JP2011075482A - Semiconductor physical quantity sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor physical quantity sensor which is enhanced in the accuracy of detection of its physical quantity sensor chip. <P>SOLUTION: In the semiconductor physical quantity sensor 1 having the physical quantity sensor chip 2 using a semiconductor mounted inside a package 4 through adhesive material 30, the physical quantity sensor chip 2 is mounted inside the package 4 by gluing at least the outer peripheral ends 2a of the sensor chip 2 at a plurality of spots in the shape of points. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a semiconductor physical quantity sensor.

  2. Description of the Related Art Conventionally, a semiconductor physical quantity sensor is known in which a sensor chip that detects a physical quantity such as acceleration is mounted on a substrate via an interposer (see, for example, Patent Document 1).

JP 2006-250760 A

  However, in the conventional technique, the sensor chip is mounted on the interposer by applying an adhesive to the entire contact surface between the sensor chip and the interposer. For this reason, stress is applied to the sensor chip due to the difference in thermal expansion coefficient between the mounted sensor chip and the adhesive, and the detection axis of the sensor chip may be shifted to reduce detection accuracy.

  Therefore, an object of the present invention is to obtain a semiconductor physical quantity sensor that can improve the detection accuracy of a physical quantity sensor chip.

  According to the first aspect of the present invention, in the semiconductor physical quantity sensor in which a physical quantity sensor chip using a semiconductor is mounted in a package via an adhesive, the physical quantity sensor chip has a plurality of locations at least at the outer peripheral end of the physical quantity sensor chip. It is mounted in the package by adhering in a dotted manner.

  According to a second aspect of the present invention, in the semiconductor physical quantity sensor according to the first aspect, the physical quantity sensor chip is formed with a sensor core portion that detects a physical quantity, and each adhesion of an outer peripheral end of the physical quantity sensor chip. The position is equidistant from the sensor core part.

  According to a third aspect of the present invention, in the semiconductor physical quantity sensor according to the second aspect, the physical quantity sensor chip is formed in a rectangular shape, and the sensor core portion is formed in a central portion of the physical quantity sensor chip. In addition, each bonding position of the outer peripheral end of the physical quantity sensor chip is a four corner portion of the physical quantity sensor chip.

  According to a fourth aspect of the present invention, in the semiconductor physical quantity sensor according to the second aspect, the physical quantity sensor chip is formed in a rectangular shape, and the sensor core part is formed in a central part of the physical quantity sensor chip. In addition, each bonding position of the outer peripheral end of the physical quantity sensor chip is a central portion of four sides of the physical quantity sensor chip.

  According to a fifth aspect of the present invention, in the semiconductor physical quantity sensor according to the first or second aspect, the physical quantity sensor chip is formed in a rectangular shape, and each bonding position of the outer peripheral end of the physical quantity sensor chip is The corner portion of the physical quantity sensor chip and the central portion of the side of the physical quantity sensor chip.

  According to a sixth aspect of the present invention, in the semiconductor physical quantity sensor according to any one of the first to fifth aspects, the physical quantity sensor chip is bonded in a dotted manner at a central portion of the physical quantity sensor chip. It is characterized by that.

  According to the first aspect of the present invention, since the physical quantity sensor chip is mounted in the package by adhering at least a plurality of locations at the outer peripheral end of the physical quantity sensor chip in a package, the bonding area of the physical quantity sensor chip can be reduced. . Therefore, it is possible to reduce the influence of the physical quantity sensor chip due to deformation due to thermal expansion of the adhesive or the package. That is, when the package is deformed due to thermal expansion or the like, the physical quantity sensor chip is suppressed from being stressed due to the difference in thermal expansion coefficient between the mounted physical quantity sensor chip and the adhesive or the package. It is possible to prevent the axis from shifting. As a result, the detection accuracy of the physical quantity sensor chip can be improved.

  According to the invention of claim 2, since each bonding position of the outer peripheral end of the physical quantity sensor chip is equidistant from the sensor core part that detects the physical quantity, the stress applied to the sensor core part from each bonding part can be made more uniform. it can. As a result, it is possible to suppress the uneven distribution of stress applied to the sensor core portion, and it is possible to further suppress the detection accuracy of the physical quantity sensor chip from being lowered.

  According to the invention of claim 3, the physical quantity sensor chip is formed in a rectangular shape, the sensor core part is formed in the center part of the physical quantity sensor chip, and each bonding position of the outer peripheral end of the physical quantity sensor chip is set to the physical quantity sensor chip. Therefore, each bonding position of the outer peripheral end of the physical quantity sensor chip can be easily equidistant from the sensor core portion.

  In addition, it is possible to improve the detection accuracy of the physical quantity sensor chip while suppressing a decrease in the mounting strength of the physical quantity sensor chip as much as possible.

  According to the invention of claim 4, the physical quantity sensor chip is formed in a rectangular shape, the sensor core part is formed in the center part of the physical quantity sensor chip, and each bonding position of the outer peripheral end of the physical quantity sensor chip is defined as the physical quantity sensor chip. Therefore, the detection accuracy of the physical quantity sensor chip can be improved while suppressing a decrease in the mounting strength of the physical quantity sensor chip as much as possible.

  According to the invention of claim 5, the physical quantity sensor chip is formed in a rectangular shape, and the bonding positions of the outer peripheral ends of the physical quantity sensor chip are the corners of the physical quantity sensor chip and the central part of the side of the physical quantity sensor chip. It is possible to improve the detection accuracy of the physical quantity sensor chip while suppressing the decrease in the mounting strength of the physical quantity sensor chip as much as possible.

  According to the sixth aspect of the present invention, since the physical quantity sensor chip is bonded in a dotted manner not only at a plurality of locations on the outer peripheral end of the physical quantity sensor chip but also at the center of the physical quantity sensor chip, The decrease can be further suppressed.

FIG. 1 is an exploded perspective view showing the semiconductor physical quantity sensor according to the first embodiment of the present invention. 2A and 2B are diagrams illustrating the semiconductor physical quantity sensor according to the first embodiment of the present invention, in which FIG. 2A is a plan view and FIG. 2B is a cross-sectional view. 3A and 3B are diagrams showing the physical quantity sensor chip according to the first embodiment of the present invention, in which FIG. 3A is a side view and FIG. 3B is a plan view. FIGS. 4A and 4B are views showing the bonding location of the physical quantity sensor chip according to the first embodiment of the present invention, where FIG. 4A is a plan view and FIG. 4B is a side view. FIGS. 5A and 5B are diagrams showing the bonding location of the physical quantity sensor chip according to the second embodiment of the present invention, where FIG. 5A is a plan view and FIG. 5B is a side view. FIGS. 6A and 6B are views showing the bonding location of the physical quantity sensor chip according to the third embodiment of the present invention, where FIG. 6A is a plan view and FIG. 6B is a side view. FIGS. 7A and 7B are views showing the bonding location of the physical quantity sensor chip according to the fourth embodiment of the present invention, where FIG. 7A is a plan view and FIG. 7B is a side view. FIGS. 8A and 8B are diagrams showing adhesion locations of the physical quantity sensor chip according to the first reference example, in which FIG. 8A is a plan view and FIG. 8B is a side view.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, a capacitance type acceleration sensor will be exemplified as the semiconductor physical quantity sensor. Note that similar components are included in the following embodiments. Therefore, in the following, common reference numerals are given to those similar components, and redundant description is omitted.

(First embodiment)
As shown in FIG. 1, the acceleration sensor 1 according to the present embodiment includes a sensor chip (physical quantity sensor chip) 2 formed using a semiconductor, and an IC chip (signal processing chip) that processes an output signal of the sensor chip 2. 3), a package 4 for mounting the sensor chip 2 on a lower step surface 4a to be described later, and mounting an IC chip 3 on an upper step surface 4b to be described later, and a lid 5 for sealing the package 4.

  As shown in FIG. 2A, the sensor chip 2 is formed in a substantially square shape (rectangular shape) in plan view, and in the center of the sensor chip 2, a plan view for detecting acceleration (physical quantity) is provided. A substantially square sensor core 20 is formed. In the present embodiment, the fixed electrode body 22, the weight part 23, the spring part 24, and the support part 25 described later correspond to the sensor core part 20.

  In this embodiment, as shown in FIG. 3A, the sensor chip 2 sandwiches both surfaces of a silicon substrate (semiconductor layer) 2A on which a semiconductor element device is formed between glass substrates 2B and 2C serving as protective layers. The silicon substrate 2A and the glass substrates 2B and 2C are integrally bonded by, for example, anodic bonding.

  As shown in FIG. 3B, a gap 21 is formed in the silicon substrate 2A by a known semiconductor process to form a frame portion 21, a fixed electrode body 22, a movable electrode body formed at the peripheral edge. A weight portion 23, a spring portion 24, and a support portion 25 that supports the weight portion 23 via the spring portion 24 are formed. A relatively shallow gap is formed on the bonding surface between the silicon substrate 2A, the glass substrate 2B, and the glass substrate 2C, thereby ensuring insulation of each part of the silicon substrate 2A and operability of the weight part 23. Yes.

  In this embodiment, by connecting the spring portion 24 to the weight portion 23 and the support portion 25, the spring portion 24 is given a function as a spring element that elastically supports the weight portion 23 with respect to the support portion 25. Yes. Furthermore, a function as a mass element (mass) supported by a support portion 25 connected to a spring portion 24 as a spring element is given to the weight portion 23, and a spring-mass system is formed by these spring elements and mass elements. It is composed. Then, a change in the capacitance value between the weight portion 23 and the fixed electrode body 22 due to the displacement of the weight portion 23 as a mass element is detected, and applied to the sensor chip 2 based on the detected change in the capacitance value. Acceleration is detected.

  Specifically, the change in the capacitance value is detected by the detection units 28 and 29 including a plurality of comb-like movable electrodes 26 and comb-like fixed electrodes 27 formed on the weight part 23 and the fixed electrode body 22, respectively. Detected.

  For example, when acceleration is applied in the X direction shown in FIG. 3B, the comb-like movable electrode 26 is displaced in the X direction and is detected by the comb-like movable electrode 26 and the comb-like fixed electrode 27 of the detection unit 28. There is a difference between the capacitance value detected and the capacitance value detected by the comb-like movable electrode 26 and the comb-like fixed electrode 27 of the detection unit 29. And the acceleration of a X direction is detected from the difference of the electrostatic capacitance value produced in this way.

  The IC chip 3 is formed using a silicon substrate, and is formed in a square shape in plan view as shown in FIGS. 1 and 2A. The IC chip 3 is integrated with an amplifier circuit that amplifies the output signal of the sensor chip 2, a temperature compensation circuit that corrects the sensitivity and offset voltage of the sensor and their temperature characteristics, a noise removal circuit that removes noise, and the like. Yes. Then, by operating these circuits, the output signal of the sensor chip 2 is processed by the IC chip 3. For example, an ASIC (Application Specific Integrated Circuit) can be used as the IC chip 3.

  In this embodiment, the package 4 is formed by laminating ceramic substrates, and has a box shape having an opening 4c on the upper side. A lower step surface 4 a for mounting the sensor chip 2 and an upper step surface 4 b for mounting the IC chip 3 are formed on the inner bottom surface of the package 4. The mounted sensor chip 2 and the IC chip 3 are electrically connected via the lead wire L2, and the IC chip 3 is connected via the terminal block 4d provided on the inner wall of the package 4 and the lead wire L1. Are electrically connected.

  The lid 5 seals the package 4, and the sensor chip 2 is mounted on the package 4, and the IC chip 3 is mounted on the package 4, and then the opening 4 c of the package 4 is sealed with the lid 5. Thus, the acceleration sensor 1 is formed. The acceleration sensor 1 formed in this way is mounted on a printed circuit board (not shown) via terminals (not shown) formed on the package 4.

  Here, in this embodiment, the sensor chip 2 is mounted in the package 4 via the adhesive 30. At this time, the sensor chip 2 is mounted in the package 4 by adhering at least a plurality of locations of the outer peripheral end 2a of the sensor chip 2 in a dot shape.

  Specifically, the sensor chip 2 has four sides 2S1 to 2S4 and four corners 2T1 to 2T4 in a plan view, and the bonding location to the package 4 at the outer peripheral end 2a of the sensor chip 2 is four. Two corners 2T1 to 2T4 are provided. At this time, since the sensor chip 2 has a substantially square shape, and the sensor core portion 20 having a substantially square shape is formed at the center thereof, each bonding position of the outer peripheral end 2 a of the sensor chip 2 is determined from the sensor core portion 20. It is equidistant.

  Furthermore, in this embodiment, the sensor chip 2 has its central portion C bonded to the package 4 in a dot shape.

  As described above, in this embodiment, the sensor chip 2 is bonded to the package 4 at the four corners 2T1 to 2T4 and the central portion C at five points.

  In addition, it is preferable that the fixed electrode body 22 and the support part 25 are not bonded at the time of bonding at the central part C (so that the adhesive 30 is not attached to the fixed electrode body 22 and the support part 25). . As described above, if the fixed electrode body 22 and the support portion 25 are not adhered, the influence of the deformation due to the thermal expansion of the adhesive 30 or the package 4 on the detection portions 28 and 29 can be reduced.

  4 exemplifies the case where the adhesive 30 protrudes from the outer periphery of the sensor chip 2 at each bonding position of the outer peripheral end 2a of the sensor chip 2. However, the adhesive protrudes from the outer periphery of the sensor chip 2. The sensor chip 2 may be bonded to the package 4 so as not to cause a problem. The same applies to the following embodiments.

  According to the present embodiment described above, since the sensor chip 2 is mounted in the package 4 by adhering at least a plurality of locations of the outer peripheral end 2a of the sensor chip (physical quantity sensor chip) 2 in a dot shape, the sensor chip 2 is bonded. The area can be reduced. Therefore, the influence of deformation on the sensor chip 2 due to thermal expansion of the adhesive 30 or the package 4 can be reduced. That is, when the package 4 is deformed due to thermal expansion or the like, stress is suppressed from being applied to the sensor chip 2 due to a difference in thermal expansion coefficient between the mounted sensor chip 2 and the adhesive 30 or the package 4. It is possible to suppress the displacement of the two detection axes. As a result, the detection accuracy of the sensor chip 2 can be improved.

  Moreover, according to this embodiment, since each adhesion position of the outer periphery end 2a of the sensor chip 2 is equidistant from the sensor core part 20 which detects a physical quantity, the stress applied to the sensor core part 20 from each adhesion part is more even. can do. As a result, the uneven distribution of stress applied to the sensor core part 20 can be suppressed, and the detection accuracy of the sensor chip 2 can be further suppressed from decreasing.

  Further, according to the present embodiment, the sensor chip 2 is formed in a square shape (rectangular shape), the sensor core portion 20 is formed in the center portion of the sensor chip 2, and each bonding position of the outer peripheral end 2a of the sensor chip 2 is determined. Since the four corner portions 2T1 to 2T4 of the sensor chip 2 are used, the bonding positions of the outer peripheral ends 2a of the sensor chip 2 can be easily equidistant from the sensor core portion 20.

  Further, by adhering at the four corner portions 2T1 to 2T4 of the sensor chip 2, it is possible to improve the detection accuracy of the sensor chip 2 while suppressing a decrease in the mounting strength of the sensor chip 2 as much as possible.

  Furthermore, according to the present embodiment, the sensor chip 2 is bonded to the sensor chip 2 not only at the four corner portions 2T1 to 2T4 but also at the central portion C of the sensor chip 2, so that the sensor chip 2 A reduction in mounting strength can be further suppressed.

(Second Embodiment)
The acceleration sensor 1 according to the present embodiment is basically configured in the same manner as in the first embodiment, and the sensor chip 2 is bonded in a dotted manner at a plurality of locations on the outer peripheral end 2a of the sensor chip 2. .

  Here, the main difference between the present embodiment and the first embodiment is that the sensor chip 2 is not bonded in the form of dots at the central portion C of the sensor chip 2 as shown in FIG. .

  That is, in this embodiment, the sensor chip 2 is bonded to the package 4 at four points of the four corners 2T1 to 2T4.

  Also according to the present embodiment described above, substantially the same operations and effects as the first embodiment can be achieved.

(Third embodiment)
The acceleration sensor 1 according to the present embodiment is basically configured in the same manner as in the first embodiment, and the sensor chip 2 is bonded in a dotted manner at a plurality of locations on the outer peripheral end 2a of the sensor chip 2. .

  Here, the main difference between the present embodiment and the first embodiment is that, as shown in FIG. It is in the central part of the side.

  In the present embodiment, the sensor chip 2 is bonded to the package 4 at three points of two corners 2T2, 2T3 and one side 2S1. It should be noted that various combinations can be set for the combination of the corner and the side to be bonded.

  Also according to the present embodiment described above, substantially the same operations and effects as the first embodiment can be achieved.

  In the present embodiment, the sensor chip 2 may be bonded in a dot shape at the center of the sensor chip 2 as in the first embodiment. In this case, it is preferable that the fixed electrode body 22 and the support portion 25 are not bonded.

  Further, the position where the sensor core part 20 is formed in the sensor chip 2 may be shifted so that the sensor core part 20 becomes the center of gravity of each adhesion part, so that each adhesion part is equidistant from the sensor core part 20.

(Fourth embodiment)
The acceleration sensor 1 according to the present embodiment is basically configured in the same manner as in the first embodiment, and the sensor chip 2 is bonded in a dotted manner at a plurality of locations on the outer peripheral end 2a of the sensor chip 2. .

  Here, this embodiment is mainly different from the first embodiment in that each bonding position of the outer peripheral end 2a of the sensor chip 2 is set to the four sides 2S1 to 2S4 of the sensor chip 2 as shown in FIG. It is in the central part.

  Also in this embodiment, the sensor chip 2 has a substantially square shape, and the sensor core portion 20 having a substantially square shape is formed at the center thereof. It is equidistant from the sensor core unit 20.

  Also according to this embodiment described above, the same operations and effects as those of the first embodiment can be achieved.

  In the present embodiment, the sensor chip 2 may be bonded in a dot shape at the center of the sensor chip 2 as in the first embodiment. In this case, it is preferable that the fixed electrode body 22 and the support portion 25 are not bonded.

(First Reference Example)
A first reference example will be described with reference to the drawings. FIG. 8 is a diagram showing an adhesion location of the physical quantity sensor chip according to this reference example. The basic structure of the acceleration sensor 1 of the present reference example is the same as the acceleration sensor 1 of the first embodiment. Therefore, it demonstrates centering on difference with 1st Embodiment, the same code | symbol is attached | subjected to the same part as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 8, in the acceleration sensor 1 of this reference example, the sensor chip 2 is not bonded to the package 4 at the outer peripheral edge 2a, but only the central portion C of the sensor chip 2 is bonded to the package 4 in a dot shape. This is different from the acceleration sensor 1 of the first embodiment.

  Even in this case, since the sensor chip 2 is bonded to the package 4 in the form of dots, the bonding area of the sensor chip 2 can be reduced, and the deformation due to the thermal expansion of the adhesive 30 or the package 4 can be reduced. The influence on the chip 2 can be reduced.

  Further, if the fixed electrode body 22 and the support portion 25 are not adhered, the influence of the deformation due to the thermal expansion of the adhesive 30 or the package 4 on the detection portions 28 and 29 can be reduced.

  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, in each of the above embodiments, the uniaxial acceleration sensor that detects the acceleration in the horizontal direction is illustrated as the physical quantity sensor chip. However, the present invention is not limited to this, and the acceleration that detects the acceleration in the vertical direction (thickness direction of the sensor chip). It is also possible to use a sensor, a 2-axis acceleration sensor, or a 3-axis acceleration sensor.

  In addition, although the physical quantity sensor chip has a three-layer structure, it is also possible to use a single-layer structure or a multilayer structure of two layers, four layers or more.

  In addition, the shape and arrangement of the frame portion, fixed electrode body, movable electrode body, spring portion, and support portion formed on the physical quantity sensor chip can be appropriately designed.

  In each of the above embodiments, the acceleration sensor is exemplified as the physical quantity sensor chip. However, the physical quantity sensor chip is not limited to this and may detect a physical quantity other than the acceleration.

  In each of the above embodiments, the capacitance type acceleration sensor is exemplified as the semiconductor physical quantity sensor. However, the present invention can also be implemented using a piezoresistance type or gas temperature distribution type semiconductor physical quantity sensor.

  In each of the above embodiments, the physical quantity sensor chip is directly bonded to the package. However, the physical quantity sensor chip may be mounted on the package via a pedestal or the like. In this case, the physical quantity sensor chip is adhered to a pedestal or the like at least at a plurality of locations on the outer peripheral end of the physical quantity sensor chip.

  In addition, the specifications (shape, size, layout, etc.) of the sensor core part, the package, and other details can be changed as appropriate.

1 Acceleration sensor (Semiconductor physical quantity sensor)
2 Sensor chip (physical quantity sensor chip)
2a Outer peripheral edge 4 Package 20 Sensor core part 30 Adhesive 2S1, 2S2, 2S3, 2S4 Side 2T1, 2T2, 2T3, 2T4 Corner part C Center part

Claims (6)

In a semiconductor physical quantity sensor that mounts a physical quantity sensor chip using a semiconductor in a package via an adhesive,
The physical quantity sensor chip is mounted in the package by adhering at least a plurality of locations on the outer peripheral end of the physical quantity sensor chip in a dot shape. In the physical quantity sensor chip, a sensor core part for detecting a physical quantity is formed,
2. The semiconductor physical quantity sensor according to claim 1, wherein the bonding positions of the outer peripheral ends of the physical quantity sensor chip are equidistant from the sensor core portion. The physical quantity sensor chip is formed in a rectangular shape, and the sensor core part is formed in the central part of the physical quantity sensor chip,
3. The semiconductor physical quantity sensor according to claim 2, wherein each bonding position of the outer peripheral end of the physical quantity sensor chip is a four corner portion of the physical quantity sensor chip. The physical quantity sensor chip is formed in a rectangular shape, and the sensor core part is formed in the central part of the physical quantity sensor chip,
3. The semiconductor physical quantity sensor according to claim 2, wherein each bonding position of an outer peripheral end of the physical quantity sensor chip is a central portion of four sides of the physical quantity sensor chip. The physical quantity sensor chip is formed in a rectangular shape,
3. The semiconductor physical quantity sensor according to claim 1, wherein each bonding position of the outer peripheral end of the physical quantity sensor chip is a corner portion of the physical quantity sensor chip and a central portion of a side of the physical quantity sensor chip.   The semiconductor physical quantity sensor according to claim 1, wherein the physical quantity sensor chip is bonded in a dot shape at a central portion of the physical quantity sensor chip.

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