JP2005101367A - High-frequency module and communication equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-frequency module which can suppress the heat generated by a power amplifier, can sufficiently radiate the heat, and can be reduced in height, and in which a passive component, such as the surface acoustic wave element etc., can be loaded together with the power amplifier; and to provide a communication terminal using the module. <P>SOLUTION: The high-frequency module is constituted by mounting a power amplifying element 5 and the passive component 6 on the surface of a dielectric substrate 2 formed by laminating dielectric layers A upon another, and, at the same time, by providing heat sinks 9 in the dielectric substrate 2 immediately under the mounting section of the power amplifying element 5 through the substrate 2 from the front surface side to the rear surface side. The minimum diameters of the heatsinks 9 in their cross sections are adjusted to become three times or more larger than the thicknesses t of the dielectric layers A. It is particularly preferable that the dielectric substrate 2 is composed of the laminate of conjugated materials A formed by embedding at least conductor layers in dielectric layers having thicknesses t of ≤0.1 mm in identical thicknesses, and the minimum diameters of the cross sections of the heatsinks 9 are ≥0.3 mm. It is also preferable that the heatsinks 9 are composed of mixtures of conductor phases 11 and dielectric phases 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a high-frequency module for transmission used in communication equipment such as a mobile communication terminal such as a mobile phone, wireless LAN, and WLL (Wireless Local Loop), and more particularly, a high-frequency module capable of reducing assembly man-hours and downsizing. It is about.

  In recent years, there is a strong demand for miniaturization and weight reduction of semiconductor devices and electronic components used in mobile communication devices such as analog or digital mobile phones. In particular, high-frequency power amplifiers used in transmitters are becoming smaller and more modular in power amplification transistors, and the heat generated from high-frequency power amplifiers affects not only the components but also the characteristics of surrounding components. Therefore, it is desired to improve heat dissipation at the time of high power output.

As a heat dissipation measure for such a high-frequency power amplifier, a heat radiator is fitted in a through hole formed in the insulating substrate immediately below the heat-generating element mounted on the insulating substrate (Patent Document 1). It has been proposed to dissipate heat generated from a heat-generating element to the back surface of the substrate by providing a via hole for heat dissipation in the substrate (Patent Documents 2 and 3).
JP 2001-68615 A JP-A-9-283700 JP2003-1000098

  High-frequency modules are required to be reduced in size and cost, and among them, it is also proposed to mount and mount passive components such as surface acoustic wave elements, FBARs, and antenna switch components together with high-frequency power amplifiers. However, since passive components easily change their high-frequency characteristics due to heat, it is necessary to minimize the influence of heat when mounting such passive components.

  However, in the structure in which the metal block for heat dissipation is fitted into the substrate as in Patent Document 1, the metal block is fitted with high accuracy without impairing the airtightness, and a joining process is required, resulting in complicated processes and cost. The rise of was inevitable.

  In addition, as in Patent Documents 2 and 3, in a structure in which a heat radiating via hole is provided, a heat radiating via hole is usually formed by filling a through hole formed in an insulating layer with a conductive paste. If the thickness of the insulating layer is too large, the conductor paste will flow out of the through hole. Therefore, if the insulating layer is not thickened, a heat radiating via hole with a large hole diameter cannot be formed. The thickness of the layer was inevitably increased.

  As a result, in order to cope with the miniaturization and high-density wiring of the module, since it is necessary to increase the number of insulating layers, the entire thickness of the module itself is increased. There was a limit to increasing the diameter of the.

  The present invention has been made in view of the above-described problems in the prior art, and its purpose is to suppress heat generation by the power amplifier, to have sufficient heat dissipation, and to mount passive components such as surface acoustic wave elements together with the power amplifier. An object of the present invention is to provide a high-frequency module that can be reduced in height and a communication terminal using the same.

  The high-frequency module of the present invention has a power amplification element and a passive component mounted and mounted on a dielectric substrate surface formed by laminating dielectric layers, and a dielectric substrate directly below the power amplification element mounting portion. Inside, a heat radiating body penetrating from the substrate surface side to the substrate back surface side is provided, and the minimum diameter in the cross section of the heat radiating body is three times or more with respect to the thickness t of the dielectric layer.

  In addition, in this high frequency module, it is suitable when mounting at least 1 sort (s) chosen from the group of a surface acoustic wave element, FBAR, and an antenna switch component as said passive component.

  Furthermore, on the dielectric substrate, at least one kind of output detection component selected from the group of a Schottky diode, a detection diode, a detection IC, and an APCID may be mounted.

  According to the high frequency module of the present invention, the thickness t of the dielectric layer is 0.1 mm or less, and the minimum diameter of the cross section of the radiator is 0.3 mm or more. It is suitable for improving heat dissipation as well.

  Further, the radiator is composed of a mixture of a conductor phase and a dielectric phase. Specifically, the radiator is composed of a mixture of 20 to 80 area% conductor phase and 80 to 20 area% dielectric phase. It is desirable to become. As a result, it is possible to suppress the generation of stress due to the difference in thermal expansion from the dielectric substrate by increasing the diameter of the radiator.

  Further, as a shape of the heat radiating body, the cross section of the heat radiating body has a donut shape having a dielectric phase inside and a conductor phase around, the heat radiating body contains a conductor phase at the center and a conductor at the periphery. The heat dissipating body having a donut shape made of a dielectric phase, the dielectric phase being scattered in the conductor phase, and the dielectric phase being scattered in a plane with respect to the conductor phase. In order to suppress stress, it is desirable that the dielectric phase is three-dimensionally scattered with respect to the conductor phase.

  Further, the dielectric substrate is preferably formed from a composite laminate in which at least a conductor layer is embedded in the same thickness in a dielectric layer having a thickness of 0.1 mm or less. It is desirable that the radiator is also formed by a laminated body of radiator layers having a thickness of 0.1 mm or less. According to such a configuration, by laminating such composites, it is possible to easily form circuits of any complicated form, and to simplify the manufacturing process.

  Note that by arranging the high-frequency module in a communication device, it is possible to reduce the size of a portable terminal or the like.

  According to the high frequency module of the present invention, the heat generated from the power amplifier can be efficiently dissipated to the back surface of the module substrate. Passive components such as wave elements and output control circuit elements can be arranged. As a result, a small and high-performance high-frequency module can be provided.

  In addition, by reducing the thickness of the dielectric layer, the module can be formed with high-density wiring, and the height of the module can be reduced.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an embodiment of the high frequency module of the present invention. In the high-frequency module 1 shown in the figure, 2 is a dielectric substrate, 3 is a high-frequency line or electrode formed on the surface or inside of the dielectric substrate 2, and 4 is for connecting the high-frequency lines 3 to each other in the vertical direction. Vertical conductor 5 is a power amplifier mounted on the substrate 2, 6 is a passive component mounted on the dielectric substrate 2, 7 is a chip component such as a chip resistor or chip capacitor mounted on the dielectric substrate 2, 8 is an output detection control component mounted on the dielectric substrate 2, 9 is a heat radiator formed in the dielectric substrate 2 below the power amplifier 5, 10 is a dielectric phase provided in the heat radiator, and 11 is a heat radiator. A conductor phase 12 is a bonding wire.

  In such a high-frequency module, each electrode (source, gate, drain) of the power amplifier 5 is electrically connected to the high-frequency line 3 on the surface of the substrate by a bonding wire 11.

  On the other hand, the passive component 6, the chip component 7, and the output detection control component 8 are mounted and mounted on a high-frequency line or electrode 3 formed on the upper surface of the dielectric substrate 2 using solder or the like.

  The power amplifier 5, the passive component 6, the chip component 7, and the output detection control component 8 mounted and mounted on the upper surface of the dielectric substrate 2 are sealed with an insulating resin 13. In addition, the high frequency module 1 is finally mounted with the electrodes 3 formed on the back surface of the module 1 by soldering or the like on the surface of an external electric circuit board 14 such as a mother board in a communication device.

  In the wiring board 2 of the present invention, a metal layer 22a penetrates through the dielectric layer 21a and has the same thickness as a part of the dielectric layer 21a containing at least a ceramic dielectric material as shown in FIG. The composite A formed is a basic component, and is composed of a laminate of the composite A.

  According to the wiring board having such a structure, the dielectric layer 21a and the conductor layer 22a are complicatedly arranged two-dimensionally and three-dimensionally by changing the pattern of the dielectric layer 21a and the conductor layer 22a of the composite A. A structure can be formed.

  Further, the conductor layer 22a forms a wiring conductor layer and an electrode 3 to be a planar circuit by extending the dielectric layer 22a in the planar direction. Further, by partially stacking the conductor layer 22a in the thickness direction, the wiring conductor layer, the vertical conductor 4 that electrically connects the electrodes 3 and the conductor layer 22a can also function as a radiator layer. By stacking in the vertical direction, the radiator 9 penetrating from the front surface to the back surface of the dielectric substrate 2 can be formed.

  According to the present invention, it is important that the minimum diameter D in the cross section of the radiator 9 is 3 times or more, particularly 4 times or more, and even 5 times or more with respect to the thickness t of the dielectric layer made of the composite A. It is. As a result, the heat dissipation from the power amplifying element 5 can be improved, and the high-frequency module can be simultaneously reduced in size and height. In particular, D / t is desirably 4 or more, particularly 5 or more.

  More specifically, the thickness of the dielectric layer 21a and the conductor layer 22a after firing is preferably 0.1 mm or less, particularly 10 to 50 μm, more preferably 15 to 30 μm. As a result, it is possible to form a wiring board having a complicated conductor pattern with a reduced thickness. The diameter D of the radiator 5 is preferably 0.3 mm or more, particularly 0.5 mm or more, and more preferably 0.6 mm or more.

  Further, according to this configuration, the arrangement of the power amplifying element 5 and the passive component 6 such as a surface acoustic wave element can be reduced to 2 mm or less, particularly 1 mm or less.

  According to the present invention, when the large-diameter radiator 5 is formed, the dielectric layer 21a and the conductor layer 22a in the composite A are controlled to dispose the composite when the composite is laminated. It is desirable to form a structure in which the body phase and the conductor phase are mixed. Thereby, the generation of stress due to the difference in thermal expansion between the conductor component and the dielectric substrate 2 can be reduced.

  For example, by changing the pattern shape or the like of the conductor layer 22a, a small-diameter radiator, a large-diameter radiator, a radiator having a donut-shaped cross section, or a radiator in which a dielectric phase is dispersed in a plane Can be formed. Furthermore, by arbitrarily changing the position of the conductor layer 22a in each composite sheet, the dielectric layers in the radiator 5 can be three-dimensionally scattered.

  The conductor layer 22a need not be composed of only the conductor phase, and may be formed by screen printing or the like in which a plurality of phases in which the conductor phase and the conductor and the dielectric are mixed at an arbitrary ratio may be formed. By using a phase in which the conductor phase is mixed inside and the conductor and dielectric are mixed at an arbitrary ratio in the outer peripheral portion, a structure that suppresses the stress generated in the radiator can be achieved.

  A specific example will be described below. As shown in FIG. 1B, the heat dissipating body 9 is formed so that the dielectric phase 10 penetrates from the front surface to the back surface of the substrate at the center of the substantially rectangular conductor phase 11. The donut shape is formed. As a result, the dielectric phase 7 located in the central portion can suppress the thermal expansion of the conductor phase 6, and can relieve stress due to the difference in thermal expansion from the dielectric substrate 2.

  FIG. 2 shows a structure in which a plurality of dielectric phases 10 are formed in the conductor phase 11 and the dielectric phases 10 are dotted in a plane. As a result, the function of the dielectric phase 7 to relieve stress can be further increased.

  FIG. 3 shows a structure in which the position of the dielectric layer 11a formed in the composite A is changed for each layer, and thus has a structure in which the dielectric phases 10 are three-dimensionally scattered. According to such a structure, the dielectric phase 7 can further increase the function of uniformly relaxing the thermal expansion of the conductor phase 6 in the planar direction and the vertical direction, thereby further suppressing the generation of stress.

  In FIG. 4, the conductor phase 11 is disposed at the center of the radiator 9 and the dielectric phase 10 a is disposed around the conductor phase 11. In particular, it is desirable that the surrounding dielectric phase 10a is formed of a mixed phase in which conductors are mixed at an arbitrary ratio. Such a mixed phase of the conductor and the dielectric has a thermal expansion characteristic intermediate between the conductor phase 11 and the dielectric substrate 2, whereby stress generated between the conductor phase 11 and the dielectric substrate 2 is caused to be generated in this dielectric. The body phase 10a has a function of relaxing. It is desirable that the dielectric has a material composition in which the conductor is difficult to diffuse and there is no rapid reaction between the two. In this case, the content of the conductor in the dielectric phase 10a is 10 to 90% by volume, desirably 20 to 80% by volume.

  According to the present invention, when the radiator is formed by the mixture of the dielectric phase and the conductor phase as described above, the conductor component is 20 to 20 as the overall ratio of the dielectric component and the conductor component in the radiator 9. It is appropriate to be composed of a mixture of 80% by volume and 80-20% by volume of the dielectric component. By setting it as this ratio, generation | occurrence | production of the stress by a thermal expansion difference can be reduced effectively.

  The dielectric phase in the radiator 9 is preferably made of the same material as the dielectric material forming the dielectric substrate 2.

  As the power amplifier 5 in the high-frequency module 1 of the present invention, for example, a pn junction gate type field effect transistor, a Schottky barrier gate type field effect transistor, a hetero junction type field effect transistor, a pn junction gate type hetero junction type is used. A field effect transistor or the like is used.

  The power transistor 5 is fixed by a die attach material such as Au / Sn, Au / Si, solder, thermosetting Ag paste, etc. and is also electrically connected, and has a thickness of about 0.03 mm made of Au or the like. The bonding wire 10 is electrically connected to the high-frequency line 3 through the connection conductor 4 led out on the upper surface of the substrate 2 or the conductor layer extended to the connection conductor 4.

  The passive component 6 in the high-frequency module 1 of the present invention includes an antenna switch that switches between transmission and reception, a diplexer that divides frequency bands, a SAW duplexer that separates transmission and reception by frequency, an FBAR (Film Bulk Acoustic Resonator), and a dielectric duplexer. A SAW band-pass filter for filtering is used.

As the RFIC, a transmission IC, a reception IC, an intermediate direct conversion IC, or the like is used.

  As the chip component 7 in the high-frequency module 1 of the present invention, a surface mount type chip resistor, a chip capacitor, or the like used as a matching circuit or a bias circuit of a power amplifier is used.

  Examples of the output detection control component 8 in the high-frequency module 1 of the present invention include an automatic output control IC and a detector IC that incorporate a coupler, a detection diode, and a temperature compensation circuit.

  The insulating resin 13 for sealing in the high-frequency module 1 of the present invention uses, for example, an epoxy resin or a silicone resin, and after the wire bonding of the power amplifier 5, the insulating resin is molded by vacuum printing or a mold and dried. -The power amplifier 5 is sealed by curing.

  In addition to this, it is possible to protect the power amplifier 5 from the external environment to ensure stability of electrical characteristics and reliability such as waterproofing, and to reduce the size of the high-frequency module by mounting the power amplifier 5 in a bare chip state. Can be achieved.

  A basic method for manufacturing the module as described above will be described with reference to FIGS. First, in manufacture, a photocurable dielectric slurry and a conductor paste are prepared.

  The photocurable dielectric slurry contains at least a photocurable monomer and a ceramic dielectric material. In preparing the slurry, it is desirable that the ceramic powder is prepared by mixing a photocurable monomer, a photopolymerization initiator, an organic binder, and a plasticizer in an organic solvent and kneading them with a ball mill.

  Examples of the photocuring component include a photocurable monomer and a photopolymerization initiator. As the photocurable monomer, it is desirable that the monomer is excellent in thermal decomposability in order to cope with a low-temperature and short-time baking process. In addition, the photo-curable monomer needs to be photopolymerized by exposure after application and drying of the slip material, and can form free radicals and chain-growth addition polymerization, and has a secondary or tertiary carbon. Preferred examples include alkyl acrylates such as butyl acrylate having at least one polymerizable ethylene group, and alkyl methacrylates corresponding thereto. In addition, polyethylene glycol diacrylates such as tetraethylene glycol diacrylate and methacrylates corresponding thereto are also effective. Examples of the photoinitiating material include benzophenones and acyloin ester compounds.

  In addition, the organic binder is desired to have good thermal decomposability like the photo-curable monomer, and at the same time, it determines the viscosity of the slip, so it is necessary to consider the wettability with the solid content. is there. According to the present invention, an ethylenically unsaturated compound having a carboxyl group and an alcoholic hydroxyl group such as an acrylic acid or methacrylic acid polymer is preferred.

  Examples of the organic solvent include at least one selected from the group consisting of ethyl carbitol acetate, butyl cellosolve, and 3 methoxybutyl acetate.

  The content of each component is 5 to 20 parts by mass of a photocurable monomer and a photopolymerization initiator, 10 to 40 parts by mass of an organic binder, 1 to 5 parts by mass of a plasticizer, and an organic solvent per 100 parts by mass of the ceramic powder. A ratio of 50 to 100 parts by mass is appropriate.

  On the other hand, the conductive paste has an organic binder such as ethyl cellulose and acrylic resin added to the inorganic component obtained by adding a ceramic material to the powder of the conductive material having an average particle size of about 1 to 3 μm as necessary. It is prepared by mixing a suitable solvent such as phthalate, α-terpineol, butyl carbitol, 2,2,4-trimethyl-3,3-pentadiol monoisobutyrate, and kneading homogeneously with a three-roller or the like.

  Next, a composite sheet is formed by the following steps using the above-mentioned photo-curing dielectric slurry and conductor paste.

  First, as shown in FIG. 5A, the conductor paste is printed and applied on a light transmissive carrier film 20 made of a resin film or the like by a general printing method such as a screen printing method. A predetermined conductive pattern layer 21 having transparency is formed.

  Next, as shown in FIG. 5B, the photocuring slurry is applied to a thickness equal to or greater than the thickness of the conductor pattern layer 31 by, for example, a doctor blade method, and applied to the entire surface with a predetermined thickness. A photocurable ceramic layer 32 is formed.

  And as shown in FIG.5 (c), it exposes from the back surface of the carrier film 30 using an ultrahigh pressure mercury lamp as a light source, for example. By this exposure, the photo-curing ceramic layer 32 in a region other than the formation of the conductor pattern layer 31 is photo-cured. In this exposure process, the photocuring ceramic layer 32 is subjected to a photopolymerization reaction from the back surface to a certain thickness depending on the amount of light irradiated in the photocuring ceramic layer 32 in a region other than the formation of the conductor pattern layer 31 to form an insolubilized portion. However, since the conductor pattern layer 31 does not pass ultraviolet rays, the photo-curing ceramic layer 32 formed on the conductor pattern layer 31 becomes a solubilized portion where the photopolymerization reaction of the photo-curable monomer does not occur. Further, the exposure amount at this time is preferably adjusted so that the thickness of the insolubilized portion is substantially the same as the thickness of the conductor pattern layer 31.

  Thereafter, the entire photocurable ceramic layer 32 is developed. The development process is to remove the solubilized portion of the photo-curing ceramic layer 32 with a developer. Specifically, for example, spray development, washing, and drying are performed using a triethanolamine aqueous solution or the like as the developer. By this treatment, as shown in FIG. 5D, a composite sheet A in which the conductor pattern layer 31 and the photo-curing ceramic layer 32 are integrated with substantially the same thickness is formed on the carrier film 30.

  In addition, this composite sheet A can obtain the composite sheet A simple substance as shown in FIG.5 (e) by peeling the composite sheet A from the carrier film 30. FIG.

  Next, in manufacturing the wiring board of FIG. 1 using the composite sheet A, the photo-curing ceramic layer 32 and the conductor pattern layer 31 having a predetermined pattern were formed according to FIGS. 5A to 5E. A plurality of composite sheets A1 to A14 are produced.

  And as shown to Fig.6 (a), while aligning these composite sheets A1-A14, the laminated body 33 is formed by carrying out superposition | stacking and crimping | bonding together. Further, when the composite sheet is thin, the carrier film 30 is overlapped with the carrier film 30 attached to the surface of the predetermined substrate without peeling from the carrier film 30, and the carrier film is peeled off. Then, the same laminated body 33 as FIG.6 (b) can be produced by repeating on a composite sheet surface similarly.

  In addition, it is desirable to perform the lamination pressure bonding while applying a temperature equal to or higher than the glass transition point of the organic binder contained in the composite sheet A. Further, an organic adhesive may be applied between the composite sheets A and pressure bonded.

  Then, by firing this laminated body 33 at a predetermined temperature, a wiring board on which a three-dimensional circuit is formed by the conductor pattern layer 31 can be produced. In firing, the produced laminate 33 is removed by a debuying process, the organic binder and the photocurable monomer contained in the molded body are lost, and the firing process is performed in an inert atmosphere such as nitrogen. The ceramic material and the conductor material used are fired at a temperature at which they can be sufficiently fired, and are densified to a relative density of 95% or more.

The ceramic dielectric used in the above wiring board according to the present invention includes (1) a ceramic material whose main component is Al ₂ O ₃ , AlN, Si ₃ N ₄ , SiC and having a firing temperature of 1100 ° C. or higher, (2) at least Ceramic material fired at 1100 ° C. or lower, particularly 1050 ° C. or lower, comprising a mixture of metal oxides containing SiO ₂ and alkaline earth metal oxides such as BaO, CaO, SrO, MgO, (3) glass powder, or At least one selected from the group of low-temperature sinterable ceramic materials fired at 1100 ° C. or less, particularly 1050 ° C. or less, comprising a mixture of glass powder and ceramic filler powder is selected.

As the mixture of (2) and the glass composition of (3) used, SiO ₂ —BaO—Al ₂ O ₃ system, SiO ₂ —B ₂ O ₃ system, SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ systems, SiO ₂ —Al ₂ O ₃ —alkali metal oxide systems, and compositions in which alkali metal oxides, ZnO, PbO, Pb, ZrO ₂ , TiO _2, etc. are blended with these systems. Examples of the ceramic filler in (3) include at least one selected from the group consisting of Al ₂ O ₃ , SiO ₂ , forsterite, cordierite, mullite, AlN, Si ₃ N ₄ , SiC, MgTiO ₃ , and CaTiO _3. The glass is preferably mixed at a rate of 20 to 80% by mass with respect to the glass.

  On the other hand, the conductor pattern layer is variously combined according to the firing temperature of the ceramic material. For example, when the ceramic material is (1), the conductor is mainly composed of at least one selected from the group consisting of tungsten, molybdenum, and manganese. Materials are preferably used. Moreover, it is good also as a mixture with copper etc. for resistance reduction.

  When the ceramic material is (2), a conductor material mainly composed of at least one selected from the group consisting of copper, silver, gold, and aluminum is preferably used.

  The conductor material preferably contains a component constituting the ceramic material when co-firing with the ceramic material.

  According to the present invention, the conductor layer 31 and the dielectric 32 formed on the surface of the carrier film 30 in FIG. 5A are simply formed into various patterns shown in FIGS. Thus, the complicated heat dissipation structure shown in FIGS. 1 to 4 can be formed.

  As shown in FIG. 4, when using a mixture of a dielectric and a conductor, a slurry made of a mixture of a dielectric and a conductor is prepared in advance, and then the conductor layer 31 shown in FIG. It may be printed and applied in the same manner, and then the photocurable dielectric slurry 32 may be applied after the conductor paste is printed and applied.

  A conductive paste was printed on a light transmissive carrier film made of PET (polyethylene terephthalate) having a thickness of 100 μm by a screen printing method to form a conductive pattern layer serving as an electrode layer having a thickness of 20 μm. In addition, the conductor paste used what mixed barium borosilicate glass powder, ethyl cellulose, 2,2,4-trimethyl-3,3-pentadiol monoisobutyrate as an organic solvent, and mixed with a three roll mill to Ag powder. .

  Next, a photosensitive slurry was applied and dried on the conductor pattern layer by a doctor blade method to form a photo-cured ceramic layer so that the thickness after drying in a place where no conductor pattern was present was 28 μm.

  The photosensitive slurry is 100 parts by mass of ceramic raw material powder, 8 parts by mass of photocurable monomer (polyoxyethylated trimethylolpropane triacrylate), 35 parts by mass of organic binder (alkyl methacrylate), and 3 parts by mass of plasticizer. Parts were mixed with an organic solvent (ethyl carbitol acetate) and kneaded with a ball mill.

The ceramic raw material powder is 10 parts by mass in terms of B ₂ O ₃ and 5 parts in terms of LiCO ₃ with respect to 100 parts by mass of the main component represented by 0.95 mol MgTiO ₃ -0.05 mol CaTiO _3. What added the mass part was used.

Next, the entire surface was exposed from the back surface side of the carrier film to the back surface of the photocurable ceramic layer for 2 seconds using an ultrahigh pressure mercury lamp (illuminance 30 mW / cm ² ) as a light source. Then, spray development was performed for 30 seconds using a triethanolamine aqueous solution having a dilution concentration of 2.5% as a developer. Thereafter, the film was dried after being washed with pure water after development.

  In this way, the completed photo-cured ceramic layer has a solubilized portion on the electrode layer removed by development to expose the electrode layer. As a result, the conductor layer and the photo-cured ceramic layer are integrated, and the thickness after firing is A 50 μm composite sheet could be produced.

  Similarly, a composite sheet having a total of 14 layers with a thickness of 50 μm after firing, comprising conductor pattern layers for the internal wiring conductor layer, the surface wiring conductor layer, the via conductor, and the radiator was prepared.

  From the composite sheet produced as described above, the carrier film was peeled off, and the carrier film was peeled off after the lamination while sequentially aligning or after lamination. Thereafter, using a press machine, pressing was performed for 5 minutes at a pressing pressure of 1 ton and a temperature of 60 ° C., and the laminate was pressure bonded. Thereafter, the binder removal treatment was performed in the atmosphere at 300 ° C. for 4 hours, and then the substrate was baked in the atmosphere at 900 ° C. for 6 hours to produce a module substrate.

  Next, after solder is printed on the surface of the module substrate, the chip component and the surface acoustic wave element are solder mounted in a reflow furnace, and then the silver paste is applied and the power amplifying element is mounted. Bonding was done with gold wire. Thereafter, resin sealing was performed using an epoxy resin. The surface acoustic wave element and the power amplifying element were separated so that the minimum distance L was 1 mm.

In addition, as the structure of the radiator, a wiring board was prepared in which the structure of the radiator having a minimum cross-sectional shape of 0.1 to 1 mm was changed. In FIG. 1 to FIG. 3, the dielectric phase is dotted with a diameter of 0.03 mm. In addition, in the radiator of FIG. 4, a dielectric having a conductor having a diameter of 0.05 to 0.2 mm in the center and a mixture of a dielectric and a conductor having a diameter of 0.1 to 0.8 mm around the conductor. A phase was set up. A bias voltage of 3.4 V and a reference voltage of 2.85 V were applied thereto, and input power was applied so that the output from the power amplifying element was 28 dBm. Under these conditions, the back surface temperature of the wiring board and the surface acoustic wave element surface temperature were measured with a thermocouple. Furthermore, this circuit board is subjected to 1000 cycles in a temperature cycle test from −40 ° C. to + 125 ° C., and after the test, it is inspected for the presence or absence of cracks and airtightness in the surroundings, and the number of defects generated. Are shown in Table 1.

  From Table 1, it was possible to reduce the height of the module with good heat dissipation by setting the minimum diameter of the radiator to three times or more the thickness of the dielectric layer. In addition, the reliability of the module could be improved by forming the heat radiator with a mixed phase of a dielectric phase and a conductor phase.

It is (a) schematic sectional drawing which shows an example of the high frequency module of this invention, (b) The schematic sectional drawing of a composite_body | complex, (c) The x1-x1 schematic plan view for demonstrating the structure of a heat radiator. It is a schematic plan view which shows the other structure of the heat radiator in the high frequency module of this invention. It is (a) schematic sectional drawing which shows other structure of the heat sink in the high frequency module of this invention, and (b) x2-x2 schematic plan view. It is (a) schematic sectional drawing which shows the other structure of the heat sink in the high frequency module of this invention, and (b) x3-x3 schematic plan view. It is process drawing for demonstrating the manufacturing process of the high frequency module of this invention. It is process drawing for demonstrating the manufacturing process of the high frequency module of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... High frequency module 2 ... Dielectric substrate 3 ... High frequency line 4 ... Vertical conductor 5 ... Power amplification element 6 ... Passive component 7 ... Chip component 8 ... Output detection Control part 9 ... Heat radiator 10..Dielectric phase 11..Metal phase 12..Bonding wire 13..Insulating resin 14 ... External circuit board

Claims (16)

A power amplifying element and a passive component are mounted and mounted on the surface of the dielectric substrate formed by laminating the dielectric layers, and the dielectric substrate just below the power amplifying element mounting portion is mounted from the substrate surface side. A high-frequency module comprising a heat dissipating body penetrating on the back side of the substrate, wherein a minimum diameter in a section of the heat dissipating member is at least three times the thickness t of the dielectric layer. 5. The high-frequency module according to claim 1, wherein the passive component is at least one selected from the group consisting of a surface acoustic wave element, an FBAR, and an antenna switch component. 2. The high-frequency module according to claim 1, wherein at least one output detection component selected from the group consisting of a Schottky diode, a detection diode, a detection IC, and an APCIC is further mounted on the dielectric substrate. The high-frequency module according to claim 1, wherein a thickness t of the dielectric layer is 0.1 mm or less. The high-frequency module according to claim 1, wherein a minimum diameter of a cross section of the radiator is 0.3 mm or more. The high-frequency module according to claim 1, wherein the heat dissipating body is composed of a mixture of a conductor phase and a dielectric phase. The high-frequency module according to claim 6, wherein the heat dissipating body comprises a mixture of a conductor phase of 20 to 80 area% and a dielectric phase of 80 to 20 area%. The high-frequency module according to claim 6, wherein a cross section of the heat dissipating body has a donut shape with a dielectric phase inside and a conductor phase around. 7. The high-frequency module according to claim 6, wherein the heat dissipating body has a donut shape having a conductor phase at the center and a dielectric phase containing a conductor at the periphery. The high-frequency module according to claim 6, wherein the heat dissipating body has the dielectric phase interspersed in the conductor phase. The high-frequency module according to claim 6, wherein the dielectric phase is scattered in a plane with respect to the conductor phase. The high-frequency module according to claim 6, wherein the dielectric phases are three-dimensionally scattered with respect to the conductor phase. 13. The high frequency device according to claim 1, wherein at least a surface acoustic wave element is mounted as the passive component, and a shortest distance between the power amplifier and the surface acoustic wave element is 2 mm or less. module. The high-frequency module according to claim 1, wherein the radiator is formed of a laminated body of radiator layers having a thickness of 0.1 mm or less. 2. The high-frequency module according to claim 1, wherein the dielectric substrate is made of a composite laminate in which at least a conductor layer is buried in the same thickness in a dielectric layer having a thickness of 0.1 mm or less. A communication device comprising the high-frequency module according to any one of claims 1 to 15.

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