JPH05326702A - Manufacture of silicon-glass junction member - Google Patents

Abstract

PURPOSE:To obtain the optimum manufacturing method for surface mounting by a method wherein a cavity and a through hole are formed in advance on the cutting line on one main surface of silicon, and an insulating film is formed on the side wall of the through hole. CONSTITUTION:Using a photomask, having a V-groove 10 and a through hole 3 pattern independently arranged on the external shape line of one main surface of a silicon wafer 1 of <100> crystal orientation having a thermal oxide film, exposing and developing operations are conducted, and the SiO2 film on the respective part is removed, and silicon is etched. A rectangular cavity 11 is formed on another surface, and after the whole surface has been thermally oxidized and washed, a Cr/Au multilayer film is formed on the surface of the wafer on the side of the V-groove and the through hole, an electrode pattern 9 is formed, a vibrator 6 is mounted, and a borosilicate glass 4, having a cavity 8, is anode-junctioned to the wafer. Accordingly, the silicon wafer 1 and the glass surface of the borosilicate glass 4 are cut along a cutting line 5 by an automatic dicing device, and the housing container of a plurality of crystal vibrators is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a device using flat silicon and a glass member.

[0002]

2. Description of the Related Art Various applications have been proposed as applications to devices and storage containers using a joining member of silicon and glass. As a typical example, Micromac
hiningand Micro Packaging of Transducers, p81, (198
A method of manufacturing the pressure sensor of FIG. 7 shown in 5) will be taken up and described.

As a method of manufacturing the pressure sensor shown in FIG. 7, a glass 74 having a plurality of through holes 79 for electrode leads is used.
And a silicon wafer 71 on which a plurality of diaphragm structures 77 are formed in the same manner, and the diaphragm and two through holes 79 for electrode leads are cut into a pair of chips and sealed with a sealant 78. It is a method of manufacturing a rectangular parallelepiped-shaped pressure sensor obtained by stopping.

On the other hand, as an application to a storage container using a flat plate-shaped insulating member, a structure in which an element is contained and sealed by a bottom member and a top member is generally used. As a typical example thereof, a method for manufacturing the crystal unit shown in FIG. 8 (Japanese Patent Publication No. 1-19290) will be taken up and described below.

The method of manufacturing the container for the crystal unit shown in FIG.
First, the etching mask 8 on the surface of the ceramic plate 81.
A plurality of two-stage cavities 8 by etching through 2
8 is processed, and the electrode pattern 89 is pulled out from the cavity to the outer peripheral portion. Secondly, the plurality of cavities are individually cut at the position of the cutting line 85 according to the finished size.
Thirdly, a crystal oscillator 86 and an upper case 8 are provided in each of the cavities.
4 are sequentially fixed to obtain a crystal resonator container.

In recent years, not only the above-mentioned parts but also general electronic parts have been actively designed for surface mounting in order to downsize the device.

[0007]

However, the above-mentioned conventional device composed of a joining member of silicon and glass, and the storage container using a flat insulating member are required to be mounted on the surface of a substrate, which is characterized by a small capacity. Is not considered as the structure of.

In general, as an electronic component compatible with surface mounting, it is necessary to devise an electrode lead portion on a mounting board. Items required for surface mounting include (1) no problem as electrode wiring, (2) solder state can be inspected from the mounting board, and (3) firm fixing to the mounting board. ..

Therefore, inevitably, the electrode lead portion is provided on the side surface of the component, and the electrode lead is formed into a three-dimensional concave portion in order to obtain a strong fixation to the mounting substrate, and solder is attached to the concave portion to form a strong structure. It is required to get fixed.

A first object of the present invention is to provide an optimum manufacturing method for surface mounting in the manufacturing method of electronic parts using a silicon wafer and glass as the flat plate-shaped member as described above.

A second object is to cut the flat plate member shown in FIG. 7 to obtain a chip,
In general, since there is a problem that chipping occurs at the cutting edge portion, it is another object of the present invention to provide a method for reducing chipping at the time of cutting a silicon-glass joining member.
In particular, since the feed speed of the cutting wheel is closely related to the probability of chipping at the cutting edge, it is not only difficult to achieve high throughput, but also when the cutting wheel wears and deteriorates, chipping easily occurs, The outer shape of the product will be significantly impaired.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the above-mentioned method is applied to the side surface of a silicon substrate when a device composed of silicon and a glass bonding member is considered for surface mounting. The present invention provides an optimum structure for providing an electrode port, a method for forming an insulating film, and a manufacturing method for minimizing chipping in the cutting process.

The manufacturing method according to the present invention is a method in which silicon and glass are bonded together and a plurality of cavities enclosed between the two members are individually cut out, and on the cutout dimension line on the surface of the silicon wafer facing the bonding surface. In advance, a step of previously providing a rectangular cavity or through hole or a plurality of V-grooves, a step of forming an insulating film on the side wall portion of the cavity portion or the through hole, and a step of joining glass and the silicon wafer, A method of manufacturing a bonded member of silicon and glass, which comprises the step of cutting the bonded substrate along the cutout dimension line.

Further, the plurality of V-grooves, the V-grooves and the through-holes, or the cavity and the V-grooves are etched at a distance larger than the side etching amount of both of the etching masks.

[0015]

In the manufacturing method according to the present invention, the cavity and the through hole are formed in advance on the cut-out dimension line on the one main surface of silicon by the photolithography method, and the insulating film is formed on the side wall of the through hole by the thermal oxide film or the sputtering method. By forming the above, since the cavity or the side wall of the through hole is exposed after the cutting in the final step, it becomes possible to form the insulating film on the side surface of the chip. Also, <10
0> Since it is the etching utilizing the anisotropy of silicon, it is possible to form a concave portion whose etching surface has an angle of 55 degrees on the side surface of the chip, and an electrode thin film is formed in the concave portion on the side surface of the chip to perform the planar mounting. It can be a corresponding chip component.

Further, by arranging a V groove wider than the cutting grindstone on the cutting dimension line so that the grindstones are applied to both slopes of the V groove, the angle between the grindstone and the cutting surface becomes 55 degrees, and the above angle is set. Compared to cutting of horizontal planes that intersect at right angles, chipping that occurs can be reduced. Although this effect becomes remarkable when a deteriorated grindstone is used, the dicing method according to the present invention makes it possible to perform cutting with very little chipping.

Further, the spacing between the plurality of V-grooves and the spacing between the V-grooves and the cavities or through-holes is characterized in that they are separated from each other by the side etching amount by the etching mask. The finished shape after etching can be increased in accordance with the designed external dimensions without breaking.

[0018]

EXAMPLES Next, examples of the present invention will be described in detail.

(Example 1) The manufacturing method of the present invention will be described in detail with reference to FIGS. 1, 2, 3 and 4 by taking a container for a crystal oscillator as an example. FIG. 1 is a top view of a silicon wafer before and after cutting, and FIG. 2 is a view showing a manufacturing process based on a sectional view of a portion AA in FIG.

As the first step, the outer shape having a 1.1-micron-thick thermal oxide film on the surface; 3 inches, thickness; 500
A V-groove 10 and a through hole 3 are formed in one main surface of a silicon wafer 1 having a micron-sided polished <100> crystal orientation by the following steps by a photolithography method.

First, a negative resist (manufactured by Tokyo Ohka: OMR-8)
On the surface of the wafer coated with 3), the V groove 10 (width: 350 microns) and the through hole 3 (width: 830 microns) are placed on the outline of which the size is 150 microns larger than the external dimensions (8 x 4 mm) of the storage container. ) Exposure is performed using a photomask on which the pattern and the pattern are arranged. In this embodiment, as the mask pattern, another through-hole pattern for electrode leads is also provided and described in the outline.

Next, after a predetermined developing treatment, the SiO ₂ film on the V groove 10 and the through hole pattern 3 part is removed by a (1: 6) buffered hydrofluoric acid aqueous solution, and then K at 80 ° C. and 20 wt%.
Etch silicon with an aqueous OH solution.

In particular, it is one of the constituent elements of the present invention that the V-groove 10 and the through-hole 3 are independently arranged with a constant gap, and the gap is an etching mask when etching silicon. The feature is that they are separated by more than the side etching amount. The effect will be described with reference to FIG. FIG. 3A shows a case where the V-grooves or the through holes are arranged orthogonally to each other, and when the silicon is etched by the potassium hydroxide aqueous solution, the <n11> plane appears at the edge portion and the edge recedes with a curvature. It has the drawback that it does not finish according to the design dimensions. In particular, it becomes remarkable when a silicon wafer having a thickness is penetrated by etching, and it becomes impossible to obtain a desired right-angled shape.

The inventors of the present invention have made earnest studies on the above-mentioned problems. As a result, when the etching solution composition is a mixed solution of an aqueous potassium hydroxide solution and an alcohol (for example, isopropyl alcohol), an orthogonal etching pattern is produced according to the finished size. I found what I could do. However, compared with etching with an aqueous solution of potassium hydroxide, the etching rate of the mixed etching solution is 1 /
The delay is about 3 to 1/4, and the effect thereof is that the workability becomes extremely poor as the wafer thickness increases.

In the mutually independent arrangement according to the present invention shown in FIG. 3B, since there is an etching mask, there are no orthogonal edge portions, and even if etching is performed with a depth,
The final tip finish shape does not change. In addition, since the etching rate is large at about 70 microns / hour,
Both workability is excellent.

After forming the V groove 10 and the through hole 3, a rectangular cavity 11 having a depth of 100 μm is formed on the other surface of the silicon wafer by the same photolithography method.

Further, after thermally oxidizing the entire surface of the wafer by 1.1 μm, a predetermined cleaning process is performed to form Cr / Au laminated films on the surface of the wafer on the V-groove and through-hole sides to 500 Å and 2000 Å, respectively. Then, the electrode pattern 9 is formed by the photolithography method.

In the second step, the vibrator piece 6 is mounted and the borosilicate glass 4 having the cavity 8 is bonded to the wafer by the following procedure.

A crystal resonator piece 6 having a size of 1.5 × 5.4 × 0.08 mm was mounted on the cavity of the silicon wafer 1 with Ag paste, and the size was 2 × 7.
A borosilicate glass 4 (thickness: 0.5 mm) having a depth of 0.2 mm and a surface cavity formed therein is prepared.

For joining, borosilicate glass 4 is superposed so that the crystal oscillator piece is enclosed in the cavity, and then 200 to 400 degrees Celsius, preferably 300 degrees Celsius.
It is held between the upper and lower electrode substrates held at 320 degrees.
At this time, it is necessary to remove the oxide film in the region to be the bonding surface of the silicon wafer 1. Then, a positive potential is applied to the electrode in contact with the silicon substrate and a negative potential is applied to the electrode on the glass substrate side to apply a potential difference of 700 V. A voltage is applied for about 10 minutes so that the current between both electrodes during the joining becomes steady, and the anodic joining is completed.

As a third step, the above-mentioned bonded substrate is cut into individual vibrator pieces by the following steps to complete a container. FIG. 4 is a perspective view of the joining member before and after cutting, in which the electrode through holes, the crystal oscillator, and the cavity are omitted.

After the bonded silicon wafer 1 and the glass surfaces of the borosilicate glass 4 were adhered to a dicing tape,
Automatic dicing machine (Tokyo Seimitsu Co., Ltd .: A-WD-250) with a cutting blade (Disco Co., Ltd. metal resin blade: P1A851, thickness 0.2 mm) set.
0B / C), the feed rate is 1 mm per second along the cutting dimension line 5 in FIG. 4, and the container for the plurality of crystal resonators shown in FIGS. 4 and 1 is completed. At this time, on the silicon side, a V groove 10 wider than the cutting grindstone is arranged on the cutting line to
By cutting so that both the slopes of the groove 10 were covered with the grindstone, no chipping occurred at all. On the other hand, since the glass side was attached to the dicing tape, chipping was unlikely to occur as in the silicon side, and almost no chipping was visually observed.

As a container for the crystal oscillator, the through hole 7 for the electrode lead is hermetically sealed with an insulating adhesive to complete the container.

(Second Embodiment) Next, a second embodiment will be described with reference to FIG.

FIG. 5 shows the etching shape on the silicon wafer and the chip shape after cutting in order to lengthen the through holes arranged on the cutting dimension line in Example 1 to insulate the entire opposite side surfaces. It is a top view.

Prepare a photomask in which a rectangular pattern having a width of 830 μm is arranged on the cutting lines facing each other on the long side for separating adjacent chips, and a rectangular pattern having a width of 350 μm is also arranged on the short side. The same process as in Example 1 is carried out as follows.

First, a resist is coated by the spin coating method, and the silicon oxide in the rectangular pattern portion for the groove and the through hole is etched by the photolithography method. Next, using the obtained silicon oxide as a masking material, the silicon is etched in a 20% by weight potassium hydroxide aqueous solution at 80 degrees Celsius.

Next, a 1-micron silicon oxide film was formed on the surface of the obtained silicon member by a sputtering method.
Similarly, borosilicate glass is prepared and anodic bonding is performed.

Finally, the glass side of the bonded sample is adhered to a dicing sheet and cut in the same manner as in Example 1 to obtain a silicon / glass bonded member.

(Embodiment 3) FIG. 6 is another embodiment in which the through hole of the embodiment 1 is used as the cavity 3 although it is similar to the embodiment 1.

This is a manufacturing method in which the silicon etching process is performed in the same manner as in Example 1, the through holes 7 for electrode leads and the cavities 3 having a depth of 400 μm are provided, and the borosilicate glass 4 is bonded by anodic bonding.

In the above-mentioned embodiment, an example in which a plurality of V-grooves and through holes or cavities are arranged on the cutout dimension line has been described, but the etching depth of this embodiment is limited to the etching of the cavity. It may be free, not something. Further, it may be a silicon-glass bonding member formed by forming a cylindrical or square through hole on the side of the borosilicate glass to be bonded and overlapping the through hole of the silicon wafer at the time of bonding. ..

Also, the thickness of silicon and glass used is not limited to this embodiment, and the method for forming the insulating film has been described by taking the silicon oxide by the thermal oxidation method and the sputtering method of silicon as an example. The material may be an organic insulating film such as aluminum oxide, glass, or polyimide, and the film thickness can be set arbitrarily. The insulating film may be formed by another coating method, for example, a dip coating method.

[0044]

As described above, according to the manufacturing method of the present invention, the insulating film can be formed on the side surface of the silicon in the cut silicon-glass joining member.
An optimal structure can be formed on the side surface portion as an electrode structure for surface mounting. Further, even in the final cutting step, a silicon-glass joining member having a highly accurate external dimension with very little chipping can be obtained.

[Brief description of drawings]

FIG. 1 is a top view of silicon before and after cutting a silicon-glass joining member according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the manufacturing method according to the first embodiment of the present invention.

FIG. 3 is a diagram showing an etching finished shape of silicon due to a difference in pattern arrangement according to the present invention.

FIG. 4 is a perspective view before and after cutting according to the first embodiment of the present invention.

FIG. 5 is a top view of silicon before and after cutting according to a second embodiment of the present invention.

FIG. 6 is a diagram showing a method of manufacturing a bonding member of silicon and glass according to a third embodiment of the present invention.

FIG. 7 is a diagram showing a method for manufacturing a joining member of silicon and glass according to a conventional technique.

FIG. 8 is a diagram showing a method for manufacturing a flat plate-shaped storage container according to a conventional technique.

[Explanation of symbols]

 1, 71 Silicon substrate 2, 72, 82 Etching mask 3 Through hole 4, 74 Glass substrate 5, 75, 85 Cutting line 6, 86 Crystal oscillator 7 Through hole for electrode lead 8 Glass cavity 9, 79, 89 Lead electrode 10 V groove 11 Silicon cavity 77 Diaphragm 78 Sealant 81 Ceramic substrate 86 Upper case 88 Ceramic cavity

Claims (6)

[Claims] 1. A method of bonding silicon and glass and individually cutting out a plurality of cavities enclosed between both members, wherein a rectangular shape is formed on a cutting dimension line on the surface of the silicon wafer facing the bonding surface. A step of previously providing a cavity or a through hole or a plurality of V-grooves, a step of forming an insulating film on a side wall surface of the cavity part or the through hole,
A method of manufacturing a bonding member for silicon and glass, comprising: a step of covering a cavity portion of the silicon wafer with glass; and a step of cutting the bonding substrate along the cutout dimension line. 2. The V-groove and the rectangular cavity or through hole have a center line that coincides with a cut-out dimension line of an adjacent storage container, and both are independently arranged on the dimension line. The method for producing a joining member of silicon and glass according to claim 1. 3. The bonding of silicon and glass according to claim 1, wherein the width of the V groove and the width of the through hole on the through surface side are equal to or larger than the cutting width of the cutting grindstone. Method of manufacturing member. 4. The method for manufacturing a bonding member for silicon and glass according to claim 1, wherein the insulating film formed on the side surface of the through hole contains at least silicon oxide by a thermal oxidation method. 5. The V-shaped groove and the rectangular through-hole are formed by an etching method, and the V-shaped groove and the V-shaped groove, or the V-shaped groove and the concave portion or the through-hole are separated from each other by a side etching amount of both etching masks. The method for manufacturing a joining member of silicon and glass according to claim 1, 2, or 3. 6. The method for producing a joining member of silicon and glass according to claim 4, wherein the plane direction of the single crystal silicon wafer is <100>.