JP2008089559A - Pressure sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and lightweight pressure sensor. <P>SOLUTION: In the pressure sensor 1 having a pressure detection element 4 mounted in such a way as to block one end of a through hole 5 formed in a protrusion part 3, main body parts (a base part 2 and the protrusion part 3) are constituted as a molded interconnect device which is formed in a prescribed shape by ceramic injection molding and in which conductor patterns 6 are formed in its surface. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pressure sensor.

  Conventionally, a pressure sensor in which a sensor chip is attached so as to close a through hole as a pressure introduction hole formed in a package body is known (for example, Patent Document 1).

In the pressure sensor disclosed in Patent Document 1, a sensor chip is mounted on a package body by wire bonding.
Japanese Patent Laid-Open No. 10-300604

  However, in the conventional pressure sensor, since the sensor chip is mounted by wire bonding, the mounting work becomes complicated, and the pressure sensor is increased in size because it is necessary to secure a space for wire bonding. There was a problem.

  Therefore, an object of the present invention is to obtain a smaller pressure sensor.

  In the first aspect of the invention, in the pressure sensor having a pressure detection element disposed in the middle or the back side of the through hole formed in the main body, the main body is formed of an insulating resin material in a predetermined shape. The pressure sensing element is flip-chip mounted on the main body portion, and is formed as a three-dimensional circuit component having a conductor pattern formed on the surface thereof.

  The invention according to claim 2 is characterized in that the pressure detection element and an element different from the pressure detection element are mounted on the main body portion so as to be spaced apart from each other substantially in parallel.

  In the invention of claim 3, the concave portion having a bottom surface and a step surface that are substantially parallel to each other is formed in the main body portion, and the through hole is formed to open to the bottom surface. The pressure detection element is mounted, and the another element is mounted on the step surface.

  In the invention of claim 4, a concave portion is formed in the main body portion, the through hole is formed to open to the bottom surface of the concave portion, a pressure detecting element is mounted on the bottom surface, and the conductor pattern is formed. The inner surface of the concave portion and the side wall surface of the main body portion are connected across the opening edge of the concave portion.

  The invention according to claim 5 is characterized in that the concave portion is vacuum-sealed.

  In the invention of claim 6, a flange portion is formed in the main body portion so as to project from the inner peripheral surface of the through hole to the axial center side of the through hole, and the pressure introducing opening of the through hole of the flange portion While the pressure detecting element is mounted on the surface on the side, the other element is mounted on the surface opposite to the pressure introduction opening of the flange portion.

  According to the first aspect of the present invention, since the main body is configured as a resinous three-dimensional circuit component, it is easy to obtain a fine conductor pattern, and the pressure detection element is flip-chip mounted on the main body, so that the pressure sensor can be made smaller. Can be configured.

  According to the second aspect of the present invention, the pressure detection element and another element can be efficiently integrated into one pressure sensor, and the circuit configuration including these elements can be configured more compactly.

  According to the invention of claim 3, by using the bottom surface and the step surface of the recessed portion with a step, the pressure detection element and the another element can be efficiently mounted in multiple stages, and a pressure sensor including these elements Can be obtained as a more compact configuration.

  According to the fourth aspect of the present invention, the potential of each electrode of the element can be easily taken out from the side wall surface of the main body by the conductor pattern straddling the opening edge of the recess.

  According to the fifth aspect of the present invention, since the concave portion on the side opposite to the detection side (back side) of the pressure detection element is vacuum-sealed, the absolute pressure can be measured.

  According to the invention of claim 6, by using the flange portion provided in the through hole, the pressure detection element and the another element can be efficiently mounted in multiple stages, and a pressure sensor including these elements is provided. It can be obtained as a more compact configuration.

  (First Embodiment) FIG. 1 is a perspective view of a pressure sensor according to the present embodiment, FIG. 2 is a plan view of the pressure sensor viewed from the back side (opposite side to the detection side by the pressure detection element), and FIG. 2 is a sectional view taken along the line III-III in FIG. 2, FIG. 4 is a sectional view taken along the line IV-IV in FIG. 2, and FIG. 5 is a plan view of the pressure sensor as viewed from the back side. FIG. 6 is a side view showing a state where the pressure sensor is mounted.

  The pressure sensor 1 according to the present embodiment has a configuration in which a substantially cylindrical protrusion 3 is provided on one plane (seal surface) 2e of a base 2 having a substantially rectangular parallelepiped appearance. In the present embodiment, the base body 2 and the protrusion 3 correspond to the main body.

  The main body (base 2 and protrusion 3) is configured as a three-dimensional circuit component (MID: Molded Interconnect Device). In the present embodiment, the main body portion is formed by molding an insulating resin material as a base material (for example, various engineering plastic materials such as polyamide and polyphthalamide) into a predetermined shape by, for example, injection molding or the like, and a conductor pattern on the surface. 6 can be obtained, and various known methods of MID (for example, UV exposure method (subtractive method, semi-additive method, additive method, etc.), laser imaging method, one-time molding method such as IVOND method, It can be obtained by a two-time molding method such as the SKW method).

  As shown in FIG. 3, a through hole 5 that penetrates the projection 3 in the axial direction is formed at the center of the projection 3, and a mounting male screw 3a is formed on the outer periphery thereof.

  On the other hand, as shown in FIGS. 3 and 4, a concave portion 2a having a substantially rectangular shape in a plan view is formed on a portion of the base portion 2 on the side opposite to the side where the protruding portion 3 is provided. Further, a through hole 5 formed in the protrusion 3 is opened at a substantially central portion of the bottom surface 2b of the recess 2a.

  And as shown in FIGS. 3-5, the pressure detection element 4 is mounted in the state which closes the opening end (one end of the extending | stretching direction of the through-hole 5) in the bottom face 2b of the through-hole 5. As shown in FIG. This pressure detecting element 4 is formed by forming a pressure receiving surface on one surface of a single crystal silicon substrate, and includes a diaphragm, a strain gauge, an electrode, etc. (all not shown), and converts pressure into electric resistance by a piezoresistive effect. To do. The through hole 5 corresponds to a pressure introducing hole.

  In the present embodiment, the pressure detection element 4 is flip-chip mounted on the conductor pattern 6 formed on the bottom surface 2b as shown in FIG. In the figure, 8 is a conductive adhesive, 9 is an underfill (resin insulating adhesive), and 10 is a bump of each electrode of the pressure detecting element 4.

  At this time, as shown by A in FIG. 5, the underfill 9 is arranged in a substantially rectangular ring shape along the outer edge of the pressure detection element 4, and the underfill 9 and the pressure detection element 4 form a through hole. The entry (leakage) of the detection target fluid (liquid or gas) from 5 into the recess 2a is suppressed. That is, the underfill 9 also functions as a seal member. Further, by using a material with high heat dissipation (for example, a silicon-based resin material) as the underfill 9, it is possible to increase the heat resistance of the pressure sensor 1 and to suppress detection errors due to the temperature of the pressure detection element 4.

  The conductor pattern 6 can be appropriately formed using various processes such as physical vapor deposition, removal of unnecessary portions by irradiation of electromagnetic waves such as laser, and pressure film formation by electrolytic plating.

  Here, as shown in FIGS. 2 to 5, the conductor pattern 6 connects the inner surface of the concave portion 2 a and the side wall surface 2 d of the main body (base portion 2) across the opening edge 2 c of the concave portion 2 a. Is formed. Therefore, the detection result of the pressure detection element 4 can be easily obtained by establishing conduction with the conductor pattern 6 exposed on the side wall surface 2d.

  The recess 2 a is closed on the opposite side of the protrusion 3 by a flat lid 7. As described above, after mounting the pressure detection element 4 while securing the seal by the underfill 9, the cover 2 is closed in the vacuum chamber, whereby the recess 2a can be vacuum-sealed. In this case, the absolute pressure can be detected by the pressure detection element 4. In addition, when not vacuum-sealing, the relative pressure (gauge pressure) with respect to atmospheric pressure is detected.

  The pressure sensor 1 having the above configuration can be equipped in a state as shown in FIG. 6, for example. That is, in this example, a female screw hole 20a corresponding to the male screw portion 3a of the protrusion 3 is formed in the partition wall 20 (for example, a tube wall) of the fluid existence region 21 to be detected, and the protrusion is formed in the female screw hole 20a. By screwing the portion 3, an annular seal member 12 (washer, gasket, O-ring, etc.) is sandwiched between the surface 20 b of the partition wall 20 and the flat surface 2 e on the side where the protrusion 3 of the base portion 2 is formed, The seal member 12 ensures a fluid seal.

  According to the above-described embodiment, since the main body portion is configured as a resinous three-dimensional circuit component, a fine conductor pattern 6 is easily obtained, and the pressure detection element 4 is flip-chip mounted on the main body portion. It can be configured more compactly.

  Further, according to the present embodiment, the potential of each electrode of the pressure detection element 4 can be easily taken out from the side wall surface 2d of the main body portion by the conductor pattern 6 straddling the opening edge 2c of the recess 2a.

  In the present embodiment, the absolute pressure can be measured by vacuum-sealing the concave portion 2a on the side opposite to the detection side (back side) of the pressure detection element 4.

  (Second Embodiment) FIG. 7 is a longitudinal sectional view (cross-sectional view corresponding to FIG. 3) of a pressure sensor according to this embodiment. In addition, 1 A of pressure sensors concerning this embodiment are provided with the component similar to the pressure sensor 1 concerning the said 1st Embodiment. Therefore, in the following, those similar components are denoted by common reference numerals, and redundant description is omitted.

  In the present embodiment, a stepped recess 2a having a bottom surface 2b and a step surface 2f formed at a substantially central portion in the depth direction is formed on the base 2A, and the pressure detection element 4 is mounted on the bottom surface 2b. In addition, an element other than the pressure detection element 4 (for example, an element including a circuit that processes an output signal from the pressure detection element 4 (for example, filtering, correction, calculation, temperature compensation, etc.)) is mounted on the step surface 2f. Except for this point, it has the same configuration as the pressure sensor 1 according to the first embodiment. Although omitted in FIG. 7, a conductor pattern similar to the conductor pattern 6 shown in FIGS. 2 to 5 is also formed on the surface of the recess 2a.

  According to such a configuration, the pressure detecting element 4 and the other element 4A are mounted on the base portion 2A so as to be spaced apart from each other in substantially parallel, so that the plurality of elements 4 and 4A are efficiently integrated in one pressure sensor 1A. Therefore, the circuit including the plurality of elements 4 and 4A can be configured more compactly.

  In particular, in the present embodiment, the pressure detection element 4 and another element 4A can be efficiently mounted in multiple stages using the bottom surface 2b and the step surface 2f of the stepped recess 2a. Pressure sensor 1A provided with 4A can be obtained as a more compact configuration.

  (Third Embodiment) FIG. 8 is a longitudinal sectional view (cross-sectional view corresponding to FIG. 3) of a pressure sensor according to this embodiment. The pressure sensor 1B according to the present embodiment includes the same components as the pressure sensors 1 and 1A according to the first or second embodiment. Therefore, in the following, those similar components are denoted by common reference numerals, and redundant description is omitted.

  In the present embodiment, an annular flange portion 13 is formed to project from the inner peripheral surface of the through hole 5 of the base portion 2B to the axial center side of the through hole 5, and the pressure introduction opening 5b of the through hole 5 of the flange portion 13 is formed. The pressure detection element 4 is flip-chip mounted on the surface 5a on the side, while the element 4B (for example, pressure detection) different from the pressure detection element 4 is provided on the surface (bottom surface 2b) opposite to the pressure introduction opening 5b of the flange portion 13. An element including a circuit that processes an output signal from the element 4 (for example, filtering, correction, calculation, etc.) is mounted.

  A conductor pattern (not shown in FIG. 8) that conducts to the pressure detection element 4 is formed on the inner end edge (inner peripheral surface) 14 of the flange portion 13, and the conductor pattern is a conductor in the recess 2a. It is connected to a pattern (similar to the conductor pattern 6 shown in FIGS. 2 to 5).

  Further, in the present embodiment, a stepped concave portion 2a having a bottom surface 2b and a step surface 2f formed at a substantially central portion in the depth direction is formed on the base body portion 2B in substantially the same manner as in the second embodiment. In addition, an element 4A different from the pressure detecting element 4 and the element 4B is mounted on the step surface 2f.

  According to such a configuration, the pressure detecting element 4 and the other elements 4A and 4B are mounted on the base portion 2B so as to be spaced apart from each other in substantially parallel, whereby a plurality of elements 4, 4A and 4B are mounted in one pressure sensor 1A. Since they can be efficiently integrated, a circuit including the plurality of elements 4, 4A, 4B can be configured more compactly.

  In particular, by using the flange portion 13 provided in the through hole 5, the pressure detection element 4 and another element 4B can be efficiently mounted in multiple stages, and the pressure sensor 1B including the plurality of elements 4 and 4B is provided. It can be obtained as a more compact configuration.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment, and various modifications can be made.

  For example, although the case where the male screw for attachment was formed in the projection part was illustrated in the said embodiment, it may replace with this and the female screw for attachment may be formed in the internal peripheral surface of a through-hole. Further, the protruding portion may be tapered.

  In addition, the outer surface of the main body is coated with a magnetic material or a conductive material (for example, composite plating of carbon nanotubes and nickel), so that the effects of external electromagnetic waves (occurrence of detection errors, noise mixing, etc.) ) Can be suppressed.

The perspective view of the pressure sensor concerning the embodiment of the present invention. The top view which looked at the pressure sensor concerning 1st Embodiment of this invention from the back surface side (opposite side of the detection side by a pressure detection element). III-III sectional drawing of FIG. IV-IV sectional drawing of FIG. It is the top view which looked at the pressure sensor concerning 1st Embodiment of this invention from the back surface side, Comprising: The figure which shows the sealing area | region of the pressure detection element by sealing agent. The side view (partial sectional view) showing the state where the pressure sensor concerning a 1st embodiment of the present invention was mounted. The longitudinal cross-sectional view of the pressure sensor concerning 2nd Embodiment of this invention. The longitudinal cross-sectional view of the pressure sensor concerning 3rd Embodiment of this invention.

Explanation of symbols

1, 1A, 1B Pressure sensor 2, 2A, 2B Base part (main part)
2a Concave part 2b Bottom surface (surface on the opposite side to the pressure introduction opening 5b of the flange part 13)
2c Opening edge portion 2d Side wall surface 2f Stepped surface 3 Protruding portion 4 Pressure detecting element 4A, 4B Another element 5 Through hole 5a Surface (of flange portion 13) 5b Pressure introducing opening 6 Conductor pattern 12 Flange portion

Claims (6)

In the pressure sensor having a pressure detection element arranged in the middle or the back side of the through hole formed in the main body,
The main body is configured as a three-dimensional circuit component in which an insulating resin material is molded into a predetermined shape and a conductor pattern is formed on the surface thereof.
A pressure sensor, wherein the pressure detection element is flip-chip mounted on the main body.   2. The pressure sensor according to claim 1, wherein the pressure detection element and an element different from the pressure detection element are mounted on the main body portion so as to be spaced apart from each other substantially in parallel. In the body portion, a recess having a bottom surface and a step surface that are substantially parallel to each other is formed, and the through hole is formed to open to the bottom surface,
The pressure sensor according to claim 2, wherein the pressure detection element is mounted on the bottom surface, and the another element is mounted on the step surface. Forming a recess in the main body, and forming the through hole so as to open to the bottom surface of the recess,
A pressure detection element is mounted on the bottom surface,
The pressure sensor according to claim 1, wherein the conductor pattern is formed so as to connect the inner surface of the recess and the side wall surface of the main body across the opening edge of the recess.   The pressure sensor according to claim 3 or 4, wherein the concave portion is vacuum-sealed. In the main body portion, a flange portion that projects from the inner peripheral surface of the through hole to the axial center side of the through hole is formed,
The pressure detection element is mounted on a surface of the flange portion on the pressure introduction opening side of the through hole, and the other element is mounted on a surface of the flange portion on the opposite side to the pressure introduction opening. Item 3. The pressure sensor according to Item 2.

Images