JPH11162542A - Sealing structure of electrode taking-out hole and sealing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To airtightly seal an electrode taking-out hole only by a pin. SOLUTION: A lead pin (an electrode) 14 is composed of a main body 14A, a seal part 14B and a press-in part 14C integrally arranged on this main body 14A. A metallic film 32 is formed around an electrode taking-out hole 13 on an outside surface of a stem 3 composed of an insulating material. The press-in part 14C is pressed in by inserting the main body part 14A of the lead pin 14 into the electrode taking-out hole 13, and the electrode taking-out hole 13 is sealed by bringing the seal part 14B into pressure contact with the metallic film 32. At this time, the stem 3 is compressed, and when expanded after finishing pressure contact, the metallic film 32 is pressed against the seal part 14B. Therefore, surface pressure is applied to a joining part of the seal part 14B and the metallic film 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing structure of an electrode extraction hole for hermetically sealing an electrode extraction hole with an electrode such as a lead pin and a sealing method thereof.

[0002]

2. Description of the Related Art Pressure sensors, semiconductor laser devices, vacuum tubes, ICs, and the like are required to have characteristics such as pressure resistance, sealability, and electrical insulation. In the case of a pressure sensor, a structure that does not transmit thermal stress to the sensor chip when sealing the sensor chip in a package is required.

In a pressure sensor that requires the above-described characteristics, a lead pin (electrode) extraction portion provided to guide an electric signal to the outside is usually configured as shown in FIG. That is, FIG. 5 is a sectional view showing a conventional example of a semiconductor pressure sensor. This semiconductor pressure sensor 1 is made of metal via a stem 3 made of an insulating material in a cylindrical package 2 made of a metal such as SUS316. The carrier 4 is housed, the sensor chip 5 is housed in the carrier 4 via a base 6 made of an insulating material, and the surface of the package 2 is covered with a pressure receiving diaphragm 7. Further, a sealing liquid 8 such as silicone oil is sealed in the package 2, and a measured pressure P 1 applied to the pressure receiving diaphragm 7 is reduced through the sealing liquid 8 to the sensor chip 5.
To be communicated to.

[0004] One end of the package 2 is open to the back side chamber 9 of the pressure receiving diaphragm 7, and the other end is connected to the package 2.
A filling liquid injection hole 10 is formed on the back surface of the filling hole for injecting the filling liquid 8 into the back side chamber 9, and the opening on the back surface is sealed with a ball 11.

The stem 3 is usually formed in a cylindrical shape from ceramics such as alumina and has a concave portion 12 for accommodating the carrier 4 and is joined to the package 2 by soldering (brazing) or the like. An electrode extraction hole 13 is formed in the thick portion of the stem 3. An elongated lead pin 14 for extracting an electric signal of the sensor chip 5 to the outside is inserted into the electrode extraction hole 13 to prevent leakage of the sealed liquid 8. It is sealed with a solder material 15 such as Sn-Ag or Pb-Sn.

The carrier 4 has excellent corrosion resistance and weldability, is made of a material having a coefficient of linear expansion substantially equal to that of the pedestal 6 of the sensor chip 5, for example, Kovar, and is inserted into the stem 3. Joined by soldering to prevent leakage.

The sensor chip 5 is formed by forming a gauge 16 acting as a piezoresistive region on the surface of a strain generating portion 5A provided on a semiconductor substrate made of Si or the like by an impurity diffusion or ion implantation technique. (Electrostatic bonding). The pedestal 6 is made of the same material as the sensor chip 5 or the same as the sensor chip 5 if thermal strain generated when the sensor chip 5 is joined is transmitted to the sensor chip 5, thereby lowering the temperature characteristics of the pressure detection device 1 and causing a zero point shift. It is formed of a material having a linear expansion coefficient close to the coefficient of linear expansion of No. 5, for example, Pyrex glass (trade name), silicon nitride, or the like. An inner chamber 17 is formed between the sensor chip 5 and the pedestal 6 and is separated from the rear chamber 9. The inner chamber 17 is opened to the atmosphere through a pressure introduction path 19 formed in the pedestal 6 and the carrier 4 to guide the atmospheric pressure P2.
The gauge 16 of the sensor chip 5 and the lead pin 1
4 are electrically connected by a lead wire 20 made of a gold wire or the like.

As described above, the electrode extraction hole 13 of the stem 3 through which the lead pin 14 is inserted is hermetically sealed by the solder material 15 to prevent leakage of the sealed liquid 8. When the electrode pins 13 are formed directly in the metal carrier 4 without using the stem 3 and the lead pins 14 are inserted, there is also a sealing method of hermetically sealing with glass.

In such a pressure detecting device 1, when the measured pressure P1 is guided to the sensor chip 5 via the sealed liquid 8 by the displacement of the pressure receiving diaphragm 7, the strain generating portion 5A is displaced and the specific resistance of the gauge 16 is reduced. Therefore, the measured pressure P1 or the differential pressure P1 -P2 can be measured by detecting the output voltage accompanying the resistance change at this time. When detecting the absolute pressure, the inner chamber 17 of the sensor chip 5 may be evacuated.

[0010]

However, in the conventional sealing structure described above, when the electrode extraction hole 13 is hermetically sealed with a solder material 15 or a glass material, the lead pin 14 is previously inserted into the electrode extraction hole 13. There is a problem that the number of steps for sealing increases because it is necessary to insert and temporarily fix.

In soldering (brazing),
There is also a problem that the wettability of the solder material is easily affected by the state of the bonding surface to be soldered, and poor airtightness is likely to occur.

On the other hand, in a sealing structure in which an electrode extraction hole 13 is directly formed in the carrier 4 and a glass hermetic seal is formed, a lead pin 14 is inserted into the electrode extraction hole 13 and a glass pellet of a predetermined size is inserted therein. And 400-1
The glass pellet is melted by heating to 000 ° C. so as to fill the gap between the electrode extraction hole 13 and the lead pin 14. At this time, the carrier 4 contracts when cooled, and the contraction causes the glass material and the lead pin 14 to shrink.
Tighten. As a result, a hermetic (shrinkage fit) is established, and the electrode extraction hole 13 is hermetically sealed.

[0013] However, the glass hermetic seal conventionally used requires a very high temperature treatment. Further, in the glass hermetic seal, voids (spaces) may be generated in the glass material filled in the gap. The presence of voids causes a decrease in airtightness.
However, the generated void cannot be removed.
In this case, in order to suppress a decrease in airtightness, the distance of the gap or the wettability of the glass material to be filled in the gap is optimized, or the amount of glass material to be filled in the gap is increased to increase the force of the hermetic. This prevents the occurrence of voids. Also, when using a glass hermetic seal,
There is a restriction that the carrier 4 needs to be formed of a material having a larger linear expansion coefficient than the base 6.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to enable reliable sealing without using a solder material, a glass material, or the like. And a method for sealing the electrode extraction hole.

[0015]

According to a first aspect of the present invention, there is provided a member made of an insulating material having an electrode extracting hole, and a metal formed around the electrode extracting hole on the surface of the member. A membrane, a metal pin formed in a rod shape and having a length equal to or greater than the thickness of the member and a seal portion and inserted into the electrode extraction hole, and having an outer peripheral surface of the pin having a diameter greater than the diameter of the electrode extraction hole. A press-fit portion having a large outer diameter and being press-fitted into the electrode take-out hole is provided integrally, and the electrode take-out hole is sealed by joining the seal portion to the metal film by pressing.

In the first aspect of the present invention, the sealing portion of the pin and the metal film are joined by pressure contact, so that the electrode extraction hole can be hermetically sealed. When the seal portion is pressed against the metal film with a large pressing force and the pin is pressed into the electrode extraction hole, the member is compressed, and expands when the pressing force is removed.
At this time, since the pin is fixed to the member at the press-fitting portion, it does not expand or contract. When the member expands, the expansion force acts to press the metal film against the seal portion, so that a large surface pressure is obtained between the seal portion and the metal film. Therefore, good sealing performance can be obtained even if joining is incomplete. Further, the surface pressure between the seal portion and the metal film does not decrease because the press-fit portion is fixed to the electrode extraction hole by press-fit.

According to a second aspect, in the first aspect,
A metal film made of the same material as the metal film is provided on the surface of the pin.

In the second aspect of the present invention, when the seal portion of the pin is pressed against the metal film, the metal films are heated and melted and joined to hermetically seal the electrode extraction hole. Gold, copper, or the like is used as the material of the metal film.

According to a third aspect of the present invention, in the first or second aspect, the press-fitting portion of the pin is constituted by a plurality of protrusions formed at predetermined intervals in the circumferential direction. I do.

In the third aspect, the projection is easily formed by crushing the outer peripheral portion of the pin with a press machine or the like.

A fourth invention is characterized in that, in the first, second or third invention, the electrode extraction hole is sealed with a solder material.

In the third aspect, the solder material hermetically seals the electrode extraction hole together with the seal portion.

According to a fifth aspect of the present invention, an electrode extraction hole is formed in a member made of an insulating material, and a metal film is formed around the electrode extraction hole on the surface of the member. A pin having a seal portion and a press-fit portion larger than the length of the electrode take-out hole and the diameter of the electrode take-out hole is press-fitted into the electrode take-out hole by a press machine, and the seal portion is joined to the metal film by press contact to thereby form the electrode take-out hole. Is sealed.

In the fifth aspect of the present invention, when the pin is pressurized by a press machine to press-fit the press-fit portion into the electrode takeout hole and join the seal portion to the metal film, the electrode takeout hole can be hermetically sealed. At this time, the member is compressed, expands when press-fitting is completed, and returns to its original state. Thereby, the metal film is pressed against the seal portion to increase the surface pressure between the seal portion and the metal film. The surface pressure does not decrease because the press-fit portion is fixed to the electrode extraction hole by press-fit.

According to a sixth aspect based on the fifth aspect,
The press machine is provided with a heater, and heats the pin at the time of press-fitting.

In the sixth aspect, when the pin is heated at the time of pressurization and press-fitted into the electrode extraction hole, bonding can be performed with a small pressing force. Pins are cooled and shortened after press-fitting.
The sealing portion is pressed against the metal film by the contraction force at this time, and the surface pressure between the sealing portion and the metal film is increased. This surface pressure does not decrease because the pin itself does not expand and contract, only the press-fit portion is fixed to the electrode extraction hole by press-fit.

A seventh invention is characterized in that, in the fifth or sixth invention, after the pins are pressed, the electrode extraction holes are sealed with a solder material.

In the seventh aspect, the solder material hermetically seals the electrode extraction hole together with the sealing portion of the pin.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. FIG. 1 is a cross-sectional view showing an embodiment in which the present invention is applied to a pressure detecting device, and FIG. 2 is a cross-sectional view showing a sealing structure of an electrode extraction hole by a lead pin. In the drawings, the same components as those shown in the section of the prior art are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. Package 2 for storing stem (member) 3
Is formed in a thin cylindrical body whose both ends are open. The hole 30 into which the stem 3 of the package 2 is fitted has a stepped portion 31 by being a different-diameter hole including a large-diameter hole portion 30a on the upper end side and a small-diameter hole portion 30b on the lower end side. The stem 3 is closely contacted with the step 31 and is fixed by soldering.

The stem 3 is formed in a cup shape large enough to fit into the large-diameter hole 30a of the package 2, and has a recess 12 at the center of the upper surface.
The carrier 4 is accommodated in 2. In a thick portion 3A surrounding the concave portion 12 of the stem 3, an electrode extraction hole 13 through which a lead pin 14 is inserted is formed to penetrate the upper and lower surfaces. Further, a metal film 32 made of gold, copper, or the like is formed by printing around the electrode extraction hole 13 on the surface of the thick portion 3A.

The lead pin 14 is formed of Kovar or the like, so that the rod-shaped main body 1 is formed as shown in FIG.
4A, a large-diameter seal portion 14B integrally provided at one end of the main body 14A, and a press-fitting portion 14C integrally provided near one end of the main body 14A.
It is plated, and a metal film identical to the metal film 32 is formed thereon by plating. Main body 14A
Is formed longer than the electrode extraction hole 13. The seal portion 14B and the press-fit portion 14C are set to be larger than the hole diameter of the electrode extraction hole 13. The seal portion 14B is joined to the metal film 32 by pressing. The press-fitting portion 14C is
It is composed of four projecting members 33 integrally protruded at 90 ° intervals in the circumferential direction of 4A. In order to manufacture such a lead pin 14, a wire having the same diameter as the main body 14A is used as a material, and its end is crushed to form a seal portion 14B.
The protrusion 33 is formed by forming a portion close to the seal portion 14B and subjecting it to plastic deformation under tension. Thereafter, it can be easily manufactured by cutting to a predetermined length and plating. The length of the lead pin 14 is 16
mm, the outer diameter of the main body 14A is about 0.45 mm, the outer diameter of the seal part 14B is about 0.8 mm, and the outer diameter of the press-fitting part 14C is about 0.57 mm. The other configuration is the same as that of the above-described conventional device.

FIG. 3 is a view for explaining a method of sealing the electrode extraction hole 13 by the lead pin 14. At the time of sealing, the stem 3 is set on the pedestal 36 and the lead pins 1
4 is inserted into the electrode extraction hole 13 and the pressurizing machine 35 is inserted.
By pressing the seal portion 14B, the press-fit portion 14C is pressed into the electrode extraction hole 13, and the seal portion 14B is pressed against the metal film 32. The pressure applied to the lead pin 14 is about 340 kg, and the stem 3 is not broken and the sealing portion 14
B and the metal film 32 can be pressed. The pressurizing machine 35 may be one that only press-fits the lead pin 14 at room temperature. However, if a pressurizing machine with a built-in heater is used and the sealing portion 14B of the lead pin 14 is heated at the time of press-fitting, a smaller pressing force can be ensured. Can be joined.

When the lead pin 14 is press-fitted at the time of press-fitting, the press-fit portion 14C bites into the hole wall of the electrode extraction hole 13 and
The lead pins 14 are fixed to the electrode extraction holes 13. When the seal portion 14B is pressed against the metal film 32 with a large pressing force, the stem 3 is compressed, but the lead pin 14 is compressed because the press-fit portion 14C is fixed to the stem 3 and is not in contact with the base 36. Not done. After the press-fitting, when the pressurizing machine 35 is raised to remove the pressing force from the lead pin 14, the stem 3 expands, and the expanding force presses the metal film 32 against the seal portion 14B. As a result, a surface pressure is generated between the seal portion 14B and the metal film 32. This surface pressure does not decrease because the pin itself is completely sealed in the movement by merely press-fitting the press-fit portion into the electrode outlet hole.

Here, when the lead pin 14 is heated and press-fitted to perform the joining with a smaller pressing force, the lead pin 14 expands due to thermal expansion. The heater temperature is 800
When heated at ~ 1000 ° C for about 1 second, lead pin 1
4 is heated to about 200 ° C. In this case, stem 3
It is important not to heat the pedestal 36 in order to prevent thermal expansion of the pedestal 36. After the press-fitting, the lead pins 14 contract when cooled. At this time, since the press-fitting portion 14C is blocked from moving by the electrode extraction hole 13, the main body portion from the press-fitting portion 14C to the seal portion 14B contracts and presses the seal portion 14 against the metal film 32. As a result, in combination with the expansion of the stem, it is possible to obtain a greater surface pressure than when the lead pins are pressed without pressing.

In the pressure detecting device 1 having such a structure, the lead pin 14 is press-fitted into the electrode extraction hole 13,
It is only necessary to press the seal portion 14B against the metal film 32, and the electrode extraction hole 13 can be sealed well. Therefore, there is no need to temporarily fix the lead pins 14 to the stem 3 or to solder them, and the sealing operation using the lead pins 14 is easy and can be performed in a short time. Also, lead pin 1
Since only the seal portion 14B and the press-fit portion 14C need to be provided integrally with the lead 4, the configuration of the lead pin 14 is simple and can be easily manufactured.

In this embodiment, since the press-fitting portion 14C of the lead pin 14 is provided near the seal portion 14B, the lead pin 14 may be inclined at the time of press-fitting.
Therefore, as shown by a two-dot chain line in FIG. 3, a large-diameter portion 3 having the same diameter as the press-fit portion 14C or an outer diameter slightly smaller than the hole diameter of the electrode extraction hole 13 on the opposite side of the press-fit portion 14C of the main body 14A.
By providing 8, it is possible to prevent the lead pin 14 from falling down. After the pressure contact, when an external force in a direction orthogonal to the axial direction is applied to the protruding end of the main body 14A protruding from the electrode extraction hole 13, the end opposite to the seal portion 14B with the press-fit portion 14C as a fulcrum is elastically deformed. Seal part 1
No large force is applied to the joint between 4B and the metal film 32,
It has no effect on the sealing performance. However, when a large external force is applied in the axial direction, the joint may be peeled off. In this case, if the electrode extraction hole 13 is sealed with a solder material after the pressure welding, the sealing can be more firmly performed. Can be. The sealing with the solder material is performed by sealing only the opening of the electrode extraction hole 13 on the side opposite to the pin insertion side, or by evacuating the electrode extraction hole 13 and filling the entire inside of the electrode extraction hole 13 with the solder material. And may be sealed.

FIG. 4 is a sectional view showing another embodiment in which the present invention is applied to a semiconductor laser device. In the figure, the semiconductor laser device includes a hermetically sealed container formed by brazing a base 40 made of an insulating material and a metal cover 41, and has GaInAsP / InP, GaAs inside.
The semiconductor laser 42 such as s is housed, and an inert gas such as argon is sealed therein. The base 40 is formed of ceramics or the like, the semiconductor laser 42 is fixed thereto, and a lead pin 44 is provided therethrough. The outer end of the base 40 is connected to a power supply (not shown), and the inner end is connected to the semiconductor via a lead wire 45. It is connected to the electrode of the laser 42. The lead pin 44 includes a rod-shaped main body 44A and a main body 44A.
A is integrally provided with a seal portion 44B provided integrally on the outer end side of A and a press-fit portion 44C provided on the opposite side to the seal portion 44B. The lead pin 44 connects the seal portion 44B to the main body 4.
It is different from the lead pin 14 shown in FIG. 2 in that it is provided near the outer end of 4A. The lead pins 44 are pressed into electrode extraction holes 46 provided in the base 40,
4B is pressed against the metal film 47 formed around the electrode extraction hole 46 on the surface of the base 40 so that the electrode extraction hole 4
6 is hermetically sealed. The inner end of the electrode extraction hole 46 is sealed with a solder material 48.

Even in such a configuration, the electrode extraction hole 4
6 can be reliably sealed by the lead pins 44 similarly to the above-described embodiment. Therefore, unlike the conventional apparatus, it is not necessary to form the base 40 with metal and seal the electrode extraction hole 46 with a glass hermetic seal, which facilitates manufacture.

In the above-described embodiment, an example in which the present invention is applied to a pressure detecting device and a semiconductor laser device has been described. However, the present invention is not limited to this, and may be applied to, for example, an IC, a vacuum tube, and the like. be able to.

[0040]

As described above, according to the electrode extraction hole sealing structure and the sealing method of the present invention, a metal pin is pressed into an electrode extraction hole provided in a member made of an insulating material. Since the pin and the metal film are joined by pressure welding, the work of sealing the electrode extraction hole can be performed easily and in a short time, and the electrode extraction hole can be reliably sealed.

Further, according to the present invention, the pin is heated at the time of press-fitting, and press-fitted, and the surface pressure is applied between the pin and the metal film by utilizing the shrinkage at the time of cooling, so that the sealing can be performed more securely. Can be. Further, when the electrode extraction hole is sealed with a solder material after the pressure welding, even better sealing performance can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment in which the present invention is applied to a pressure detecting device.

FIG. 2 is a cross-sectional view showing a sealing structure of an electrode extraction hole by a lead pin.

FIG. 3 is a diagram for explaining press fitting of a lead pin.

FIG. 4 is a sectional view showing another embodiment in which the present invention is applied to a semiconductor laser device.

FIG. 5 is a sectional view showing a conventional example of a pressure detecting device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pressure detection device, 2 ... Package, 3 ... Stem, 4 ...
Carrier, 5: Pressure sensor, 5A: Strain generating section, 6: Base,
7 ... pressure receiving diaphragm, 8 ... filled liquid, 9 ... filled liquid injection hole, 13 ... electrode extraction hole, 14 ... lead pin, 14A ... pin body, 14B ... seal part, 14C ... press-fitting part, 19 ... pressure introduction hole, 32 ... Metal film, 33 ... protrusion, 35 ... pressing machine,
40 ... base, 44 ... lead pin, 46 ... electrode extraction hole, 4
8 ... Solder material.

Claims (7)

[Claims] A member made of an insulating material having an electrode extraction hole;
A metal film formed around the electrode extraction hole on the surface of the member, and a metal pin formed in a rod shape and having a length equal to or greater than the thickness of the member and a sealing portion and inserted into the electrode extraction hole. The outer peripheral surface of the pin is provided with a press-fitting portion having an outer diameter larger than the hole diameter of the electrode extraction hole and press-fitted into the electrode extraction hole, and the sealing portion is joined to the metal film by press contact to thereby form the electrode. A sealing structure for an electrode extraction hole, wherein the extraction hole is sealed. 2. The sealing structure for an electrode extraction hole according to claim 1, wherein a metal film made of the same material as the metal film is applied to the surface of the pin. 3. The sealing structure for an electrode extraction hole according to claim 1, wherein the press-fitting portion of the pin is constituted by a plurality of protrusions integrally provided with a predetermined interval in a circumferential direction. A sealing structure for an electrode extraction hole. 4. The sealing structure for an electrode extraction hole according to claim 1, wherein the electrode extraction hole is sealed with a solder material. 5. An electrode extraction hole is formed in a member made of an insulating material, and a metal film is formed around the electrode extraction hole on the surface of the member, and is formed in a rod shape and has a length equal to or greater than the thickness of the member. By pressing a metal pin having a seal portion and a press-fit portion larger than the hole diameter of the electrode take-out hole into the electrode take-out hole by a press, and joining the seal portion to the metal film by pressing, the electrode take-out hole is formed. A method for sealing an electrode extraction hole, characterized by sealing. 6. The method for sealing an electrode extraction hole according to claim 5, wherein the pressurizing device includes a heater and heats the pin at the time of press-fitting. 7. The method for sealing an electrode extraction hole according to claim 5, wherein the electrode extraction hole is sealed with a solder material after pressing the pins.