JP2000241274A - Semiconductor pressure sensor, manufacture thereof and parts thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable semiconductor pressure sensor having high strength and high shock resistance and excellent in adhesion to a glass base. SOLUTION: The semiconductor pressure sensor comprises a joint part 10 including a silicon chip 11 forming a pressure-sensitive diaphragm and a glass base 12 having a coefficient of linear expansion approximate to that of the silicon chip 11 and being bonded thereto, and a metal base 14 being bonded to the glass base 12 through a solder 13. The glass base 12 is made of crystalline glass and a metal film of Cr, Ti is formed on the lower surface thereof. This part is obtained by forming a diaphragm on a silicon wafer, forming a metal film on one surface of a glass wafer principally comprising Li2O-Al2O3- SiO2, making a plurality of through holes in the glass wafer formed with the metal film, anode jointing the surface of the silicon wafer for forming a diaphragm to other surface of the glass wafer, and then separating the wafers individually. A semiconductor pressure sensor is constituted using this part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor pressure sensor using a diaphragm as a pressure-displacement conversion element.

[0002]

2. Description of the Related Art FIG. 8 is a sectional view showing the schematic structure of a conventional general semiconductor pressure sensor. This pressure sensor is composed of a joined body 10PA, a metal pedestal 44 joined to the joined body 10PA and solder 13 and , And the like.

Here, the bonded body 10PA is made of a silicon chip 11 forming a pressure-sensitive diaphragm and, for example, Pyrex glass (trademark of Corning Incorporated, USA), and a through hole 121 for introducing a detection pressure is formed at the center. And a lower surface of the silicon chip 11 and an upper surface of the glass pedestal 12PA are joined by anodic bonding. The joined body 10PA is joined to the metal pedestal 44 by the solder 13.

[0004] As a structure similar to such a structure, there is a crystallized glass described in JP-A-5-9039.

Japanese Patent Application Laid-Open No. 55-47425 discloses a crystallized glass having a linear expansion coefficient similar to that of a silicon diaphragm so that a reference pressure chamber is formed around a strain sensing element in a diaphragm. A waterproof semiconductor pressure transducer having a structure in which a low-melting glass is adhered and fixed to a silicon diaphragm is disclosed.

Further, Japanese Patent Application Laid-Open No. 55-6816 discloses that a nickel plating layer (metal film layer) of 2 to 5 microns is formed on the surface of a pressure receiving table made of crystallized glass having a thermal expansion coefficient similar to that of silicon. A semiconductor pressure transducer having a structure is disclosed.

[0007]

However, in Japanese Patent Application Laid-Open No. Hei 5-9039, the method of joining the crystallized glass and the metal pedestal is unknown.

In Japanese Patent Application Laid-Open No. 55-47425, since a crystallized glass and a silicon diaphragm are bonded and fixed by a low-melting glass, the bonding temperature is 500 ° C.
And the temperature is high, and the effect of heat on the element and the terminal is large, and wire bonding is difficult. Further, since the low-melting glass is water-soluble, there is a limit to the usable pressure medium.

Further, in Japanese Patent Application Laid-Open No. 55-6816, Ni, A is attached to the surface of a pressure receiving table made of crystallized glass.
Since the metal film layer is formed of u, Ag or Cu, there is a problem in adhesion.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a highly reliable semiconductor pressure sensor having high strength, high impact resistance, and excellent adhesion to a glass pedestal. .

[0011]

According to a first aspect of the present invention, there is provided a component of a semiconductor pressure sensor, comprising: a silicon element forming a pressure-sensitive diaphragm; and a line similar to the silicon element. A joined body composed of a glass pedestal having an expansion coefficient and joined to the silicon element, and a metal pedestal joined to the joined body by a soft solder, the glass pedestal is formed of crystalline glass, One surface has a metal film containing Cr or Ti as a component.

In this structure, since the glass pedestal is formed of crystalline glass, the development of cracks at the crystal grain boundaries can be suppressed. Further, the adhesion to the glass pedestal is improved by the metal film containing Cr or Ti as a component. Thus, if a semiconductor pressure sensor is configured using the present component, a highly reliable semiconductor pressure sensor having high strength, high impact resistance, and excellent adhesion to the glass pedestal can be obtained.

According to a second aspect of the present invention, there is provided a semiconductor pressure sensor, comprising: a silicon element forming a pressure-sensitive diaphragm;
And a bonded body composed of a glass pedestal having a linear expansion coefficient similar to that of the silicon element and bonded to the silicon element, and a metal pedestal bonded to the bonded body by a soft solder, wherein the glass pedestal is , Made of crystalline glass and having a metal film containing Cr or Ti on one surface.

In this structure, since the glass pedestal is formed of crystalline glass, the development of cracks at the crystal grain boundaries can be suppressed. Further, the adhesion to the glass pedestal is improved by the metal film containing Cr or Ti as a component. This makes it possible to obtain a highly reliable semiconductor pressure sensor having high strength, high impact resistance, and excellent adhesion to the glass pedestal.

The glass pedestal may have a structure in which three or four metal films are formed, the outermost metal film is formed of Au, and the metal film of the underlayer is formed of Pt or Ni. (Claim 3). According to this structure,
At the time of, for example, anodic bonding between the joined body and the metal pedestal, deterioration due to heating is prevented, and the joining reliability between the joined body and the metal pedestal is improved. The three-layer metal film may be formed of four types of materials (claim 4).

Further, the soft solder may be a gold-based material and used for hermetic joining between the joined body and the metal pedestal. According to this, the heat resistance and the durability of the joining portion are improved as compared with the Sn-Pb soft solder or the Sn-based soft solder.

Each of the glass pedestal and the metal pedestal has a through hole through which the pressure of the medium to be measured passes, and the diameter of the through hole of the glass pedestal is larger than the diameter of the through hole of the metal pedestal. It may have a structure (claim 6).
According to this structure, the heat shrinkage of the soft solder is suppressed by the metal pedestal, the stress applied to the glass pedestal is reduced, and the heat resistance and durability of the joint are improved.

Furthermore, the glass pedestal may have a surface having a roughness Rmax of 0.5 to 6 μm at the joint surface with the metal pedestal. According to this design, bonding reliability is improved.

An eighth aspect of the present invention is a method of manufacturing the semiconductor pressure sensor, comprising the steps of forming a diaphragm on a Si wafer, and forming the diaphragm mainly on Li ₂ O—Al ₂ O ₃ —SiO _2. Forming a metal film on one surface of the glass wafer to be formed, anodically bonding the surface of the Si wafer on which the diaphragm is formed and the other surface of the glass wafer, A step of individually dividing the glass wafer to obtain the joined body; and a step of joining each of the joined bodies to the metal pedestal.

According to this method, the glass pedestal is made of Li ₂ O.
Since it is formed of crystalline glass containing -Al ₂ O ₃ -SiO ₂ as a main component, the development of cracks at the crystal grain boundaries can be suppressed. Further, the adhesion to the glass pedestal is improved by the metal film containing Cr or Ti as a component.
This makes it possible to obtain a highly reliable semiconductor pressure sensor having high strength, high impact resistance, and excellent adhesion to the glass pedestal. Further, since the glass pedestal does not contain Na as a main component, the problem of the withstand voltage deterioration of the silicon element due to Na does not occur.

According to a ninth aspect of the present invention, there is provided a method of manufacturing the semiconductor pressure sensor, comprising the steps of forming a diaphragm on a Si wafer, and forming the diaphragm with Li ₂ O—Al ₂ O ₃ —SiO ₂ as a main component. Forming a metal film on one surface of the glass wafer, forming a plurality of through-holes in the glass wafer on which the metal film is formed, and forming a surface of the Si wafer on which a diaphragm is formed and the glass wafer. Anodically bonding the other surface of the substrate, the step of individually dividing the anodically bonded Si wafer and the glass wafer to obtain the bonded body, and bonding each of the bonded bodies to a metal pedestal having a pressure introducing hole. And

According to this method, the glass pedestal is made of Li ₂ O.
Since it is formed of crystalline glass containing -Al ₂ O ₃ -SiO ₂ as a main component, the development of cracks at the crystal grain boundaries can be suppressed. Further, the adhesion to the glass pedestal is improved by the metal film containing Cr or Ti as a component.
This makes it possible to obtain a highly reliable semiconductor pressure sensor having high strength, high impact resistance, and excellent adhesion to the glass pedestal. Further, since the glass pedestal does not contain Na as a main component, the problem of the withstand voltage deterioration of the silicon element due to Na does not occur. Further, since the pressure can be directly detected by the pressure-sensitive diaphragm of the silicon element, the measurement response can be improved.

[0023]

FIG. 1 is an enlarged sectional view showing components of a semiconductor pressure sensor according to a first embodiment of the present invention. The first embodiment will be described below with reference to this drawing.

The components of the present semiconductor pressure sensor include a silicon chip (silicon element) 11 having a pressure-sensitive diaphragm formed on the lower surface side and a linear expansion coefficient similar to that of the silicon chip 11. A bonded body 10 composed of a glass pedestal 12 bonded by anodic bonding or the like, formed into a plate shape by, for example, Kovar or 42 alloy, and bonded to a lower surface side of the glass pedestal 12 of the bonded body 10 by a solder (soft solder) 13. And a metal base 14 to be formed. However, the glass pedestal 12 has a through-hole 121 for passing the pressure of the medium to be measured to the silicon chip 11. Further, the metal pedestal 14 has a through hole 141 having a diameter larger than the through hole 121 of the glass pedestal 12 at the center.

Here, the glass pedestal 12 is made of, for example, Li
It is formed of crystalline glass containing ₂ O—Al ₂ O ₃ —SiO ₂ as a main component. Thus, when the glass pedestal 12 is formed of crystalline glass, the development of cracks at the crystal grain boundaries is suppressed. Therefore, for example, if this component is fixed to a body block (not shown), and a semiconductor pressure sensor is formed by electrically connecting a substrate, a signal extraction pin or the like to the silicon chip 11 with a bonding wire or the like, a high-strength impact can be obtained. A highly reliable semiconductor pressure sensor can be obtained. Further, since the glass pedestal 12 does not contain Na as a main component, the problem of deterioration of the withstand voltage of the silicon chip 11 due to Na does not occur.

On the lower surface of the glass pedestal 12, a metal film (not shown) containing Cr or Ti as a component is formed.
If such a metal film is formed on the lower surface of the glass pedestal 12, the adhesion to the glass pedestal is improved.

Further, since the through holes 121 and 141 reaching the pressure-sensitive diaphragm of the silicon chip 11 are formed, the pressure can be directly detected by the pressure-sensitive diaphragm, and the measurement response can be improved.

FIG. 2 is an enlarged sectional view showing a semiconductor pressure sensor according to a second embodiment of the present invention. Referring to FIG. 2, another embodiment according to the components of the semiconductor pressure sensor of the present invention will be described. It will be explained together.

This semiconductor pressure sensor has a silicon chip (silicon element) 21 forming a pressure-sensitive diaphragm, and a linear expansion coefficient similar to that of the silicon chip 21.
A bonded body 20 composed of a glass pedestal 22 bonded to a silicon chip 21 by anodic bonding or the like;
2, a metal pedestal 24 joined to the lower surface side of the glass pedestal 22 of the joined body 20 by the solder 13, and a signal extraction pin 25 having an outer diameter smaller than the diameter of the hole 242 and inserted into each hole 242. And a bonding wire 26 for electrically connecting one end of each of the signal extraction pins 25 to (the predetermined electrode of) the silicon chip 21 and an insulating material such as soda barium borosilicate glass. A sealing member 27 for sealing a gap between the holes 242 generated by the insertion of the pins 25 and a pressure introducing pipe 281 are provided at the upper center, and the joined body 20, one end of each signal extraction pin 25 and each bonding wire 26 are provided. Box-shaped cover 28 for closing
And a liquid 29 sealed in the cover 28, and the pressure from the pressure introducing pipe 281 is detected by the silicon chip 21 via the liquid 29. However, in the example shown in FIG. 2, the pressure-sensitive diaphragm is formed on the lower surface side of the silicon chip 21. In addition, metal pedestal 2
4 is formed in a plate shape by, for example, Kovar or 42 alloy.

Here, the glass pedestal 22 is made of, for example, Li
It is formed of crystalline glass containing ₂ O—Al ₂ O ₃ —SiO ₂ as a main component. Thus, when the glass pedestal 22 is formed of crystalline glass, the development of cracks at the crystal grain boundaries is suppressed. As a result, a highly reliable semiconductor pressure sensor having high strength and strong impact resistance can be obtained.

On the lower surface of the glass pedestal 12, a metal film containing Cr or Ti as a component is formed. If such a metal film is formed on the lower surface of the glass pedestal 12, the adhesion to the glass pedestal is improved.

Furthermore, the liquid 2 transmitting the pressure to be measured
9 can be increased in pressure resistance and corrosion resistance.

FIG. 3 is an enlarged sectional view showing a semiconductor pressure sensor according to a third embodiment of the present invention. Referring to FIG. 3, another embodiment relating to the components of the semiconductor pressure sensor of the present invention will be described. It will be explained together.

The present semiconductor pressure sensor includes a joint 10 similar to that of the first embodiment and a pressure introducing pipe 343 extending downward.
A metal pedestal 34 joined to the lower surface of the glass pedestal 12 of the joined body 10 by the solder 13, a plurality of signal extraction lead wires 35, one end of each of the signal extraction lead wires 35, and the silicon chip 11. And a cover for closing the bonding body 10, one end of each signal extraction lead 35 and the bonding wire 26 in a state where the other end of each signal extraction lead 35 is pulled out to the outside. 38, and the pressure from the pressure introducing pipe 343 is detected by the silicon chip 11. However, the metal pedestal 34 is formed in a cylindrical shape having a flange portion on the upper portion by, for example, Kovar or 42 alloy. The cover 38 is made of, for example, a heat-resistant resin such as a liquid crystal polymer.

As described above, according to the third embodiment, since the same joined body 10 as that of the first embodiment is used, the same effect as that of the first embodiment can be obtained.

FIG. 4 is an enlarged sectional view showing a semiconductor pressure sensor according to a fourth embodiment of the present invention. Referring to FIG. 4, another embodiment relating to the components of the semiconductor pressure sensor of the present invention will be described. It will be explained together.

The present semiconductor pressure sensor has a joint 10 similar to that of the first embodiment and a pressure introducing pipe 443 made of, for example, Kovar or 42 alloy and extending downward.
A metal pedestal 44 joined to the lower surface of the glass pedestal 12 of the joined body 10 by the solder 13, and a plurality of signal extraction pins 2
And bonding wires 26 for electrically connecting one end of each of the signal extraction pins 25 to the silicon chip 11.
And a sealing material 47 made of an insulating material such as soda barium borosilicate glass for sealing all holes inside the metal pedestal 44, the joined body 10, one end of each signal extraction pin 25, and a bonding wire. And a box-shaped cover 48 for closing the pressure sensor 26. The pressure from the pressure introducing pipe 443 is detected by the silicon chip 11.

As described above, according to the fourth embodiment, since the same joined body 10 as that of the first embodiment is used, the same effect as that of the first embodiment can be obtained.

FIG. 5 is an enlarged sectional view showing a semiconductor pressure sensor according to a fifth embodiment of the present invention. Referring to FIG. 5, another embodiment relating to the components of the semiconductor pressure sensor of the present invention will be described. It will be explained together.

The present semiconductor pressure sensor includes a joint 10 similar to that of the first embodiment and a pressure introducing pipe 543 extending downward.
Is formed of, for example, Kovar or 42 alloy in a plate shape having a center at the center, and a plurality of holes 54
2, a metal pedestal 54 joined to the lower surface side of the glass pedestal 12 of the joined body 10 and the solder 13;
A plurality of signal extraction pins 25 and each of the signal extraction pins 25
And a bonding wire 26 for electrically connecting one end of the semiconductor chip 11 to the silicon chip 11 and an insulating material such as soda barium borosilicate glass.
And a box-shaped cover 5 for closing the joint body 10, one end of each signal extraction pin 25, and the bonding wire 26.
The pressure from the pressure introducing pipe 543 is detected by the silicon chip 11.

Since the glass pedestal 12 is made of crystalline glass mainly composed of Li ₂ O—Al ₂ O ₃ —SiO ₂ as in the first embodiment, the glass pedestal 12 is high in strength and resistant to impact. A highly reliable semiconductor pressure sensor can be obtained.

Further, since a metal film containing Cr or Ti is formed on the lower surface of the glass pedestal 12, the adhesion to the glass pedestal is improved.

Further, the through-hole 121 of the glass pedestal 12
Has a larger diameter than the through hole 541 of the pressure introduction pipe 543. Thereby, the joining material (solder 13)
Of the through hole 121 is suppressed by the metal pedestal 54.
Since the stress applied to the surface is reduced, the heat resistance and durability of the joint are improved.

FIG. 6 is an enlarged sectional view showing components of a semiconductor pressure sensor according to a sixth embodiment of the present invention. The sixth embodiment will be described below with reference to FIG.

The components of the present semiconductor pressure sensor include a silicon chip (silicon element) 11 having a pressure-sensitive diaphragm formed on the lower surface side, and a linear expansion coefficient similar to that of the silicon chip 11. A joined body 60 constituted by a glass pedestal 62 joined by anodic joining or the like, and a metal pedestal formed in a plate shape by, for example, Kovar or 42 alloy and joined to the lower side of the glass pedestal 62 of the joined body 60 by the solder 13 64.

Here, the diameter A of the through hole 621 of the glass pedestal 62 is larger than the diameter B of the through hole 641 of the metal pedestal 64. Thereby, the heat shrinkage of the bonding material (solder 13) is suppressed by the metal pedestal 64, and the heat resistance and durability of the bonding portion are improved.

On the lower end side of the glass pedestal 62, layers (metal films) 621 to 623 are formed in this order.
Layer 621 has a thickness of about 0.2 μm and is made of Ti or Cr, layer 622 has a thickness of about 0.2 μm and is made of Pt or Ni, and layer 623 has a thickness of 0.05 to 0.05 μm.
It is made of Au at 0.5 μm. As described above, when the layer 621 made of Ti or Cr is formed on the glass pedestal 62, the adhesion to the glass pedestal 62 is improved. Also,
When the layer 623 made of Au is used for the outermost layer (lowermost layer) and the layer 622 made of Pt or Ni is used for the base layer (upper layer), the anodic bonding between the joined body 60 and the metal pedestal 64 is performed. The deterioration of the component due to the above is prevented, and the joining reliability between the joined body 60 and the metal base 64 is improved. As long as such a condition is satisfied, a structure in which four metal films are formed on the lower end side of the glass pedestal 62 may be used. Also,
Even in the case of three layers, four types of materials may be used.

In the first to sixth embodiments, a solder is used for joining the joined body and the metal pedestal. The solder may be one containing Sn and Pb as main components.
Alternatively, for example, Au-20Sn, Au-12Ge, A
A material mainly composed of u-3Si gold may be used. In the latter case, the heat resistance and the durability of the joint are improved as compared with the former.

When the roughness of the joint surface of the joined body with the metal pedestal is set to Rmax = 0.5 to 6 μm, the joining reliability is improved. If the roughness is 0.5 μm or less, the anchor effect is reduced and the bonding strength is reduced. Conversely, if the roughness is 6 μm or more, the adhesive portion of the dicing tape remains and causes bonding at the bonding portion. It is.

FIG. 7 is an explanatory view of an embodiment showing a method of manufacturing a semiconductor pressure sensor according to the present invention. The embodiment will be described below with reference to this figure. However, in this embodiment,
The semiconductor pressure sensor is manufactured after manufacturing the components of the semiconductor pressure sensor of the sixth embodiment.

First, a plurality of circular grooves (bottomed round holes) 111 are formed on the lower surface of a semiconductor single crystal wafer, for example, a silicon wafer 1 by etching to form diaphragms (see FIG. 1). A diffusion strain gauge (not shown) is installed on the upper surface of the silicon wafer 1 corresponding to the position (1). Each diffusion strain gauge is formed by selectively diffusing impurities such as boron, for example, through a window opened only at a desired location by photoetching, using an insulating layer formed by oxidizing the entire surface of a silicon wafer by heat treatment as a selection mask. .

Next, the surface roughness Rmax of the upper surface of the glass wafer 2 containing Li ₂ O—Al ₂ O ₃ —SiO ₂ as a main component.
Is made to be 0.1 μm or less, and the lower surface thereof is made to have a surface roughness Rmax of 0.5 to 6 μm.

Thereafter, a layer of Ti, for example, having a thickness of about 2000 ° (see 621 in FIG. 6) is formed on the lower surface (hereinafter referred to as a film forming surface) of the glass wafer 2, and a thickness of 2000 ° is formed on this layer. A layer made of Pt to the extent (62 in FIG. 6)
2) and a thickness of 500 to 500
A layer made of Au is formed at 5000 ° (see 623 in FIG. 6). It is needless to say that these three layers are not limited to Ti, Pt, and Au, but may be Ti, Ni, and Au, Cr, Pt, and Au, or Cr, Ni, and Au.

Thereafter, as shown in FIG.
A plurality of round through holes 621 are formed in the glass wafer 2 on which the layer is formed by ultrasonic processing. In addition, each through hole 6
The formation of the layer 21 may be before or after the formation of the above three layers, but is preferably performed after the formation because a metal film is not formed inside the through hole.

Next, the central axis of each groove 111 and each through hole 62
Then, the diaphragm side of the silicon wafer 1 and the non-film-forming surface of the glass wafer 2 are joined by anodic bonding so that the center axis of the wafer 1 coincides with the center axis (see FIG. 7B). The conditions of the anodic bonding are as follows: a temperature of 350 ° C. to 450 ° C .;
00V.

Next, the bonded silicon wafer 1 and glass wafer 2 are cut with a dicing saw with the metallized surfaces in close contact (see FIG. 7C). Thereby, a plurality of joined bodies 60 are obtained.

Thereafter, as shown in FIG. 7D, the joined body 60 is placed on a metal pedestal (for example, the metal pedestal 44 shown in FIG. 4).
The bonding is performed by using an n-based or Au-based solder 13.
For Sn-based solder, Sn-0 to 10.5Sb or S
n-0 to 5 Ag. Au-based solder includes Au-20Sn. These solders do not contain flux and are heated and joined in a nitrogen or reducing atmosphere.

Thereafter, each signal extraction pin 25 and the silicon chip 11 are electrically connected by wire bonding or the like, and these wiring portions are sealed with silicon gel.
Is fixed. Thus, the manufacture of the semiconductor pressure sensor is completed.

[0059]

As is apparent from the above, according to the first aspect of the present invention, a silicon element forming a pressure-sensitive diaphragm, and a silicon element having a linear expansion coefficient similar to that of the silicon element, It comprises a joined body constituted by a glass pedestal to be joined, and a metal pedestal joined to the joined body by a soft solder, wherein the glass pedestal is formed of crystalline glass and has Cr or Ti on one surface. Since it has a metal film that is strong and resistant to impact,
A highly reliable semiconductor pressure sensor having excellent adhesion to the glass pedestal can be obtained.

According to the second aspect of the invention, a silicon element forming the pressure-sensitive diaphragm, and a joined body constituted by a glass pedestal having a linear expansion coefficient similar to that of the silicon element and joined to the silicon element And a metal pedestal joined to the joined body by a soft solder. The glass pedestal is formed of crystalline glass, and has a C surface on one surface.
Since it has a metal film containing r or Ti as a component, it is possible to obtain a highly reliable semiconductor pressure sensor that is high in strength and resistant to impact and excellent in adhesion to a glass pedestal.

According to the third aspect of the present invention, three or four metal films are formed on the glass pedestal, the outermost metal film is formed of Au, and the metal film of the underlayer is P.
According to the fourth aspect of the present invention, since the three-layer metal film is formed of four types of materials, the reliability of bonding between the bonded body and the metal pedestal is improved. Becomes possible.

According to the fifth aspect of the present invention, the soft solder is a gold-based material and is used for hermetic bonding between the joined body and the metal pedestal. It is possible to improve the heat resistance and the durability of the joints as compared with the soft solder.

According to the present invention, each of the glass pedestal and the metal pedestal has a through hole through which the pressure of the medium to be measured is passed, and the diameter of the through hole of the glass pedestal is such that the metal pedestal has Since the diameter of the through hole is larger than the diameter of the through hole, the heat resistance and durability of the joint can be improved.

According to the seventh aspect of the present invention, the roughness of the bonding surface of the glass pedestal with the metal pedestal is Rmax.
Since the thickness is 0.5 to 6 μm, the bonding reliability can be improved.

According to the eighth aspect of the present invention,
7. A method for manufacturing a semiconductor pressure sensor according to any one of claims 7, wherein a step of forming a diaphragm on a Si wafer and a step of forming a diaphragm on a Si wafer are performed by using a glass wafer formed mainly of Li ₂ O—Al ₂ O ₃ —SiO _2. Forming a metal film on the surface of the silicon wafer, anodically bonding the surface of the Si wafer on which the diaphragm is formed and the other surface of the glass wafer, and individually bonding the anodically bonded Si wafer and the glass wafer. Since it has a step of dividing and obtaining the joined body and a step of joining each of the joined bodies to the metal pedestal, a high-reliability semiconductor having high strength and strong impact and excellent adhesion to the glass pedestal A pressure sensor can be obtained. Further, the withstand voltage of the silicon element can be improved.

According to a ninth aspect of the present invention, there is provided a method of manufacturing a semiconductor pressure sensor according to any one of the second to seventh aspects, wherein a step of forming a diaphragm on a Si wafer,
Forming a metal film _{2 O-Al 2 O 3 -SiO} 2 on one surface of the glass wafer which is formed as a main component, to form a plurality of through-holes in the glass wafer to the metal film is formed A step of anodically bonding a surface of the Si wafer on which a diaphragm is formed and another surface of the glass wafer,
A step of individually dividing the anodically bonded Si wafer and the glass wafer to obtain the joined body; and a step of joining each of the joined bodies to a metal pedestal having a pressure introducing hole, so that the joint body has a high strength and is resistant to impact. It is possible to obtain a highly reliable semiconductor pressure sensor that is strong and has excellent adhesion to the glass pedestal. Further, the withstand voltage of the silicon element can be improved. Further, the measurement response can be improved.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing components of a semiconductor pressure sensor according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a semiconductor pressure sensor according to a second embodiment of the present invention.

FIG. 3 is an enlarged sectional view showing a semiconductor pressure sensor according to a third embodiment of the present invention.

FIG. 4 is an enlarged sectional view showing a semiconductor pressure sensor according to a fourth embodiment of the present invention.

FIG. 5 is an enlarged sectional view showing a semiconductor pressure sensor according to a fifth embodiment of the present invention.

FIG. 6 is an enlarged sectional view showing components of a semiconductor pressure sensor according to a sixth embodiment of the present invention.

FIG. 7 is an explanatory diagram of one embodiment showing a method for manufacturing a semiconductor pressure sensor of the present invention.

FIG. 8 is a sectional view showing a schematic structure of a conventional general semiconductor pressure sensor.

[Explanation of symbols]

 10, 20, 60 Joined body 11, 21, Silicon chip 12, 22, 62 Glass pedestal 13 Solder 14, 24, 34, 44, 54, 64 Metal pedestal 25 Signal extraction pin 26 Bonding wire 27, 47 Sealant 28, 38 , 48, 58 Cover 29 Liquid 35 Signal lead wire

Claims (9)

[Claims] 1. A silicon element forming a pressure-sensitive diaphragm, a joined body composed of a glass pedestal having a linear expansion coefficient similar to that of the silicon element and joined to the silicon element, and a soft solder with the joined body A glass pedestal formed of crystalline glass and having a metal film containing Cr or Ti as a component on one surface. 2. A silicon element forming a pressure-sensitive diaphragm, a joined body composed of a glass pedestal having a linear expansion coefficient similar to that of the silicon element and joined to the silicon element, and a soft solder with the joined body. And a metal pedestal joined by a metal pedestal, wherein the glass pedestal is formed of crystalline glass, and has a metal film containing Cr or Ti as a component on one surface. 3. A three-layer or four-layer metal film is formed on the glass pedestal, the outermost metal film is formed of Au, and the underlying metal film is formed of Pt or Ni. A semiconductor pressure sensor according to claim 1. 4. The semiconductor pressure sensor according to claim 3, wherein the three metal films are formed of four kinds of materials. 5. The soft solder is a gold-based material and is used for hermetic joining between the joined body and the metal pedestal.
5. The semiconductor pressure sensor according to any one of claims 1 to 4. 6. The glass pedestal and the metal pedestal each have a through hole through which the pressure of the medium to be measured is passed, and the diameter of the through hole of the glass pedestal is larger than the diameter of the through hole of the metal pedestal. The semiconductor pressure sensor according to claim 2. 7. The semiconductor pressure sensor according to claim 2, wherein a roughness of a bonding surface of the glass pedestal with the metal pedestal is Rmax 0.5 to 6 μm. 8. A method of manufacturing a semiconductor pressure sensor according to any of claims 2-7, forming a diaphragm on Si _{wafer, Li 2 O-Al 2 O} 3 -SiO 2 main Forming a metal film on one surface of a glass wafer formed as a component; anodically bonding a surface of the Si wafer on which a diaphragm is formed and another surface of the glass wafer; A method for manufacturing a semiconductor pressure sensor, comprising: a step of individually dividing the Si wafer and the glass wafer to obtain the joined body; and a step of joining each of the joined bodies to the metal pedestal. 9. A method for manufacturing a semiconductor pressure sensor according to claim 2, wherein a step of forming a diaphragm on a Si wafer and a step of forming a diaphragm on a Si wafer are performed mainly by using Li ₂ O—Al ₂ O ₃ —SiO ₂ . A step of forming a metal film on one surface of a glass wafer formed as a component; a step of forming a plurality of through holes in the glass wafer on which the metal film is formed; and a surface of the Si wafer on which a diaphragm is formed. Anodically bonding the silicon wafer and the other surface of the glass wafer to each other; a step of individually dividing the anodically bonded Si wafer and the glass wafer to obtain the bonded body; and each of the bonded bodies having a pressure introducing hole. Joining to a metal pedestal.