JP2007248188A - Angular velocity sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a downsized angular velocity sensor. <P>SOLUTION: This angular velocity sensor is equipped with a substrate 1 having a recessed part 2, an IC 3 mounted in the recessed part 2 of the substrate 1, an adhesive agent 23 for ICs to bond/fix the IC 3 to the substrate 1, and first and second vibration elements 4 and 5 mounted on the substrate 1 and electrically connected to the IC 3. The recessed part 2 of the substrate 1 comprises an IC mount part 8 mounted with the IC 3, and an injection part 9 connected to the mount part 8 for allowing a nozzle 22 to come therein for thereinto injecting the adhesive agent 23. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an angular velocity sensor that can be used in an electronic apparatus such as a camera shake prevention system for a digital still camera and a vehicle system such as an automobile navigation system.

  An angular velocity sensor in which a vibration element and an IC are mounted on one substrate is known (see Patent Document 1).

An angular velocity sensor having two vibrating elements is also known (see Patent Document 2).
JP 11-325908 A Japanese Utility Model Publication No. 5-92635 (Microfilm of Japanese Utility Model Application No. 4-64819)

  In the conventional angular velocity sensor, since the vibration element and all the electric circuit components are mounted on the same plane on the substrate, it is difficult to reduce the size of the angular velocity sensor.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide an angular velocity sensor that can be miniaturized.

  In order to achieve the above object, the present invention has the following configuration.

  The invention according to claim 1 of the present invention is a substrate having a recess, an IC mounted in the recess of the substrate, an IC adhesive for bonding and fixing the IC to the substrate, and attached to the substrate. And a vibration element electrically connected to the IC, the concave portion of the substrate is connected to the IC mounting portion for mounting the IC, and the IC mounting portion is injected, and the adhesive for the IC is injected. In this configuration, the concave portion of the substrate is connected to the IC mounting portion for mounting the IC and the IC mounting portion, and the IC Since the nozzle for injecting the adhesive for injection enters the injection part for entering, the adhesive for IC can be surely poured between the IC mounting part and the IC, thereby ensuring the adhesion of the IC Can be done for high And it has a effect that it is possible to reduce the size of upon obtaining-reliability.

  The invention according to claim 2 of the present invention is particularly formed in the concave portion of the substrate so as to be shallower than the depth of the IC mounting portion and the injection portion and directly connected to the injection portion without being directly connected to the IC mounting portion. According to this configuration, the creeping distance from the injection portion to the upper surface of the substrate increases, so that the adhesive for IC does not easily overflow from the concave portion onto the substrate. Since the reservoir portion is shallower than the injection portion, the electrical wiring can be provided on the substrate portion on the bottom surface of the first reservoir portion.

  In the invention according to claim 3 of the present invention, in particular, the first pool portion is formed in a portion of the concave portion of the substrate closest to the mounting portion of the vibration element. Since the creepage distance to the mounting portion increases, it is possible to prevent the IC adhesive from coming into contact with the vibration element, thereby eliminating the adverse effect on the vibration of the vibration element. .

  The invention according to claim 4 of the present invention includes, in particular, the first vibration element and the second vibration element as the vibration elements, and the first reservoir is the most of the first vibration element in the recess of the substrate. A second portion formed in a portion close to the mounting portion and formed in the concave portion of the substrate so as to be shallower than the IC mounting portion and the injection portion and directly connected to the IC mounting portion without being directly connected to the injection portion. In addition, the second reservoir portion is formed in a portion of the concave portion of the substrate closest to the mounting portion of the second vibration element. According to this configuration, the biaxial angular velocity is Also in the sensor, it is possible to prevent the adhesive for IC from coming into contact with the vibration element, thereby having an effect of eliminating an adverse effect on the vibration of the vibration element.

  As described above, the angular velocity sensor of the present invention includes a substrate having a recess, an IC mounted in the recess of the substrate, an IC adhesive for bonding and fixing the IC to the substrate, and attached to the substrate. A vibration element electrically connected to the IC, the concave portion of the substrate is connected to an IC mounting portion for mounting the IC, and the IC mounting portion is injected, and the adhesive for IC is injected. Since it is composed of an injection part for the nozzle to enter, the IC adhesive can be reliably poured between the IC mounting part and the IC, and thereby the IC can be securely bonded. Thus, it is possible to provide an angular velocity sensor that can be miniaturized while obtaining high reliability.

  Hereinafter, the invention described in claims 1 to 4 of the present invention will be described with reference to the drawings.

  1 is a cutaway perspective view of an angular velocity sensor according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the angular velocity sensor, FIG. 3 is a plan view of the angular velocity sensor, and FIG. 4 is a longitudinal sectional view of FIG. 5 is a cross-sectional view of FIG.

  1 to 5, reference numeral 1 denotes a substrate formed by laminating and firing ceramics, and 2 denotes a recess provided in the substrate 1. Reference numeral 3 denotes an IC mounted in the concave portion 2 of the substrate 1, 4 denotes a first vibration element attached to the substrate 1, and the first vibration element 4 includes two legs 4 a that partially vibrate and the 2 The base 4b that fixes the leg 4a of the book is formed into a tuning fork shape. Reference numeral 5 denotes a second vibration element which is attached to the substrate 1 and arranged so as to intersect the first vibration element 4 by 90 °. The second vibration element 5 vibrates in part. The two leg portions 5a and the base 5b for fixing the two leg portions 5a are formed in a tuning fork shape. Since the first vibration element 4 and the second vibration element 5 and the IC 3 are electrically connected, a driving signal is transmitted from the IC 3 to the first vibration element 4 and the second vibration element 5. The detection signals from the first vibration element 4 and the second vibration element 5 are sent to the IC 3, and the IC 3 performs predetermined signal processing. Reference numeral 6 denotes a chip part attached to the substrate 1, and this chip part 6 constitutes an electric circuit together with the IC 3. Reference numeral 7 denotes a case that covers the concave portion 2, the IC 3, the first vibration element 4, the second vibration element 5, and the chip component 6. The case 7 is attached to the substrate 1.

  8 is an IC mounting portion that constitutes a part of the recess 2 and includes a space in which the IC 3 is mounted, and 9 is an injection portion that is continuous with a part of the recess 2 and is adjacent to the IC mounting portion 8. The injection portion 9 constitutes a space for a nozzle to enter when an adhesive for IC described later is injected. Reference numeral 10 denotes a first reservoir portion that is continuous with a part of the recess 2, and the first reservoir portion 10 is shallower than the IC mounting portion 8. Reference numeral 11 denotes a second reservoir portion continuous with a part of the recess 2, and the second reservoir portion 11 is shallower than the IC mounting portion 8 in the same manner as the first reservoir portion 10. The first reservoir 10 is located below the first vibration element 4, and the second reservoir 11 is located below the second vibration element 5.

  Reference numeral 12 denotes an element electrode formed on the substrate 1, and the element electrode 12 is electrically connected to the first vibration element 4 and the second vibration element 5. Reference numeral 13 denotes a component electrode formed on the substrate 1, and this component electrode 13 is electrically connected to the chip component 6. 14 is an interelectrode groove formed on the substrate 1, and 15 is a wire in wire bonding for electrically connecting the first vibration element 4 and the second vibration element 5 and the element electrode 12 on the substrate 1. . Reference numeral 16 denotes a positioning mark formed on the substrate 1, and the positioning mark 16 serves as a positioning or marker in the manufacturing process.

  A method for manufacturing the angular velocity sensor according to the embodiment of the present invention configured as described above will be described below.

  6 to 12 are views for explaining a method of manufacturing an angular velocity sensor according to an embodiment of the present invention. FIG. 6 is a plan view showing a sheet substrate of the angular velocity sensor according to an embodiment of the present invention. 7 is a plan view of an IC mounting process in the angular velocity sensor, FIG. 8 is a longitudinal sectional view of an IC adhesive injection process in the angular velocity sensor, FIG. 9 is a plan view of a component adhesive application process in the angular velocity sensor, and FIG. FIG. 11 is a plan view of a component placement process in the angular velocity sensor, FIG. 11 is a plan view of a detection process in the angular velocity sensor, and FIG. 12 is a flowchart showing a manufacturing process of the angular velocity sensor.

  In FIG. 6, reference numeral 20 denotes a sheet-like sheet substrate formed by laminating and firing ceramics. The sheet substrate 20 is provided with a plurality of dividing grooves 21 for dividing into a plurality of individual substrates 1. ing.

  FIG. 7 shows a plan view of an IC mounting process in the angular velocity sensor. In FIG. 7, for the sake of easy understanding, the entire sheet substrate 20 is not shown, but a portion forming one angular velocity sensor. Only shows. The same applies to FIGS. 8 to 10.

  In FIG. 7, the IC 3 is mounted on the IC mounting portion 8 connected to a part of the recess 2 formed on the sheet substrate 20. In this case, a bump electrode (not shown) is formed on an electrode portion (not shown) of the IC 3, and this is pressed against an electrode (not shown) formed on the substrate 1 to be bump electrode by ultrasonic welding. The face-down method is used to melt and mount.

  FIG. 8 is a longitudinal sectional view of the IC adhesive injection step in the angular velocity sensor. In FIG. 8, 22 is a nozzle, and this nozzle 22 enters the injection portion 9 connected to a part of the recess 2. It is what. An IC adhesive 23 is ejected from the nozzle 22, and this IC adhesive 23 enters between the injection portion 9 and the IC 3 and the bottom surface of the IC mounting portion 8. As the IC adhesive 23, a so-called underfill agent can be used, and specifically, an epoxy-based thermosetting resin can be used.

  FIG. 9 shows a plan view of the component adhesive application process in the angular velocity sensor. In FIG. 9, reference numeral 24 denotes a portion of the sheet substrate 20 to which the first vibration element 4 is attached and the second vibration element 5. An element adhesive applied to each of the portions to be attached, and an epoxy thermosetting resin can be used for the element adhesive 24. A component adhesive 25 is applied onto the component electrode 13, and a conductive thermosetting resin in which Ag and a resin are pasted can be used for the component adhesive 25.

  FIG. 10 is a plan view of a component placement process in the angular velocity sensor. In this component placement process, the first vibration element 4 and the second vibration element 5 are respectively inserted into the sheet substrate with an element adhesive 24 interposed therebetween. The chip component 6 is disposed on the component electrode 13 with the component adhesive 25 interposed therebetween.

  Then, after the first vibration element 4, the second vibration element 5 and the chip component 6 are arranged on the sheet substrate 20 in this component arranging step, the sheet substrate 20 is heated, and the IC adhesive 23, the element adhesive 24 and the component adhesive 25 are thermally cured. The temperature at this time may be higher than the temperature at which the IC adhesive 23, the element adhesive 24, and the component adhesive 25 are cured, and the temperature profile depends on the components of these adhesives. In such a case, it may be set at 150 ° C. for about 1 hour 30 minutes to 2 hours.

  Thereafter, in order to electrically connect the first vibrating element 4 and the second vibrating element 5 and the element electrode 12 on the sheet substrate 20, both are connected by wire bonding using a wire 15.

  Through the above steps, predetermined electrical connection is made to the electrical components mounted on the sheet substrate 20.

  FIG. 11 shows a plan view of a detection process in the angular velocity sensor. In FIG. 11, reference numeral 26 denotes a rotation shaft, and the sheet substrate 20 is rotated around the rotation shaft 26 so that an angular velocity is applied. . The rotation shaft 26 is in a 45 ° direction with respect to the detection axis of the first vibration element 4 and is also in a 45 ° direction with respect to the detection axis of the second vibration element 5. Here, since the detection axis of the first vibration element 4 is the vertical direction of the paper surface in FIG. 11 and the detection axis of the second vibration element 5 is the horizontal direction of the paper surface, the rotation shaft 26 is 45 ° on the paper surface. Direction. When the angular velocity is applied in this direction, the output values generated by the angular velocity are both square roots as compared with the case where the detection axes of the first vibration element 4 and the second vibration element 5 are parallel to the rotation axis 26. Since this output value is multiplied by the square root of 2, since the output value is multiplied by the square root of 2, the output when the detection axis of the vibration element and the rotation axis 26 are parallel can be obtained. The characteristics of the angular velocity sensor can be detected.

  In the detection step, the characteristics of the first vibration element 4 and the second vibration element 5 mounted on the sheet substrate 20 are measured, and the characteristic data is stored in storage means (not shown) such as a memory. .

  Following the detection process, an adjustment process is performed to adjust these characteristics within a predetermined range according to the characteristic data of the first vibration element 4 and the second vibration element 5 obtained in the detection process. In this adjustment process, in particular, the zero point of the output value is adjusted. Specifically, a chip resistor is used in the chip component 6, and the resistor of this chip resistor is trimmed with a laser. A method of changing the resistance value is taken.

  After the adjustment step, a case attaching step for attaching the case 7 to the sheet substrate 20 is performed, and then a dividing step for dividing the sheet substrate 20 into pieces along the plurality of dividing grooves 21 is performed, whereby one angular velocity is obtained. A sensor can be obtained. In this way, a biaxial angular velocity sensor can be obtained.

  In the angular velocity sensor according to the embodiment of the present invention described above, the IC 3 is mounted face down, and the first vibration element 4 and a part of the second vibration element 5 are positioned on the IC 3. Therefore, the angular velocity sensor can be downsized. That is, by positioning a part of the first vibration element 4 and the second vibration element 5 on the IC 3, the area of the substrate 1 can be reduced, and by mounting the IC 3 face down, the wire can be reduced. Since wires and lead terminals by bonding are not positioned on the IC 3, the first vibration element 4 and the second vibration element 5 can be disposed on the IC 3. In particular, in the case of an angular velocity sensor having two vibration elements whose detection axes cross each other by 90 °, the vibration element crosses the IC in the vertical and horizontal directions. Therefore, the IC is mounted by wire bonding or the like. In this case, at least one of these two vibration elements may interfere with wire bonding or the like, but the angular velocity sensor in one embodiment of the present invention performs face-down mounting. Such a situation does not occur, and downsizing is possible.

  In addition, since the leg portion 4a of the first vibration element 4 and the leg portion 5a of the second vibration element 5 are arranged above the recess 2, the space below the leg portion 4a and the leg portion 5a is a space. Thus, the vibrating leg portion 4a and leg portion 5a do not come into contact with the substrate 1, so that the area on the substrate 1 that supports and fixes the first vibrating element 4 and the second vibrating element 5 is projected. This eliminates the necessity, and thereby the thickness of the angular velocity sensor can be reduced.

  Further, the concave portion 2 of the substrate 1 is connected to the IC mounting portion 8 for mounting the IC 3 and the injection portion 9 for connecting the IC mounting portion 8 and the nozzle 22 for injecting the IC adhesive 23 to enter. Therefore, the IC adhesive 23 can be reliably poured between the IC mounting portion 8 and the IC 3, and thereby the IC 3 can be securely bonded. That is, when there is no injection part 9, since the IC adhesive 23 is injected between the inner wall surface of the recess 2 and the IC 3, the IC adhesive 23 is poured between the recess 2 and the IC 3. Although this becomes difficult, such a phenomenon does not occur in the case of the angular velocity sensor according to the embodiment of the present invention.

  Further, a first reservoir 10 formed in the recess 2 of the substrate 1 is formed so as to be shallower than the IC mounting portion 8 and the injection portion 9 and directly connected to the injection portion 9 without being directly connected to the IC mounting portion 8. Therefore, the creeping distance from the injection portion 9 to the upper surface of the substrate 1 is increased, so that the IC adhesive 23 does not easily overflow from the recess 2 onto the substrate 1. Further, since the first reservoir 10 is shallower than the injection portion 9, electrical wiring can be performed on the substrate portion on the bottom surface of the first reservoir 10.

  Furthermore, the first reservoir portion 10 and the second reservoir portion 11 are formed in a portion of the recess 2 of the substrate 1 that is closest to the mounting portion of the first vibration element 4 and the second vibration element 5. Therefore, the creeping distance to the mounting portion of the first vibration element 4 and the second vibration element 5 is increased, whereby the first vibration element 4 and the second vibration element 5 are used for the IC. Since the contact of the adhesive 23 can be prevented, adverse effects on the vibration of the first vibration element 4 and the second vibration element 5 can be eliminated.

  In addition, in the state of the sheet-like sheet substrate 20, a detection process for detecting the characteristics of the plurality of angular velocity sensors by applying an angular velocity to the sheet substrate 20, and to reduce variations in the characteristics of the plurality of angular velocity sensors. The adjustment process for adjusting the characteristics of the plurality of angular velocity sensors is performed, and then the division process is performed. Therefore, the productivity is higher than that in which the detection process and the adjustment process are performed after being divided into individual pieces. It can be improved.

  In addition, after the adjustment process and before the dividing process, a process of attaching the case 7 covering the first vibration element 4 and the second vibration element 5 to the sheet substrate 20 for each angular velocity sensor is added. Therefore, the case 7 can also reliably prevent the burr and the like that may be generated when the sheet substrate 20 is divided into the individual substrates 1 from coming into contact with the first vibration element 4 and the second vibration element 5. As a result, the first vibration element 4 and the second vibration element 5 can be reliably protected in the dividing step. Further, since the case 7 is configured to cover the IC 3, the IC 3 can be protected in the dividing step.

  Furthermore, since only a part of the case 7 and the substrate 1 is fixed with an adhesive so that a gap is formed between the case 7 and the substrate 1, the case 7 causes the first vibration element 4 and the second vibration element 4. The vibration element 5 can be protected. Further, since the inside of the case 7 is not sealed, the manufacturing process can be simplified. Here, the angular velocity sensor has an advantage that the zero point shift is reduced when the space in which the vibration element is housed is evacuated or when the gas having a low molecular weight such as helium is filled in the space. 20 and the case 7 need to be sealed without gaps, and the manufacturing process becomes complicated, such as a process for checking whether the seal is really sealed or not. is there. However, there is a case where the zero point shift does not become a problem as in the case of using the angular velocity sensor for the camera shake detection device. In this case, it is not necessary to seal the case 7, so that the manufacturing process by not sealing is not necessary. Advantages such as simplification can be enjoyed.

  Furthermore, the element adhesive 24 that bonds the first vibration element 4 and the second vibration element 5 and the IC adhesive 23 that bonds the IC 3 both use a thermosetting resin, and the chip component 6. Since the component adhesive 25 used for bonding is made of a conductive thermosetting resin, the thermosetting resin and the conductive thermosetting resin can be cured in the same process, thereby improving the production efficiency. It can be planned. As described above, when the conductive thermosetting resin is used, the surface tension is not so large as in the case of the conductive metal adhesive such as solder. Therefore, the conductive thermosetting resin is formed from the component electrode 13 formed on the substrate 1. If the conductive thermosetting resin on one electrode side of the chip component 6 comes into contact with the conductive thermosetting resin on the other electrode side, a short circuit occurs. For this reason, in one embodiment of the present invention, by forming the interelectrode groove 14 between the opposing component electrodes 13, the creepage distance between the pair of component electrodes 13 is lengthened to prevent a short circuit. Yes.

  In the angular velocity sensor according to the embodiment of the present invention, two vibration elements whose detection axes intersect each other by 90 ° are used. However, a single vibration element may be used. is there.

  Further, although the manufacturing method is such that a plurality of angular velocity sensors are obtained from the sheet substrate 20, the manufacturing method may be such that one angular velocity sensor is obtained from the beginning without using the sheet substrate 20.

  In addition, as the component adhesive 25 used for bonding the chip component 6, a conductive metal adhesive such as solder may be used instead of the above-described conductive thermosetting resin. In this case, after the thermosetting step of curing the thermosetting resin used as the element adhesive 24 and the IC adhesive 23 in an environment of a predetermined temperature, the thermosetting step is continued from the thermosetting step. This can be done by adding a reflow process in which the conductive metal adhesive is melted at a high temperature. For example, in the thermosetting process, the thermosetting resin is cured at a temperature profile of 150 ° C. for about 30 minutes to 2 hours, and then a reflow process is performed at 260 ° for 5 minutes.

  As described above, the reflow process using the conductive metal adhesive has a track record and is highly reliable. However, the thermosetting resin is cured at a relatively low temperature for a long time profile. Since the conductive metal adhesive is melted and bonded with a relatively high temperature and a short temperature profile, it is difficult to bond using these different types of adhesives. That is, since the conductive metal adhesive does not melt at a temperature profile appropriate for the thermosetting resin, the chip component 6 cannot be bonded. On the other hand, the thermosetting resin at a temperature profile appropriate for the conductive metal adhesive. The temperature of the substrate 1 or the like becomes high before curing, and the IC 3, the first vibration element 4 and the second vibration element 5 are normally bonded by the influence of the warp of the substrate 1 or the like due to the high temperature. It may not be possible. However, if heating is performed with the above-described unique temperature profile, adhesion by the thermosetting resin and adhesion by the conductive metal adhesive can be made compatible and normal adhesion can be performed by these. . In addition, when using an electroconductive metal adhesive, the groove | channel 14 between electrodes does not need to form.

  In the angular velocity sensor according to the present invention, the concave portion of the substrate is composed of an IC mounting portion for mounting an IC, and an injection portion connected to the IC mounting portion and into which a nozzle for injecting an adhesive for IC enters. Thus, the reliability of the angular velocity sensor can be improved and the size can be reduced, which is useful when applied to electronic devices and vehicles.

The fracture | rupture perspective view of the angular velocity sensor in one embodiment of this invention Exploded perspective view of the same angular velocity sensor Plan view of the same angular velocity sensor 3 is a longitudinal sectional view Cross-sectional view of FIG. The top view which shows the sheet | seat board | substrate of the angular velocity sensor in one embodiment of this invention Plan view of IC mounting process in the same angular velocity sensor Longitudinal sectional view of IC adhesive injection process in the same angular velocity sensor Plan view of adhesive application process for parts in the same angular velocity sensor Plan view of component placement process in the same angular velocity sensor Plan view of the detection process in the angular velocity sensor Flow diagram showing the manufacturing process of the same angular velocity sensor

Explanation of symbols

1 Substrate 2 Recess 3 IC
4 First vibration element 4a Leg 4b Base 5 Second vibration element 5a Leg 5b Base 6 Chip component 7 Case 8 IC mounting part 9 Injection part 10 First accumulation part 11 Second accumulation part 12 Element Electrode 13 Component electrode 14 Interelectrode groove 15 Wire 16 Positioning mark 20 Sheet substrate 21 Dividing groove 22 Nozzle 23 IC adhesive 24 Element adhesive 25 Component adhesive 26 Rotating shaft

Claims (4)

A substrate having a recess, an IC mounted in the recess of the substrate, an IC adhesive for bonding and fixing the IC to the substrate, and a vibration element attached to the substrate and electrically connected to the IC The concave portion of the substrate is composed of an IC mounting portion for mounting the IC, and an injection portion connected to the IC mounting portion and into which a nozzle for injecting the adhesive for IC enters. Angular velocity sensor. 2. The first reservoir portion formed in the concave portion of the substrate, which is shallower than the depth of the IC mounting portion and the injection portion and formed directly connected to the injection portion without being directly connected to the IC mounting portion. Angular velocity sensor. The angular velocity sensor according to claim 2, wherein the first pool portion is formed in a portion of the concave portion of the substrate closest to the mounting portion of the vibration element. The first vibration element and the second vibration element are provided as vibration elements, and the first reservoir is formed in a portion of the recess of the substrate closest to the mounting portion of the first vibration element. And forming a second reservoir portion which is shallower than the depth of the IC mounting portion and the injection portion and formed directly connected to the IC mounting portion without being directly connected to the injection portion, and further to the second reservoir portion. The angular velocity sensor according to claim 3, wherein the angular velocity sensor is formed in a portion of the concave portion of the substrate closest to the mounting portion of the second vibration element.

Images