JP2008082903A - Sensor module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sensor module having a constitution for achieving miniaturization and allowing protection of a diaphragm part of a sensor element. <P>SOLUTION: The sensor element 1 and an IC chip 2 are mounted and arranged on a mounting substrate 3 made of glass epoxy resin or ceramics. The sensor element 1 has a shape having a recessed part 1b and a cross section of a U shape. The sensor element 1 is made of a semiconductor substrate (silicon substrate), and the diaphragm part 1a having a thin structure is formed and the recessed part 1b is formed by etching one main surface of the semiconductor substrate. The IC chip 2 is arranged in the space (recessed part 1b) formed of the recessed part 1b of the sensor element 1 and the mounting substrate 3, and flip-chip-mounted on the mounting substrate 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sensor module.

  By etching one main surface of a semiconductor substrate (silicon substrate), a diaphragm portion having a thin structure is formed to constitute a sensor element. From the surface of the diaphragm portion, a piezoresistor whose resistance value changes due to bending or metal There is known a sensor module that forms an electrode to detect displacement or deflection of a diaphragm portion due to external pressure or the like as a change in resistance value or a change in capacitance.

  FIG. 8 is a cross-sectional view showing a configuration of a sensor module according to the prior art. The sensor module shown in FIG. 8 is a semiconductor pressure sensor module that measures pressure. Reference numeral 16 denotes a body portion, and the semiconductor pressure sensor portion 17 is mounted on the chip mounting surface 16a so as to surround the pressure introduction hole 16b so that the diaphragm portion 17a is displaced by receiving pressure from the pressure introduction hole 16b. ing. An IC unit 18 for signal processing is mounted on the upper surface of the semiconductor pressure sensor unit 17, and further, a trimming function for correcting characteristics of the semiconductor pressure sensor unit 17 is provided on the upper surface of the IC unit 18. The ROM mounting unit 19 is mounted.

  On both the upper and lower surfaces of the IC portion 18 are formed metal electrodes (not shown) and wiring patterns (not shown) that are in electrical contact with the electrodes, and through wirings 20 that electrically connect the upper and lower surfaces are provided. It has been.

  An electrode (not shown) of the semiconductor pressure sensor unit 17 and the through wiring 20 of the IC unit 18 are electrically connected by a bump 21a. Further, the wiring pattern (not shown) of the IC part 18 and the electrode (not shown) of the ROM mounting part 19 are electrically connected by the bump 21b, and the semiconductor pressure sensor part 17, the IC part 18 and the ROM mounting part. Electrical connection with 19 is made. An electrode (not shown) of the IC unit 18 and the wiring pattern 22 are electrically connected by a bump 21 c and a TAB (TAPE AUTOMATED BONDING) 23.

  The semiconductor pressure sensor module has a configuration in which the IC portion 18 and the ROM mounting portion 19 are three-dimensionally arranged on the semiconductor pressure sensor portion 17.

  Further, although not shown, the electronic parts such as the IC part 18 and the ROM mounting part 19 that are components of the sensor module are mounted and disposed adjacent to the chip mounting surface 16a of the semiconductor pressure sensor part 17. Are also very commonly used.

  The semiconductor pressure sensor module having the above-described configuration is disclosed, for example, in Patent Document 1.

JP 2002-168716 A

  The sensor modules described above are often used in mobile terminals and the like, and with the miniaturization of the mobile terminals, there is an increasing demand for miniaturization of components such as sensor modules mounted thereon. However, the sensor module is composed of a sensor element and other IC chip components, and it is necessary to secure a mounting area for the IC chip.

  In the sensor module, since components such as an IC chip are stacked on the sensor element, the height of the module increases, which is disadvantageous for thinning. Further, when mounting on the same mounting surface adjacent to the sensor element, a mounting area for both the sensor element and the IC chip is required, and the mounting area is enlarged. Any of the mounting forms is disadvantageous for thinning and miniaturization.

  In addition, since the sensor element performs a detection operation with displacement and deflection of the thin-walled diaphragm portion, there is a possibility that the diaphragm portion may be mechanically damaged such as a crack. Therefore, it is necessary to protect the diaphragm portion. However, the sensor module having the conventional configuration has not yet been configured to achieve the object.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a sensor module having a configuration capable of realizing downsizing and protecting a diaphragm portion of a sensor element.

A sensor that includes at least a sensor element having a diaphragm part, an IC chip for signal processing, and a substrate on which the sensor element and the IC chip are mounted, and that electrically detects the amount of deflection of the diaphragm part of the sensor element. A module,
The IC chip is a sensor module that is disposed in a space formed between the diaphragm portion of the sensor element and the facing portion of the substrate.

  The sensor element has a U-shaped cross section having a recess, and a space in which the IC chip is disposed is a sensor module formed by the recess of the sensor element and the substrate.

  The sensor element has a thin plate shape, a concave portion is formed in a portion of the substrate on which the sensor element is mounted facing the diaphragm portion of the sensor element, and a space in which the IC chip is disposed is The sensor module is a space formed by the sensor element and the concave portion of the substrate.

  In the space, the sensor module is provided with a stopper member for restricting the amount of deflection of the diaphragm portion of the sensor element.

  The stopper member is a sensor module that is a wire that electrically connects the IC chip and the substrate.

  The stopper member is a sensor module that is a protective resin filled to protect the IC chip.

  The protective resin is a sensor module made of silicon resin.

  By disposing the IC chip in a space formed between the diaphragm portion of the sensor element and the substrate, the mounting area can be minimized, and the sensor module can be miniaturized.

  Furthermore, in the space, by providing a stopper member for restricting the amount of deflection of the diaphragm portion of the sensor element, the amount of deflection of the diaphragm portion can be restricted to a fixed position, and the diaphragm portion can be extremely displaced, Since the deformation can be suppressed, the diaphragm can be protected.

  In addition, the stopper member can be configured such that a wire that electrically connects the IC chip and the substrate or a protective resin filled to protect the IC chip can also serve as the stopper member. There is no need to use it as a separate member, and the purpose of protecting the diaphragm can be easily achieved, resulting in an advantageous configuration in terms of cost.

  A sensor module comprising at least a sensor element having a diaphragm portion, an IC chip for signal processing, and a substrate on which the sensor element and the IC chip are mounted, and electrically detecting a deflection amount of the diaphragm; The IC chip is arranged in a space formed between opposing portions of the diaphragm portion of the sensor element and the substrate. With this configuration, the mounting area of the sensor element and the IC chip is minimized, and a thin and small sensor module is realized.

  FIG. 1 is a cross-sectional view of a sensor module showing a first embodiment of the present invention. Reference numeral 1 denotes a sensor element, and 2 denotes an IC chip for signal processing. The sensor element 1 and the IC chip 2 are mounted on a mounting substrate 3 made of glass epoxy resin or ceramics. The sensor element 1 has a U-shaped cross section having a recess 1b. The sensor element 1 is made of a semiconductor substrate (silicon substrate), and by etching one main surface of the semiconductor substrate, a diaphragm portion 1a having a thin structure is formed and a concave portion 1b is formed. The IC chip 2 is flip-chip mounted on the mounting substrate 3 so as to be disposed in a space (recessed portion 1 b) formed by the recess 1 b of the sensor element 1 and the mounting substrate 3. Reference numeral 4 denotes a wire made of gold or aluminum, which connects a pad portion (not shown) on the sensor element 1 and a wiring pattern (not shown) on the mounting substrate 3 to form a signal line. According to the sensor module having this configuration, the IC chip 2 is arranged inside the recess 1b of the sensor element 1, so that an IC chip component is stacked on the sensor element as shown in the prior art or mounted on the mounting substrate. Since IC chip components are not arranged and mounted on the same surface so as to be adjacent to the sensor element, it is possible to reduce the thickness and size.

  By the way, the sensor module of the present invention detects displacement and deflection of the diaphragm portion 1a of the sensor element 1 caused by external pressure or the like through an electrode made of piezoresistor or metal formed on the surface of the diaphragm portion 1a. This is electrically detected as a change in resistance value or a change in capacitance. When the sensor module of the present invention is used as, for example, a pressure sensor for measuring pressure, the pressure from the arrow direction shown in FIG. 1 is received. In this case, the diaphragm portion 1a is bent toward the IC chip disposed inside the concave portion 1b of the sensor element 1. Since the diaphragm 1a has a thin-walled structure, it is a mechanically fragile part with respect to extreme bending. In addition, since the IC chip 2 is disposed in the bending direction of the diaphragm portion 1a, that is, on the concave portion 1b side of the sensor element 1, the contact with the IC chip 2 due to the bending of the diaphragm portion 1a is mechanically This situation must be avoided because it may cause electrical breakdown. Therefore, a stopper member for regulating the amount of deflection of the diaphragm portion 1a of the sensor element 1 may be formed in the recess 1b space of the sensor element 1. Below, the sensor module of this invention which provided the said stopper member is demonstrated.

  FIG. 2 is a cross-sectional view of a sensor module provided with a stopper member in the first embodiment of the present invention. In this figure, the diaphragm part 1a of the sensor element 1 receives the pressure from the arrow direction in FIG. Reference numeral 5 denotes a stopper member for regulating the amount of deflection of the diaphragm portion 1a. The stopper member 5 is a frame-like body formed of an insulating resin, and is disposed so as to surround the outer periphery of the IC chip 2. According to this structure, since the upper end part of the said stopper member 5 becomes a control position with respect to the bending of the said diaphragm part 1a, and the bending beyond it will be restrict | limited, the mechanical damage of the said diaphragm part 1a can be prevented. Further, since contact with the IC chip 2 can be prevented, mechanical and electrical destruction of both can be prevented. In addition, the restriction position with respect to the bending of the diaphragm portion 1a can be arbitrarily set by adjusting the height of the stopper member. Further, the stopper member 5 is not limited to a frame shape, and at least two pieces formed in a pole shape are used so as to face the center or corner position of each side at the outer peripheral position of the IC chip 2. The arrangement may be arranged.

  FIG. 3 is a cross-sectional view showing another example of a sensor module provided with a stopper member in the first embodiment of the present invention. The diaphragm portion 1a of the sensor element 1 receives a pressure from the arrow direction in FIG. Reference numeral 6 denotes a protective resin filled to protect the IC chip 2. By providing the protective resin 6, the surface portion of the protective resin 6 becomes a restriction position for the bending of the diaphragm portion 1 a, serves as a stopper, and restricts further bending. Therefore, mechanical damage to the diaphragm 1a can be prevented. Further, since direct contact with the IC chip 2 can be prevented, mechanical and electrical destruction of both can be prevented. Furthermore, the buffering effect is improved by adopting a soft silicone resin as the protective resin even after curing.

  FIG. 4 is a cross-sectional view showing another example of a sensor module provided with a stopper member in the first embodiment of the present invention. The diaphragm portion 1a of the sensor element 1 receives a pressure from the direction of the arrow in FIG. Reference numeral 7 denotes an IC chip, which has a different mounting form from the above-described IC chip 2 and is based on a wire bonding technique in which electrical connection is made by wires 8. The sensor module of this configuration uses the wire 8 and has a configuration in which the loop apex of the wire 8 is also used as a stopper as a restriction position for the deflection of the diaphragm portion 1a. According to the said structure, the further bending will be restrict | limited and the mechanical damage of the said diaphragm part 1a can be prevented. Further, since direct contact with the IC chip 2 can be prevented, mechanical destruction of both can be prevented. In addition, it is necessary to prevent a short circuit due to contact between the diaphragm portion 1a and the wire 8, but if an insulating film is formed on the contact surface of the diaphragm portion 1a with the wire 8, there is a problem. Absent. It should be noted that the restriction position for the deflection of the diaphragm portion 1a can be arbitrarily set by adjusting the loop height of the wire 8.

  FIG. 5 is a cross-sectional view of a sensor module showing a second embodiment of the present invention. A sensor element 9 is formed in a thin plate shape. The sensor element 9 has a diaphragm portion 9a at a portion excluding a part of the outer peripheral portion from the center. Reference numeral 10 denotes an IC chip for signal processing. The sensor element 9 and the IC chip 10 are mounted on a mounting substrate 11 made of glass epoxy resin or ceramics. The mounting substrate 11 is formed with a recess 11a, and the sensor element 9 is mounted so as to cover the recess 11a. The concave portion 11a is located at a position facing the diaphragm portion 9a of the sensor element 9, and is configured to bend in the spatial direction of the concave portion 11a upon receiving pressure from the arrow direction in FIG. The space in which the IC chip 10 is disposed is a space formed by the sensor element 9 and the recess 11 a of the mounting substrate 11. The IC chip 10 is flip-chip mounted on a mounting substrate 11 in the space. Reference numeral 12 denotes a wire made of gold or aluminum, which connects a pad portion (not shown) on the sensor element 9 and a wiring pattern (not shown) on the mounting substrate 11 to form a signal line. The sensor element 9 can also be flip-chip mounted. According to the sensor module having this configuration, the sensor element 9 is formed in a thin plate shape, and the IC chip 10 is disposed inside the recess 11a provided in the mounting substrate 11, so that the sensor element as shown in the prior art In addition, since the IC chip components are not stacked or mounted so as to be adjacent to the sensor element on the same surface of the mounting substrate, the thickness and size can be reduced.

  Also in the second embodiment, for the purpose of protecting the diaphragm portion 9 a and preventing contact with the IC chip 10, the amount of deflection of the diaphragm portion 9 a of the sensor element 9 in the recess 11 a space of the mounting substrate 11. It is preferable to form a stopper member for regulating the above. Hereinafter, the sensor module of the present invention in which the stopper member is formed will be described.

  FIG. 6 is a cross-sectional view of a sensor module provided with a stopper member in the second embodiment of the present invention. The diaphragm portion 9a of the sensor element 9 receives the pressure from the direction of the arrow in FIG. Reference numeral 13 denotes a protective resin filled to protect the IC chip 10. By providing the protective resin 13, the surface portion of the protective resin 13 becomes a restriction position for the bending of the diaphragm portion 9 a, serves as a stopper, and restricts further bending. Therefore, mechanical damage to the diaphragm portion 9a can be prevented. Further, since direct contact with the IC chip 2 can be prevented, mechanical and electrical destruction of both can be prevented. Furthermore, the buffering effect is improved by adopting a soft silicone resin as the protective resin even after curing.

  FIG. 7 is a cross-sectional view showing another example of a sensor module provided with a stopper member in the second embodiment of the present invention. The diaphragm portion 9a of the sensor element 9 receives the pressure from the arrow direction in FIG. Reference numeral 14 denotes an IC chip having a mounting form different from that of the IC chip 10 described above, which is based on wire bonding in which electrical connection is made by a wire 15. The sensor module of this configuration is configured to use the wire 15 and also serve as a stopper, with the loop apex of the wire 15 serving as a restriction position for the deflection of the diaphragm portion 9a. According to this configuration, further bending is restricted, the load on the diaphragm portion 9a itself can be reduced, and direct contact with the IC chip 14 can be prevented, so that mechanical destruction of both can be prevented. Electrically, it is necessary to prevent a short circuit due to contact between the diaphragm portion 9a and the wire 15, but an insulating film may be formed on a contact surface of the diaphragm portion 9a with the wire 15. It should be noted that the restriction position for the deflection of the diaphragm portion 9a can be arbitrarily set by adjusting the loop height of the wire 8.

  The stopper member described above uses a protective resin that protects the IC chip and a wire that connects the IC chip and the substrate. However, as shown in FIG. 2 of the first embodiment, a completely separate member is disposed. You may do it.

  In the above-described embodiments, the sensor module of the present invention has been described as a sensor module for pressure measurement. However, the sensor type is not limited to this, and can be widely applied to various sensors using a sensor element having a diaphragm portion. Applicable. For example, an acceleration sensor configured to add a weight to the diaphragm portion and detect a displacement amount of the diaphragm portion that is displaced by a stress applied thereto is an example.

Sectional drawing of the sensor module which shows 1st Embodiment of this invention. Sectional drawing of the sensor module which provided the stopper part in 1st Embodiment of this invention. Sectional drawing which shows the other example of the sensor module which provided the stopper member in 1st Embodiment of this invention. Sectional drawing which shows the other example of the sensor module which provided the stopper member in 1st Embodiment of this invention. Sectional drawing of the sensor module which shows 2nd Embodiment of this invention. Sectional drawing of the sensor module which provided the stopper member in 2nd Embodiment of this invention. Sectional drawing which shows the other example of the sensor module which provided the stopper member in 2nd Embodiment of this invention. Sectional drawing which shows the structure of the sensor module by a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sensor element 1a Diaphragm part 1b Recessed part 2 IC chip 3 Mounting board 4 Wire 5 Stopper member 6 Protective resin 7 IC chip 8 Wire 9 Sensor element 9a Diaphragm part 10 IC chip 11 Mounting board 11a Recessed part 12 Wire 13 Protective resin 14 IC chip 15 Wire 16 Body 16a Chip mounting surface 16b Pressure introduction part 17 Semiconductor pressure sensor part 18 IC part 19 ROM mounting part 20 Through wiring 21a Bump 21b Bump 21c Bump 22 Wiring pattern 23 TAB

Claims (7)

A sensor module comprising at least a sensor element having a diaphragm portion, an IC chip for signal processing, and a substrate on which the sensor element and the IC chip are mounted, and electrically detecting a deflection amount of the diaphragm portion of the sensor element. Because
The IC module is arranged in a space formed between a diaphragm portion of the sensor element and a facing portion of the substrate.   2. The sensor element according to claim 1, wherein the sensor element has a U-shaped cross section having a recess, and a space in which the IC chip is disposed is a space formed by the recess of the sensor element and the substrate. Sensor module.   The sensor element has a thin plate shape, a concave portion is formed in a portion of the substrate on which the sensor element is mounted facing the diaphragm portion of the sensor element, and a space in which the IC chip is disposed is The sensor module according to claim 1, wherein the sensor module is a space formed by the sensor element and a concave portion of the substrate.   The sensor module according to any one of claims 1 to 3, wherein a stopper member for restricting a deflection amount of the diaphragm portion of the sensor element is provided in the space.   The sensor module according to claim 4, wherein the stopper member is a wire that electrically connects the IC chip and the substrate.   The sensor module according to claim 4, wherein the stopper member is a protective resin filled to protect the IC chip.   The sensor module according to claim 6, wherein the protective resin is a silicon-based resin.

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