulating cap 32 caused by the thermal cycle.
[0033]
Further, in the present embodiment, since the heat radiating plate 34 is provided on the insulating cap 32 and the back surface of the silicon semiconductor element 21 is connected to the heat radiating plate 34 via the via 9, the operation of the silicon semiconductor element 21 during operation is Temperature rise is suppressed, and the efficiency of the power amplifier is improved.
[0034]
The present invention is not limited to the above embodiment, and may be variously changed without departing from the gist of the invention. For example, in the first and second embodiments, alumina and aluminum nitride are used as the insulating substrate of the multilayer substrate. However, glass-ceramic-based insulators, aramid-epoxy-based insulators, and glass-epoxy-based insulators May be used.
[0035]
Although the cavity is provided on the first main surface of the multilayer substrate, the cavity is not necessarily required.
[0036]
【The invention's effect】
According to the present invention, it is possible to provide a highly reliable semiconductor device having electromagnetic shielding performance and excellent confidentiality.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a high-frequency module according to a first embodiment of the present invention.
FIG. 2 is a sectional view showing a high-frequency module according to a second embodiment of the present invention.
FIG. 3 is a sectional view showing a conventional high-frequency module.
[Explanation of symbols]
Reference Signs List 1 multilayer substrate 2 cavity 3a, 3b, 3c, 3d, 3e insulating substrate 4a, 4b, 4c, 4d second wiring layer 5 third wiring layer 6 first wiring layer 7, 9 via 8 thermal via 21, 21a, 121 Semiconductor element 22, 122 Chip resistor 23, 123 Chip capacitor 24 Inductor 25, 125 Alloy material 26, 126 Electrode 27, 127 Bonding wire 128 External terminal 31 Adhesive 32 Insulating cap 33 Bump 34 Heat sink 101 Metal substrate 102 Insulating layer 105 Wiring layer 130 Mold resin 40, 40a, 140 High frequency module

Claims (3)

An insulating substrate having a wiring layer on the main surface is laminated, a first wiring layer is provided on a first main surface of the insulating substrate having the laminated structure, and a second wiring layer is provided between the insulating substrates having the laminated structure. Is provided, a third wiring layer is provided on a second main surface opposite to the first main surface, and the first to third wiring layers are electrically connected via vias. And a multilayer substrate containing ferrite in the insulating substrate,
A semiconductor element and a passive element provided on a first main surface of the multilayer substrate and electrically connected to the first wiring layer;
An insulating cap that covers the semiconductor element and the passive element, is sealed to the first main surface of the multilayer substrate, and includes ferrite;
A semiconductor device comprising: An insulating substrate having a wiring layer on the main surface is laminated, a first wiring layer is provided on a first main surface of the insulating substrate having the laminated structure, and a second wiring layer is provided between the insulating substrates having the laminated structure. Is provided, a third wiring layer is provided on a second main surface opposite to the first main surface, and the first to third wiring layers are electrically connected via vias. And a multilayer substrate containing ferrite in the insulating substrate,
A first semiconductor element provided on the multilayer substrate with its main surface face-down, and electrically connected to the first wiring layer;
A second semiconductor element and a passive element provided on a first main surface of the multilayer substrate and electrically connected to the first wiring layer;
An insulating cap that covers the first semiconductor element, the second semiconductor element, and the passive element, is sealed to the first main surface of the multilayer substrate, and includes ferrite;
With
The insulating cap has an inner surface in contact with a surface opposite to the main surface of the first semiconductor element, and has a heatsink on an outer surface, and the heatsink is opposite to the first semiconductor element via a via. A semiconductor device which is in contact with a surface. 3. The semiconductor device according to claim 1, wherein a material forming the insulating substrate and the material forming the insulating cap are the same.

Images