JPH09162688A - Surface acoustic wave device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily keep a space around the comb-line electrode part of a surface acoustic wave element and also to miniaturize a surface acoustic wave device by locating a part of a projecting member of a specific shape formed on the side of mounting surface of a mounting substrate at a position between the comb-line electrode and a metallic bump. SOLUTION: The main surface of a surface acoustic wave element 15 where an electrode pad part 16 and a comb-line electrode part 17 are formed is mounted on a mounting substrate 1 in a face-down system. At the same time, the insulating resin 14 is prepared around a metallic bump 12 where the conductive resin 13 is applied with transcription to secure the electrical connection among an input/output electrode 4, a ground electrode 5 and the part 16. Furthermore, a projecting member 11 lower than the bump 12 is formed on the mounting surface of the substrate 1 and also a part of the member 11 is positioned between the part 17 and the bump 12. As a result, a space is easily kept around the part 17 of the element 15 even when the viscosity and amount of the resin 14 are not properly adjusted. Then a surface acoustic wave device an be miniaturized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface acoustic wave device, and more particularly to a surface acoustic wave device packaging structure in which surface acoustic wave elements are mounted in a face-down manner.

[0002]

2. Description of the Related Art With the development of mobile communication technology, demands for electrical characteristics and miniaturization of surface acoustic wave devices used as an interstage filter for transmitting and receiving of various mobile communication devices and an antenna filter are becoming more and more severe. It has become to.

A face-down mounting method is an effective method for downsizing the surface acoustic wave device. The face-down mounting method makes the functional surface of the element and the circuit board face each other, and electrically and mechanically connects both by a conductive bump or the like, and has a characteristic that a bonding wire is unnecessary. In the surface acoustic wave element, since the surface acoustic wave propagates through its functional surface, a space is required on the functional surface that does not hinder the propagation of the surface acoustic wave.

Now, a conventional surface acoustic wave device will be described with reference to FIG. 11A is a cross-sectional view of the surface acoustic wave device [A-B cross-sectional view in FIG. 11B], and FIG. 11B is a top view of a mounting substrate in the device.

In FIG. 11, reference numeral 21 denotes a mounting board, and 22
Is a dielectric layer, 23 is an input / output electrode, 24 and 25 are ground electrodes, 26 is an external electrode, 27 is an external terminal, 28 is a via hole, 29 is a metal bump, 30 is a conductive resin, 31 is an insulating resin, 32 Is a surface acoustic wave element, 33 is an electrode pad portion,
34 is a comb-shaped electrode part, 35 is a metal cap, and 36 is solder.

The surface acoustic wave device configured as described above will be described. An electrode pad portion 33 and a comb-shaped electrode portion 34 are formed on the surface acoustic wave element 32, and the electrode pad portion 33 is made of metal made of gold or aluminum. A mounting substrate 21 in which bumps 29 are formed, a conductive resin 30 is transferred and applied to the tips thereof, and input / output electrodes 23 and ground electrodes 24 are formed on the main surface side of the surface acoustic wave element 32 and the dielectric layer 22.
After facing each other and performing alignment, the surface acoustic wave element 32 is mounted. After that, the conductive resin 30 is heated and hardened, and the surface acoustic wave element 32 is fixed to the mounting substrate 21 for electrical and mechanical connection. Further, the viscosity and amount around the surface acoustic wave element 32 are properly adjusted. The adjusted insulating resin 31 was injected and cured by heating to reinforce the adhesive strength between the surface acoustic wave element 32 and the mounting substrate 21.

The input / output electrode 23 and the ground electrode 24 are electrically connected to the external electrode 26 via the via hole 28, and the ground electrode 25 is connected to the external electrode 2 via the external terminal 27.
6 was electrically connected to the metal cap 35, and the metal cap 35 was adhered to the ground electrode 25 with the solder 36 for hermetic sealing. In this way, the surface acoustic wave element 32
It was possible to maintain a space around the comb-shaped electrode portion 34.

[0008]

However, according to the above-mentioned structure, since it is necessary to maintain a space around the comb-shaped electrode portion 34 of the surface acoustic wave element 32, the viscosity is adjusted to a high viscosity and the amount is also adjusted. Although it is necessary to inject the insulating resin 31 thus prepared, it is difficult to properly adjust the insulating resin 31 because its proper range is narrow.

Since the insulating resin 31 is adjusted to have a high viscosity, the space S between the surface acoustic wave element 32 and the mounting substrate 21 is increased.
If the width is narrowed, it becomes difficult to inject the insulating resin 31, and the insulating resin 31 does not stably permeate to the periphery of the metal bump 29. Therefore, the adhesive strength between the surface acoustic wave element 32 and the mounting substrate 21 can be reinforced. In order to stably permeate the insulating resin 31 to the periphery of the metal bumps 29, it is necessary to widen the distance S between the surface acoustic wave element 32 and the mounting substrate 21, which makes it difficult to reduce the size.

The present invention solves the above problems,
(EN) Provided is a surface acoustic wave device which can easily maintain a space around the comb-shaped electrode portion of a surface acoustic wave element and can be downsized even when the viscosity and amount of the insulating resin are not properly adjusted. To aim.

[0011]

To achieve the above object, the surface acoustic wave device of the present invention has the following structure.

In the first structure, the input / output electrode and the ground electrode are formed on one mounting surface side and the external electrode is provided on the other surface side, and the input / output electrode and the ground electrode are respectively connected to the external electrode. A mounting substrate electrically connected, and a surface acoustic wave element having a principal surface on which an electrode pad portion and a comb-shaped electrode portion are formed mounted on the mounting substrate in a face-down manner,
Metal bumps provided on the side of the input / output electrodes and the ground electrodes, on which conductive resin that transfers and electrically connects these electrodes and the electrode pad portions, respectively, is transferred, and insulation disposed around the metal bumps. In a surface acoustic wave device made of a conductive resin, a convex member shorter than a metal bump is formed on the mounting surface side of the mounting substrate, and a part of the convex member is the comb-shaped electrode portion and the metal bump. It is a surface acoustic wave device configured to be located between.

In the second structure, the input / output electrode and the ground electrode are provided on one mounting surface side and the external electrode is provided on the other surface side, and the input / output electrode and the ground electrode are respectively the external electrode. A mounting substrate electrically connected to the surface acoustic wave device having a principal surface on which the electrode pad portion and the comb-shaped electrode portion are formed mounted on the mounting substrate in a face-down manner, and the input / output electrode and the ground electrode side. A metal bump that is provided with a conductive resin that is provided and electrically connects each of the electrodes and the electrode pad portion,
In a surface acoustic wave device formed of an insulating resin arranged around the metal bumps, a groove is formed on the mounting surface side of the mounting board, and a part of the groove is formed by the comb-shaped electrode and the metal bump. It is a surface acoustic wave device configured to be located between.

In the third structure, the input / output electrode and the ground electrode are provided on one mounting surface side and the external electrode is provided on the other surface side, and the input / output electrode and the ground electrode are respectively the external electrode. A mounting substrate electrically connected to the surface acoustic wave device having a principal surface on which the electrode pad portion and the comb-shaped electrode portion are formed mounted on the mounting substrate in a face-down manner, and the input / output electrode and the ground electrode side. A metal bump that is provided with a conductive resin that is provided and electrically connects each of the electrodes and the electrode pad portion,
In a surface acoustic wave device formed of an insulating resin arranged around the metal bumps, a groove is formed on the mounting surface side of the mounting board, and the groove is located outside the surface acoustic wave element. It is a configured surface acoustic wave device.

According to each of the above constructions, even if the viscosity and amount of the insulating resin are not properly adjusted, it is possible to easily maintain a space around the comb-shaped electrode portion of the surface acoustic wave element, and also to perform insulation. Since it is not necessary to adjust the viscosity of the conductive resin to a high level, even if the distance between the surface acoustic wave element and the mounting substrate is narrowed, the insulating resin can permeate the periphery of the metal bumps stably and easily. It is possible to reduce the size of the device.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. 1A is a cross-sectional view of the surface acoustic wave device according to the first embodiment of the present invention [A-B cross-sectional view in FIG. 1B], and FIG. 1B is the first embodiment of the present invention. FIG. 3 is a top view of the mounting board in the form of FIG.

In FIG. 1, 1 is a mounting substrate, 2 and 3
Is a dielectric layer, 4 is an input / output electrode, 5 and 6 are ground electrodes, 7
Is an external electrode, 8 is an external terminal, 9 and 10 are via holes,
Reference numeral 11 is a convex member, 12 is a metal bump, 13 is a conductive resin, 14 is an insulating resin, 15 is a surface acoustic wave element, 16 is an electrode pad portion, 17 is a comb-shaped electrode portion, 18 is a metal cap, and 19 is solder. Is.

The surface acoustic wave device configured as described above will be described. In the first embodiment, the mounting substrate 1 is composed of dielectric layers 2 and 3 made of a low temperature firing material that can be fired at 1000 ° C. or less, and has a green sheet-like dielectric layer 2 having via holes 9 and 10. The input / output electrode 4 and the ground electrode 5 are printed on the main surface side with an electrode paste, and after the electrode paste is dried, the surface acoustic wave device 1
5 is mounted, linear convex members 11 are formed of glass paste at two locations substantially parallel to each other so as to be located on both sides of the comb-shaped electrode portion 17 and between the metal bumps 12 and the comb-shaped electrode portion 17. It is a thing. Then, the ground electrode 6 is printed on the main surface side of the green sheet-shaped dielectric layer 3 having the concave portion, the dielectric layer 3 and the dielectric layer 2 are laminated in this order from above and baked at 900 ° C.

Next, the external electrodes 7 are printed with an electrode paste, and the external terminals 8 are applied or printed with the electrode paste and baked, and nickel / gold plating is applied. In this way, the external electrode 7 is electrically connected to the input / output electrode 4 via the via hole 9, the ground electrode 5 via the via hole 10, and the ground electrode 6 via the external terminal 8, respectively.

In the first embodiment, an Ag-based electrode paste is used as the electrode paste for the input / output electrodes, ground electrodes, external electrodes and external terminals. On the other hand, the surface acoustic wave element 15 uses 36 ° Y-X lithium tantalate in the present embodiment, and a conventional photolithography technique is used to form a metal mainly containing aluminum on the main surface side of the piezoelectric substrate. The electrode pad section 16 and the comb-shaped electrode section 17 are formed to form a surface acoustic wave filter used as an interstage filter of mobile communication equipment.

Next, the metal bumps 12 are formed on the electrode pad portion 16 of the surface acoustic wave element 15 using a known ball bonding device by using gold wires, and the height of the metal bumps 12 formed by the horizontal base is made uniform. After that, the conductive resin 13 is transferred and applied to the tip of the metal bump 12. Book first
In the embodiment described above, a thermoplastic conductive resin containing Ag—Pd alloy particles is used as the conductive resin.

Then, the input / output electrode 4 and the ground electrode 5 of the mounting substrate 1 are aligned with the metal bumps 12 formed on the surface acoustic wave element 15, and the conductive resin 13 is cured to electrically and mechanically. The thermosetting insulating resin 14 is injected (filled) from between the surface acoustic wave element 15 and the mounting substrate 1 to the periphery of the metal bump 12 to be hardened, and the surface acoustic wave element 15 is then cured. To reinforce the adhesive strength between the mounting substrate 1 and the mounting substrate 1. Further, the metal cap 18 is adhered to the ground electrode 6 with the solder 19 to maintain hermetic sealing.

In the surface acoustic wave device according to the first embodiment configured as described above, the convex member made of the glass paste is provided on the mounting surface side of the mounting substrate located between the metal bump and the comb-shaped electrode portion. Since it is formed, the convex member becomes a wall even if the viscosity and amount of the insulating resin are not properly adjusted,
The insulating resin does not flow into the periphery of the comb-shaped electrode portion of the surface acoustic wave element, so that a space can be easily maintained around the comb-shaped electrode portion of the surface acoustic wave element. As a result, the degree of freedom in the proper range of the viscosity and amount of the insulating resin is increased.

Further, since the degree of freedom of adjusting the viscosity of the insulating resin is increased, the insulating resin can be stably and easily injected into the periphery of the metal bump even if the distance between the surface acoustic wave element and the mounting substrate is narrow. Therefore, the adhesive strength between the surface acoustic wave element and the mounting substrate can be obtained, and the surface acoustic wave device can be downsized.

In the first embodiment, the convex member is formed at a position between the metal bump and the comb-shaped electrode portion, but it is sufficient if a space can be maintained around the comb-shaped electrode portion. The member may be formed at a position approaching the comb-shaped electrode portion, and the forming method is not limited to that of the first embodiment.

Although the convex member is made of glass paste, it may be made of dielectric paste or insulating resin. Further, although a low-temperature firing dielectric material that can be fired at 1000 ° C. or lower is used and a mounting board having a recess is used, the material and shape of the mounting board are not limited to this.

Further, although the input / output electrodes and the ground electrode of the mounting board are electrically connected to the external electrodes through the via holes, the connecting method is not limited to this, and the electrodes of the mounting board are Ag-based electrodes. Although the paste is used, the electrode material is not limited to this.

Next, a second embodiment of the present invention will be described with reference to FIG. 2A is a sectional view of the surface acoustic wave device according to the second embodiment of the present invention [A-B sectional view in (b)], and FIG. 2B is a second embodiment of the present invention. FIG. 3 is a top view of the mounting board in the form of FIG.

In FIG. 2, the same parts as those shown in FIGS. 1A and 1B are designated by the same reference numerals. Explaining the surface acoustic wave device configured as described above, the input / output electrode 4 and the ground electrode 5 are printed with an electrode paste on the main surface side of the green sheet-shaped dielectric layer 2 having the via holes 9 and 10. When the surface acoustic wave element 15 is mounted after the electrode paste is dried, the U-shaped convex member 11 is formed of glass paste at a position surrounding the metal bumps 12 from three sides. . Except for this portion, it is formed by the method shown in the above-described first embodiment, whereby a microminiature surface acoustic wave device having a convex member can be obtained.

The surface acoustic wave device according to the second embodiment configured as described above has the same operation and effect as the surface acoustic wave device according to the above-described first embodiment. In the second embodiment, a U-shaped convex member is formed for each metal bump, but as shown in the top view of FIG. 2C, the U-shaped convex member is formed. 2 in member 11
There may be more than one metal bump 12. Further, the material of the convex member, the material and configuration of the mounting board, and the method of constructing the convex member and the mounting board are limited to those of the second embodiment as described in the first embodiment. is not.

Next, a third embodiment of the present invention will be described with reference to FIG. 3A is a sectional view of the surface acoustic wave device according to the third embodiment of the present invention [A-B sectional view in FIG. 3B], and FIG. 3B is the third embodiment of the present invention. FIG. 3 is a top view of the mounting board in the form of FIG.

In FIG. 3, the same parts as those shown in FIGS. 1A and 1B are designated by the same reference numerals. Explaining the surface acoustic wave device configured as described above, the input / output electrode 4 and the ground electrode 5 are printed with an electrode paste on the main surface side of the green sheet-shaped dielectric layer 2 having the via holes 9 and 10. When the surface acoustic wave element 15 is mounted after the electrode paste is dried, the convex member 11 is formed of glass paste at a position that covers the entire comb-shaped electrode portion 17, that is, a size that covers the entire surface. It was done. Except for this part, the above-mentioned first
It is formed by the method shown in the above embodiment, and thereby a microminiature surface acoustic wave device having a convex member is obtained.

The surface acoustic wave device according to the third embodiment configured as described above has the same operation and effect as the surface acoustic wave device according to the above-described first embodiment. The material of the convex member, the material and configuration of the mounting board,
The method of configuring the convex member and the mounting board is not limited to the third embodiment, as described in the first embodiment.

Next, a fourth embodiment of the present invention will be described with reference to FIG. 4A is a sectional view of the surface acoustic wave device according to the fourth embodiment of the present invention [A-B sectional view in FIG. 4B], and FIG. 4B is the fourth embodiment of the present invention. FIG. 3 is a top view of the mounting board in the form of FIG.

In FIG. 4, the same parts as those shown in FIGS. 1A and 1B are designated by the same reference numerals. Explaining the surface acoustic wave device configured as described above, the input / output electrode 4 and the ground electrode 5 are printed with an electrode paste on the main surface side of the green sheet-shaped dielectric layer 2 having the via holes 9 and 10. Then, when the surface acoustic wave element 15 is mounted after the electrode paste is dried, the convex member 11 is formed of glass paste at a position surrounding the entire comb-shaped electrode portion 17. Except for this portion, it is formed by the method shown in the above-described first embodiment, whereby a microminiature surface acoustic wave device having a convex member can be obtained.

The surface acoustic wave device according to the fourth embodiment configured as described above has the same operation and effect as the surface acoustic wave device according to the first embodiment described above. The material of the convex member, the material and configuration of the mounting board,
The method of configuring the convex member and the mounting board is not limited to the fourth embodiment, as described in the first embodiment.

Next, a fifth embodiment of the present invention will be described with reference to FIG. 5A is a sectional view of the surface acoustic wave device according to the fourth embodiment of the present invention [A-B sectional view in FIG. 5B], and FIG. 5B is a fifth embodiment of the present invention. FIG. 3 is a top view of the mounting board in the form of FIG.

In FIG. 5, reference numeral 20 denotes a groove portion, and other symbols are assigned the same reference numerals for the same parts as those in FIGS. 1 (a) and 1 (b). The surface acoustic wave device configured as above will be described.

The mounting substrate 1 is composed of dielectric layers 2 and 3, and the dielectric layer 2 is composed of a plurality of layers 2-1 and 2-2. The input / output electrode 4 and the ground electrode 5 are printed with an electrode paste on the main surface side of the green sheet-shaped dielectric layer 2-1 having the via holes 9 and 10, and after the electrode paste is dried, a surface acoustic wave is formed. When the element 15 is mounted, the linear groove portion 20 is formed at two locations substantially parallel to each other so as to be located between the metal bump 12 and the comb-shaped electrode portion 17. Further, the ground electrode 6 is printed on the main surface side of the green sheet-shaped dielectric layer 3 having the concave portion, and the dielectric layer 3, the dielectric layer 2-1, and the dielectric layer 2-2 are arranged in this order from above. They are stacked and fired at 900 ° C. The external electrodes 7 and the external terminals 8 are formed by the method shown in the above-described first embodiment.

By mounting the surface acoustic wave element 15 on such a mounting substrate 1 by the method described in the first embodiment, a microminiature surface acoustic wave device having the groove 20 can be obtained. .

In the surface acoustic wave device according to the fifth embodiment having the above structure, the groove is formed on the mounting surface side of the mounting substrate located between the metal bump and the comb-shaped electrode portion. Even if the viscosity and amount of the insulating resin are not properly adjusted, the insulating resin does not flow into the groove and the insulating resin does not flow around the comb-shaped electrode portion of the surface acoustic wave element, and therefore the surface acoustic wave element is easily formed. It is possible to maintain a space around the comb-shaped electrode portion. As a result, the degree of freedom in the appropriate range of viscosity and amount of the insulating resin is increased. Other effects are similar to those of the surface acoustic wave device according to the first embodiment described above.

In the fifth embodiment, the groove is formed at the position between the metal bump and the comb-shaped electrode portion, but it is sufficient if a space can be maintained around the comb-shaped electrode portion. It may be arranged at a position approaching a part, and the method of forming the structure is not limited to that of the fifth embodiment.

Although a low-temperature firing dielectric material capable of firing at 1000 ° C. or lower was used and a mounting board having a recess was used, the material and shape of the mounting board are not limited to this. Absent.

Further, although the input / output electrode and the ground electrode of the mounting board are electrically connected to the external electrodes through the via holes, the connecting method is not limited to this, and the electrodes of the mounting board are made of Ag-based material. Although the electrode paste is used, the electrode material is not limited to this.

Next, a sixth embodiment of the present invention will be described with reference to FIG. 6A is a sectional view of the surface acoustic wave device according to the sixth embodiment of the present invention [A-B sectional view in FIG. 6B], and FIG. 6B is a sixth embodiment of the present invention. FIG. 3 is a top view of the mounting board in the form of FIG.

In FIG. 6, (a) and (b) of FIG.
Parts that are the same as the above are given the same reference numerals. Explaining the surface acoustic wave device configured as described above, the input / output electrode 4 and the ground electrode 5 are made of an electrode paste on the main surface side of the green sheet-shaped dielectric layer 2-1 having the via holes 9 and 10. When the surface acoustic wave element 15 is mounted after printing and drying the electrode paste, a U-shaped groove 20 is formed at a position surrounding the metal bump 12. Except for this portion, it is formed by the method shown in the above-described fifth embodiment, whereby a microminiature surface acoustic wave device having a groove portion can be obtained.

The surface acoustic wave device according to the sixth embodiment configured as described above has the same operation and effect as the surface acoustic wave device according to the fifth embodiment described above. Although the U-shaped groove portion is formed for each metal bump in the sixth embodiment, as shown in the top view of FIG. There may be more than one metal bump 12. Further, the material and structure of the mounting board and the method of forming the mounting board and the groove are not limited to those of the sixth embodiment, as described in the fifth embodiment.

Next, a seventh embodiment of the present invention will be described with reference to FIG. 7A is a cross-sectional view of the surface acoustic wave device according to the seventh embodiment of the present invention [A-B cross-sectional view of FIG. 7B], and FIG. 7B is the seventh embodiment of the present invention. FIG. 3 is a top view of the mounting board in the form of FIG.

In FIG. 7, (a) and (b) of FIG.
Parts that are the same as the above are given the same reference numerals. Explaining the surface acoustic wave device configured as described above, the input / output electrode 4 and the ground electrode 5 are made of an electrode paste on the main surface side of the green sheet-shaped dielectric layer 2-1 having the via holes 9 and 10. When the surface acoustic wave element 15 is mounted after printing and drying the electrode paste, the groove portion 20 is formed at a position that covers the entire comb-shaped electrode portion 17, that is, a size that covers the groove portion 20. . Except for this portion, it is formed by the method shown in the above-described fifth embodiment, whereby a microminiature surface acoustic wave device having a groove portion can be obtained.

The surface acoustic wave device according to the seventh embodiment configured as described above has the same operation and effect as the surface acoustic wave device according to the fifth embodiment described above. The material and structure of the mounting board and the method of forming the mounting board and the groove are not limited to those in the seventh embodiment as described in the fifth embodiment.

Next, an eighth embodiment of the present invention will be described with reference to FIG. 8A is a sectional view of the surface acoustic wave device according to the eighth embodiment of the present invention [A-B sectional view in FIG. 8B], and FIG. 8B is the eighth embodiment of the present invention. FIG. 3 is a top view of the mounting board in the form of FIG.

In FIG. 8, (a) and (b) of FIG.
Parts that are the same as the above are given the same reference numerals. The surface acoustic wave device configured as above will be described.

The mounting substrate 1 is composed of dielectric layers 2 and 3, the dielectric layer 2 is composed of a plurality of layers 2-1 and 2-2, and is a green sheet-shaped dielectric layer having via holes 9 and 10. The input / output electrode 4 and the ground electrode 5 are printed with an electrode paste on the main surface side of 2-1 and when the surface acoustic wave element 15 is mounted after the electrode paste is dried, the entire comb-shaped electrode portion 17 is removed. The groove portion 20 is formed so as to surround it.

Except for this portion, it is formed by the method shown in the above-mentioned fifth embodiment, whereby a microminiature surface acoustic wave device having a groove can be obtained. The surface acoustic wave device according to the eighth embodiment configured as described above has the same operation and effect as the surface acoustic wave device according to the fifth embodiment described above.

The material and structure of the mounting board and the method of forming the mounting board and the groove are not limited to those of the eighth embodiment as described in the fifth embodiment.

Next, a ninth embodiment of the present invention will be described with reference to FIG. 9A is a sectional view of the surface acoustic wave device according to the ninth embodiment of the present invention [A-B sectional view in FIG. 9B], and FIG. 9B is a ninth embodiment of the present invention. FIG. 3 is a top view of the mounting board in the form of FIG.

In FIG. 9, (a) and (b) of FIG.
Parts that are the same as the above are given the same reference numerals. The surface acoustic wave device configured as above will be described.

The mounting substrate 1 is composed of dielectric layers 2 and 3, the dielectric layer 2 is composed of a plurality of layers 2-1 and 2-2, and a green sheet-shaped dielectric layer having via holes 9 and 10. When the input / output electrode 4 and the ground electrode 5 are printed with an electrode paste on the main surface side of 2-1 and the surface acoustic wave element 15 is mounted, the groove portion 20 is formed so as to be located outside the surface acoustic wave element. It is formed in two places in parallel. And
The ground electrode 6 is printed on the main surface side of the green sheet-shaped dielectric layer 3 having a recess, and the dielectric layer 3 and the dielectric layer 2 are arranged from above.
-1, and the dielectric layer 2-2 are laminated in this order and fired at 900 ° C.

The external electrode 7 and the external terminal 8 are the above-mentioned first electrodes.
It is formed by the method shown in the embodiment. By mounting the surface acoustic wave element 15 on such a mounting substrate 1 by the method described in the first embodiment, a microminiature surface acoustic wave device having a groove can be obtained.

In the surface acoustic wave device according to the ninth embodiment configured as described above, since the groove portion is formed on the mounting surface of the mounting substrate located outside the surface acoustic wave element, the insulating resin Even if the viscosity and amount are not adjusted properly, the insulating resin does not flow into the groove and the insulating resin does not flow around the comb-shaped electrode portion of the surface acoustic wave element. A space can be retained around. As a result, the degree of freedom in the proper range of the viscosity and amount of the insulating resin is increased. Besides, it has the same operation and effect as the surface acoustic wave device according to the first embodiment.

In the ninth embodiment, the groove is formed outside the surface acoustic wave element, but it is sufficient if a space can be maintained around the comb-shaped electrode, that is, the groove is outside the metal bump. If it is in the
However, the present invention is not limited to the embodiment.

Although a low-temperature firing dielectric material capable of firing at 1000 ° C. or lower was used and a mounting board having a recess was used, the material and shape of the mounting board are not limited to this. Absent.

Further, although the input / output electrodes and the ground electrode of the mounting board are electrically connected to the external electrodes through the via holes, the connecting method is not limited to this, and the electrodes of the mounting board are Ag. Although the system electrode paste was used, the electrode material is not limited to this.

Next, a tenth embodiment of the present invention will be described with reference to FIG. 10A is a sectional view of the surface acoustic wave device according to the tenth embodiment of the present invention [A-B sectional view in FIG. 10B], and FIG. 10B is the tenth embodiment of the present invention. FIG. 3 is a top view of the mounting board in the form of FIG.

In FIG. 10, the same parts as those in FIGS. 5A and 5B are designated by the same reference numerals. The surface acoustic wave device configured as above will be described.

The mounting substrate 1 is composed of dielectric layers 2 and 3, the dielectric layer 2 is composed of a plurality of layers 2-1 and 2-2, and is a green sheet-shaped dielectric layer having via holes 9 and 10. The input / output electrode 4 and the ground electrode 5 are printed on the main surface side of 2-1 with an electrode paste, and the ground electrode 6 is printed on the main surface side of the green sheet-shaped dielectric layer 3 having a recess. , From the top, the dielectric layer 3, the dielectric layer 2-1, the dielectric layer 2-
It is laminated in the order of 2.

After that, when the surface acoustic wave element 15 is mounted, the groove portion 20 is formed in the dielectric layer 2-1 at a position surrounding the entire surface acoustic wave element 15, and is baked at 900 ° C. The external electrodes 7 and the external terminals 8 are formed by the method shown in the above-described first embodiment.

By mounting the surface acoustic wave element 15 on such a mounting substrate 1 by the method described in the first embodiment, a microminiature surface acoustic wave device having a groove can be obtained.

The surface acoustic wave device according to the tenth embodiment configured as described above has the same operation and effect as the surface acoustic wave device according to the ninth embodiment. The material and structure of the mounting board and the method of forming the mounting board and the groove are not limited to those of the tenth embodiment, as described in the ninth embodiment.

[0070]

As described above, according to the present invention, when the surface acoustic wave element is mounted, the mounting surface side of the mounting substrate is shorter than the metal bump so as to be located between the comb-shaped electrode portion and the metal bump. A convex member made of glass paste, dielectric paste or insulating resin is formed, or a groove is formed on the mounting surface side of the mounting board so as to be located between the comb-shaped electrode portion and the metal bump, or a surface acoustic wave is formed. By forming a groove on the mounting surface side of the mounting board so as to be located outside the element,
Even if the viscosity and amount of the insulating resin are not properly adjusted, a space can be easily maintained around the comb-shaped electrode portion of the surface acoustic wave element.

Therefore, it is not necessary to adjust the insulating resin to have a high viscosity. Therefore, even if the distance between the surface acoustic wave element and the mounting substrate is narrowed, the insulating resin can stably and easily permeate to the periphery of the metal bump. However, the surface acoustic wave device can be downsized.

[Brief description of the drawings]

1A and 1B show a structure of a surface acoustic wave device according to a first embodiment of the present invention, FIG. 1A is a sectional view of the device, and FIG. 1B is a top view of a mounting substrate of the device.

2A and 2B show a structure of a surface acoustic wave device according to a second embodiment of the present invention, wherein FIG. 2A is a sectional view of the device, FIG. 2B is a top view of a mounting substrate of the device, and FIG. It is a top view which shows the other example of arrangement | positioning of the convex-shaped member in the 2nd Embodiment.

FIG. 3 shows a structure of a surface acoustic wave device according to a third embodiment of the present invention, (a) is a sectional view of the device, and (b) is a top view of a mounting substrate of the device.

FIG. 4 shows a structure of a surface acoustic wave device according to a fourth embodiment of the present invention, (a) is a sectional view of the device, and (b) is a top view of a mounting substrate of the device.

5A and 5B show a structure of a surface acoustic wave device according to a fifth embodiment of the present invention, FIG. 5A is a sectional view of the device, and FIG. 5B is a top view of a mounting substrate of the device.

6A and 6B show a structure of a surface acoustic wave device according to a sixth embodiment of the present invention, wherein FIG. 6A is a sectional view of the device, FIG. 6B is a top view of a mounting substrate of the device, and FIG. It is a top view which shows the other example of arrangement | positioning of the groove part in the same device of the 6th Embodiment.

7A and 7B show a structure of a surface acoustic wave device according to a seventh embodiment of the present invention, FIG. 7A is a sectional view of the device, and FIG. 7B is a top view of a mounting substrate of the device.

8A and 8B show a structure of a surface acoustic wave device according to an eighth embodiment of the present invention, FIG. 8A is a sectional view of the device, and FIG. 8B is a top view of a mounting substrate of the device.

9A and 9B show a structure of a surface acoustic wave device according to a ninth embodiment of the present invention, FIG. 9A is a sectional view of the device, and FIG. 9B is a top view of a mounting substrate of the device.

FIG. 10 shows a structure of a surface acoustic wave device according to a tenth embodiment of the present invention, (a) being a sectional view of the device,
(B) is a top view of the mounting substrate of the same apparatus.

11A and 11B show a structure of a surface acoustic wave device in a conventional example, FIG. 11A is a sectional view of the device, and FIG. 11B is a top view of a mounting substrate of the device.

[Explanation of symbols]

 1 Mounting Substrate 2, 3 Dielectric Layer 4 Input / Output Electrodes 5, 6 Ground Electrode 7 External Electrode 8 External Terminal 9, 10 Via Hole 11 Convex Member 12 Metal Bump 13 Conductive Resin 14 Insulating Resin 15 Surface Acoustic Wave Element 16 Electrode Pad part 17 Comb-shaped electrode part 18 Metal cap 19 Solder 20 Groove part

Claims (19)

[Claims] 1. An input / output electrode and a ground electrode on one mounting surface side and an external electrode on the other surface side, and the input / output electrode and the ground electrode are electrically connected to the external electrode, respectively. A mounting substrate, a surface acoustic wave element whose main surface on which the electrode pad portion and the comb-shaped electrode portion are formed is mounted on the mounting substrate in a face-down manner, and the input / output electrodes and the ground electrode, and these electrodes. In a surface acoustic wave device including a metal bump coated with a conductive resin for electrically connecting the electrode pad portion and the electrode pad portion, and an insulating resin arranged around the metal bump, mounting the mounting substrate on the surface acoustic wave device. A convex member shorter than the metal bump is formed on the surface side, and a part of the convex member is arranged between the comb-shaped electrode portion and the metal bump. Sex surface acoustic wave device. 2. The surface acoustic wave device according to claim 1, wherein the convex member is linearly formed. 3. The surface acoustic wave device according to claim 2, wherein the linear convex members are formed at least at two positions on both sides of the comb-shaped electrode portion and are substantially parallel to each other. 4. The convex member is formed in a U-shape so as to surround the metal bump from three sides.
The surface acoustic wave device according to claim 1. 5. The surface acoustic wave device according to claim 1, wherein the convex member is formed in a size so as to cover the entire comb-shaped electrode portion. 6. The surface acoustic wave device according to claim 1, wherein the convex member is formed at a position surrounding the entire comb-shaped electrode portion. 7. The surface acoustic wave device according to claim 1, wherein the convex member is formed of a glass paste. 8. The surface acoustic wave device according to claim 1, wherein the convex member is formed of a dielectric paste. 9. The surface acoustic wave device according to claim 1, wherein the convex member is made of an insulating resin. 10. An input / output electrode and a ground electrode on one mounting surface side and an external electrode on the other surface side, and the input / output electrode and the ground electrode are electrically connected to the external electrode, respectively. A mounting substrate, a surface acoustic wave element whose main surface on which the electrode pad portion and the comb-shaped electrode portion are formed is mounted on the mounting substrate in a face-down manner, and the input / output electrodes and the ground electrode, and these electrodes. In a surface acoustic wave device comprising a metal bump coated with a conductive resin that electrically connects the electrode pad portion and the electrode pad portion, and an insulating resin arranged around the metal bump,
A surface acoustic wave device characterized in that a groove portion is formed on the mounting surface side of the mounting substrate, and a part of the groove portion is located between the comb-shaped electrode portion and the metal bump. 11. The surface acoustic wave device according to claim 10, wherein the groove is formed linearly. 12. The surface acoustic wave device according to claim 11, wherein the linear groove portions are formed at least at two positions on both sides of the comb-shaped electrode portion and are substantially parallel to each other. 13. The groove is formed in a U shape so as to surround the metal bump from three sides.
The surface acoustic wave device according to claim 1. 14. The surface acoustic wave device according to claim 10, wherein the groove is formed in a size so as to cover the entire comb-shaped electrode portion. 15. The surface acoustic wave device according to claim 10, wherein the groove portion is formed at a position surrounding the entire comb-shaped electrode portion. 16. An input / output electrode and a ground electrode are provided on one mounting surface side and an external electrode is provided on the other surface side, and the input / output electrode and the ground electrode are electrically connected to the external electrode, respectively. A mounting substrate, a surface acoustic wave element whose main surface on which the electrode pad portion and the comb-shaped electrode portion are formed is mounted on the mounting substrate in a face-down manner, and the input / output electrodes and the ground electrode, and these electrodes. In a surface acoustic wave device comprising a metal bump coated with a conductive resin that electrically connects the electrode pad portion and the electrode pad portion, and an insulating resin arranged around the metal bump,
A surface acoustic wave device, characterized in that a groove is formed on the mounting surface side of the mounting substrate, and the groove is located outside the surface acoustic wave element. 17. The surface acoustic wave device according to claim 16, wherein the groove is formed linearly. 18. The surface acoustic wave device according to claim 17, wherein the linear groove portions are formed at least at two positions on both sides of the comb-shaped electrode portion and are substantially parallel to each other. 19. The surface acoustic wave device according to claim 16, wherein the groove portion is formed at a position surrounding the entire surface acoustic wave element.