JPS63228038A - Semiconductor pressure transducer - Google Patents

Abstract

PURPOSE:To fix a pedestal and to reduce the cost of a semiconductor pressure transducer by clamping and fixing the pedestal through a metallic collar and pressing it from below with an O ring. CONSTITUTION:The pedestal 2 is formed in a projection shape to weaken a stress from a pedestal fixation side to a sensor chip 3. Further, the collar 6 is pressed from the top surface of the bottom part 2A of the pedestal 2 and a clearance 7 is provided between the bottom part 2A and collar 6. Then a stress due to clamping is applied only to the bottom part 2A perpendicularly to eliminate a radial stress. Consequently, an external stress and a thermal stress applied to the chip 3 are reduced in combination with the projection structure. Further, the squeezing margin of the O ring 4 can be prescribed by the size and shape of the collar 6, and sealing performance by the ring 4 is obtained. Further, when a clamping part 1c is clamped, no impact force is applied to the pedestal 2, which is prevented from breaking. The pedestal 2 is therefore fixed and the cost in mass-production is reducible.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a high-pressure semiconductor pressure transducer, and in particular, the present invention relates to a high-pressure semiconductor pressure transducer, and in particular, the present invention relates to a high-pressure semiconductor pressure transducer, in which a convex pedestal on which a sensor chip is mounted is airtightly attached to a housing part while reducing the influence of external stress. Regarding the structure for fixing to.

[Prior Art] In order to fix a pedestal made of glass or the like on which a sensor chip is mounted in a conventional high-pressure semiconductor pressure transducer, the pedestal is fixed to a base member made of, for example, Kovar, which has a total bending coefficient close to that of the pedestal. A structure is used in which the base member is adhered by means such as welding and the base member is fixed to a housing or the like.

[Problem that the invention seeks to solve]

The conventional fixing means for the glass pedestal has a complicated shape and has poor workability in order to prevent stress due to heat in the periphery from being applied to the sensor chip. On the other hand, if the shape is simplified, stress is added to the sensor chip, resulting in poor temperature characteristics.

[Means for solving problems]

In the present invention, a sensor chip is mounted on the top surface of a convex part of a convex pedestal, and the top surface of the base of this pedestal is pressed against the bottom surface of a concave part of a housing part via a collar. The housing is configured to be tightened by the pedestal, and an O-ring is interposed between the base and the bottom surface of the recessed portion of the housing portion.

Further, in the present invention, a clearance is formed around the side surface of the base portion of the base.

[Effect]

In the present invention, since the pedestal receives almost no stress and thermal stress due to fixation, the sensor chip receives less stress from sources other than the pressure medium, resulting in high precision, and no impact force is applied to the pedestal during tightening, so it will not break.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention shown in the drawings will be described. 1st
The figure is a cross-sectional view showing the overall configuration of the first embodiment of the semiconductor pressure transducer according to the present invention, and FIG. 2 is an enlarged cross-sectional view of the main part thereof.

In Fig. 1.2, reference numeral 1 denotes a metal housing part, which includes a recess IB with a circular cross section in which a pressure inlet IA for the pressure to be measured (for example, oil pressure) is opened, and a constriction formed at the upper end of the recess IB. The portion 1c and the threaded portion ID are integrally formed. Reference numeral 2 denotes a convex glass pedestal (for example, Pyrex glass (trade name)), and a sensor chip 3 made of a semiconductor pressure-sensitive element or the like is fixed onto the convex portion 2B by anodic bonding technology. includes a ring-shaped rubber O-ring 4 and a ring-shaped soft material such as Teflon (trade name).
A backup ring 5 made by Manufacturer Co., Ltd. is inserted. This maintains airtightness from the medium to be measured such as oil. Reference numeral 6 denotes a cylindrical metal collar, and after being inserted into the recess IB, the periphery of the upper end surface of the collar 6 is tightened and fixed by deformation of the tightening portion IC as shown in the figure. At this time, in order to reduce the stress from the constriction part IC, the tip of the constriction part IC is located outside the outer circumferential part of the base part 2A of the base 2, and is set so as not to be located directly above the base part 2A. Further, an appropriate clearance 7 is set between the outer peripheral side surface of the base portion 2A of the base 2 and the collar 6 to reduce the stress applied to the base 2 from the radial direction as much as possible. Note that the material of the pedestal 2 is not limited to glass, and other brittle materials in general may be used.

Next, 8 is a hybrid IC board on which an output compensation circuit and an amplifier circuit are mounted, a hole is formed in the center of the board, and the convex part 2B of the pedestal 2 is exposed on this board. electrically connected.

10 is a silicone gel for protecting the element, 11 is a lead wire for taking it out to the outside, 12 is a shield plate for electromagnetic shielding,
13 is a feedthrough capacitor; 14 is a second metal housing portion; 15 is a third housing portion; 16 is an atmosphere opening port for introducing atmospheric pressure into the upper surface of the sensor chip 3;
7.18 is a resin for sealing.

According to the above configuration, the pedestal 2 is made convex to weaken transmission of stress from the pedestal fixed side to the sensor chip 3,
Moreover, by pressing the collar 6 against the upper surface of the base 2A of the base 2 and providing a clearance 7 between the base 2A and the collar 6, stress due to tightening is reduced from the base 2A.
Since the stress is applied only in the direction perpendicular to A, stress in the radial direction is substantially eliminated, and in combination with the convex structure, external stress and thermal stress applied to the sensor chip 3 can be reduced as much as possible. Moreover, since the pedestal 2 can be fixed by tightening, mass productivity is high and costs can be reduced.

Further, depending on the size and shape of the collar 6, the crushing margin of the O-ring 4 can be determined, and high sealing performance can be obtained by the O-ring 4. Furthermore, when the constriction part IC is tightened, the tip of the constriction part IC is set to be located outside the outer periphery of the two people at the base 2, and the impact force is applied to the base 2 through the collar 6. Damage can be prevented without adding damage.

Next, FIG. 3 shows a second embodiment of the present invention, which is an absolute pressure type pressure sensor in which a vacuum chamber 21 is provided by bonding a glass pedestal 2 and a glass cap 20 with low melting point glass. . The pedestal 2 is sandwiched between the pressure contact portion 6A of the collar 6 and the O-ring 4, and the stress centers of both 6A and 4 are set to substantially coincide. Moreover, this collar 6 is fixed at its peripheral upper end by the constriction part 1C of the housing 1. The measured pressure P is passed through the pressure introduction holes IA and 2C to the sensor chip 3 which is anodically bonded to the pedestal 2.
and is converted into an electrical signal.

This electrical signal is transmitted to the bonding wires 9, 9B and the conductor 9A.
The signal is transmitted to the circuit elements on the hybrid and RAD IC board 8 fixed to the upper surface of the housing 1, subjected to temperature compensation, etc., and subjected to amplification processing.

22 is an adhesive.

The feature of this embodiment is that it is configured so that stress generated by fixing the glass pedestal 2 is not applied to the sensor chip 1. Therefore, the mounting position of the O-ring 4 is set at a position almost opposite to the pressure contact part 6A of the collar 6 (that is, the position where the stress centers of both 4 and 6A almost coincide) to offset both stresses, and the O-ring 4 is This suppresses bending stress from being generated in the glass pedestal 2 due to the compressive reaction force and the stress from the pressure contact portion 6A.

Next, FIG. 4 shows a third embodiment of the present invention, which differs from the first embodiment in the structure of the collar 50.

In this example, the function of the collar 50 to press against the upper surface of the base 2 of the pedestal 2 is the same as in the first embodiment. 6, whereas in this example, the depth dimension of the recessed portion IB is used, and the former method can improve the processing accuracy from the viewpoint of manufacturing.

〔Effect of the invention〕

In the semiconductor pressure transducer according to the present invention, the convex pedestal is tightened and fixed via the metal collar, and this pedestal is held down from below by the O-ring provided in the recessed part of the housing. You can get an effect like this.

(1) The pedestal can be fixed with a shark, leading to cost reduction during mass production.

(2) Since the pedestal receives almost no stress or thermal stress due to fixation, the sensor chip receives less stress from sources other than the pressure medium, resulting in a highly accurate product.

(3) Cost is low because no technology is required to bond the pedestal to metal or the like.

(4) Since the collar shape in the present invention allows the crushing margin of the O-ring to be defined, high sealing performance can be obtained.

(5) No impact force is applied to the pedestal when tightening, and it will not break.

[Brief explanation of drawings]

1 and 2 are a sectional view and a longitudinal sectional view of essential parts showing the overall configuration of a first embodiment of a semiconductor pressure transducer according to the present invention, and FIGS. FIG. 1...Housing, 2...→→One pedestal, 3...Sensor chip, 4...0 ring, 5...Backup ring. 6...Metal collar, 7...Clearance.

Claims (3)

[Claims] (1) A metal housing portion having a recessed portion with an inlet for the pressure to be measured; a convex pedestal housed in the recessed portion and having a pressure passage for transmitting the pressure to be measured from the inlet; an O-ring interposed between the bottom surface of the recess and the pedestal; a collar that abuts an upper surface of the base of the pedestal and at least one surface of the housing portion; a portion of the periphery of the collar is part of the housing portion; A shape in which the opening of the pressure passage is closed on a convex portion of the base, and a convex portion for fixing the pedestal in the recessed portion of the housing through the collar; What is claimed is: 1. A semiconductor pressure transducer comprising: a semiconductor sensor chip which is fixed to a semiconductor sensor chip and which generates an electrical signal in response to an introduced pressure to be measured; (2) The semiconductor pressure transducer according to claim 1, wherein a clearance is formed around the side surface of the base of the base. (3) The semiconductor pressure transducer according to claim 1, wherein the contact portion of the collar against the upper surface of the base of the pedestal and the O-ring are arranged to face each other with the pedestal interposed therebetween.