JP3753242B2 - Pressure sensor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pressure sensor with improved pressure resistance.
[0002]
[Prior art]
FIG. 5 is a diagram for explaining the configuration of a conventional example that is generally used in the past, and is disclosed in, for example, Japanese Utility Model Publication No. 63-63737.
In the figure, 1 is a sensor chip. In this case, silicon is used.
[0003]
Reference numeral 2 denotes a recess provided in the sensor chip 1 and constituting a diaphragm 3 which is a strain generating part of the sensor chip 1.
Reference numeral 4 denotes a semiconductor pressure detecting element provided in the strain generating portion 3 of the sensor chip 1.
Reference numeral 5 denotes a support substrate made of Pyrex (registered trademark) glass, which is connected to one surface of the sensor chip and forms the recess 2 and the pressure introducing chamber 6.
[0004]
In this case, the sensor chip 1 is bonded by anodic bonding or the like.
Reference numeral 7 denotes a pressure guide hole provided in the glass support substrate 5 and communicating with the pressure introducing chamber 6.
8 is a pedestal. The other surface of the support substrate 5 is bonded.
[0005]
In the above configuration, when the pressure introduction chamber 6 is kept in the vacuum P0 and the measurement pressure Pm is applied from the outside of the diaphragm 3, the diaphragm 3 is displaced by the measurement pressure Pm. If this displacement is electrically detected by the semiconductor pressure detecting element 4, an electric signal output corresponding to the measured pressure Pm can be obtained.
[0006]
[Problems to be solved by the invention]
However, such an apparatus has the following problems.
The glass substrate of the pressure sensor is bonded to the metal base 8 with a low melting point glass.
[0007]
There is a problem of variation in burst pressure or delayed fracture (a phenomenon in which fracture occurs when a long-time application is continued even at a pressure that does not break even when applied for a short time) at this joint.
In the present invention, the pressure resistance of only the joint portion between the glass support substrate 5 and the metal base 8 is a problem.
[0008]
An object of the present invention is to solve the above-described problems and to provide a pressure sensor with improved pressure resistance.
That is, an object of the present invention is to provide a pressure sensor having a sufficiently high breaking pressure including delayed fracture of the joint between the glass support substrate 5 and the metal base 8.
[0009]
[Means for Solving the Problems]
In order to achieve such an object, in the present invention, in the pressure sensor according to claim 1,
In a pressure sensor comprising a pedestal made of a metal material, a support substrate made of glass with one surface connected to one surface of the pedestal, and a pressure guide hole communicating the support substrate and the pedestal,
A pipe inserted into the pressure introducing hole, a bonding film provided at a connection portion between the support substrate and the pedestal excluding the pressure guiding hole portion, and an elastic filled between the bonding film and the pipe And a filler injection hole that is provided on any one of the support substrate and the pedestal and fills the filler.
In Claim 2 of this invention, in the pressure sensor of Claim 1,
An elastomer is used as the filler.
In Claim 3 of this invention, in the pressure sensor of Claim 1 or Claim 2,
A silicon elastomer is used as the filler. According to a fourth aspect of the present invention, in the pressure sensor according to any one of the first to third aspects,
A fluororubber elastomer is used as the filler.
In a fifth aspect of the present invention, in the pressure sensor according to any one of the first to fourth aspects,
As the bonding film, low melting point glass is used.
According to a sixth aspect of the present invention, in the pressure sensor according to any one of the first to fifth aspects,
An adhesive is used as the bonding film.
According to claim 7 of the present invention, in the pressure sensor according to any one of claims 1 to 6,
As the bonding film, solder bonding is used.
According to Claim 8 of the present invention, in the pressure sensor according to any one of Claims 1 to 7,
A trade name Pyrex (registered trademark) glass is used as the support substrate, and a trade name Kovar is used as the pedestal.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is an explanatory view of a main part configuration of an embodiment of the present invention, FIG. 2 is a side view of FIG. 1, FIG. 3 is a cross-sectional view taken along line AA of FIG. .
In the figure, configurations with the same symbols as in FIG. 5 represent the same functions.
Only the differences from FIG. 5 will be described below.
[0011]
Reference numeral 11 denotes a pipe inserted into the pressure introducing hole 7.
Reference numeral 12 denotes a bonding film provided at a connection portion between the support substrate 5 and the base 8 except for the pressure guide hole 7 portion.
In this case, low-melting glass is used, and as shown in FIG.
[0012]
As shown in FIG. 4, reference numeral 13 denotes a filler that is filled between the bonding film 12 and the pipe 11 and has elasticity.
In this case, a silicon-based elastomer is used.
[0013]
As shown in FIG. 2, reference numeral 14 denotes a filler injection hole that is provided on one of the support substrate 5 and the base 8 and fills the filler 13.
In this case, the filler injection hole 14 is provided on the base 8 side.
[0014]
In this case, a trade name Pyrex (registered trademark) glass is used as the support substrate 5.
As the pedestal 8, a product name Kovar is used.
In addition, as shown in FIG. 4, the arrow B is a portion where stress is concentrated if there is no elastomer 13.
[0015]
In the above configuration, assembly is performed as follows.
(1) A printed pattern of the low melting point glass 12 is prepared and placed on the surface of the glass support substrate 5 or the Kovar base 8 in advance.
[0016]
(2) A thin pipe 11 is inserted into the pressure introducing hole 7 of the Kovar base 8.
(3) Insert the hole of the support substrate 5 into the thin pipe 11.
(4) Increase the temperature and perform low melting point glass bonding.
[0017]
(5) The elastomer 13 is injected from the elastomer inlet 14 of the Kovar pedestal 8.
At this time, care should be taken that the upper surface of the elastomer 13 does not exceed the upper surface of the pipe.
(6) The elastomer 13 is rubberized by baking.
[0018]
As a result,
(1) Since the filler 13 having elasticity is filled between the bonding film 12 and the pipe 11, stress is not transmitted to the edge portion between the supporting substrate 5 made of glass weak in structure and the bonding film 12. Concentration does not occur [0019]
The peeling force of the bonding surface between the support substrate 5 and the pedestal 8 due to pressure opposes the entire bonding surface of the bonding film 12, but the peeling force is pressure × inner diameter area of the pipe 11. If the small pipe 11 is used, the peeling force can be reduced, the pressure resistance can be increased, and a pressure sensor capable of realizing a high pressure resistance can be obtained.
[0020]
(2) Since an elastomer is used as the filler 13, it can be injected in a liquid state and can be solidified into a rubber-like shape, so that a pressure sensor that can prevent stress concentration and secure a pressure seal can be obtained.
[0021]
(3) Since a silicon-based elastomer is used as the filler 13, a pressure sensor that can secure fluidity and heat resistance as the filler 13 can be obtained.
(4) Since the low melting point glass is used as the bonding film 12, a pressure sensor that can easily bond the base 8 made of a metal material and the support substrate 5 made of glass is obtained.
[0022]
(5) Since the product name Pyrex (registered trademark) glass is used as the support substrate 5 and the product name Kovar is used as the pedestal 8, the thermal expansion coefficient is close and there is no risk of destruction based on the difference in expansion coefficient. A pressure sensor is obtained.
[0023]
In the above-described embodiment, it has been described that a silicon-based elastomer is used as the filler 13. However, the present invention is not limited to this. For example, a fluororubber-based elastomer may be used. What is necessary is just the filling body 13 which is filled between the bonding film 12 and the pipe 11 and has elasticity.
[0024]
If a fluororubber elastomer is used as the filler 13, a pressure sensor with improved chemical resistance and moisture resistance can be obtained.
Further, the stability when the pressure sensor is filled with silicone oil can be improved.
[0025]
In the above-described embodiment, it has been described that the low melting point glass is used as the bonding film 12. However, the present invention is not limited to this, and may be, for example, an adhesive or a soldered bonding film. The bonding film 12 provided at the connection portion between the support substrate 5 and the pedestal 8 may be used except for the pressure guiding hole 7 portion.
[0026]
If an adhesive is used as the bonding film 12, an optimal adhesive for bonding the base 8 and the support substrate 5 can be used, and a pressure sensor with improved bonding force can be obtained.
Further, if a soldered bonding film is used as the bonding film 12, the pressure sensor can be firmly bonded and a strongly bonded pressure sensor can be obtained.
[0027]
The above description merely shows a specific preferred embodiment for the purpose of explanation and illustration of the present invention. Therefore, the present invention is not limited to the above-described embodiments, and includes many changes and modifications without departing from the essence thereof.
[0028]
【The invention's effect】
As described above, according to the first aspect of the present invention, the following effects can be obtained.
Since the elastic filler is filled between the bonding film and the pipe, stress is not concentrated because no pressure is transmitted to the edge portion between the supporting substrate made of structurally weak glass and the bonding film.
[0029]
The peeling force of the bonding surface between the support substrate and the pedestal due to pressure will counter the entire bonding surface of the bonding film, but the peeling force will be the pressure x inner diameter area of the pipe. In this case, a pressure sensor can be obtained in which the peeling force can be reduced and the withstand voltage can be increased, and a high withstand voltage can be realized.
[0030]
According to claim 2 of the present invention, there are the following effects.
Since an elastomer is used as the filling body, it can be injected in a liquid state and can be solidified into a rubber-like shape, so that a pressure sensor that can prevent stress concentration and secure a pressure seal can be obtained.
[0031]
According to claim 3 of the present invention, there are the following effects.
Since a silicon-based elastomer is used as the filler, a pressure sensor that can ensure fluidity and heat resistance as the filler can be obtained.
[0032]
According to claim 4 of the present invention, there are the following effects.
Since a fluororubber elastomer is used as the filler, a pressure sensor with improved chemical resistance and moisture resistance can be obtained.
Further, the stability when the pressure sensor is filled with silicone oil can be improved.
[0033]
According to claim 5 of the present invention, there are the following effects.
Since low-melting glass is used as the bonding film, a pressure sensor that can easily bond a base made of a metal material and a support substrate made of glass is obtained.
[0034]
According to claim 6 of the present invention, there are the following effects.
Since an adhesive is used as the bonding film, an optimal adhesive can be used for bonding between the base and the support substrate, and a pressure sensor with improved bonding force can be obtained.
[0035]
According to claim 7 of the present invention, there are the following effects.
Since a soldered bonding film is used as the bonding film, the pressure sensor can be firmly bonded and a strongly bonded pressure sensor can be obtained.
[0036]
According to claim 8 of the present invention, there are the following effects.
The product name Pyrex (registered trademark) glass is used as the support substrate, and the product name Kovar is often used as the pedestal, so that a pressure sensor with a close thermal expansion coefficient and no risk of breakage based on the difference in expansion coefficient can be obtained. .
[0037]
Therefore, according to the present invention, a pressure sensor with improved pressure resistance can be realized.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a main part configuration of an embodiment of the present invention.
FIG. 2 is a side view of FIG.
3 is a cross-sectional view taken along the line AA in FIG.
FIG. 4 is a detailed explanatory diagram of a main part of FIG. 1;
FIG. 5 is an explanatory diagram of a main part configuration of a conventional example generally used conventionally.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sensor chip 2 Recess 3 Diaphragm 4 Semiconductor pressure detecting element 5 Support substrate 6 Pressure introducing chamber 7 Pressure introducing hole 8 Base 11 Pipe 12 Bonding film 13 Filler 14 Filler injection hole B

Claims (8)

A base made of metal,
A support substrate made of glass with one surface connected to one surface of the pedestal;
In a pressure sensor comprising a pressure introducing hole communicating with the support substrate and the pedestal,
A pipe inserted into the pressure guiding hole;
A bonding film provided at a connection portion between the support substrate and the pedestal except for the pressure guiding hole portion,
A filler filled with elasticity between the bonding film and the pipe;
A pressure sensor, comprising: a filler injection hole provided on one of the support substrate and the pedestal to fill the filler. The pressure sensor according to claim 1, wherein an elastomer is used as the filler. The pressure sensor according to claim 1 or 2, wherein a silicon-based elastomer is used as the filler. The pressure sensor according to any one of claims 1 to 3, wherein a fluoro rubber elastomer is used as the filler. The pressure sensor according to any one of claims 1 to 4, wherein low melting point glass is used as the bonding film. The pressure sensor according to any one of claims 1 to 5, wherein an adhesive is used as the bonding film. The pressure sensor according to claim 1, wherein solder bonding is used as the bonding film. As the support substrate, trade name Pyrex (registered trademark) glass is used,
The pressure sensor according to any one of claims 1 to 7, wherein a product name Kovar is used as the pedestal.

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