JP4260835B2 - High frequency module parts - Google Patents

Description

  The present invention is a circuit module in which a surface acoustic wave bare element (SAW element) is directly flip-chip mounted on a ceramic multilayer substrate, which is suitable for use in communication equipment such as a cellular phone. The present invention relates to a smaller and more reliable high-frequency module component mounted so as to exhibit high characteristics.

In general, there is always a market demand for downsizing electronic devices, and parts used are always required to be downsized and lightened. In particular, it is represented by mobile phones that have been rapidly spreading in recent years. This tendency is prominent in portable devices, and there is a great demand for miniaturization and weight reduction of components used.
As a result, the density of parts used in such portable devices has been particularly increased, and miniaturization and weight reduction corresponding to demands have been made.

One means for meeting such a demand for miniaturization is modularization of a circuit.
Module parts are collective elements on which various parts are mounted, and of course they are effective in terms of miniaturization, but in order to organize the circuits by function, the conventional discrete parts are mounted one by one. Compared to the forming method, there is also an advantage that the structure of the device becomes simple and it is possible to provide a device having excellent reliability and characteristics. In addition, the conventional discrete parts combine the characteristics of each part to perform the functions, and the design is complicated, but the characteristics specifications are determined for each module by modularization. This makes it possible to structure the design of the equipment, shorten the development period, and save labor.

Further, in order to meet such a demand for miniaturization, a multilayer substrate having a plurality of conductor layers is used instead of a substrate having a single conductor layer in a substrate on which an element is mounted. . In particular, as a substrate for constituting a high-frequency circuit used in communication equipment such as a mobile phone, a ceramic multilayer substrate in which an insulating layer is formed of an electrically insulating ceramic and a conductive layer is formed of silver or the like is used. It is like that.
The ceramic multilayer substrate has characteristics such as less loss at high frequency, good heat conduction, good dimensional accuracy, and excellent reliability as compared with a general resin multilayer substrate. Moreover, an inductor or a capacitor can be formed in the inside by making the inner conductor into a coil shape or facing in parallel. Since these elements have low loss and good dimensional accuracy, the elements have high Q (quality factor), small tolerances, and very high characteristics.
These characteristics are very effective for forming a high-frequency circuit, and as a result, suitable for application to a mobile phone or the like in which various components are mounted on a ceramic multilayer substrate to form a high-frequency circuit. Small high-frequency module components have been developed.

By the way, the modularization of circuits in actual mobile phone circuits has been performed with several functions. Currently, for example, the power amplifier part and the antenna switch part of the dual-band mobile phone are modularized for each function. Has been.
An example of such a module component is shown in FIG.
FIG. 8 is a diagram showing the structure of the antenna switching module.
In FIG. 8, chip components 914 such as a diode element, an inductor element, and a resistance element are mounted on a substrate 901. A shield case 915 is disposed so as to cover these components and the board. Further, an outer conductor 909 is formed on the side surface of the substrate 901, and an inner conductor 910a and a surface conductor 910b are formed and arranged on the inside and the surface, respectively, to form a capacitor 912, an inductor 913, and the like. Further, these conductors 910 are vertically connected through the substrate layer by via holes 911.

As described above, communication devices such as mobile phones are still modularized for each single function. However, if a wider range of functions are modularized, the advantages of modularization as described above can be obtained. It is effective because it will be pulled out further.
In order to modularize a wider range of functions, it is important to add a module that includes a surface acoustic wave element (SAW element) such as a surface acoustic wave filter (SAW filter) that is usually used in such communication devices. It is.
A SAW filter is an element in which a phenomenon in which a resonator is formed with a comb-shaped electrode due to propagation of surface waves on the element surface is applied to a use such as a filter. Since this surface wave is very sensitive, it is generally practical to take a sealing structure on the element surface, and the SAW element is often used in the form of a so-called package component that is usually sealed in a package. (For example, refer to Patent Document 1).
JP 2000-216660 A

When such a SAW element is applied to a module component, as shown in FIG. 9, it is possible to mount a SAW element package 917 to make a module. However, when a package component 917 is mounted on a multilayer substrate to constitute a module component, there is a limit to the reduction in size and height as apparent from FIG. Can not.
In particular, the ceramic multilayer substrate has a feature that an inductance and a capacitance can be built in, but has a disadvantage that it is difficult to reduce the height. Therefore, if the package product 917 having a higher height is mounted, it becomes impossible to sufficiently meet the demand for a low profile, and the problem becomes more remarkable.

Further, when the package product 917 is mounted, a large occupied area is required as compared with the case where the bare chip is mounted. In particular, the SAW element is one of the tallest components in use and has a large occupation area.
Therefore, it is desired that the SAW element is directly mounted on the ceramic multilayer substrate in a bare chip state without using a package form.
However, in order to realize a high-frequency module component in which a bare chip SAW element is directly mounted on a ceramic multilayer substrate, there are various problems as described below, and improvements are desired.

As described above, the characteristics of the SAW element are very sensitive to the pressure applied to the comb electrode and the surface state, and the comb electrode should not substantially contact the sealing member or the manufacturing stage. Therefore, when this SAW element is mounted on a multilayer substrate in a bare chip state, it is necessary to secure a highly confidential space with respect to the comb-shaped electrode surface.
However, general resin sealing is intended to fill the entire space with resin, and in this case, the surface of the SAW comb electrode is also covered, which has a serious adverse effect on the characteristics of the SAW element. Become.

Even if such a space is ensured by the sealing resin, in the module component in which such a gold-gold bonding component and a solder bonding component are simultaneously mounted, the bonding of the sealing resin becomes weak and the multilayer substrate There is a possibility of peeling from.
This is due to the following reasons.
First, in order to mount a SAW chip by flip-chip bonding by gold-gold bonding and simultaneously mount a soldered component, for example, a silver sintered body and a nickel layer and a gold layer are often formed thereon. . In such a case, the surface conductor layer has irregularities on the surface with a certain thickness. Due to the unevenness, the sealing resin may be peeled off from the multilayer substrate.
In addition, a conductor pattern is usually formed on the surface of the multilayer substrate, but the gold conductor is easily peeled off from the resin in terms of material. That is, there is a possibility that the sealing resin may peel from the multilayer substrate due to a cause different from the unevenness of the substrate.
In particular, as shown in FIG. 10, in a module in which the conductor 920 is formed on the side surface, when resin sealing is performed, the bonding between the sealing resin and the substrate becomes unstable and the possibility of peeling is high. This is thought to be because the irregularities on the surface of the substrate increase by forming a conductor on the side surface.

  Furthermore, in the module parts in which the soldered parts and the SAW elements are mixedly mounted, the solder is piled up around the rounds of the soldered parts, but the tin contained in the solder tends to move at a high temperature and is slightly Even a gap may be transmitted through the gap by capillary action. Then, if such tin movement is transmitted from the vicinity of the outer peripheral portion to the outside through the resin ceramic interface, a crack is caused, and there arises a problem that the initial purpose of sealing the SAW element is not fulfilled. Note that such a problem does not occur in a single SAW product that is not intended to be mixed and is inherently generated when a soldered component and a SAW element are mixedly mounted.

The present invention has been made in view of such problems, and the object of the present invention is to
A high-frequency module component in which a bare surface acoustic wave elastic element is directly flip-chip mounted on a ceramic multilayer substrate. In particular, the resin sealing is performed while ensuring a space for maintaining the characteristics of the SAW element, and with the multilayer substrate. It is an object of the present invention to provide a high-frequency module component in which a SAW element exhibits stable and high characteristics by performing appropriately with good bonding properties.

  In order to solve the above problems, a high-frequency module component according to the present invention includes at least one surface acoustic wave element (SAW element), a multilayer substrate in which an electric circuit connected to the surface acoustic wave element is built, A sealing member formed on the surface acoustic wave element mounting surface of the multilayer substrate so as to cover and seal the surface acoustic wave element; and an input / output terminal of the electric circuit provided on the multilayer substrate. In the module component, the multilayer substrate is formed such that a conductor pattern does not exist in a peripheral region within a predetermined distance from a peripheral side surface of the surface acoustic wave device mounting surface, and the surface acoustic wave device includes a comb electrode Is mounted on the multilayer substrate so as to face the element mounting surface of the multilayer substrate, and the sealing member is fixed to the multilayer substrate at least in the peripheral region, and the surface acoustic wave The surface acoustic wave element is covered and sealed so as to maintain a space between the comb-shaped electrode of the child and the multilayer substrate, and the input / output terminal is provided on the surface acoustic wave element mounting surface of the multilayer substrate. It is provided on the opposite surface.

Preferably, the SAW element is mounted by gold-gold bonding to the multilayer substrate in a bare chip state by face-down bonding such as a flip chip method.
Preferably, the peripheral region is a region whose distance from the peripheral side surface of the multilayer substrate is about 100 μm or less.
Preferably, the multilayer substrate is a low-temperature simultaneous sintering substrate (LTCC substrate) in which an inductor and a capacitor (LC circuit) are formed.

In the high-frequency module component having such a configuration, the sealing member and the multi-layer substrate are directly bonded to each other in the peripheral region without using a conductive pattern that is a metal body, so that the sealing member is peeled off firmly. Less likely to do. As a result, the space formed for the comb electrode of the SAW element is stably secured, the characteristics of the SAW element are stabilized, and desired high characteristics can be secured.
In the present invention, since the sealing member and the multilayer substrate are firmly bonded in the peripheral region, even if the soldering component and the SAW element are mixedly mounted, the tin contained in the solder There is almost no inconvenience such as the generation of cracks due to the movement of.

Preferably, the multilayer substrate is formed so as not to further include an internal conductor in the peripheral region.
In the high-frequency module component having such a configuration, the unevenness on the surface of the multilayer substrate is further reduced at the peripheral portion, and a relatively flat surface is secured. Therefore, the sealing member and the multilayer substrate are further firmly bonded, and the SAW element The characteristics are stable.

Preferably, the sealing member includes a plurality of the surface acoustic wave elements, and the sealing member includes one continuous space between the comb-shaped electrode of each of the plurality of surface acoustic wave elements and the multilayer substrate. The plurality of surface acoustic wave elements are covered and sealed so as to be formed as a space.
The high-frequency module component having such a configuration can be mounted at a very high density when a plurality of SAW elements are mounted. It is also expected that the structure is simple and can be manufactured by an easier method. In addition, variations in characteristics among mounted SAW elements are suppressed.

Preferably, the sealing member is fixed to the surface acoustic wave element only on the surface opposite to the surface on which the comb-shaped electrode is formed, and does not adhere to the side surface of the surface acoustic wave element. As described above, the surface acoustic wave element is covered and sealed.
In the high-frequency module component having such a configuration, no force acts on the SAW element from the side surface, so that an external pressure factor can be eliminated from the characteristics of the SAW element including the comb-shaped electrode and the piezoelectric element. The characteristics of the element can be stabilized. Further, when a plurality of SAW elements are mounted, variation in characteristics among the plurality of SAW elements is suppressed, and characteristics as a whole module component are ensured.
Preferably, the sealing member is formed so that a surface opposite to a surface in contact with the multilayer substrate is smooth.
The smoothness is desirably smooth enough to be absorbed by, for example, a pick-and-place apparatus. With such a configuration, the high-frequency module component according to the present invention is easily adsorbed by the pick-and-place apparatus, and for example, it is easy to automate the assembly work of a device such as a mobile phone.

  As described above, according to the present invention, resin sealing can be appropriately performed while ensuring a space for maintaining the characteristics of the SAW element and with good bonding properties to the multilayer substrate. As a result, according to the present invention, it is possible to provide a high-frequency module component in which a bare surface acoustic wave elastic element is directly flip-chip mounted on a ceramic multilayer substrate, and the SAW element exhibits stable and high characteristics.

An embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, a high-frequency module component on which two bare chip SAW filters are mounted, which is desirable when applied to a GMS dual-band mobile phone widely used worldwide, will be described.

First, a schematic configuration of the circuit of the GSM dual-band mobile phone will be described with reference to FIG.
FIG. 1 is a block diagram of a GSM dual-band mobile phone.
The transmission signal I / Q (I signal and Q signal of the baseband signal) is input to the I / Q modulator 137. The IF signal is input to the I / Q modulator 137 from the IFVCO 1220 via a division cycle DIV138, 90 ° shifter and modulated. The signal output from the IQ modulator 137 is input to the mixer 132 via the phase detector 133. 900 VCO and 1800 VCO 136 are connected to the phase detector 133 through low-pass filters 134 and 135. Similarly, 900 VCO and 1800 VCO 117 are connected to the mixer 132.

  The signal output from the mixer 132 is modulated to 900 MHz or 1800 MHz, and is input to the diplexer 102 through the balun transformer 131 through the path of the power amplifier 129, the coupler 125, the low-pass filter 104, and the T / R switch 103, respectively. Alternatively, the signal is input to the diplexer 102 through a path of the power amplifier 130, the coupler 126, the low-pass filter 124, and the T / R switch 123. A signal input to the diplexer 102 is transmitted from the antenna 101.

  Similarly, a 900 MHz or 1800 MHz reception signal input from the antenna 101 to the diplexer 102 is mixed through the T / R switch 103 or the T / R switch 123 through the path of the band pass filter 105, the amplifier 106, and the balun transformer 107. The signal is input to the mixer 111 or is input to the mixer 111 through the path of the band pass filter 108, the amplifier 109, and the balun transformer 110. 900 VCO and 1800 VCO 117 are connected to the mixer 111.

  The IF-modulated signal output from the mixer 111 is input to the mixer 114 via the band pass filter 112 and the amplifier 113. An IFVCO 120 is connected to the mixer 114. The signal output from the mixer 114 is input to the modulator 116 by I / Q via the automatic gain controller 115 and demodulated. The IF signal is input to the I / Q demodulator 116 from the IFVCO 120 via the division cycle DIV138, 90 ° shifter and modulated. Also, IFPLL 119 and RFPLL 118 are connected to IFVCO 120, 900 VCO, and 1800 VCO 117, respectively.

In such a circuit, the modularization of the partial circuit is performed by several functions and blocks. In the present embodiment, the diplexer 102, the T / R switch 103, the low-pass filter 104, the SAW filter 105, T The present invention will be described by exemplifying a case where an antenna switching unit including the / R switch 123, the low-pass filter 124, and the SAW filter 108 is mounted on a ceramic substrate as a circuit module.
FIG. 2 is a circuit diagram of the antenna switching unit, in other words, a circuit diagram of the high-frequency module component of the present embodiment.
Hereinafter, a high-frequency module component obtained by modularizing such a circuit will be described.

FIG. 3 is a diagram showing the structure of the high-frequency module component (antenna switching module) 1.
First, the structure of the high frequency module component 1 will be described.
As shown in FIG. 3, the high-frequency module component 1 includes a ceramic multilayer substrate 10, two SAW elements 21, a solder bonding element 22, and a sealing member 30.

The ceramic multilayer substrate 10 is an LTCC substrate having an alumina glass composite ceramic as an insulating layer and 15 inner conductor layers.
In the ceramic multilayer substrate 10, a desired conductor pattern 13 is formed in the inner conductor layer or the surface layer, and a via hole (through hole) penetrating the interlayer is formed, so that a desired inductor and Capacitors, these inductors, signal wirings connecting the capacitors and mounted components to each other, power lines for supplying power to these elements, GND lines for providing a reference potential to these elements, and the like are formed.

A SAW element 21 and a solder joint element 22 are mounted on the component mounting surface 11 of the ceramic multilayer substrate 10.
The SAW element 21 is provided as a bare chip, and is flip-chip mounted by gold-gold bonding so that the comb electrode faces the component mounting surface 11 of the ceramic multilayer substrate 10.
The bonding state of the SAW element 21 will be described with reference to FIG.
As shown in FIG. 4, the SAW element 21 is arranged on the terminals composed of the sintered silver layer 23, the Ni layer 24, and the Au plating layer 25 so that the Au bumps 27 of the SAW element 21 are located via the solder balls 26. Has been. In this state, by applying a weight of 600 g while applying ultrasonic waves from the SAW element 21 side, the gold bump and the gold surface of the substrate can be joined.
At this time, the SAW element 21 is mounted between the comb-shaped electrode forming surface 28 and the component mounting surface 11 so that a gap 31 is formed as shown in FIGS.

An input / output terminal 15 for the realized circuit is formed on the bottom surface 12 of the ceramic multilayer substrate 10 opposite to the component mounting surface 11.
In the high-frequency module component 1, the input / output terminals 15 are all provided on the bottom surface 12, and no conductor including the input / output terminals is provided on the side surface of the ceramic multilayer substrate 10.

In the high-frequency module component 1, the SAW element 21 and the solder joint element 22 mounted on the ceramic multilayer substrate 10 and the functional components such as capacitors, inductors, and wirings formed on or in the ceramic multilayer substrate 10 are as follows. Both are arranged or formed avoiding the peripheral area (conductor arrangement prohibition area) that falls within a predetermined distance a from the side surface of the ceramic multilayer substrate 10.
This will be described with reference to FIG.
FIG. 5 is a view of the ceramic multilayer substrate 10 as viewed from the component mounting surface 11, and a region indicated by oblique lines is a conductor placement prohibition region 14. The predetermined distance a is preferably 100 μm or more.
In this region 14, no conductor pattern is formed on the component mounting surface 11. Also, the conductor layer is not substantially formed even inside the ceramic multilayer substrate 10.
Accordingly, each functional component such as the SAW element 21, the junction element 22, the capacitor, the inductor, or the wiring is disposed in an internal region of the ceramic multilayer substrate 10 surrounded by the prohibited region 14.

Then, the ceramic multilayer substrate 10 configured in this way is sealed on the component mounting surface 11 of the ceramic multilayer substrate 10 so as to cover all the component mounting surface 11 including the SAW element 21 and the solder bonding element 22. 30 is formed of a resin mold.
At this time, the sealing member 30 is formed so as to secure a gap 31 provided between the SAW element 21 and the component mounting surface 11 of the ceramic multilayer substrate 10 for each SAW element 21.
Further, as shown in FIG. 3, the sealing member 30 is higher than the tallest component in the SAW element 21 and the solder bonding element 22 so as to cover all the components mounted on the ceramic multilayer substrate 10. Also formed slightly higher. The upper surface 32 is parallel to the component mounting surface 11 of the ceramic multilayer substrate 10 and has a smoothness that can be appropriately sucked and transported when the high-frequency module component 1 is sucked and transported as a component by a pick and place device or the like. It is formed with flatness.

The high frequency module component 1 has such a structure.
In the present embodiment, the high frequency module component 1 has an outer shape of about 5.4 mm × 4 mm, the ceramic multilayer substrate 10 has a thickness h ₁ of 0.8 mm, and the entire high frequency module component 1 has a height h ₂ of 1.6 mm. .

Next, the manufacturing process of the high frequency module component 1 having such a structure will be described.
First, the ceramic multilayer substrate 10 is formed.
To form a ceramic multilayer substrate, first, an organic binder and an organic solution are mixed with powder based on alumina and glass, and this is applied to a carrier tape by a doctor blade method.
Next, this is dried, and the sheet is cut into about 10 cm square.
A portion that becomes a through hole is drilled in this sheet by a laser.
A silver powder pattern is applied to the obtained sheet by screen printing. At this time, the silver powder used for printing is generally a powder having a particle diameter of 0.1 μm to 1 μm, and is a paste that can be screen-printed with an organic binder and a solvent.
The sheet is peeled off from the carrier tape and laminated and pressed by a press. The pressure is 500 to 700 kg / cm ² . By this press treatment, the surface silver conductor layer is also smoothed.
Then, this is cut into predetermined pieces and baked at 900 ° C. for 15 minutes. During firing, the ceramic, inner conductor and surface layer conductor are sintered together.

Next, 2 μm of nickel electroless plating is applied, and 0.5 μm of gold electroless plating is applied.
Predetermined SMT parts are mounted on this and soldered by passing through a reflow furnace.
After performing the cleaning process, the bare SAW element is mounted by gold-gold bonding.

Next, resin molding is performed on the mixed module.
The resin mold is preferably performed by either a method of forming a resin in a B-stage state after embossing in advance, or a method of printing and applying a paste-like resin using a metal mask.
First, in the method of embossing, about 200 μm of an epoxy resin is applied on a PET film by a doctor blade method, the solvent is dried at 70 ° C., and the B stage state fluidity is maintained to some extent.
Subsequently, a mold that reproduces the irregularities of the module is heated to 80 ° C. and pressed against the resin on the PET, and then separated after cooling. Thereby, clear irregularities are formed in the resin by the pressing die.
Next, the PET film is cut into the same size as the module, combined with the module, and heat-pressed together with the PET film at 120 ° C. After that, the PET film is peeled off, followed by heat curing at 170 ° C. for 1 hour.

  In the printing application method, a metal mask having an open portion corresponding to the entire module component is pressed against the surface of the module component, and a paste-like resin is printed and applied. At this time, the printing application may be performed in a single direction with a normal rubber squeegee, but it is preferable to apply the printing so as to be pushed in with a scraper.

  As described above, in the high-frequency module component 1 of the present embodiment, the molding is performed by the sealing member 30 while the gap 31 is secured between the flip-mounted SAW element 21 and the ceramic multilayer substrate 10. Therefore, the comb-shaped electrode forming surface 28 of the SAW element 21 can be appropriately protected, and a high-performance SAW element 21 can be realized.

The ceramic multilayer substrate 10 is configured not to form a surface pattern in a peripheral region within 100 μm from the periphery of the component mounting surface 11. Therefore, in the peripheral region 14, the sealing member 30 is very strongly bonded to the ceramic multilayer substrate 10, and the possibility that the sealing member 30 is peeled off is very small.
Further, the ceramic multilayer substrate 10 is configured not to form an internal conductor in the peripheral region 14. Therefore, the unevenness of the component mounting surface 11 can be kept to a minimum, and also from this point, the sealing member 30 is very firmly bonded to the ceramic multilayer substrate 10 and the possibility of the sealing member 30 peeling off is reduced. Yes.
Furthermore, in the ceramic multilayer substrate 10, no conductor is provided on the side surface. Therefore, instability of the bonding state of the sealing member 30 due to the presence of the side conductor can be avoided, and the possibility that the sealing member 30 peels is reduced from this point.
As described above, in the high-frequency module component 1 of the present embodiment, the sealing member 30 is very firmly and stably bonded to the ceramic multilayer substrate 10, and therefore, between the SAW element 21 and the ceramic multilayer substrate 10. Space can be secured appropriately. As a result, stable characteristics of the SAW element 21 can be maintained.

  In addition, since the high-frequency module component 1 has a structure in which the user terminal conductor is formed only on the bottom surface, the occupied area during mounting can be reduced as compared with a module having side terminals.

Moreover, in the high frequency module component 1, since the upper surface of the sealing member is formed to be flat, the high frequency module component 1 can be adsorbed by a pick and place device or the like as before, for example, portable. In addition to being able to be put into the assembly process of a device such as a telephone, it is effective because it can maintain confidentiality inside the sealing portion and a space holding function.
That is, in the high-frequency module component 1, since the mold structure also serves as an adsorption application and a sealing function, it is not necessary to use a conventional metal shield case, and a lighter and cheaper module component can be provided. .

  Moreover, in the high frequency module component 1, since the surface conductor of the ceramic substrate is processed with the gold plating layer, both solder bonding and gold-gold bonding are possible. That is, flip chip mounting by gold-gold bonding such as SAW elements and solder bonding of other components can be mixedly mounted.

In addition, this embodiment is described in order to make an understanding of this invention easy, and does not limit this invention at all. Each element disclosed in the present embodiment includes all design changes and equivalents belonging to the technical scope of the present invention, and various suitable modifications are possible.
For example, the form of the gap formed in the vicinity of the SAW element is not limited to a form that secures the space 31 for each SAW element 21 shown in FIG. The gist of the present invention is to secure a highly airtight space (gap) with respect to the comb-shaped electrode of the SAW element 21 by the sealing member 30, and various forms can be considered as more specific forms.

For example, as shown in FIG. 6, when a plurality of SAW elements 21 are mounted on the ceramic multilayer substrate 10, one space 33 may be formed for the plurality of SAW elements 21. . That is, the SAW elements 21 are arranged close to each other on the component mounting surface 11, and the space between the comb-shaped electrode forming surface 28 and the ceramic multilayer substrate 10 in each SAW element 21 is formed as one continuous common space. You may make it do.
One of the features of the high-frequency module component according to the present invention is that the input / output terminals are arranged on the bottom surface and the mounting area can be reduced. When a plurality of high-frequency module components 1 are arranged close to each other in such a high-frequency module component, the configuration of the sealing member 30 is simplified by forming a common space in this way, and the sealing member 30 The manufacturing process is also simplified. Moreover, compared with the case where the high frequency module component 1 is formed independently of each high frequency module component 1, the high frequency module component 1 can be arranged closer to each other, which is effective for downsizing and increasing the density of the high frequency module component. It is.
It is clear that the high-frequency module component 2 having such a configuration is also within the scope of the present invention.

For example, as shown in FIG. 7, when the SAW element 21 is covered and sealed, the sealing member 30 may contact only the upper surface (top plate) of the SAW element 21 and not the side surface. . In other words, the SAW element 21 may be configured such that pressure is applied only to the upper surface and no pressure is applied to the side surface.
The SAW element 21 is generally configured by forming comb-shaped electrodes on a piezoelectric substrate, and is an element that is very sensitive to pressure. Therefore, by adopting such a configuration, a change in characteristics due to pressure from the side can be prevented, and variations in characteristics of each SAW element 21 can be reduced.
In addition, by experiment, dispersion | distribution of center frequency (when the SAW element 21 is mounted with the sealing member 30 in contact with the upper surface and the side surface and when the SAW element 21 is mounted with the sealing member 30 in contact with only the upper surface) When comparing σ), the former was 1.2 whereas the latter was about 0.8, and it was found that the effect was effective.
It is obvious that the high-frequency module component 3 having such a configuration is also within the scope of the present invention.

Hereinafter, the present invention will be described based on more specific examples.
The high-frequency module component according to the present invention was manufactured, and the stability of the structure as the high-frequency module component with respect to the width of the conductor placement prohibited region and the installation location of the terminal electrode was tested and verified.
The method for manufacturing the high-frequency module component is the same as the method described above in the embodiment, and the high-frequency module component 1 in which the width a of the conductor placement prohibited region is 0 μm, 100 μm, 200 μm, and 300 μm is manufactured.
Further, for a comparative experiment of the stability of the structure, a similar high-frequency module component having a side electrode was similarly manufactured and tested for a high-frequency module component having a conductor placement prohibition region of 300 μm.
In addition, the high-frequency module having the side electrode, like the high-frequency module component of the present embodiment, a new paste is applied by rubber transfer to the sintered body after the ceramic, internal conductor, and surface layer conductor are collectively sintered, Further, it is formed by performing a baking treatment.

In the verification, a thermal shock test is performed on 100 high-frequency module parts for each condition under the conditions of −40 ° C. and 85 ° C. (the duration at each temperature is 30 minutes and the temperature switching time is 30 seconds). The appearance of each high-frequency module component was observed after 200 cycles, and the number of cracks at the bonding interface between the sealing member 30 and the ceramic multilayer substrate 10 was counted.
The experimental results are shown in Table 1.

As shown in Table 1, for high-frequency module parts having side electrodes, even if a sufficient conductor disposition prohibiting area is secured, a large number of peelings between the sealing member and the ceramic multilayer substrate occur, and the structure is not stable. found.
In general, good results were obtained for the high-frequency module component having the bottom electrode. For the case where the conductor disposition prohibited region was secured at 200 μm or more, there was no peeling between the sealing member and the ceramic multilayer substrate, which was a particularly preferable result.
Further, it is not an exaggeration to say that almost no peeling occurs if the conductor placement prohibited area is 100 μm from the periphery, so it has been found that this can also be practically used.
That is, the formation position of the surface conductor and the inner conductor may be avoided in the range of about 100 μm in the peripheral portion, and is preferably 200 μm or more if more reliability is taken into consideration.

FIG. 1 is a block diagram showing a schematic configuration of a circuit of a dual-band GSM telephone to which the high-frequency module component of one embodiment of the present invention is applied. FIG. 2 is a circuit diagram of a circuit that is modularized as a high-frequency module component according to an embodiment of the present invention. FIG. 3 is a diagram showing the structure of the high-frequency module component of one embodiment of the present invention. FIG. 4 is a view for explaining a bonding state of the SAW element to the ceramic multilayer substrate. FIG. 5 is a diagram of the ceramic multilayer substrate as viewed from the component mounting surface, and is a diagram for explaining a conductor placement prohibited region. FIG. 6 is a diagram showing the structure of a high-frequency module component according to another embodiment of the present invention. FIG. 7 is a diagram showing the structure of a high-frequency module component according to still another embodiment of the present invention. FIG. 8 is a diagram illustrating a general structure of a conventional antenna switching module. FIG. 9 is a diagram showing a module configured using a conventional packaged SAW element. FIG. 10 is a diagram showing a structure of a module having an electrode pattern on a conventional side surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2, 3 ... High frequency module component 10 ... Ceramic multilayer substrate 11 ... Component mounting surface 12 ... Bottom surface 13 ... Conductor pattern 14 ... Conductor arrangement | positioning prohibition area | region 15 ... Input / output terminal 21 ... SAW element 22 ... Solder junction element 23 ... Al- Cu alloy layer 24 ... Ni layer 25 ... Au plating layer 26 ... Solder ball 27 ... Au bump 28 ... Comb electrode forming surface 30 ... Sealing resin 31, 33, 34 ... Void (space)
32 ... Upper surface

Claims (8)

A plurality of surface acoustic wave elements;
A multilayer substrate in which an electric circuit connected to the surface acoustic wave element is built;
A sealing member formed on the surface acoustic wave element mounting surface of the multilayer substrate so as to cover and seal the surface acoustic wave element;
A module component having an input / output terminal of the electric circuit provided on the multilayer substrate,
The multilayer substrate, the surface acoustic wave element mounting surface, the peripheral region within a predetermined distance from the circumferential side, is formed such that there is a conductor pattern Rutotomoni, so as not to include the inner conductor further in the peripheral region Formed into
The surface acoustic wave device is mounted on the multilayer substrate such that the comb-shaped electrode faces the surface acoustic wave device mounting surface of the multilayer substrate,
The sealing member is fixed to the multilayer substrate at least in the peripheral region, maintains the spaces between the comb electrodes of the surface acoustic wave elements and the multilayer substrate, and the spaces are continuous. Covering and sealing the plurality of surface acoustic wave elements so as to be formed as one space,
The input / output terminal is a high frequency module component provided on a surface of the multilayer substrate opposite to the surface acoustic wave element mounting surface. The peripheral region is a region whose distance from the peripheral side surface of the multilayer substrate is within 100 μm.
The high-frequency module component according to claim 1 . The sealing member is fixed to each of the plurality of surface acoustic wave elements only on the surface opposite to the surface on which the comb-shaped electrode is formed, and does not adhere to the side surface of each surface acoustic wave element. As described above, the plurality of surface acoustic wave elements are covered and sealed
The high-frequency module component according to claim 1 or 2 . Each of the plurality of surface acoustic wave elements is mounted on the multilayer substrate by face-down bonding.
The high-frequency module component according to any one of claims 1 to 3. Each of the plurality of surface acoustic wave elements is flip-chip mounted on the multilayer substrate by gold-gold bonding.
The high-frequency module component according to claim 4 . The sealing member is formed so that the surface opposite to the surface in contact with the multilayer substrate is smooth.
The high-frequency module component according to any one of claims 1 to 5 . The multilayer substrate is a low-temperature simultaneous sintered substrate in which an inductor and a capacitor are formed.
The high-frequency module component according to any one of claims 1 to 6 . The sealing member is formed by a resin mold.
The high-frequency module component according to claim 1 .

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