JP2015090318A - Semiconductor pressure sensor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor pressure sensor device equipped with a structure capable of preventing an adhesive from being stuck to an electronic component, in a structure fixing a frame component onto a circuit substrate with the adhesive.SOLUTION: A circuit substrate 20 has a step 25 in which an area corresponding to a first opening end 52 of a sleeve 50 of one surface 21 projects from the one surface 21 in a direction perpendicular to the one surface 21 and on which the first opening end 52 of the sleeve 50 is fixed via an adhesive 70. The step 25 has an offset area 26 projecting from an inner wall surface 56 configuring a hollow portion 51 of the sleeve 50, in a surface direction parallel to the one surface 21. Furthermore, the inner wall surface 56 of the sleeve 50 is formed in a tapered shape such that opening size of the first opening end 52 side of the sleeve 50 becomes smaller than opening size of a second opening end 54 side on the opposite side to the first opening end 52.

Description

  The present invention relates to a semiconductor pressure sensor device including a sensor chip for detecting the pressure of a pressure medium.

  Conventionally, for example, Patent Document 1 proposes a semiconductor pressure sensor device including a sensor chip configured to detect pressure and a case for housing the sensor chip. In this semiconductor pressure sensor device, a recess is formed in the case, and a sensor chip is disposed in the recess.

  Further, the sensor chip is electrically connected to an electrical connection portion provided in the recess of the case via a bonding wire. The electrical connection portion is electrically connected to a mounting component mounted on another circuit board. Further, a protective member is filled in the recess of the case. Thereby, the sensor chip, the bonding wire, and the electrical connection portion are covered and protected by the protective member.

JP 2004-251741 A

  However, in the above conventional technique, it is difficult to mount a mounting component different from the sensor chip in the concave portion of the case. Therefore, the mounting component is mounted not on the case but on the circuit board. For this reason, conventionally, in a structure in which the sensor chip is covered and protected with a protective member, it has not been possible to integrate the sensor chip mounted in the concave portion of the case with other mounting components.

  Therefore, a structure including a circuit board on which a sensor chip is mounted and a hollow cylindrical frame component is conceivable. In this structure, the sensor chip is fixed to one surface of the circuit board via an adhesive in a state where the sensor chip is disposed in the hollow part of the frame part. Thereby, in the circuit board, the partition region corresponding to the hollow part of the frame component and the mounting region where the mounting component is mounted are separated. According to this, the sensor chip can be arranged in the partition area and protected by the protective member, while the mounting component can be mounted in the mounting area. Therefore, the sensor chip and other mounting components can be integrated on the circuit board.

  However, the adhesive between one surface of the circuit board and the frame component may flow out into the hollow part of the frame component and adhere to electronic components such as sensor chips.

  In view of the above points, the present invention provides a semiconductor pressure sensor device having a structure in which an adhesive can be prevented from adhering to an electronic component in a structure in which a frame component is fixed to a circuit board with an adhesive. Objective.

  In order to achieve the above object, in the first aspect of the present invention, the sensor chip (30) has one surface (21) and the other surface (22) opposite to the one surface (21), and detects the pressure of the pressure medium. ) Is mounted on one surface (21), and a mounting component (23, 40) different from the sensor chip (30) is mounted on either one surface (21) or the other surface (22). A substrate (20) is provided.

  Moreover, it is the hollow cylinder shape which has a hollow part (51), Comprising: The frame component (50) by which the sensor chip (30) is arrange | positioned in the said hollow part (51) is provided. Furthermore, in a state where the sensor chip (30) is arranged in the hollow portion (51) of the frame component (50), the first opening end (on the one surface (21) side of the circuit board (20) of the frame component (50) ( 52) and the circuit board (20) are provided with an adhesive (70).

  In the circuit board (20), a region corresponding to the first opening end (52) of the frame component (50) on one surface (21) projects from the one surface (21) in a direction perpendicular to the one surface (21). At the same time, the first open end (52) of the frame part (50) has a step (25) fixed with an adhesive (70).

  Further, the step (25) has an offset region (26) protruding from the inner wall surface (56) constituting the hollow portion (51) of the frame component (50) in the plane direction parallel to the one surface (21). ing.

  Further, the inner wall surface (56) of the frame component (50) has a second opening size on the first opening end (52) side of the frame component (50) opposite to the first opening end (52). It is formed in a taper shape so as to be smaller than the opening size on the opening end (54) side.

  According to this, since the inner wall surface (56) of the frame component (50) is tapered, the adhesive (70) causes the taper-shaped inner wall surface (56) to be moved to the second opening end (54) side by surface tension. Crawling up. For this reason, the adhesive (70) passes from between the step (25) of the circuit board (20) and the first opening end (52) of the frame component (50) to the hollow part (51) side of the frame component (50). Even if it flows out, it can be prevented from adhering to electronic components such as the sensor chip (30) located in the hollow portion (51).

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

1 is an overall cross-sectional view of a semiconductor pressure sensor device according to a first embodiment of the present invention. It is the A section enlarged view of FIG. It is a partial cross section figure of the semiconductor pressure sensor apparatus which concerns on 2nd Embodiment of this invention. It is a partial cross section figure of the semiconductor pressure sensor apparatus which concerns on 3rd Embodiment of this invention. It is a partial cross section figure of the semiconductor pressure sensor apparatus which concerns on 4th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. The semiconductor pressure sensor device according to this embodiment is configured to detect the pressure of a pressure medium to be measured. As shown in FIG. 1, the semiconductor pressure sensor device 10 includes a circuit board 20, a sensor chip 30, a circuit chip 40, a sleeve 50, beads 60, an adhesive 70, and a protective gel 80.

  The circuit board 20 has one surface 21 and another surface 22 opposite to the one surface 21. The circuit board 20 is a laminated board on which pads such as Au (not shown) and wiring patterns are formed. In the present embodiment, a ceramic multilayer substrate in which a plurality of ceramic substrates are stacked is employed as the circuit board 20. A printed circuit board may be used as the circuit board 20.

  A mounting component 23 different from the sensor chip 30 is mounted on the other surface 22 of the circuit board 20. As the mounting component 23, an IC, a microcomputer chip, a passive component or the like is mounted. The passive component is, for example, a ceramic chip resistor or a ceramic multilayer capacitor.

  The sensor chip 30 is mounted on the one surface 21 of the circuit board 20 via a base 31 such as glass. The sensor chip 30 is configured as a pressure sensor that detects the pressure of the pressure medium, and is formed on a semiconductor substrate such as a silicon substrate.

  Specifically, a part of the semiconductor substrate is etched to form a recess (not shown), whereby a part of the semiconductor substrate is configured as a thin diaphragm. A plurality of gauge resistors are formed in the diaphragm so as to constitute a Wheatstone bridge circuit. Thereby, each gauge resistance detects the pressure applied to the diaphragm using the piezoresistance effect, and outputs an electric signal corresponding to the pressure. The sensor chip 30 is fixed to the pedestal 31 with an adhesive so that the space of the recess becomes a vacuum chamber. That is, the sensor chip 30 detects absolute pressure.

  The circuit chip 40 is one of the mounting components 23 mounted on the one surface 21 of the circuit board 20. The circuit chip 40 is formed with a control circuit having functions such as outputting a drive signal to the sensor chip 30, inputting an electric signal from the sensor chip 30, calculating and amplifying the signal, and outputting the signal to the outside. Has been.

  The pads of the sensor chip 30 and the pads of the circuit chip 40 are electrically connected via bonding wires 32. The pads of the circuit chip 40 and the pads of the circuit board 20 are electrically connected via bonding wires 41.

  The sleeve 50 is a frame component for covering the sensor chip 30 and the circuit chip 40 with the protective gel 80. The sleeve 50 has a hollow cylindrical shape having a hollow portion 51 and is formed of a material such as resin. The sleeve 50 is open at both ends of the cylinder. In the sleeve 50, the first open end 52 on the one surface 21 side of the circuit board 20 of the sleeve 50 is fixed to the circuit board 20. Accordingly, the sensor chip 30 is disposed in the hollow portion 51 of the sleeve 50.

  The sleeve 50 has an alignment portion 53 at the first opening end 52 that faces the side surface 24 of the circuit board 20 and fixes the sleeve 50 to a predetermined position of the circuit board 20. In other words, a protrusion is formed on the outer wall surface side of the sleeve 50 in the first opening end 52 of the sleeve 50, and the circuit board 20 is fitted in a recess formed by the protrusion and the first opening end 52. It has become. By this alignment portion 53, the sleeve 50 can be easily aligned with a predetermined position of the circuit board 20. The alignment portion 53 may be provided so as to go around the first opening end 52 of the sleeve 50 or may be provided intermittently.

  Further, the sleeve 50 has a groove portion 55 at the second opening end 54 on the opposite side of the sleeve 50 from the one surface 21 side of the circuit board 20. In particular, the groove portion 55 is formed on the hollow portion 51 side of the sleeve 50. The groove portion 55 serves to prevent the protective gel 80 provided in the hollow portion 51 of the sleeve 50 from creeping up. That is, since the protective gel 80 enters the groove 55, the protective gel 80 can be prevented from flowing out of the sleeve 50.

  The bead 60 is a component that is disposed between the first open end 52 of the sleeve 50 and the one surface 21 of the circuit board 20. That is, the beads 60 serve to keep the distance between the first opening end 52 of the sleeve 50 and the one surface 21 of the circuit board 20 constant. The beads 60 are made of, for example, resin.

  The adhesive 70 serves to fix the sleeve 50 to the circuit board 20. In the present embodiment, the adhesive 70 is a state in which the sensor chip 30 is disposed in the hollow portion 51 of the sleeve 50 and the first opening end 52 on the one surface 21 side of the sleeve 50 and the one surface of the circuit substrate 20. 21 is bonded. As the adhesive 70, an elastic adhesive such as fluorine rubber or silicone rubber is employed.

  As described above, since the distance between the circuit board 20 and the sleeve 50 is kept constant by the beads 60, the thickness of the adhesive 70 is ensured. That is, the bead 60 functions as one that fixes the thickness of the adhesive 70 constant. Further, since the adhesive 70 fixes the sleeve 50 to the circuit board 20, the protective gel 80 can be held by the sleeve 50 and the circuit board 20.

  The protective gel 80 plays a role of covering and protecting the connection portion between the sensor chip 30, the bonding wires 32 and 41, and the bonding wires 32 and 41 and a pad (not shown). The protective gel 80 is disposed in the hollow portion 51 of the sleeve 50. Therefore, the sensor chip 30 performs pressure detection by receiving the pressure of the pressure medium applied to the protective gel 80 from the outside with the diaphragm via the protective gel 80.

  As the protective gel 80, fluorine gel, silicone gel, fluorosilicone gel or the like is employed. The protective gel 80 can prevent physical damage to the bonding wires 32 and 41, prevent corrosion of each pad, and prevent foreign matters from being mixed.

  In the configuration of the semiconductor pressure sensor device 10 described above, the circuit board 20 has a step 25 on one surface 21 of the circuit board 20 as shown in FIG. The step 25 is a portion in which the region corresponding to the first opening end 52 of the sleeve 50 on the one surface 21 of the circuit board 20 protrudes from the one surface 21 in a direction perpendicular to the one surface 21. The surface of the step 25 is a part of one surface 21 of the circuit board 20. In the present embodiment, the step 25 has two steps.

  When the first opening end 52 of the sleeve 50 is fixed to the step 25 via the adhesive 70, a part of the step 25 protrudes from the inner wall surface 56 that forms the hollow portion 51 of the sleeve 50. That is, the step 25 has an offset region 26 protruding from the inner wall surface 56 of the sleeve 50 in a plane direction parallel to the one surface 21 of the circuit board 20. When the one surface 21 side is viewed in a direction perpendicular to the one surface 21 of the circuit board 20, the offset region 26 of the step 25 is a region not covered with the sleeve 50.

  Further, the inner wall surface 56 of the sleeve 50 is configured such that the opening size on the first opening end 52 side of the sleeve 50 is smaller than the opening size on the second opening end 54 side opposite to the first opening end 52. It is formed in a taper shape. The “opening size of the sleeve 50 on the first opening end 52 side” is at least the opening size of the portion of the inner wall surface 56 that forms the groove 55. The “opening size of the sleeve 50 on the second opening end 54 side” is the opening size of the inner wall surface 56 closest to the second opening end 54.

  The semiconductor pressure sensor device 10 having the above-described configuration is manufactured as follows. First, a circuit board 20 having a step 25 on one surface 21 is prepared. Then, the circuit chip 40 is mounted on the one surface 21 of the circuit board 20. In addition, the sensor chip 30 is mounted on the one surface 21 of the circuit board 20 via the pedestal 31. On the other hand, another mounting component 23 is mounted on the other surface 22 of the circuit board 20. Subsequently, wire bonding is performed at a location where the bonding wires 32 and 41 need to be connected.

  Thereafter, the sleeve 50 is prepared, and the sleeve 50 is fixed to the one surface 21 of the circuit board 20, that is, the step 25 with the adhesive 70 through the beads 60. The beads 60 are mixed in the adhesive 70 in advance. Finally, the protective gel 80 is potted in the hollow portion 51 of the sleeve 50. Thus, the semiconductor pressure sensor device 10 shown in FIGS. 1 and 2 is completed.

  As described above, when the sleeve 50 is fixed to the step 25 of the circuit board 20 by the adhesive 70, an excess portion of the adhesive 70 is formed between the step 25 of the circuit board 20 and the first opening end 52 of the sleeve 50. It oozes into the offset region 26 of the step 25 from between. However, the adhesive 70 creeps up the tapered inner wall surface 56 toward the second opening end 54 due to surface tension. For this reason, since the excess part of the adhesive 70 adheres to the inner wall surface 56 of the sleeve 50, it does not flow down to the sensor chip 30 side of the one surface 21 down the step 25 of the circuit board 20.

  As described above, since the excess portion of the adhesive 70 can be held by the inner wall surface 56 of the sleeve 50, the electronic component such as the sensor chip 30 in which the excess portion of the adhesive 70 is located in the hollow portion 51 of the sleeve 50. Can be prevented from adhering to a wiring pattern such as a pad.

  As for the correspondence between the description of the present embodiment and the description of the claims, the sleeve 50 corresponds to the “frame part” in the claims. Further, the circuit chip 40 corresponds to “mounting component” in the claims.

(Second Embodiment)
In the present embodiment, parts different from the first embodiment will be described. First, in the present embodiment, the adhesive 70 that bonds the first opening end 52 of the sleeve 50 and the step 25 of the circuit board 20 is defined as the first adhesive 70.

  As shown in FIG. 3, in this embodiment, the step 25 has a second adhesive 71 provided on the center side of the one surface 21 of the circuit board 20 in the offset region 26. The second adhesive 71 is a dike means for preventing the first adhesive 70 that has oozed into the offset region 26 from flowing down the step 25 toward the sensor chip 30. The second adhesive 71 is made of the same material as the first adhesive 70, for example.

  The second adhesive 71 is applied to a position corresponding to the offset region 26 in the step 25 of the circuit board 20 before the sleeve 50 is fixed to the circuit board 20. The second adhesive 71 is preferably pre-cured.

  As described above, since the second adhesive 71 is provided in the offset region 26 of the step 25, when the sleeve 50 is fixed to the step 25 of the circuit board 20 via the first adhesive 70, the second adhesive 71. This restricts the movement of the first adhesive 70 toward the sensor chip 30. Therefore, it is possible to prevent the first adhesive 70 from flowing down to the sensor chip 30 side down the step 25 and to reliably prevent the first adhesive 70 from adhering to the sensor chip 30.

  In addition, regarding the correspondence between the description of the present embodiment and the description of the claims, the second adhesive 71 corresponds to the “bank” in the claims.

(Third embodiment)
In the present embodiment, parts different from the first and second embodiments will be described. As shown in FIG. 4, in the present embodiment, the circuit board 20 has a protrusion 27 in which a part of the offset region 26 of the step 25 protrudes in a direction perpendicular to the one surface 21. The protrusion 27 is obtained by patterning the uppermost layer of a plurality of laminated ceramic substrates.

  According to such a configuration, since the projecting portion 27 for preventing the adhesive 70 from seeping out is provided in advance on the circuit board 20, it is necessary to assemble another component functioning as a dike means to the offset region 26. There is no merit. As described above, the protruding portion 27 that is a part of the circuit board 20 can prevent the adhesive 70 from flowing down the step 25 to the sensor chip 30 side.

  As for the correspondence between the description of the present embodiment and the description of the claims, the protruding portion 27 corresponds to the “embankment means” of the claims.

(Fourth embodiment)
In the present embodiment, parts different from the first embodiment will be described. In the present embodiment, as shown in FIG. 5, the inner wall surface 56 of the sleeve 50 is subjected to a surface treatment that makes the inner wall surface 56 uneven. The surface treatment of the inner wall surface 56 of the sleeve 50 is performed on at least the circuit board 20 side of the inner wall surface 56. In the present embodiment, the entire inner wall surface 56 of the sleeve 50 is subjected to surface treatment.

  The surface treatment is, for example, a treatment for performing plasma irradiation, UV irradiation, graining or the like on the inner wall surface 56 of the sleeve 50. For example, the inner wall surface 56 of the sleeve 50 may be rubbed with a sandpaper or the like. That is, it can be said that the surface treatment is a treatment for roughening the inner wall surface 56.

  According to this, it is possible to make it easier for the adhesive 70 to scoop up the uneven inner wall surface 56. In particular, by performing plasma irradiation or UV irradiation as the surface treatment, there is an advantage that the inner wall surface 56 of the sleeve 50 can be made uneven, and dirt on the inner wall surface 56 can be removed.

(Other embodiments)
The configuration of the semiconductor pressure sensor device 10 shown in each of the above embodiments is an example, and the present invention is not limited to the configuration shown above, and other configurations that can realize the present invention may be employed. For example, the protective gel 80 covering the sensor chip 30 may not be provided in the hollow portion 51 of the sleeve 50, or the groove portion 55 may not be provided in the sleeve 5.

  Further, the mounting component 23 may be mounted only on the other surface 22 of the circuit chip 40. The step 25 may be composed of at least one stage, or may be composed of three or more stages. The beads 60 may not be mixed in the adhesive 70 (first adhesive 70).

  In the first embodiment, the entire inner wall surface 56 of the sleeve 50 is tapered, but the tapered portion is provided on a part of the inner wall surface 56 of the sleeve 50 on the second opening end 54 side. But it ’s okay. Moreover, the taper part should just be provided in the part which wants to prevent the bleeding of the adhesive agent 70 from the level | step difference 25 among the inner wall surfaces 56. FIG.

  In 2nd, 3rd embodiment, although the 2nd adhesive agent 71 and the protrusion part 27 were provided in the offset area | region 26 of the level | step difference 25 as a bank means, these are examples. Therefore, another part may be provided as an embankment means in the offset region 26 of the step 25. Moreover, the bank means should just be provided in the part which wants to prevent the adhesive 70 from seeping out at least from the level | step difference 25 to the sensor chip 30 side.

  The surface treatment shown in the fourth embodiment may be applied to the inner wall surface 56 of the sleeve 50 according to the second and third embodiments. Thereby, in the structure provided with the bank means, the creeping of the adhesive 70 (first adhesive 70) on the inner wall surface 56 can be further improved.

20 Circuit board 21 One side 25 Step 26 Offset area 50 Sleeve (frame part)
51 Hollow portion 52 First open end 54 Second open end 56 Inner wall surface 70 Adhesive

Claims (5)

A sensor chip (30) having one surface (21) and the other surface (22) opposite to the one surface (21) and detecting the pressure of the pressure medium is mounted on the one surface (21), and the sensor A circuit board (20) in which mounting components (23, 40) different from the chip (30) are mounted on one of the one surface (21) and the other surface (22);
A frame part (50) having a hollow cylindrical shape having a hollow part (51), wherein the sensor chip (30) is disposed in the hollow part (51);
The first opening on the one surface (21) side of the circuit board (20) of the frame component (50) in a state where the sensor chip (30) is disposed in the hollow portion (51) of the frame component (50). An adhesive (70) for bonding the end (52) and the circuit board (20);
With
The circuit board (20) has a region corresponding to the first opening end (52) of the frame component (50) in the one surface (21) in a direction perpendicular to the one surface (21) from the one surface (21). The first opening end (52) of the frame part (50) protrudes and has a step (25) fixed through the adhesive (70),
The step (25) has an offset region (26) protruding from an inner wall surface (56) constituting the hollow portion (51) of the frame component (50) in a plane direction parallel to the one surface (21). Have
The inner wall surface (56) of the frame component (50) has a second opening size on the first opening end (52) side of the frame component (50) opposite to the first opening end (52). A semiconductor pressure sensor device, wherein the semiconductor pressure sensor device is tapered so as to be smaller than the opening size on the opening end (54) side.   2. The semiconductor pressure sensor device according to claim 1, wherein the step (25) has levee means (27, 71) provided in the offset region (26). 3. When the adhesive (70) for bonding the first opening end (52) of the frame component (50) and the step (25) of the circuit board (20) is a first adhesive (70),
3. The semiconductor pressure sensor device according to claim 2, wherein the levee means is a second adhesive (71) provided in the offset region (26).   3. The embankment means according to claim 2, wherein a part of the offset region (26) of the step (25) is a projecting portion (27) projecting in a direction perpendicular to the one surface (21). The semiconductor pressure sensor device described.   The semiconductor pressure sensor device according to any one of claims 1 to 4, wherein the inner wall surface (56) is subjected to a surface treatment such that the inner wall surface (56) is uneven.

Images