JP2004312636A - Surface acoustic wave device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface acoustic wave (SAW) device small in size and high in airtightness, and to provide its manufacturing method. <P>SOLUTION: A cap for sealing a SAW element 30 is composed of a metal cap 40. The metal cap 40 includes a flange 41 in its adhesive portion, which is adhered to a wiring board 10 by glass or metal wax or an adhesives. An inner dimension of the metal cap 40 is made larger than the SAW element 40 within 150μm in a cross section A-A'. Besides, four corners of an inner surface of the metal cap 40 in the same cross section are rounded within a diameter 75μm. Further, a corner formed from an upper surface and a side surface in the same inner surface is rounded within 50μm. Moreover, an angle formed of the upper surface and the side surface in the same inner surface is made larger than 90°and smaller than or equal to 102°. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a surface acoustic wave device and a method for manufacturing the same.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as electronic devices become smaller and have higher performance, electronic components mounted thereon have also been required to be smaller and have higher performance. Particularly, a surface acoustic wave (Surface Acoustic Wave) used as, for example, a transmission band-pass filter, a reception band-pass filter, an antenna duplexer, an intermediate frequency filter, or an FM modulator in an electronic device that transmits or receives radio waves. Devices (abbreviated as SAW) are widely used in high-frequency (RF) sections of mobile phones and the like for the purpose of suppressing unnecessary signals. It is required to have a low profile, a small size and a high performance. In addition, as the demand for SAW devices has rapidly increased due to expansion of applications, reduction of manufacturing costs has become an important factor.
[0003]
Conventionally, in general, when realizing an airtight surface mount structure in a SAW device, a package structure using ceramics as disclosed in Patent Document 1 exemplified below is often used. Here, the configuration of the SAW device disclosed in Patent Document 1 will be described with reference to FIG.
[0004]
As shown in FIG. 1A, conventionally, a flip chip mounting structure in which a SAW element (also referred to as a SAW device chip) 110 and a package wiring 106 are electrically and mechanically connected via a metal bump 111 is provided. A package structure of the SAW device 100 is disclosed. In such a configuration, in the SAW device 100, the SAW element 110 is flip-chip bonded via a metal bump 111 to the inside of a package having a frame 103 in which ceramics or the like are stacked, a metal cap 105 is covered, and gold (Au) In many cases, hermetic sealing is performed using a brazing material 104 such as (Sn). In this case, the frame 103 made of ceramics or the like often has a width of about 350 μm in order to maintain the sealing characteristics. On the other hand, FIG. 1B proposes a package structure in which a metal cap 202 is placed on a wiring board 201 made of a ceramic having a flat plate structure or the like, and hermetically sealed with a brazing material 204 such as Au or Sn or an adhesive. ing.
[0005]
[Patent Document 1]
JP-A-4-170811
[0006]
[Problems to be solved by the invention]
However, when ceramics are used as described above, it is necessary to make caps and other packages relatively thick in order to improve airtightness. Therefore, there is a problem that miniaturization of the SAW device is limited.
[0007]
The present invention has been made in view of such a problem, and has as its object to provide a small and highly airtight surface acoustic wave device and a method of manufacturing the same.
[0008]
[Means for Solving the Problems]
To achieve this object, the present invention provides a surface acoustic wave device having a comb-shaped electrode formed on a piezoelectric substrate, an insulating substrate on which the surface acoustic wave device is mounted, In a surface acoustic wave device having a metal cap for hermetically sealing the surface acoustic wave element, an inner dimension of the metal cap in a cross section including a surface of the surface acoustic wave element opposite to the insulating substrate is the same. It has a configuration that is larger than the size of the surface acoustic wave element by 150 μm or less. A metal cap can be made very thin compared to a ceramic or resin cap. Therefore, by making the size of the inside (also referred to as a cavity) of the metal cap larger than the size of the surface acoustic wave element by at most 150 μm, the advantage of using a thin cap can be fully utilized and the surface acoustic wave can be fully utilized. It is possible to further reduce the size of the device. In addition, metal is generally resistant to deformation due to load or heat and has a high-density solid structure. By applying this to the cap, the airtightness can be further improved. In addition, metal is easy to process, and it is possible to accurately realize a fine shape to avoid interference with the SAW element as compared with ceramics and resins, etc., and to self-align the mounting position of the cap with respect to the SAW element. Therefore, the surface acoustic wave device can be easily manufactured and the possibility of damaging the surface acoustic wave element during sealing can be reduced, and the manufacturing method can be simplified.
[0009]
Further, the surface acoustic wave device according to claim 1 is preferably configured such that four corners of the inner surface of the metal cap in the cross section have a radius of 75 μm or less in the cross section. By reducing the roundness of the corners on the inner surface of the metal cap, it is possible to suppress the dead space in the cavity of the metal cap, and to prevent the surface acoustic wave device from being enlarged.
[0010]
Preferably, in the surface acoustic wave device according to the first aspect, a corner portion formed by an upper surface and a side surface of the inner surface of the metal cap has a roundness having a diameter of 50 μm or less. Be composed. By reducing the roundness of the upper four sides of the inner surface of the metal cap, the height of the metal cap is reduced as much as possible with respect to the surface acoustic wave element, and even if the size is reduced, the surface acoustic wave element is damaged during bonding. Instead, it is possible to adopt a configuration in which the bonding position is self-aligned. Further, by setting the diameter of the roundness to 50 μm or less, it is possible to suppress the dead space in the cavity of the metal cap, thereby preventing the surface acoustic wave device from being enlarged.
[0011]
The surface acoustic wave device according to claim 1 is preferably configured such that an angle formed between an upper surface and a side surface on the inner surface of the metal cap is greater than 90 ° and equal to or less than 102 °. Is done. By making the angle between the upper surface and the side surface of the inner surface of the metal cap an obtuse angle, that is, having a taper angle, the bonding position can be self-aligned without damaging the surface acoustic wave element during bonding.
[0012]
The surface acoustic wave device according to a first aspect of the present invention preferably includes a flange portion at a connection portion of the metal cap with the insulating substrate, as described in the fifth aspect. By having the flange portion, the bonding surface with the insulating substrate is increased, so that the bonding strength is increased and the airtightness is improved.
[0013]
In the surface acoustic wave device according to a fifth aspect, the flange portion and the insulating substrate may be bonded to each other with a glass or metal brazing material or an adhesive.
[0014]
According to the present invention, there is provided a surface acoustic wave element having a comb-shaped electrode formed on a piezoelectric substrate, an insulating substrate on which the surface acoustic wave element is mounted, and the surface acoustic wave element. A manufacturing method for manufacturing a surface acoustic wave device having a metal cap for hermetically sealing; a first step of mounting the surface acoustic wave element on the insulating substrate; The mounted surface acoustic wave element is sealed with the metal cap whose inner dimension in a cross section including the surface of the surface acoustic wave element opposite to the insulating substrate is within 150 μm larger than the dimension of the surface acoustic wave element. And a second step. A metal cap can be made very thin compared to a ceramic or resin cap. Therefore, the size of the inside (also referred to as a cavity) of the metal cap is set to be larger than the size of the surface acoustic wave element by 150 μm or less at maximum, so that the advantage of using a thin cap is fully utilized and the size is reduced. It becomes possible to manufacture a surface acoustic wave device. In addition, metal is generally resistant to deformation due to load or heat and has a high-density solid structure. By applying this to the cap, the airtightness can be further improved. In addition, metal is easy to process, and it is possible to accurately realize a fine shape to avoid interference with the SAW element as compared with ceramics and resins, etc., and to self-align the mounting position of the cap with respect to the SAW element. Therefore, the surface acoustic wave device can be easily manufactured and the possibility of damaging the surface acoustic wave element during sealing can be reduced, and the manufacturing method can be simplified.
[0015]
Preferably, in the second step, the surface acoustic wave element is sealed with the metal cap having four corners of the inner surface of the cross section having a radius of not more than 75 μm. It is configured to stop. By reducing the roundness of the inner corner of the metal cap, the bonding position can be self-aligned without damaging the surface acoustic wave element at the time of bonding, thereby suppressing dead space in the cavity of the metal cap. This makes it possible to manufacture a surface acoustic wave device in which an increase in size is prevented.
[0016]
In the second step, preferably, the corner portion formed by the upper surface and the side surface on the inner surface has the metal cap having a radius of 50 μm or less. It is configured to seal the surface acoustic wave element. By reducing the roundness of the upper four sides of the inner surface of the metal cap, the height of the metal cap is reduced as much as possible with respect to the surface acoustic wave element, and even if the size is reduced, the surface acoustic wave element is damaged during bonding. In addition, since the bonding position can be self-aligned, the manufacturing method can be simplified. Further, by setting the diameter of the roundness to 50 μm or less, it is possible to suppress a dead space in the cavity of the metal cap, and it is possible to manufacture a surface acoustic wave device in which an increase in size is prevented.
[0017]
The second step according to claim 7 is preferably such that the angle between the upper surface and the side surface of the inner surface is greater than 90 ° and less than or equal to 102 °. It is configured to seal the wave element. By making the angle between the upper surface and the side surface of the metal cap inner surface an obtuse angle, that is, having a taper angle, the bonding position can be self-aligned without damaging the surface acoustic wave element during bonding, The manufacturing method is simplified.
[0018]
In the second step of the present invention, preferably, the surface acoustic wave element is sealed with the metal cap having a flange at a connection portion with the insulating substrate. It is configured as follows. By using a metal cap having a flange portion, the bonding surface with the insulating substrate is increased, so that the bonding force is increased and the airtightness is improved.
[0019]
The second step described in claim 11 is configured such that, for example, the flange portion and the insulating substrate are bonded to each other with a glass or metal brazing material or an adhesive as described in claim 12. You may.
[0020]
Further, in the manufacturing method according to claim 7, preferably, as in claim 13, the insulating substrate has a multi-chamfered structure in which a region where the surface acoustic wave element is mounted is two-dimensionally arranged, It is configured to include a third step of individually singulating the area where the surface acoustic wave element is mounted. By using a substrate having a multi-planar structure, a plurality of surface acoustic wave devices can be manufactured at a time. Therefore, the labor and cost required to manufacture one surface acoustic wave device can be reduced, and the cost can be reduced. A surface acoustic wave device can be realized.
[0021]
In the first step of the present invention, preferably, the surface acoustic wave element is faced with the surface on which the comb-shaped electrodes are formed on the insulating substrate. It is configured to be flip-chip mounted. With the configuration in which the surface acoustic wave element is mounted in a so-called face-down state, the size of the surface acoustic wave device can be further reduced.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 2 is a diagram showing the configuration of the surface acoustic wave (SAW) device 1 according to the present embodiment. (A) is a cross-sectional view of the SAW device 1, and (b) is a cross-sectional view along AA 'of (a).
[0023]
As shown in FIG. 2A, the SAW device 1 includes a comb-shaped electrode, a wiring pattern electrically connected to the comb-shaped electrode, and an electrode pad on one main surface (hereinafter referred to as a first main surface) of the piezoelectric substrate. Are formed, a SAW element 30 on which the SAW element 30 is formed, a wiring board 10 to which the SAW element 30 is bonded face down by a bump 20, and a metal cap 40 for sealing the SAW element 30. The metal cap 40 is bonded to the wiring board 10 with a brazing material 50 such as gold / tin (hereinafter, referred to as AuSn) or solder, or an adhesive such as frit glass or resin. As a result, it is possible to process a very thin cap as compared with a conventionally used ceramic cap, and as a result, it is possible to reduce the size of the SAW device 1. Further, even when the SAW element 30 is formed thin, the airtightness of the SAW element 30 does not decrease.
[0024]
The wiring substrate 10 is formed of an insulating substrate, for example, a flat plate in which a wiring pattern is formed on a single ceramic substrate, or a flat plate in which a plurality of ceramic substrates on which a predetermined wiring pattern is formed are stacked. The SAW element 30 is flip-chip mounted in a state where the first main surface faces the die attach surface of the wiring substrate 10 on which the electrode pads are formed, that is, in a so-called face-down state. At this time, the electrode pad on the SAW element 30 and the electrode pad on the die attach surface are connected by the metal bump 20. Thereby, the SAW element 30 is electrically connected to the wiring board 10 and is mechanically fixed.
[0025]
FIG. 2B illustrates a state in which the AA ′ section of FIG. 2A is cut open and the SAW device 1 is looked down. In FIG. 2B, the cap 30 is shown in a state where the cross section and the outermost peripheral portion are visible.
[0026]
In the AA ′ section, assuming that the length of the long side of the SAW element 30 is Ls and the length of the long side inside the metal cap 40 (also referred to as a cavity) is Lc, in the present embodiment, Lc is represented by the following equation. 1 is satisfied. That is, Lc is made larger than that of the SAW element 30 within a range of 150 μm or less.
Ls ≦ Lc ≦ Ls + 150 μm (Equation 1)
[0027]
Similarly, the length of the short side of the SAW element 30 in the AA ′ cross section is set to be larger than the length of the short side inside the metal cap 40 by 150 μm or less. As described above, in the present embodiment, the margin (also referred to as clearance) of the metal cap 40 is increased within a range of 150 μm or less, that is, the surface of the SAW element 30 opposite to the wiring substrate 10 (the opposite side to the first main surface). Of the metal cap 40 in a cross section (corresponding to the AA ′ cross section) including the main surface of the SAW element 30 within 150 μm. It is possible to minimize the extra space in the cavity for accommodating the SAW element 30 while avoiding an extreme increase in the accuracy required for the above.
[0028]
Next, four corners inside the metal cap 40 in the AA 'section will be described below. FIG. 3A is an enlarged view of one corner inside the metal cap 40. As shown in FIG. 3A, in the present embodiment, when the corner inside the metal cap 40 has a smaller radius R1, the interference with the SAW element when the metal cap 40 is put on the SAW element 30 is obtained. Can be avoided, and the position can be self-aligned without damaging the SAW element 30. Further, by setting the diameter R1 to be, for example, half of 150 μm, which is a margin of the metal cap 40 with respect to the SAW element 30, that is, 75 μm or less, it is possible to realize a configuration capable of self-alignment while suppressing the metal cap 40 from being enlarged. Become.
[0029]
Further, the four sides on the inner upper surface of the metal cap 40, that is, the corner formed by the side wall (taper 42) of the metal cap 40 and the upper wall 43 have a radius R2 as shown in FIG. 3B. are doing. By reducing the roundness, even if the metal cap is made as short as possible with respect to the surface acoustic wave element and the SAW element 30 is covered with the metal cap 40, the SAW element 30 is damaged. Without this, the position can be self-aligned. Further, by setting the diameter R2 to, for example, 50 μm or less, it becomes possible to provide a configuration capable of self-alignment while suppressing an increase in the size of the metal cap 40.
[0030]
In this embodiment, as shown in FIG. 3B, the taper 42 and the wiring board 10 (or the upper wall 43) may be configured to have a predetermined angle θ1. This makes it possible to configure the metal cap 40 to be positioned by self-alignment when the metal cap 40 is put on the SAW element 30. In addition, the angle θ1 is set to, for example, 12 ° or less, in other words, the angle between the upper surface and the side surface of the inner surface of the metal cap 40 is set to be larger than 90 ° and 102 ° or less, thereby increasing the size of the metal cap 40. It is possible to make a configuration capable of performing self-alignment while suppressing it.
[0031]
Further, as shown in FIGS. 2A and 2B, the metal cap 40 is provided with a flange 41 so that the bonding of the brazing material 50 to the wiring board 10 is further strengthened. I have.
[0032]
With the above configuration, in the present embodiment, as shown in FIGS. 4A to 4C, when the metal cap 40 is bonded, the metal cap 40 is displaced from a predetermined position with respect to the SAW element 30, for example, SAW. Even when the SAW element 30 comes into contact with the element 30, the SAW element 30 is self-aligned to a predetermined position within a margin that is considered in advance without being damaged. FIG. 4 shows the relative positional relationship between the SAW element 30 and the metal cap 40 when the metal cap 40 is maximally displaced, and (a) or (b) shows that the metal cap 40 or the SAW element 30 is in the drawing. FIG. 4C shows an example of a case where the metal cap 40 (or the SAW element 30 may be rotated) from a predetermined position is bonded. Is shown.
[0033]
Further, an example of specific dimensions of the SAW device 1 according to the present embodiment will be described below. In this specific example, in the AA ′ cross section, the dimensions of the SAW element 30 are long side length (Ls) 1.35 mm, short side length 0.85 mm, and thickness 0.25 mm. The length of the long side (Lc) was 1.50 mm and the length of the short side was 1.00 mm. That is, the margin of the metal cap 40 with respect to the SAW element 30 in the AA ′ cross section is set to 75 μm in the entire periphery. The corner diameters R1 at the four corners inside the metal cap 40 were set to 50 μm, and the corner diameters R2 at the four sides of the metal cap 40 were set to 50 μm. Further, the outside dimensions of the bottom of the metal cap 40 (the side to be bonded to the wiring board 10) are set such that the length of the long side is 1.80 mm and the length of the short side is 1.30 mm, and the inside of the bottom of the metal cap 40 is set. The length of the long side was 1.60 mm, the length of the short side was 1.10 mm, and the height of the inner upper wall 43 was 0.32 mm. That is, the angle θ1 between the taper 42 and the upper wall 43 was set to about 10.5 °. Furthermore, the dimensions of the wiring board 10 were 2.00 mm in the long side and 1.50 mm in the short side in a plane parallel to the AA ′ section, and the thickness of the metal cap 40 was 0.05 mm. .
[0034]
In the case of the above configuration, the maximum area at the bottom position of the metal cap 40 due to the displacement of the metal cap 40 is the clearance ± 0.075 mm provided between the SAW element 30 and the metal cap 40 in the AA ′ cross section. Decided. That is, the effective area at the bottom of the metal cap 40 is 1.95 mm in the long side direction and 1.55 mm in the short side direction. Since the length of the long side of the wiring board 10 is 2.00 mm and the length of the short side is 1.50 mm, a clearance of ± 0.025 mm from the outermost periphery of the metal cap 40 is left.
[0035]
As described above, the dimension of R1 of the corner inside the AA ′ section of the metal cap 40 is set to 50 μm. However, if the allowable clearance for the displacement of the metal cap 40 is within ± 75 μm, the SAW element 30 is Since there is no contact at two or more places at a time, the chip is not damaged when the cap is inserted. However, the dimensions described above are only specific examples of the SAW device 1 according to the present embodiment, and can be appropriately modified without departing from the spirit of the present invention.
[0036]
Further, as another specific configuration example, in the AA ′ cross section, the length inside the metal cap 40 is set to 1.45 mm for the long side length (Lc) and 0.95 mm for the short side length. You can also. That is, the margin of the metal cap 40 with respect to the SAW element 30 in the AA ′ section was set to 100 μm. In addition, the outside dimension of the bottom of the metal cap 40 (the side to be bonded to the wiring board 10) is 1.75 mm for the long side and 1.25 mm for the short side. The length of the long side is 1.55 mm, the length of the short side is 1.05 mm, and the height of the inner upper wall 43 is 0.32 mm. That is, the angle θ1 between the taper 42 and the upper wall 43 is set to about 10.5 °. The other configuration is the same as the above-described specific example.
[0037]
With such a specific configuration, the clearance provided between the SAW element 30 and the metal cap 40 in the AA ′ cross section becomes ± 0.05 mm, so that the maximum possible displacement of the metal cap 40 can occur. The width becomes ± 0.05 mm. At this time, the effective area at the bottom of the metal cap 40 is 1.85 mm in the long side direction and 1.35 mm in the short side direction. Therefore, even if the size of the wiring board is reduced to a length of the long side of 1.90 mm and a length of the short side of 1.40 mm, the clearance from the outermost periphery of the metal cap 40 is still ± 0.025 mm. Therefore, the size of the package can be further reduced.
[0038]
However, if the value of the R2 dimension of the upper four inner sides of the metal cap 40 is large, the corner may contact the end of the SAW element 30 in the AA ′ cross section. Therefore, it is necessary to make the height of the metal cap 40 higher than the upper surface (AA ′) of the SAW element 30 by the sum of the value of the dimension of R2 and the thickness of the metal cap 40. However, recent SAW devices are also strongly required to have a reduced package height. Therefore, in this embodiment, in order to keep the height of the metal cap 40 as low as possible, the R2 dimension of the four inner upper sides is kept within 50 μm, which is about the thickness of the metal cap 40. This makes it possible to keep the height of the metal cap 40 within 100 μm from the upper surface of the SAW element 30, thereby suppressing an increase in the size of the SAW device 1.
[0039]
The metal cap 40 can be formed by squeezing. At this time, as described above, the angle of the taper 42 (hereinafter, referred to as the taper angle) excluding the corner diameter R1 of the inner side wall of the metal cap 40 with respect to the wiring board 10 is set to within 12 °, so that the metal cap 40 is formed. The bottom can be widened to about 100 μm or less than the inner dimension in the AA ′ cross section, and it is easy to avoid interference with the SAW element 30 when the metal cap 40 is mounted.
[0040]
Further, in the present embodiment, the metal cap 40 has a flange 41 at a bottom portion, that is, a bonding portion with the wiring board 10. The width of the flange 41 can be assured to be approximately 100 μm even when the taper angle excluding the corner diameter R1 of the inner wall of the metal cap 40 is set to 12 °, so that a brazing material such as gold tin (AuSn), solder or frit glass is used. Approximately 100 μm can be secured between the metal cap 40 and the wiring board 10 using a metal or an adhesive or the like, and stable hermetic sealing can be performed.
[0041]
In the above description of the SAW device 1, the structure of only one completed product has been described as an example. However, in the manufacturing process of the SAW device 1, the present invention is not limited to the above-described configuration. For example, a substrate having a multi-plane configuration in which a plurality of circuit boards 10 are two-dimensionally arranged (hereinafter, referred to as a base substrate) may be used. Thereby, a plurality of SAW devices 1 can be created at a time, and the manufacturing cost can be reduced. Hereinafter, a method of manufacturing the SAW device 1 using the base substrate having such a multi-plane configuration will be described in detail with reference to FIGS.
[0042]
First, as shown in FIG. 5A, a SAW element 30 is flip-chip mounted face-down by bumps 20 on a base substrate 10A having a multi-cavity structure in which wiring substrates 10 are two-dimensionally arranged. At this time, an electrode pattern (including a wiring pattern) 11 for electrically and mechanically connecting to the SAW element 30 and a row for adhering a metal cap 40 are formed in the region of each wiring substrate 10 in the base substrate 10A. A material 50 is formed.
[0043]
Next, as shown in FIG. 5B, the mounted SAW element 30 is sealed with a metal cap 40, and these are heated and pressurized to temporarily melt the brazing material 50 and bond them (FIG. 5B). (C)). However, as shown in FIGS. 5D and 5E, after the metal cap 40 is adhered, a sheet 51 of a metal material such as Au or Sn may be adhered to the adhered portion by heating and pressing. Thereby, the sealing state of the SAW device 1 can be improved.
[0044]
When the individual SAW elements 30 are sealed with the metal caps 40, the base substrate 10A is placed on a UV (ultraviolet) film 60 as shown in FIG. After being held by the frame 61, the base substrate 10A is singulated into the SAW device 1 by, for example, a rotary cutting blade (also referred to as a dicing blade) 62 (see FIG. 6B). However, besides this, individual SAW devices 1 may be singulated using, for example, a laser beam.
[0045]
After that, the base film 10A is irradiated with ultraviolet rays from the UV film 60 side to soften the UV film 60 to facilitate the handling of the substrate (see FIG. 6C), and then the base substrate 10A is taken out from the UV film 60. Thus, the individual SAW devices 1 are singulated (see FIG. 6D).
[0046]
With the configuration as described above, in this embodiment, a miniaturized SAW device that can be easily manufactured can be realized. Note that the package having such a structure is not limited to the above-described SAW device, but may be applied to any electronic component mounted by flip chip bonding. Further, in the above-described embodiment, the SAW device 1 including one SAW element 30 has been described as an example. However, the present invention is not limited to this. For example, a duplexer or the like in which a plurality of SAW elements are incorporated. The same can be applied to electronic components. In this case, it can be easily applied by assuming and replacing the outermost peripheral portion of the area where a plurality of chips are mounted with one chip.
[0047]
The embodiments described above are merely preferred embodiments of the present invention, and the present invention can be implemented in various modifications without departing from the gist thereof.
[0048]
【The invention's effect】
As described above, a small and highly airtight surface acoustic wave device and a method for manufacturing the same can be realized.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a configuration of a conventional SAW device.
FIGS. 2A and 2B are diagrams showing a configuration of a SAW device 1 according to an embodiment of the present invention, wherein FIG. 2A is a cross-sectional view thereof, and FIG. 2B is a cross-sectional view taken along line AA ′ of FIG.
3A is an enlarged view of a corner inside the metal cap 40 in an AA ′ cross section of FIG. 2A, and FIG. 3B is a side view of four side walls (tapered) on the inner upper surface of the metal cap 40. 42) is an enlarged view of a corner formed by the upper wall 43.
FIG. 4 is an AA ′ sectional view showing a positional relationship between the metal cap 40 and the SAW element 30 when the metal cap 40 is bonded.
FIG. 5 is a process diagram for explaining a method of manufacturing the SAW device 1 according to one embodiment of the present invention (1).
FIG. 6 is a process diagram for explaining a method of manufacturing the SAW device 1 according to one embodiment of the present invention (2).
[Explanation of symbols]
1 SAW device
10 Wiring board
11 Electrode pattern
10A base board
20 bumps
30 SAW element
40 metal cap
41 Flange
42 Taper
50 brazing material
51 sheets
60 UV film
61 frames
62 rotary cutting blade

Claims (14)

A surface acoustic wave device having a surface acoustic wave element having a comb-shaped electrode formed on a piezoelectric substrate, an insulating substrate on which the surface acoustic wave element is mounted, and a metal cap for hermetically sealing the surface acoustic wave element On the device,
A surface acoustic wave device, wherein an inner dimension of the metal cap in a cross section including a surface of the surface acoustic wave element opposite to the insulating substrate is larger than a dimension of the surface acoustic wave element by 150 μm or less. 2. The surface acoustic wave device according to claim 1, wherein four corners of the inner surface of the metal cap in the cross section have a radius of 75 μm or less. 2. The surface acoustic wave device according to claim 1, wherein a corner formed by an upper surface and a side surface of the inner surface of the metal cap has a radius of not more than 50 [mu] m. The surface acoustic wave device according to claim 1, wherein an angle between an upper surface and a side surface of the inner surface of the metal cap is greater than 90 ° and equal to or less than 102 °. The surface acoustic wave device according to claim 1, further comprising a flange portion at a connection portion of the metal cap with the insulating substrate. The surface acoustic wave device according to claim 5, wherein the flange portion and the insulating substrate are adhered by a glass or metal brazing material or an adhesive. A surface acoustic wave device having a surface acoustic wave element having a comb-shaped electrode formed on a piezoelectric substrate, an insulating substrate on which the surface acoustic wave element is mounted, and a metal cap for hermetically sealing the surface acoustic wave element In a manufacturing method for manufacturing a device,
A first step of mounting the surface acoustic wave element on the insulating substrate;
The internal dimension of the surface acoustic wave element mounted on the insulating substrate in a section including the surface of the surface acoustic wave element opposite to the insulating substrate is larger than the dimension of the surface acoustic wave element by 150 μm or less. And a second step of sealing with the metal cap. 8. The surface acoustic wave device according to claim 7, wherein, in the second step, the surface acoustic wave element is sealed with the metal cap having four corners of the inner surface of the cross section having a radius of 75 μm or less. 9. Production method. 8. The surface acoustic wave device according to claim 7, wherein the second step includes sealing the surface acoustic wave element with the metal cap having a corner formed by an upper surface and a side surface of the inner surface having a radius of 50 μm or less. A method for manufacturing a surface acoustic wave device. 8. The elastic surface acoustic wave device according to claim 7, wherein in the second step, the surface acoustic wave element is sealed with the metal cap having an angle between the upper surface and the side surface of the inner surface that is greater than 90 ° and equal to or less than 102 °. 9. A method for manufacturing a surface acoustic wave device. 8. The method of manufacturing a surface acoustic wave device according to claim 7, wherein in the second step, the surface acoustic wave element is sealed with the metal cap having a flange at a connection portion with the insulating substrate. . The method according to claim 11, wherein in the second step, the flange portion and the insulating substrate are bonded to each other with a glass or metal brazing material or an adhesive. The insulating substrate has a multi-chamfered structure in which a region where the surface acoustic wave element is mounted is two-dimensionally arranged,
8. The method for manufacturing a surface acoustic wave device according to claim 7, further comprising a third step of individually singulating the area on which the surface acoustic wave element is mounted. 8. The surface acoustic wave according to claim 7, wherein in the first step, the surface acoustic wave element is flip-chip mounted on the insulating substrate with the surfaces on which the comb-shaped electrodes are formed facing each other. Device manufacturing method.

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