Patent Application
20140063753
1. Technical Field
The present invention relates to an electronic module, an electronic device, and a mobile unit.
2. Related Art
According to a related art, an electronic module having an acceleration sensor element, angular velocity sensor element or the like as an example of a sensor for detecting attitudes or the like of an object is known. Such an electronic module is configured with three sensor elements provided on a flexible substrate, with the substrate being bent in such a way that detection axes of the three sensor elements become orthogonal to each other.
For example, JP-A-7-306047 discloses a structure in which a sensor element and a circuit element for processing a signal outputted from the sensor element are provided on each of three substrates, with two of the substrates standing up vertically on the one substrate, thus forming a rectangular column-like shape.
However, in the electronic module described in JP-A-7-306047, since a sensor element and a circuit element for performing a signal processing circuit are provided on each substrate, a large mounting area is required and the substrates are large-sized. Therefore, it is not easy to reduce the size of the electronic module. Moreover, electromagnetic noise generated from the circuit elements and heat may influence the operation of the sensor elements.
An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.
This application example is directed to an electronic module including: a first substrate having a first surface on which a first sensor element is provided and a second surface on which a circuit element is provided; a second substrate provided with a second sensor element; and a connecting portion which connects the first substrate and the second substrate with each other. The first substrate is provided with a shield layer between the first sensor element and the circuit element.
According to such an electronic module, the first sensor element and the second sensor element are provided, corresponding to the first substrate and the second substrate. Also, the circuit element which processes a signal outputted from each sensor element is provided on the second surface of the first substrate, which is arranged opposite to the first surface provided with the first sensor element via the shield layer. Thus, since a circuit element need not be provided on the second substrate, the substrate can be reduced in size. Moreover, since the circuit element is concentrated on the first substrate and is arranged opposite to the first sensor element via the shield layer, the influence of electromagnetic noise generated from the circuit element on each sensor element can be restrained.
In the electronic module according to the application example described above, it is preferable that the electronic module has a supporting portion having plural fixing surfaces, and the first substrate and the second substrate are fixed to each of the fixing surfaces.
According to such an electronic module, the first substrate and the second substrate connected to the first substrate via the connecting portion are fixed to the supporting portion. Thus, the first sensor element and the second sensor element provided on the first substrate and the second substrate have constant positions to each other and the direction of angular velocity and acceleration detected by each sensor element is made constant. Therefore, reliability of detection can be increased.
In the electronic module according to the application example described above, it is preferable that the supporting portion has an opening which accommodates one of the first sensor element, the second sensor element, and the circuit element.
According to such an electronic module, since the supporting portion has the opening, the first sensor element or the circuit element provided on the first substrate fixed to the supporting portion, or the second sensor element provided on the second substrate can be accommodated. As the first sensor element, the second sensor element, and the circuit element are accommodated in the opening, the first substrate and the second substrate can be fixed in close contact with the supporting portion.
In the electronic module according to the application example described above, it is preferable that the first sensor element is arranged on the side of the supporting portion and that the circuit element is arranged on the side opposite to the supporting portion.
According to such an electronic module, the first sensor element is arranged on the side of the supporting portion. Therefore, electromagnetic noise entering from outside the electronic module can be attenuated by the first substrate and propagation of the electromagnetic noise to the first sensor element can be restrained. Also, since the circuit element is arranged on the side opposite to the supporting portion, electromagnetic noise generated from the circuit element can be attenuated by the first substrate and propagation of the electromagnetic noise to the first sensor element can be restrained.
In the electronic module according to the application example described above, it is preferable that the electronic module has a pedestal for fixing the supporting portion thereon and that the circuit element is fixed to the pedestal.
According to such an electronic module, the circuit element is fixed to the pedestal on which the supporting portion is fixed.
Thus, heat generated from the circuit element can be transmitted to the pedestal and radiated there. The influence of heat generated from the circuit element on the first sensor element and the second sensor element can be restrained.
In the electronic module according to the application example described above, it is preferable that the circuit element has a first circuit portion provided on the second surface and a second circuit portion provided on the first circuit portion, and that a separation layer is provided between the first circuit portion and the second circuit portion.
In such an electronic module, the separation layer is provided between the first circuit portion and the second circuit portion of the circuit element. Thus, propagation of electromagnetic noise generated in the first circuit or the second circuit to the other circuit portion can be restrained.
In the electronic module according to the application example described above, it is preferable that the first circuit portion includes an analog circuit which amplifies an output signal from the first sensor element or the second sensor element, and that the second circuit portion includes a digital circuit which converts the signal amplified by the analog circuit to a digital signal.
In such an electronic module, the first circuit portion of the circuit element includes the analog circuit and the second circuit portion has the digital circuit.
Thus, compared with a first circuit portion including an analog circuit, the second circuit portion including the digital circuit with a greater amount of heat generation abuts on the pedestal and therefore heat can be transmitted to the pedestal and radiated there. Therefore, the influence of heat generation in the circuit element on each sensor element can be restrained.
This application example is directed to an electronic device including the electronic module described above.
According to such an electronic device, since the electronic device is equipped with the above electronic module, the influence of electromagnetic noise is retrained and detection accuracy in detecting attitudes or the like of the electronic device can be enhanced.
This application example is directed to a mobile unit including the electronic module described above.
According to such a mobile unit, since the mobile unit is equipped with the above electronic module, the influence of electromagnetic noise is retrained and detection accuracy in detecting attitudes or the like of the mobile unit can be enhanced.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
Hereinafter, embodiments of the invention will be described with reference to the drawings. In the drawings, the dimension and proportion of each component may be different from the actual component according to need, in order to show each component in a size large enough to be recognized in the drawings. Also, an XYZ orthogonal coordinate system is set and the positional relation of each part is described with reference to the XYZ orthogonal coordinate system. A predetermined direction in vertical plane is referred to as an X-axis direction. A direction orthogonal to the X-axis direction in the vertical plane is referred to as a Y-axis direction. A direction orthogonal to both the X-axis direction and the Y-axis direction is referred to as a Z-axis direction.
A module according to a first embodiment is shown in
An electronic module 1 of this embodiment shown in
The mounting substrate 2 has a first substrate 21 as a first substrate, and a second substrate 22, a third substrate 23 and a fourth substrate 24 as second substrates, and is supported by the supporting portion 3. The casing 6 has a pedestal 7 for fixing the mounting substrate 2 supported by the supporting portion 3, and a lid 10 covering the pedestal 7.
The electronic module 1 of this embodiment is described as an electronic module which detects acceleration or angular velocity, with the second substrate 22, the third substrate 23 and the fourth substrate 24 as plural second substrates connected to the first substrate 21 as a first substrate. As the second substrate, plural second substrates may be used depending on the acceleration to be detected or the direction in which angular velocity is to be detected. Hereinafter, the configuration of the electronic module 1 will be described in detail.
The mounting substrate 2 is a rigid-flexible substrate formed by a combination of the first substrate 21, the second substrate 22, the third substrate 23 and the fourth substrate 24 as rigid substrates that are hard and hardly deformable, and connecting portions 26 as flexible substrates that are soft and deformable. As such a mounting substrate 2, a known rigid-flexible substrate, for example, a rigid-flexible substrate formed by bonding a hard layer such as a glass epoxy substrate to both sides of a flexible substrate so that the hard layer part can be used as a rigid substrate, can be used.
As shown in
Hereinafter, for convenience of explanation, a first surface 211 of the first substrate 21, a third surface 221 of the second substrate 22, a fifth surface 231 of the third substrate 23, and a seventh surface 241 of the fourth substrate 24 shown in
The connecting portions 26 include a first connecting portion 261 connecting the first substrate 21 with the second substrate 22, a second connecting portion 262 connecting the first substrate 21 with the third substrate 23, and a third connecting portion 263 connecting the first substrate 21 with the fourth substrate 24.
Each of the first connecting portion 261 to the third connecting portion 263 is flexible and can be easily deformed in planar directions.
Also, holes 21a, 21b are formed near both ends (two diagonal corners) of the first substrate 21. Also, holes 22a, 22b are formed near both ends of the second substrate 22. Holes 23a, 23b are formed near both ends of the third substrate 23. Holes 24a, 24b are formed near both ends of the fourth substrate 24.
These holes 21a to 23b are used to fix the first substrate 21 to the fourth substrate 24, to the supporting portion 3 (see
Such a mounting substrate 2 can be deformed into the shape of a rectangular parallelepiped as shown in
Specifically, by bending the connecting portions 26 (261 to 263) in such a way that the face-side mounting surfaces (first surfaces) 211 to 241 of the first substrate 21 to the fourth substrate 24 face inside, the mounting substrate 2 can be deformed into the shape of a rectangular parallelepiped in which substrates next to each other are orthogonal to each other. In this state, the first substrate 21 forms a lower side 31b (see
A conductor wire, not shown, is formed in the first substrate 21 to the fourth substrate 24 and the connecting portions 26 forming the mounting substrate 2. Plural electronic components 4, described later, are electrically connected to the first substrate 21 via this conductor wire.
As shown in
Hereinafter, the arrangement of these electronic components 4 on the mounting substrate 2 will be described in detail.
On the first surface (face-side mounting surface) 211 of the first substrate 21, the first sensor element 411 which detects angular velocity or the like about the Z axis is provided. On the second surface (back-side mounting surface) 212, the circuit element 40 which processes output signals from the first to third sensor elements 411 to 413 is provided.
On the third surface (face-side mounting surface) 221 of the second substrate 22, the second sensor element 412 which detects angular velocity or the like about the Y axis is provided.
On the fifth surface (face-side mounting surface) 231 of the third substrate 23, the third sensor element 413 which detects angular velocity or the like about the X axis is mounted.
On the eighth surface (back-side mounting surface) 242 of the fourth substrate 24, the interface connector 50 is provided. This enables easy input and output of signals.
As shown in
The lower side 31b, the lateral side 33, and the lateral side 32 are sides where the first substrate 21 to the third substrate 23 with the first sensor element 411 to the third sensor element 413 mounted thereon are fixed (engaged), as described later. Therefore, by forming these three sides orthogonally to each other, the first sensor element 411 to the third sensor element 413 can be arranged accurately in an attitude such that detection axes A (see
Therefore, according to the electronic module 1, angular velocity or the like can be detected with high accuracy about each axis (x axis, y axis, and z axis).
The lower side 31b forms a fixing surface to fix (engage) the first substrate 21. The first substrate 21 is fixed to the lower side 31b in the state where the first surface 211 thereof faces toward the supporting portion 3 (inside). Specifically, the supporting portion 3 has two protrusions 312, 313 protruding from the vicinities of both ends (two diagonal corners) of the lower side 31b, and the holes 21a, 21b formed in the first substrate 21 are engaged with these protrusions 312, 313. Thus, the first substrate 21 is fixed to the lower side 31b, as shown in
The inside of the supporting portion 3 surrounded by the lateral sides 32, 35 facing each other and the lateral sides 33, 34 facing each other is hollow. Therefore, the first substrate 21 can be fixed to the supporting portion 3 without interference by the first sensor element 411 provided on the first surface 211 of the first substrate 21. The same applies in the case where the circuit element 40 is provided on the first surface 211.
The lateral side 32 forms a fixing surface to fix (engage) the second substrate 22. The second substrate 22 is fixed to the lateral side 32 in the state where the first connecting portion 261 is bent and where the third surface 221 faces the supporting portion 3 (inside). Specifically, the supporting portion 3 has two protrusions 322, 323 protruding from both ends of the lateral side 32, and the holes 22a, 22b formed in the second substrate 22 are engaged with these protrusions 322, 323. Thus, the second substrate 22 is fixed to the lateral side 32, as shown in
The supporting portion 3 also has a recessed portion 321 opened on the lateral side 32. This recessed portion 321 is formed corresponding to the position and outer shape of the second sensor element 412. In the state where the second substrate 22 is fixed to the lateral side 32, the second sensor element 412 is accommodated in the recessed portion 321. That is, the recessed portion 321 forms an escape portion to prevent the supporting portion 3 and the second sensor element 412 from contacting each other. As such a recessed portion 321 is formed, the influence of electromagnetic noise on the second sensor element 412 from outside the electronic module 1 can be restrained by providing the second sensor element 412 on the side of the supporting portion 3. Also, the inner space of the supporting portion 3 can be effectively utilized and the electronic module 1 can be reduced in size.
The lateral side 33 forms a fixing surface to fix the third substrate 23. The third substrate 23 is fixed to the lateral side 33 in the state where the second connecting portion 262 is bent and where the fifth surface 231 faces toward the supporting portion 3 (inside). Specifically, the supporting portion 3 has two protrusions 332, 333 protruding from both ends of the lateral side 33, and the holes 23a, 23b formed in the third substrate 23 are engaged with these protrusions 332, 333. Thus, the third substrate 23 is fixed to the lateral side 33, as shown in
The supporting portion 3 also has a recessed portion 331 opened on the lateral side 33. This recessed portion 331 is formed corresponding to the position and outer shape of the third sensor element 413. In the state where the third substrate 23 is fixed to the lateral side 33, the third sensor element 413 is accommodated in the recessed portion 331. That is, the recessed portion 331 forms an escape portion to prevent the supporting portion 3 and the third sensor element 413 from contacting each other. As such a recessed portion 331 is formed, the influence of electromagnetic noise on the third sensor element 413 from outside the electronic module 1 can be restrained by providing the third sensor element 413 on the side of the supporting portion 3. Also, the inner space of the supporting portion 3 can be effectively utilized and the electronic module 1 can be reduced in size.
The lateral side 34 forms a fixing surface to fix the fourth substrate 24. The fourth substrate 24 is fixed to the lateral side 34 in the state where the third connecting portion 263 is bent and where the seventh surface 241 as a face-side mounting surface faces toward the supporting portion 3 (inside).
In other words, the fourth substrate 24 is fixed to the lateral side 34 in the state where the connector 50 is exposed outside the electronic module 1.
Specifically, the supporting portion 3 has two protrusions 342, 343 protruding from both ends of the lateral side 34, and the holes 24a, 24b formed in the fourth substrate 24 are engaged with these protrusions 342, 343. Thus, the fourth substrate 24 is fixed to the lateral side 34, as shown in
The material forming the supporting portion 3 is not particularly limited. However, hard materials are preferable in order to prevent deformation, for example, when external pressure is applied. Such materials may be, for example, various metals such as iron (Fe), nickel (Ni), copper (Cu), and aluminum (Al), or an alloy or intermetallic compound containing at least one of these metals, or oxides of these metals and the like. Among them, the alloys may be, for example, stainless steel, Inconel, and various aluminum-based alloys such as duralumin.
In the mounting substrate 2a shown in
In the mounting substrate 2b shown in
With respect to the mounting substrate 2a, though an example of providing the shield layer 61 on the second surface 212 is described, the shield layer 61 may also be provided between the first sensor element 411 and the first surface 211.
The circuit element 40 is equipped with a so-called digital circuit which carries out digital processing of signals outputted from the first to third sensor elements 411 to 413 in order to output these signals to outside the electronic module 1. Therefore, in some cases, electromagnetic noise may be generated from the circuit element 40 due to the operation of the digital circuit.
In the electronic module 1 having such mounting substrates 2a, 2b, the resulting noise can be cut off by the shield layer 60 and entry of the electromagnetic noise into very weak signals outputted from the first to third sensor elements 411 to 413 can be restrained.
The very weak signals outputted from the first to third sensor elements 411 to 413 are so-called analog signals and susceptible to the influence of electromagnetic noise. Therefore, as the electromagnetic noise generated from the circuit element 40 is cut off by the shield layer 60, the influence of the electromagnetic noise can be restrained.
Meanwhile, in amounting substrate 2c shown in
In the electronic module 1 having such a mounting substrate 2c, since the shield layer 63 is provided inside the circuit element 40, entry of electromagnetic noise generated from the controller 46 or the like provided in the second circuit portion 40d, into the first circuit portion 40a, and the influence of the electromagnetic noise can be restrained.
The material forming the shield layer 60 is not particularly limited. However, various metals including materials with excellent shielding capability against electric fields and with high conductivity such as copper (Cu) and aluminum (Al), and materials with excellent shielding capability against magnetic fields and with high initial permeability such as permalloy, iron (Fe), and nickel (Ni), or an alloy or intermetallic compound containing at least one of these metals, may be used.
As shown in
The mounting substrates 2a and 2b shown in
The mounting substrate 2c shown in
Thus, heat generated in the circuit element 40 can be radiated to the pedestal 7. The influence of the heat on the first to third sensor elements 411 to 413 can be restrained. Change in characteristics of each sensor element due to the heat can be restrained. Also, strain of the mounting substrate 2 to which the first substrate 21, the second substrate 22 and the third substrate 23 are joined can be restrained and misalignment of the detection axis of the sensor element provided on each substrate can be restrained.
Next, the structure of the first to third sensor elements 411 to 413 will be described. Each of the first to third sensor elements 411 to 413 has a vibrating piece 5.
The vibrating piece 5 shown in
In such a vibrating piece 5, if an angular velocity ω about a normal A to the vibrating piece 5 is applied in the state where the vibrating arms for drive 156, 158 and the vibrating arms for drive 157, 159 are made to vibrate in the way of repeating moves toward and away from each other by applying a voltage to the drive electrodes, a Coriolis force is applied to the vibrating piece 5, exciting vibration of the vibrating arms for detection 152, 153. Then, by detecting, with the detection electrodes, strain of the vibrating arms for detection 152, 153 generated by the vibration of the vibrating arms for detection 152, 153, the angular velocity applied to the vibrating piece 5 can be found.
Back to
As shown in
As shown in
At two diagonal corners of the pedestal 7, slots 711, 712 opening to the outer circumference (outer edge) are formed. These slots 711, 712 extend in the same direction as each other.
The material forming the pedestal 7 is not particularly limited. However, a material with good thermal conductivity (high thermal conductivity) is preferable. This enables radiation of heat emitted from the circuit element 40 provided on the mounting substrate 2 and enables restraint on the influence due to the heat on the first to third sensor elements 411 to 413, that is, change in vibrating characteristics of the vibrating piece 5 due to temperature change. Such a material may be, for example, a metal such as copper (Cu) or aluminum (Al), an alloy containing these metals, or a magnesium alloy, iron-based alloy, copper alloy or the like.
According to the above first embodiment, the following advantages can be achieved.
According to such an electronic module 1, the circuit element 40 which processes signals outputted from the first to third sensor elements 411 to 413 is provided via the shield layer 60 on the first substrate 21 where the first sensor element 411 is provided.
This eliminates the need to provide the circuit element 40 on the second substrate 22 and the third substrate 23 where the second sensor element 412 and the third sensor element 413 are provided. Therefore, the area (size) of the second substrate 22 and the third substrate 23 can be decreased.
Thus, the height of the second substrate 22 and the third substrate 23 standing up substantially vertically by bending the connecting portion 26 connecting to the first substrate 21 can be restrained. Reduction in size and height of the electronic module 1 can be realized.
Also, electromagnetic noise generated from the circuit element 40 can be cut off by the shield layer 60 and entry of the electromagnetic noise into signals outputted from the first to third sensor elements 411 to 413 can be restrained.
Moreover, since the shield layer 63 is provided between the first circuit portion 40a and the second circuit portion 40d of the circuit element 40, electromagnetic noise generated from the second circuit portion 40d can be cut off, and entry of the electromagnetic noise into a signal outputted from the first sensor element 411 and into the first circuit portion 40a amplifying the signal can be restrained.
Also, the first to third sensor elements 411 to 413 are provided on the inner side of the electronic module 1 where the supporting portion 3 is provided. The first sensor element 411 is surrounded by the pedestal 7 and the supporting portion 3. The second sensor element 412 and the third sensor element 413 are surrounded by the lid 10 and the supporting portion 3 (321, 331).
Therefore, electromagnetic noise generated outside the electronic module 1 is attenuated by the casing 6 and the first to third substrates 21 to 23 and the influence of the electromagnetic noise on the first to third sensor elements 411 to 413 can be restrained.
Thus, the electronic module 1 with a reduced size in which the influence of electromagnetic noise generated by the circuit element 40 is reduced can be provided.
Next, examples of application of the electronic module 1 according to an embodiment of the invention will be described with reference to
First, electronic devices to which the electronic module 1 according to the first embodiment of the invention is applied will be described with reference to
Even when electromagnetic waves due to communication are emitted from the mobile phone 1200, the use of the electronic module 1 that is not likely to be affected by the electromagnetic noise (electromagnetic waves) enables stable detection of the moving direction or the like.
A display section 1308 is provided on the back side of a case (body) 1302 of the digital still camera 1300 and presents a display based on a picked-up image signal generated by the CCD. The display section 1308 functions as a viewfinder to show a subject as an electronic image. Also, a light receiving unit 1304 including an optical lens (image pickup system) and CCD is provided on the front side of the case 1302 (backside in
As a cameraman checks a subject image shown in the display section 1308 and presses a shutter button 1306, a picked-up image signal generated by the CCD at that point is transferred to and stored in a memory 1310. Also, in the digital still camera 1300, a video signal output terminal 1312 and a data communication input/output terminal 1314 are provided on a lateral side of the case 1302. As illustrated, a television monitor 1430 is connected to the video signal output terminal 1312 and a personal computer 1440 is connected to the data communication input/output terminal 1314 according to need. Moreover, a predetermined operation causes the picked-up image signal stored in the memory 1310 to be outputted to the television monitor 1430 and the personal computer 1440. The electronic module 1 functioning as a gyro sensor or the like to detect the inclination of the digital still camera 1300 is arranged inside the digital still camera 1300.
Even when electromagnetic noise is emitted from a digital circuit which carries out photoelectric conversion as the digital still camera 1300 operates, the use of the electronic module 1 that is not likely to be affected by the electromagnetic noise enables stable detection of attitudes such as inclination.
The electronic module 1 according to the first embodiment of the invention can also be applied to electronic devices such as an ink jet ejection device (for example, ink jet printer), laptop personal computer, television set, video camera, video tape recorder, car navigation system, pager, electronic notebook (including those with communication functions), electronic dictionary, electronic calculator, electronic game device, word processor, workstation, TV phone, surveillance television monitor, electronic binocular, POS terminal, medical equipment (for example, electronic thermometer, sphygmomanometer, glucose meter, electrocardiograph, ultrasonic diagnosis device, and electronic endoscope), fishfinder, various measuring devices, gauges (for example, gauges in vehicles, aircraft and vessels), and flight simulator, as well as the personal computer (mobile personal computer) of
The entire disclosure of Japanese Patent Application No. 2012-189631, filed Aug. 30, 2012 is expressly incorporated by reference herein.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-189631 | Aug 2012 | JP | national |
