JPH0697315A - Circuit element module - Google Patents

Abstract

PURPOSE:To provide a small-sized, lightweight and inexpensive high-frequency module, on which a function unit appropriately including an impedance matching circuit, a delay line and a low-noise amplifier in addition to a surface acoustic wave device can be mounted. CONSTITUTION:Provided are a multilayered board 10, a high-frequency element mounted thereon, and a conductive cap 40 for hermetically sealing the upper surface of the board 10. The board 10 is composed of an organic material, and has first metallic films 21a, 21b on the first principal surface thereof and a second metallic film 20 provided on the second principal surface thereof. The board 10 has an internal connection electrode 22a for connection with the element, an external connection electrode 22b for connection with the outside, a via 25 for connecting the internal connection electrode 22a and the external connection electrode 22b, and a wiring conductor 24. The cap 40 is closely contacted with the first metallic film 21a with the opening thereof being electrically conductive.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit element module in which elements are mounted on a substrate, and more particularly to a circuit element module in which high frequency elements are mounted.

[0002]

2. Description of the Related Art A circuit element module used in a portable radio terminal or the like is a functional unit including constituent elements such as a surface acoustic wave element, an impedance matching circuit, a delay line, a low noise amplifier, and a function such as a surface acoustic wave filter. The unit is mounted on a board. These components, particularly the surface acoustic wave device, require hermetic sealing and electromagnetic wave shielding.

In a conventional surface acoustic wave filter, as a technique for hermetically sealing at low cost without impairing the electromagnetic wave shielding function, there is, for example, one described in Japanese Patent Application Laid-Open No. 2-283112. That is, this technique places a surface acoustic wave device on a single-layer substrate made of ceramics, covers the metal cap sealing part of the electrode pattern for external connection except the ground terminal with an insulating film, and further covers the inorganic conductor film. The surface acoustic wave filter is formed by soldering a metal cap formed on the surface. In addition, JP-A-2-17760
No. 9 publication discloses that a surface acoustic wave device is placed in a cavity of an engineering plastic case with a lead frame,
There is disclosed a surface acoustic wave filter having a configuration in which substantially the entire case, except for the periphery of the electrode lead for external connection, is covered with a metal film such as plating.

[0004]

However, the above-described conventional surface acoustic wave filter is a low-cost technology for a package of a surface acoustic wave element alone, and is a functional unit including peripheral circuits such as an impedance matching circuit. , Not mentioned. In particular, in order to realize compact and lightweight mounting of mobile wireless terminals, downsizing and cost reduction of functional units centering on surface acoustic wave devices are important issues, and this can be achieved without impairing hermetic sealing and electromagnetic wave shielding function. Must be resolved.

By the way, one of the obstacles to cost reduction in this type of circuit element module is the substrate. That is, conventionally, an inorganic material such as alumina, mullite, or glass has been used as the substrate. This substrate of an inorganic material is troublesome to manufacture, and has problems such as poor yield, so that it is difficult to reduce the cost.

On the other hand, the present inventors have considered using a substrate made of an organic material that is easy to manufacture and can be manufactured at low cost. However, it has been found that a substrate made of an organic material has a problem that it is not suitable for mounting a surface acoustic wave device or the like that is sensitive to humidity because it easily transmits water.

An object of the present invention is to solve the above problems and provide a circuit element module in which a functional unit including a surface acoustic wave element or the like is mounted in a small size, light weight, and low cost.

[0008]

To achieve the above object, according to the present invention, a substrate having first and second main surfaces, the first main surface serving as an element mounting region, and a first A circuit element module having at least one element arranged in the element mounting area of the main surface and a conductive cap covering at least the element mounting area of the substrate, wherein the substrate is made of an organic material, and A first metal film which is provided on the first main surface and surrounds at least the element mounting region, and a second metal which is provided on the second main surface and covers at least the region facing the element mounting region. And a first metal film and a first metal film which are not covered by the cap and which are arranged in the element mounting region and are connected to the element, and the internal connection electrodes for connecting to the element. Placed in a position that does not contact the metal film of No. 2 An external connection electrode for connecting with the outside, and via which one end is connected to the internal connection electrodes, together with a part thereof connected to said corresponding vias,
A state in which one end has a wiring conductor connected to the external connection electrode, the cap has an opening whose size can include an element mounting region to be covered, and the opening is electrically conductive. Then, a circuit element module is provided, which is closely attached to the first metal film.

The substrate has at least a first insulating layer provided with the via and a second insulating layer provided under the via and provided with the wiring conductor, and these are laminated. Can have a multilayer structure. Further, the upper surface of the first insulating layer may be the first main surface, and the first metal film may be arranged in the element mounting region. In this case, at least one element can be mounted on the first metal film in the element mounting region.

As the element mounted on the first metal film, an element sensitive to moisture, for example, a surface acoustic wave element can be mentioned.

Further, the present invention can further include, as an element, a planar coil arranged in the element mounting region. The planar coil is composed of wiring having a planar spiral structure, and may have a structure having an internal connection electrode and a via in the center of the spiral.

Specifically, a surface acoustic wave filter having a built-in matching circuit, which is formed by forming a plurality of the plane coils and connecting the plurality of plane coils with the surface acoustic wave element, is mounted as a functional unit. A circuit element module can be configured.

In the present invention, the element mounting region may be covered with the first metal film except for the portion where the planar coil is arranged.

The external connection electrode may be provided on the side surface of the multilayer substrate. In addition, the multilayer substrate may have a structure further including a third metal film that covers a region of a side surface of the multilayer substrate other than a portion where the external connection electrode is arranged.

Further, according to the present invention, it is possible to adopt a structure further including a waterproof resin which covers a portion of the element mounting region which is not covered with the metal film.

Examples of the organic material constituting the substrate used in the present invention include glass epoxy resin, BT resin (bismaleimide / triazine resin), polytetrafluoroethylene and the like.

Further, according to the present invention, the coil, the capacitor and the resistor can be built in the multilayer substrate.

The substrate used in the present invention is formed by cutting from a mother substrate, and has a groove-shaped electrode portion extending in the thickness direction of the substrate on the side surface of the substrate. This circuit element module substrate is, for example, a mother substrate capable of taking a plurality of the substrates, through holes are provided at positions to be the electrode portions of each substrate,
Next, the mother substrate is cut into a plurality of the above substrates,
Further, each substrate can be manufactured by forming a metal film on the side surface of the substrate and the electrode portion except for the boundary portion thereof.

[0019]

The substrates used in the present invention are the first and second substrates.
The main surface of the first main surface is the element mounting area. Then, this substrate is made of an organic material. Since the organic material is inexpensive and easy to mold, it can be easily manufactured from a ceramic substrate in the case of forming a multilayer substrate as shown in Examples described later. Therefore, it can be manufactured at low cost.

An element mounting area for mounting an element is set on the first main surface of the substrate. This element mounting area is
It is covered with a cap and shielded from the outside. With this cap, direct infiltration of moisture is prevented and electromagnetic shielding is performed.

Further, according to the present invention, the first metal film provided on the first main surface of the substrate reduces the moisture permeation area on the upper surface of the substrate and is also effective for the electromagnetic shield.
Therefore, it is preferable that a large area can be received as much as possible. However, since the first metal film is provided so as to surround at least the element mounting region, it does not hinder the mounting of the element.

Furthermore, the second metal film provided on the second main surface of the substrate prevents moisture from entering from the bottom side of the substrate and is also effective as an electromagnetic shield. The second metal film has a second metal film that covers at least a region facing the element mounting region, and the substrate further includes an internal connection electrode for connecting to the device. The external connection electrode for connecting to the outside, which is not covered with the cap, and is arranged on the first metal film and the second metal film.
It is placed at a position where it does not come into contact with the metal film. And these are connected by the via and the wiring conductor. This prevents wiring from being provided on the upper surface of the substrate when connecting the element arranged in the element mounting region and the outside, so that the upper surface of the substrate should be covered with the cap in close contact with the first metal film. You can Therefore, it is possible to prevent the entry of moisture and improve the effect of the electromagnetic shield.

Further, in the case of a circuit element module including a surface acoustic wave element, there is a demand for connecting an element such as a coil in the immediate vicinity of the surface acoustic wave element. However, in the case of a ceramic substrate, its surface is rough, and therefore, when a coil or the like is formed by a thin film technique, the resistance is increased due to the unevenness of the surface, which makes it difficult to obtain the desired characteristics.
In the present invention, since the surface of the substrate can be formed smoothly by using the organic material, the coil and the like can be formed accurately.

The other effects of the present invention are listed below. (1) By making the substrate a multi-layered structure, it is possible to make the module multifunctional.

(2) By using the metal film as the ground layer,
The electromagnetic shield function can be effectively performed, the signal wiring can be configured as a strip line, and the distortion of the high frequency signal waveform can be reduced. When this is used as a delay line, the effective permittivity does not decrease like a micro strip line. The line length becomes shorter and contributes to downsizing of the module size.

(3) Incorporation of the coil, the capacitance, and the resistor in the substrate contributes to miniaturization of the module size. (4) By disposing the impedance matching coil in the immediate vicinity of the surface acoustic wave element, the passage loss of the surface acoustic wave filter can be reduced.

(5) By covering most of the side surface of the substrate with the metal film, the airtightness and the electromagnetic wave shielding property when the organic material is used for the substrate can be improved.

(6) By patterning the planar spiral wiring on the uppermost layer and the intermediate layer of the substrate and electrically connecting at the center of the spiral wiring to form a coil, the number of turns of the coil is increased, and a large inductance is obtained with a small area occupied by the coil. Can be obtained. Further, by reducing the thickness of the insulating layer between the uppermost layer of the substrate and the intermediate layer, the coupling coefficient of the coils formed in both layers can be increased, and as a result, a large inductance can be obtained with a small coil occupation area. This means that the wire length of the coil can be shortened to obtain the same inductance, the resistance of the coil can be suppressed low, and the Q value can be increased. Further, by increasing the thickness of the insulating layer between the intermediate layer and the ground layer, it is possible to reduce the decrease in the inductance and Q value due to the proximity of the ground layer and the coil.

(7) By incorporating the delay line in the intermediate layer having the stripline structure, the duplexer module can be made compact by the above-mentioned operation.

(8) By integrating the demultiplexer module, the low noise amplifier and the surface acoustic wave filter with a matching circuit, it is possible to obtain a front end module which is smaller and less expensive than individual packaging.

(9) The circuit element module can be manufactured at low cost by performing the plating on the side surface of the substrate at the same time as the plating process for the through holes.

(10) The water resistance of the circuit element module can be improved by covering the end face of the substrate not covered with the metal film with the waterproof resin.

[0033]

Embodiments of the circuit element module of the present invention will be described below with reference to the drawings. The circuit element module of the present invention is not particularly limited to the frequency, but in the following embodiments, a high frequency module will be taken as an example.

FIG. 1 is a sectional view schematically showing the structure of a high frequency module showing an embodiment of the present invention.

The high frequency module of this embodiment basically has a multilayer substrate 10 and a high frequency element 30 mounted thereon.
And a conductive cap 40 that hermetically seals the upper surface of the multilayer substrate 10.

The multilayer substrate 10 has a first main surface (upper side in the drawing) and a second main surface (lower side in the drawing), and the first main surface serves as an element mounting area DA. In the element mounting area DA,
A high frequency element 30 and other chip components 14 are mounted as at least one element. Further, the plane coil 11 is provided in the element mounting area DA.

The multilayer substrate 10 is made of glass epoxy, B
T resin (bismaleimide / triazine resin), polytetrafluoroethylene (Teflon: DuPont trade name)
Composed of organic materials such as. Any of these organic materials can be manufactured at a lower cost than in the case of using a conventional inorganic material. Further, as the high frequency element 30,
When using a surface acoustic wave element (SAW), it is preferable that the substrate and the high frequency element have similar thermal expansion coefficients. Table 1 shows the thermal expansion coefficients of these materials and conventionally used inorganic materials.

[0038]

[Table 1]

As shown in Table 1, all organic materials have values close to the coefficient of thermal expansion of SAW. On the other hand, the coefficient of thermal expansion of inorganic materials differs from that of SAW by one digit, so
There is a risk that stress will be generated in the SAW due to temperature change and strain will occur. In this embodiment, since the coefficient of thermal expansion is close, this danger does not occur.

The multi-layer substrate 10 has a first insulating layer 10a and a second insulating layer 10b arranged below the first insulating layer 10a, each of which is made of the above-mentioned organic material. Composed. The upper surface (the surface not in contact with the second insulating layer) of the first insulating layer 10a constitutes the first main surface. Further, the lower surface (the surface not in contact with the first insulating layer) side of the second insulating layer 10b constitutes the second main surface.

A first metal film 21a surrounding the element mounting area DA is provided on the first main surface of the multilayer substrate 10. A second metal film 2 is provided on the second main surface of the multilayer substrate 10 so as to cover at least the area facing the element mounting area DA. In the present embodiment, the second metal film 20 is provided in most of the region of the multilayer substrate 10 except the peripheral portion of the second main surface.

Further, a first metal film 21b is provided in the element mounting area DA. The first metal film 21a
Is located outside the element mounting region, and includes the first metal film 21b.
Is located inside the element mounting region. The two are substantially the same, only the positions where they are arranged are different. Therefore, both may be connected. For example,
It can be formed simultaneously as an integral membrane.

Although not shown in the present embodiment, for example, as shown in FIG. 3B, a third metal film 23 is provided on the side surface of the multilayer substrate 10. The third metal film 23 is connected to the first metal film 21a and the second metal film 20 described above. As a result, in the high frequency module of this embodiment, almost the entire surface of the multilayer substrate 10 is covered with the metal film, and the electromagnetic shield and the moisture resistance are improved. The third metal film 23 is provided via a boundary so as not to contact the external connection electrode 22b described later.

The first, second and third metal films can be configured to function as a ground conductor.
Further, it is preferable that these have a large area so as to cover the surface of the multilayer substrate 10 as much as possible. Thereby, the permeation of water can be prevented more effectively.

The metal film and the planar coil 11 are
For example, a plating film of copper, nickel, chromium or the like can be patterned and configured. Further, gold may be plated on these films. The metal film and the planar coil 11 are, like other embodiments described later,
The structure may be embedded in the upper surfaces of the insulating layers 10a and 10b. This is because the upper surface of the insulating layers 10a and 10b is provided with a recess having a desired pattern in a direction such as dry etching
This part can be formed by filling a metal such as copper by plating or the like. Alternatively, an insulating sheet provided with these metal patterns may be prepared, a resin may be applied to the insulating sheet, and these metal patterns may be embedded in the upper surface of the insulating layer.

Further, the multilayer substrate 10 is not covered with the internal connection electrode 22a arranged in the device mounting area DA for connecting with the device and the cap 40,
In addition, an external connection electrode 22b for connecting to the outside is provided at a position not in contact with the first metal films 21a and 21b and the second metal film 20. At least two internal connection electrodes 22a are provided for connecting the mounted elements. In fact, as described above, the number of elements is two or more because there are other elements in addition to the high frequency element 30. The internal connection electrode 22a is made of, for example, a metal film, and the end surface of the via 25 described later may be used as the internal connection electrode 22a. External connection electrode 22
Similarly, at least two b are provided. The external connection electrode 22b is provided on the side surface of the multilayer substrate 10.

Further, the multilayer substrate 10 is provided with a via 25. The via 25 is provided in the above-described first and second insulating layers 10a and 10b. Out of this via 25
At least 2 is provided only in the first insulating layer 10a,
One end thereof is connected to the internal connection electrode 22a described above. In each of the present embodiments, the internal connection electrode 22a is formed on one end thereof. The end portion of the via 25 itself may be the internal connection electrode 22a.

The other vias 25 include the first and second vias.
Through the insulating layers 10a and 10b. Some of these vias 25 have one end on the first metal film 21a,
The other ends are connected to the second metal film 20, respectively. Also,
The other via 25 has one end connected to the first metal film 21b and the other end connected to the second metal film 20. As a result, the first, second and third metal films 22a, 20 and 22b provided on both surfaces of the multilayer substrate 10 form equipotential surfaces and can be used as ground conductors.

A wiring conductor 24 is provided on the upper surface (interface with the first insulating layer) of the second insulating layer. One end of at least two of the wiring conductors 24 is connected to the external connection electrode 22b. The other end of the via 25 connected to the internal connection electrode 22a is connected to the other part of the wiring conductor 24. As a result, the internal connection electrode 22a and the external connection electrode 22b are connected. In the present embodiment, only the wiring conductor 24 for electrode connection is shown, but in addition to this, there are wiring conductors 24 that are internally used for connection between elements and connected to the corresponding vias 25. be able to.

In the present embodiment, the wiring conductor 24 has the metal films 21a, 21b and 20 serving as ground layers above and below the wiring conductor 24, and is arranged so as to be sandwiched between them. Therefore, the wiring conductor 24 constitutes a strip line. For this reason,
The distortion of the high-frequency signal waveform can be reduced as much as possible, and when this is used as a delay line, the effective permittivity does not decrease unlike the microstrip line, the line length becomes short, and the module size can be miniaturized. In addition, in this embodiment, the high frequency element 30 sensitive to moisture is used as the first metal film 2.
It is mounted on 1b. Thereby, the high frequency element 30
In addition, it is possible to prevent water from directly entering from the substrate 10 side.

The cap 40 has an opening 40a in the form of a tray, for example, as shown in FIG. 3 described later. The cap 40 is provided outside the element mounting region of the multilayer substrate 10 and has the first metal film 2 on the upper surface of the substrate 10.
The opening 40a is brought into close contact with 1a. The close contact is performed with, for example, the solder 41.

According to this structure, the high frequency element 30
The space in which is mounted is the cap 40 and the first, second and third metal films 21a, 21b, 20, of the multilayer substrate 10.
With 23, it is hermetically sealed as well as the electromagnetic shield. An organic material as the insulating material of the multilayer substrate 10 has some moisture permeability. However, in this embodiment, since the multilayer substrate 10 is covered with the first, second and third metal films, for example, as shown in FIG. 1, the moisture intrusion route 100 can be made as long as possible. Therefore, the moisture resistance is improved accordingly.

Further, since it is an organic material, the surface of the insulating layer can be formed smoothly. Therefore, when a coil or the like is formed on the insulating layer, the unevenness of the substrate surface is small, so that the error in the characteristics caused by the unevenness can be reduced,
The desired performance can be formed with high yield.

Next, a second embodiment of the present invention will be described with reference to FIG.

The second embodiment shown in FIG. 2 is a multilayer substrate 10.
Has a three-layer structure having a first insulating layer 10a, a second insulating layer 10b, and a third insulating layer provided therebetween, and is provided with many circuit elements. The other features are the same as those of the first embodiment. Here, the difference will be mainly described.

The third insulating layer 10c is made of the same organic material as the above-mentioned first and second insulating layers 10a and 10b. A plurality of vias 25, wiring conductors 24, and resistance elements 13 are provided inside thereof. Further, the planar coil 11 is provided on the third insulating layer 10c. The plane coil 11 is connected to the plane coil 11 provided on the first insulating layer 10a via the via 25. In addition, in the present embodiment, the third insulating layer 10c
Of the wiring conductor 24 provided on the second insulating layer 10
Part of the wiring conductor 24 provided in b is connected to the external connection electrode 22b. Further, electrodes 12a and 12b facing each other are arranged on the upper surface of the third insulating layer and the corresponding upper surface of the first insulating layer 10a, and the capacitor 12 is formed with the insulating layer 10a interposed therebetween. ing. This embodiment also has the same effect as that of the first embodiment described above.

Next, a third embodiment of the present invention will be described with reference to FIG.

The present embodiment is an example of a high frequency module having a surface acoustic wave filter with a matching circuit equipped with a surface acoustic wave element as a functional unit. FIG. 3A shows a circuit example of the surface acoustic wave filter. That is, in this embodiment,
The surface acoustic wave device SAW and impedance matching coils L1, L2, L3, and L4 are included. The surface acoustic wave filter is designed to reduce its passage loss.
It is desirable to perform impedance matching as close to the surface acoustic wave element SAW as possible. In this embodiment, the impedance matching coils L1, L2, L3, and L4 are realized by patterning and forming planar spiral wiring on the multilayer substrate 10.

A concrete mounting structure of this embodiment is shown in FIG.
And (c). The present embodiment has a multilayer substrate 10 on which a surface acoustic wave element or the like is mounted, and a cap 40.

The multi-layer substrate 10 used in this embodiment has a first insulating layer 10a and a second insulating layer 10b as in the first embodiment. The first insulating layer 10a includes the first metal films 21a and 21b and the coils L1 and L.
2, L3, L4, the internal connection electrode 22a, and the via 25 are provided. Further, the wiring conductor 24 and the second metal film 20 are provided on the second insulating layer 10b. In the present embodiment, the first metal films 21a and 21b and the coils L1 and L
2, L3, L4 are formed by being embedded in the upper surface of the first insulating layer 10a. In addition, the wiring conductor 24 and the second
The metal film 20 is formed by patterning a plating film or the like on the second insulating layer 10b. Note that the wiring conductor 24 and the second metal film 20 are the same as the first insulating film 10a.
The mask may be formed so as to be embedded in the bay. Note that such a structure can also be adopted in other embodiments.

An external connection electrode 22b is provided on the side surface of the multilayer substrate 10. The external connection electrode 22b is
A part of the side surface of the multilayer substrate 10 is cut out in a semi-cylindrical shape, and an equivalent metal film is formed in this part by plating or the like. It should be noted that this portion can be provided as a via when a plurality of multi-layer substrates 10 are provided on a larger substrate and are cut and formed.

Further, the first metal films 21a and 21b are also provided.
Is provided so as to cover almost the entire upper surface of the multilayer substrate 10, except for the coils L1, L2, L3, L4 and the external connection electrode 22. Similarly, the second metal film 20
Is provided so as to cover almost the entire lower surface of the second insulating substrate 10b. In this case, the portion is provided so as not to contact the external connection electrode 22b. Further, as shown in FIG. 3B, a metal film 23 is provided on the side surface of the multilayer substrate 10. The metal film 23 is connected to the first metal film 21a and the second metal film 20 described above. As a result, in the high frequency module of this embodiment, almost the entire surface of the multilayer substrate 10 is covered with the metal film,
The electromagnetic shield and moisture resistance are improved.

Further, since the wiring conductor 24 constitutes a strip line, the distortion of the high frequency signal can be suppressed as much as possible.

Next, a fourth embodiment of the present invention will be described with reference to FIG.

In this embodiment, the high frequency module of the third embodiment is further waterproofed. Here, only that point will be described.

That is, as shown in FIG. 10, in this embodiment, in the element mounting area DA on the upper surface of the first insulating layer 10a, the portion not covered with metal is covered with the waterproof resin 20.
Cover with 0. This portion is the portion where the coil 11 is provided in FIG. With this configuration, in the space where the SAW is mounted, the first metal films 21a and 21b, the metal film of the coil 11, the waterproof resin 200, and the cap 4 are provided.
Surrounded by 0 and 0, the prevention of water intrusion becomes more reliable.

The waterproof treatment with this waterproof resin is
Not only the portion covered with the cap 40, but also the portion not covered with the metal film in the multilayer substrate can be widely performed. Further, it goes without saying that this waterproofing treatment can be widely applied not only to the high frequency module having the structure of the embodiment shown in FIG. 10 but also to the high frequency module shown in FIGS. 1 and 2 and the application module described below. Nor.

Next, examples of various application modules will be described using the configuration concept of the high frequency module of the present invention.

FIG. 4 shows an embodiment in which the above-described concept of the high frequency module of the present invention is applied to a duplexer module.

FIG. 4A is a circuit example of the duplexer module of this embodiment. The duplexer module is composed of two sets of the surface acoustic wave filters with a matching circuit and two sets of delay lines D having an electric length of about 1/4. FIG. 4B is a sectional view schematically showing the mounting structure.

The module structure is almost the same as that of the surface acoustic wave filter with a built-in matching circuit, but the delay line D2 set, which requires a relatively large wiring area, can be arranged in the intermediate layer as a strip line, and the duplexer module is small. Can be formed. The structure of the multilayer substrate 10 is basically the same as that of the above-described embodiments.

FIG. 5 shows an embodiment in which the above-described concept of the high frequency module of the present invention is applied to a front end module such as a radio device.

FIG. 5A shows an example of the circuit of the front end module. The front-end module includes the above-mentioned duplexer module, a surface acoustic wave filter F with a matching circuit, a high-frequency transistor T, a plurality of coupling capacitors 12, a bypass capacitor 15, and a coil 11.
This is a configuration in which a low noise amplifier composed of is added.

FIG. 5B is a sectional view schematically showing the mounting structure. The module configuration is almost the same as that of the demultiplexer module described above, but the module substrate size is expanded, and a high frequency transistor T and a plurality of coupling capacitors 12, a bypass capacitor 15, a coil 11 and a matching circuit for a low noise amplifier are provided. The built-in surface acoustic wave filter F is also mounted on the same multilayer substrate 10. By adopting such a module configuration, it is possible to obtain a small-sized and inexpensive front-end module rather than packaging each individual functional module. The structure of the multilayer substrate 10 is basically the same as that of each of the above-mentioned embodiments. Therefore, the same effect can be obtained.

FIG. 6 shows an example of a coil formed on the multilayer substrate 10 used in the example of the present invention.

In FIG. 6A, the spiral wiring is patterned on the uppermost layer of the substrate and used as the coil 11. The coil 11 is electrically connected to another circuit from the external connection electrode 22b or the like via the wiring conductor 24 forming the strip line by the via 25. The coil 11 having this configuration has a relative dielectric constant of about 1 in the upper half space of the coil 11.
Can be filled with the gas, and the parasitic capacitance can be reduced.
Therefore, the self-resonant frequency of the coil 11 can be increased.

In FIG. 6B, a spiral wiring is patterned on the intermediate layer and used as the coil 11. The center of the coil 11 is drawn out to the upper surface of the multilayer substrate 10 via the via 25. The end 25a of the via 25 is connected to a high frequency element 30 such as a surface acoustic wave element SAW (not shown) mounted on the multilayer substrate 10 by wire bonding or the like. According to this configuration, the moisture intrusion route 100 can be lengthened and the opening area of the via 25 portion can be reduced, so that the substrate configuration is excellent in airtightness.

In FIG. 6C, the plane spiral wiring is patterned on the uppermost layer and the intermediate layer of the substrate, and these are used as the coil 11. By electrically connecting the center of the coil 11 with the via 25, the number of turns of the coil can be increased, and a large inductance can be obtained with a small area occupied by the coil. In addition, the insulating layer thickness t between the uppermost layer of the substrate and the intermediate layer
By making 1 thin, the coupling coefficient of the coils formed on both layers can be increased, and as a result, a large inductance can be obtained with a small coil occupation area. This means that the wiring length of the coil 11 can be shortened to obtain the same inductance, the resistance of the coil 11 can be lowered, and the Q value can be increased.

Further, in any of FIGS. 6A, 6B, and 6C, if the insulating layer thickness t2 between the intermediate layer and the ground layer is increased, the ground layer 20 and the coil 11 approach each other. It is possible to reduce the decrease in the inductance and the Q value.

Next, a method of manufacturing the circuit element module of the present invention will be described with reference to the drawings.

FIG. 7 is a process conceptual diagram showing a method of plating the substrate end face 23 of the multilayer substrate 10 in the module configuration described in FIG. FIG. 7 is a front view of a multi-piece substrate 10 '(four substrates are shown in this figure) as seen from above.

The external connection electrode 2 is formed on the multi-piece substrate 10 '.
A hole for a through via is provided at the position of 2, and a peripheral portion of the substrate is cut by a router or the like at a position spaced from the insulating distance by this, and both are plated at the same time, and the third metal film 23 is formed on the side surface. To form. The separation of the multilayer substrate 10 is performed in the last step along the one-dot chain line. In this way, the plating of the substrate end face 23 is performed by using the through via, that is, the external connection electrode 22.
The high frequency module can be produced at low cost by performing the plating process simultaneously. At this time, the first and second metal films may be plated at the same time.

FIG. 8 is an explanatory diagram of a mounting method for further improving the airtightness of the high frequency module M such as the surface acoustic wave filter with a matching circuit, the duplexer module and the front end module, especially the water resistance thereof. .

After the high-frequency module M is soldered to the set board S such as a portable wireless terminal 42, the board end surface, particularly the board end surface not covered with the metal film, is covered with the waterproof resin 2.
By covering with 00, the water resistance of the high frequency module can be improved. As a result, the reliability of the set can be improved.

FIG. 9 is an explanatory view of the sealing method in the sealing step with the metal cap 40 of the high frequency module.

According to the embodiment of FIG. 9A, the opening 40
The cap 40 pre-coated with the solder 41 on a is momentarily thermocompression-bonded by the pulse heater H, so that solder sealing can be performed without flux. This is
It contributes to the prevention of contamination inside the module due to the flux and leads to the improvement of reliability. In addition, when the instantaneous heating method is adopted, the surface acoustic wave element SAW can be sealed without raising the temperature to high temperature, so that element deterioration in the sealing step can be prevented.

Further, according to the embodiment of FIG. 9B, flux-less solder sealing can be performed even if the pre-soldered solder 41 is used instead of the solder pre-coating on the cap 40. The effect of is obtained.

As described above, according to each embodiment of the present invention, the high frequency module such as the surface acoustic wave filter with built-in matching circuit, the duplexer module and the front end module has a plurality of functions combined. Nevertheless,
It can be formed into a small size. Moreover, in miniaturization,
In particular, it becomes possible to deal with airtightness of an element sensitive to surface contamination such as a surface acoustic wave element at a low price without impairing high frequency characteristics. In addition, since the organic material is used, the surface of the insulating layer is smooth, and in each of the above-described examples in which elements such as coils having desired characteristics can be easily formed, an example of a high-frequency module is shown. It is not limited to this.

[0089]

As described above, according to the present invention, a functional unit including a surface acoustic wave element or the like can be mounted in a small size, a light weight and a low cost.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing the configuration of a first embodiment of a high frequency module of the present invention.

FIG. 2 is a sectional view schematically showing the configuration of the second embodiment of the present invention.

3A and 3B show a configuration of a third embodiment of the present invention, in which FIG. 3A is a circuit diagram thereof, FIG. 3B is a perspective view showing the structure, and FIG.
Sectional drawing which shows the structure of the Example of FIG.

4A and 4B show an embodiment in which the present invention is applied to a duplexer module, FIG. 4A is a circuit diagram thereof, and FIG. 4B is a sectional view schematically showing the configuration of the embodiment.

5A and 5B show an embodiment in which the present invention is applied to a front-end module, FIG. 5A is a circuit diagram thereof, and FIG. 5B is a sectional view schematically showing a configuration of the embodiment.

FIG. 6 is a sectional view schematically showing an embodiment of a coil that can be used in the present invention.

FIG. 7 is a process conceptual diagram showing a method of cutting out a module of the present invention and a method of manufacturing external electrodes from a plurality of substrates.

FIG. 8 is an explanatory diagram of a mounting method that can be further applied to the present invention in order to improve water resistance.

FIG. 9 is an explanatory diagram of a sealing method according to the present invention.

FIG. 10 is a sectional view schematically showing the configuration of a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Multilayer substrate 10 '... Multi-piece substrate (mother substrate) 11 ... Coil 12 ... Capacitor 13 ... Resistor 14 ... Chip component 15 ... Bypass capacitor 20 ... Second metal film 21a, 21b ... First metal film 22 ... External connection electrode 23 ... Third metal film 24 ... Wiring conductor 25 ... Via 30 ... High frequency element 40 ... Cap 41 ... Solder 100 ... Water entry path 200 ... Waterproof resin SAW ... Surface acoustic wave element D ... Delay line T ... High frequency transistor S ... Set substrate L1, L2, L3, L4 ... Impedance matching coil F ... Matching circuit built-in surface acoustic wave filter t1, t2 ... Insulating layer thickness

Claims (18)

[Claims] 1. A substrate having first and second main surfaces, the first main surface serving as an element mounting region, and at least one element arranged in the element mounting region of the first main surface, In a circuit element module having a conductive cap that covers at least the element mounting area of the substrate, the substrate is made of an organic material, and is provided on a first main surface thereof, and at least the element mounting area is provided. It has a first metal film that surrounds it, and a second metal film that is provided on a second main surface of the second metal film and covers at least a region facing the element mounting region. Further, the substrate is arranged in the element mounting region. The internal connection electrode for connecting to the element and the external connection are arranged at a position not covered by the cap and not in contact with the first metal film and the second metal film. External connection electrode for performing The device has a via connected to the internal connection electrode and a wiring conductor having a part connected to the corresponding via and one end connected to the external connection electrode. A circuit element module comprising an opening having a size capable of including a region inside, and being closely attached to the first metal film in a state where the opening is electrically conductive. 2. The substrate according to claim 1, wherein the substrate has at least a first insulating layer provided with the via and a second insulating layer provided below the first insulating layer and provided with the wiring conductor. , A circuit element module configured by stacking these. 3. The method according to claim 2, wherein the upper surface of the first insulating layer is the first main surface, and the first metal film is
A circuit element module which is also arranged in the element mounting area. 4. The circuit element module according to claim 3, wherein at least one element is mounted on the first metal film in the element mounting region. 5. The circuit element module according to claim 4, wherein the element mounted on the first metal film is an element sensitive to moisture. 6. The circuit element module according to claim 4, wherein the element mounted on the first metal film is a surface acoustic wave element. 7. The circuit element module according to claim 6, further comprising a planar coil arranged in the element mounting area. 8. The circuit element module according to claim 7, wherein the planar coil is composed of wiring having a planar spiral structure, and has an internal connection electrode and a via in the center of the spiral. 9. A functional unit of a surface acoustic wave filter with a built-in matching circuit, comprising a plurality of the plane coils, wherein the plurality of plane coils are connected to the surface acoustic wave element. Circuit element module to be installed as. 10. The circuit element module according to claim 9, wherein the element mounting region is covered with the first metal film except a portion where the planar coil is arranged. 11. Claims 1, 2, 3, 4, 5, 6, 7,
In 8, 9, or 10, the external connection electrode is provided on a side surface of the multilayer substrate, and the multilayer substrate covers a third side surface of the multilayer substrate except a portion where the external connection electrode is arranged. A circuit element module further having a metal film. 12. A method according to claim 1, 2, 3, 4, 5, 6, 7,
In 8, 9, or 10, the external connection electrode is provided on a side surface of the multilayer substrate, and the multilayer substrate covers a third side surface of the multilayer substrate except a portion where the external connection electrode is arranged. A circuit element module further comprising a metal film and a waterproof resin that covers a portion of the element mounting region that is not covered with the metal film. 13. The method according to claim 1, 2, 3, 4, 5, 6, 7,
8. The circuit element module according to 8, 9, or 10, wherein the multilayer substrate further includes a waterproof resin that covers a portion of the element mounting region that is not covered with a metal film. 14. Claims 1, 2, 3, 4, 5, 6, 7,
Glass epoxy resin, BT at 8, 9 or 10
A circuit element module using a substrate (bismaleimide / triazine resin) or polytetrafluoroethylene as an substrate material. 15. A duplexer module having two sets of surface acoustic wave filters with a built-in matching circuit according to claim 9 and two sets of wiring conductors of substantially 1/4 electric length formed in an intermediate layer of a multilayer substrate. A circuit element module provided as a functional unit. 16. A circuit element module comprising the circuit element module according to claim 15 as a front-end module functional unit for a wireless device, which further has a high-frequency transistor, a coil, a capacitor, and a resistor. 17. A circuit element module according to claim 1, wherein the coil, the capacitor and the resistor are incorporated in a multilayer substrate. 18. A method for manufacturing a circuit element module substrate, which is formed by cutting from a mother substrate and has groove-shaped electrode portions extending in the thickness direction of the substrate on the side surface of the substrate, wherein a plurality of the substrates can be taken. Through-holes are provided in the mother substrate at positions that will be the electrode portions of the respective substrates, and then the mother substrate is cut into a plurality of the above-mentioned substrates. A method for manufacturing a circuit element module substrate, characterized in that a metal film is formed on the electrode portion excluding a boundary portion thereof.