JP2505987Y2 - Acceleration sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an acceleration sensor, and more particularly to an acceleration sensor capable of detecting acceleration for each coordinate axis direction component in a three-dimensional orthogonal coordinate system.

[Conventional technology]

With the progress of semiconductor technology, various sensors using semiconductors have been developed. For example, International Publication No. WO88 / 08522, which is an international application based on the Patent Cooperation Treaty, discloses a force / acceleration / magnetism sensor using a resistance element according to the invention of the same person as the inventor of the present application. The sensor disclosed in this publication arranges a resistance element having a property of a piezoresistive effect that an electric resistance is changed by mechanical deformation on a semiconductor substrate, and a force is applied from a change in resistance value of the resistance element,
Acceleration or magnetism is detected, and each physical quantity can be detected in the form of an electrical signal for each coordinate axis direction component in the three-dimensional orthogonal coordinate system. In general, a sensor using such a semiconductor is commercialized with a semiconductor substrate enclosed in a package. A user usually uses such a packaged sensor by mounting it on a printed circuit board or the like on which an electric circuit for detection is formed.

[Problems to be solved by the device]

In a sensor that can detect a physical quantity for each coordinate axis direction component in the Cartesian coordinate system, it is necessary to firmly recognize which lead axis lead out of the package outputs the detection signal related to the coordinate axis direction component. If the package is not implemented in, the correct physical quantity cannot be detected. However, when the package is picked up, it is necessary to recognize which direction of the package corresponds to which coordinate axis according to the description such as the product specification. For this reason, there is a problem in that it takes time and effort when mounting and there is a possibility that the direction is wrongly mounted.

Then, this invention aims at providing the acceleration sensor which can be correctly mounted easily.

[Means for solving the problem]

A first feature of the present invention is that a substrate having a flat upper surface, a first detection element arranged along a first axis on the upper surface of the substrate, and a first detection element orthogonal to the first axis on the upper surface of the substrate. A second detection element arranged along the axis of 2, a first lead terminal electrically connected to the first detection element, and a second lead terminal electrically connected to the second detection element. A lead terminal and a package accommodating or fixing each of these components are provided, and a detection value of an acceleration component acting in a direction along the first axis is obtained at the first lead terminal. 2nd to the lead terminal of
An acceleration sensor configured to obtain a detection value of an acceleration component acting in a direction along the axis of the package, in which a mark indicating the direction of the first axis and the direction of the second axis is attached to the outer surface of the package. Is.

A second feature of the present invention is the acceleration sensor according to the above-mentioned first feature, in which an acceleration component acting in a direction along a third axis orthogonal to both the first axis and the second axis is detected. A third detection element for obtaining a value is formed on the upper surface of the substrate, a third lead terminal electrically connected to the third detection element is further provided, and a mark indicating the direction of the third axis is provided. It is further attached to the outer surface of the package.

A third feature of the present invention is the acceleration sensor according to the above-mentioned first or second feature, in which an outer fixing portion is fixed to a package, and an inner working portion is joined with a weight cone to fix the fixing portion. A substrate on which a flexible portion having flexibility is formed is used between the acting portion and the pyramid so that the heavy pyramid is supported by the substrate in a displaceable state inside the package. As the second detection element, when the external force is applied to the pyramidal body due to the action of acceleration to cause the flexible portion to bend, the second detection element has a property that the electrical characteristics change based on the state of the generated bending. It was done.

A fourth feature of the present invention is the acceleration sensor according to the above-mentioned third feature, wherein the first detection element and the second detection element are resistors having a property that electric resistance changes due to bending of the flexible portion. The element is used.

[Action]

On the outer surface of the package of the acceleration sensor according to the present invention,
Since a mark indicating the direction of the coordinate axis corresponding to the detected acceleration is attached, the mounting operator can mount the package in the correct direction based on this mark. Therefore, the mounting work is simplified, and it is possible to prevent mounting in the wrong direction.

〔Example〕

Hereinafter, the present invention will be described based on illustrated embodiments. FIG. 1 is a perspective view of an acceleration sensor according to an embodiment of the present invention. The package 50 contains a sensor unit capable of separately detecting the acceleration in the three-dimensional coordinate system for each coordinate axis direction component as described later. Further, the lead terminals 52 are led out from both side surfaces of the package 50 so as to be bent downward. The lower ends of the lead terminals 52 are inserted into the through holes of the printed board at the time of mounting and soldered to the wiring pattern on the printed board.

The acceleration acting on the entire package is separately detected for each of the X-axis direction component, the Y-axis direction component, and the Z-axis direction component in the XYZ three-dimensional orthogonal coordinate system. The detected acceleration value of each direction component is output as an electric signal from a predetermined lead terminal.

The features of this package are the arrow mark 61, the letter mark "X" 62, and the arrow mark 63 and "Y" on the upper surface.
The sign 64 of the character is attached respectively, and further, the sign 65 of the arrow and the sign 66 of the character "Z" are attached on the front side. These signs indicate the direction of the coordinate axis corresponding to the detected acceleration, and the implementer uses this sign to determine in which direction the detected value output from each lead terminal is the detected acceleration value. Can be recognized.

In order to explain the meaning of each sign in a little more detail, the internal structure of the acceleration sensor will be briefly described. FIG. 2 is a front sectional view of the acceleration sensor shown in FIG. Here, as shown in FIG. 2, the right direction of the drawing is defined as the X-axis direction, the upper direction of the drawing is defined as the Z-axis direction, and the direction perpendicular to the plane of the drawing is defined as the Y-axis direction. The central unit of this sensor is the semiconductor pellet 10. A top view of the semiconductor pellet 10 is shown in FIG. The cross section of the semiconductor pellet 10 shown in the central portion of FIG. 2 corresponds to the cross section of FIG. 3 taken along the X-axis. The semiconductor pellet 10 is divided into three regions, that is, a working portion 11, a flexible portion 12, and a fixing portion 13 in order from the inside to the outside. As shown by a broken line in FIG. 3, an annular groove is formed on the lower surface of the flexible portion 12. Due to this groove, the flexible portion 12 becomes thin and has flexibility. Therefore,
When a force is applied to the acting portion 11 with the fixing portion 13 fixed,
The flexible portion 12 bends to cause mechanical deformation. As shown in FIG. 3, on the upper surface of the flexible portion 12, resistance elements Rx1 to Rx4, Ry1 to Ry are provided.
4, Rz1 to Rz4 are formed in a predetermined direction.

As shown in FIG. 2, a weight body 20 is joined below the acting portion 11, and a pedestal 21 is connected below the fixed portion 13. A control member 30 is connected below the pedestal 21, and a control member 40 covers the upper surface of the semiconductor pellet 10. Grooves 31 and 41 are formed on the upper surface of the control member 30 and the lower surface of the control member 40, respectively. Control member
The bottom surface of 30 is bonded to the inner bottom surface of the package 50,
The semiconductor pellet 10 and the weight body 20 are supported by a pedestal 21. The weight body 20 is suspended in the air inside.
The package 50 is covered with a lid 51. Semiconductor pellet
Bonding pad 14 provided on 10 (see FIG. 3)
Are electrically connected to each resistance element in the pellet, and the bonding pad 14 and the lead 52 provided on the side of the package are connected by the bonding wire 15.

When acceleration is applied to this sensor, an external force acts on the weight body 20. This external force is transmitted to the acting portion 11, and the flexible portion 12 is mechanically deformed.

This causes a change in the electrical resistance of the resistance element, and this change can be taken out to the outside via the bonding wire 15 and the lead 52. X of force applied to acting part 11
The directional component is due to the change in the electrical resistance of the resistance elements Rx1 to Rx4,
The Y-direction component is detected by a change in electric resistance of the resistance elements Ry1 to Ry4, and the Z-direction component is detected by a change in electric resistance of the resistance elements Rz1 to Rz4. This detection method is not the purpose of the present invention, and therefore its explanation is omitted here. For details, see International Publication WO88 / 0 for international applications based on the Patent Cooperation Treaty.
See Japanese Patent No. 8522.

When used as an acceleration sensor, an excessive external force acts on the weight body 20 when a large acceleration is applied.
As a result, the flexible portion 12 undergoes large mechanical deformation, which may damage the semiconductor pellet 10. In order to prevent such damage, the sensor shown in FIG.
40 are provided. The control member 30 controls the downward displacement of the weight body 20 so as not to exceed an allowable value,
The control member 40 controls so that the upward displacement of the weight body 20 (actually, the action portion 11) does not exceed an allowable value.
Further, the pedestal 21 plays a role of controlling the lateral displacement of the weight body so as not to exceed an allowable value. Even if an excessive external force acts on the weight body 20 to try to move it beyond the above allowable value,
The weight body 20 collides with these members and their movement is blocked. As a result, the semiconductor pellet 10 is protected from breakage without being subjected to mechanical deformation exceeding the allowable value.

Now, after all, from the lead terminals electrically connected to the resistance elements Rx1 to Rx4 shown in FIG. 3 (which will be referred to as lead terminals 52X), the acceleration component detection values in the X-axis direction in the figure are From the lead terminals that are obtained and electrically connected to the resistance elements Ry1 to Ry4, the acceleration component detection values in the Y-axis direction of the figure are obtained, and from the lead terminals that are electrically connected to the resistance elements Rz1 to Rz4. Means that the acceleration component detection value in the Z-axis direction in the figure is obtained. It should be noted here that each coordinate axis has directionality. For example, if the detected value obtained at the lead terminal 52X is a positive value, it indicates that the acceleration is acting in the positive direction of the X-axis, and if the detected value is a negative value, the acceleration is in the negative direction of the X-axis. Indicates that it is working.

Marks 61 to 66 shown in FIG. 1 correspond to the coordinate axes shown in FIGS. 2 and 3. Therefore, for example, it can be recognized that the detection value obtained at the lead terminal 52X corresponds to the acceleration component acting in the direction indicated by the arrow 61. In general, the specifications of such a sensor include information on which lead terminals are numbered to obtain the detection value of each axial component of X, Y, Z. . The user of the sensor can immediately recognize which direction the X, Y, Z coordinate axes described in the specification correspond to the actual sensor by the marks 61 to 66. Therefore, it is possible to easily grasp in which direction the package should be mounted at the time of mounting, and it is possible to prevent the mistake of mounting in the wrong direction.

Although the present invention has been described above based on the illustrated embodiment, the main point of the present invention is that a mark indicating the direction of the coordinate axis corresponding to the detected physical quantity is attached to the outer surface of the package. It can be applied. For example, the embodiment of FIG. 1 is an example in which the present invention is applied to a DIP type package, but any type of package including a type of package shown in FIGS. 4 and 5 can be used. The present invention can be applied. Further, as the sign indicating the direction of the coordinate axis, the arrow and the character of the coordinate axis name are used in the embodiment of FIG. 1, but other signs can be used as long as the sign can recognize the direction of the coordinate axis and the name of the coordinate axis. May be used, and the position where a label is attached may be arbitrary. Furthermore,
Although the embodiment of FIG. 1 is an acceleration sensor, the present invention can be applied to a sensor such as a magnetic sensor or a force sensor that detects any directional physical quantity. 6 and 7 are a perspective view and a top view, respectively, of an embodiment in which the present invention is applied to a force sensor. Further, the present invention can be applied not only to a sensor that detects a three-dimensional physical quantity but also to a sensor that detects a two-dimensional physical quantity.

[Effect of device]

As described above, according to the acceleration sensor of the present invention, since the sign indicating the direction of the coordinate axis corresponding to the detected acceleration is attached to the outer surface, the mounting worker can orient the package in the correct direction based on this sign. It can be implemented and can be prevented from being implemented in the wrong direction.

[Brief description of drawings]

FIG. 1 is a perspective view of an acceleration sensor according to an embodiment of the present invention, FIG. 2 is a front sectional view of the sensor shown in FIG. 1, and FIG. 3 is a semiconductor pellet which is the center of the sensor shown in FIG. Top views, FIGS. 4 and 5 are perspective views of a sensor package according to another embodiment of the present invention, and FIGS. 6 and 7 are for a sensor according to an embodiment in which the present invention is applied to a force sensor. It is a perspective view and a top view of a package. 10 …… Semiconductor pellet, 11 …… Operating part, 12 …… Flexible part,
13 ... Fixing part, 14 ... bonding pad, 15 ... bonding wire, 20 ... weight body, 21 ... pedestal, 30 ... control member, 31 ... groove, 40 ... control member, 41 ... Groove, 50 ...
Package, 51 …… Lid, 52 …… Lead terminal, 61-66 ……
Signs, Rx1 to Rx4, Ry1 to Ry4, Rz1 to Rz4 ... Resistance elements.

Claims (4)

(57) [Scope of utility model registration request] 1. A substrate having a flat upper surface, a first detection element arranged along a first axis on the upper surface of the substrate, and a second detection element orthogonal to the first axis on the upper surface of the substrate. A second detection element arranged along an axis, a first lead terminal electrically connected to the first detection element, and a second lead terminal electrically connected to the second detection element. A lead terminal and a package accommodating or fixing each of these components, wherein a detection value of an acceleration component acting in a direction along the first axis is obtained for the first lead terminal, In an acceleration sensor configured to obtain a detection value of an acceleration component acting on the second lead terminal in a direction along the second axis, a direction of the first axis and a second axis. Acceleration characterized by attaching a mark indicating the direction of the to the outer surface of the package Capacitors. 2. The acceleration sensor according to claim 1, wherein a first value for obtaining a detected value of an acceleration component acting in a direction along a third axis orthogonal to both the first axis and the second axis is provided. The third detection element is formed on the upper surface of the substrate, and a third lead terminal electrically connected to the third detection element is further provided,
An acceleration sensor, wherein a mark indicating the direction of the third axis is further attached to the outer surface of the package. 3. The acceleration sensor according to claim 1, wherein an outer fixing portion is fixed to the package, and a weight cone is joined to the inner working portion, and the space between the fixing portion and the working portion. Is a substrate on which a flexible portion having flexibility is formed, the weight cone is supported by the substrate in a displaceable state inside the package, and the first detection element and the second The detection element has a property that when an external force is applied to the weight cone by the action of acceleration to cause the flexible portion to bend, the electrical characteristics change based on the state of the bending that has occurred. . 4. The acceleration sensor according to claim 3, wherein, as the first detection element and the second detection element, a resistance element having a property that electric resistance changes due to bending of the flexible portion is used. Characteristic acceleration sensor.