JP4241672B2 - Method for manufacturing physical quantity sensor and lead frame - Google Patents

Description

  The present invention relates to a method for manufacturing a physical quantity sensor for measuring the azimuth and direction of a physical quantity such as magnetism and gravity, and a lead frame used for manufacturing the physical quantity sensor.

2. Description of the Related Art Recently, mobile terminal devices such as mobile phones have appeared that have a GPS (Global Positioning System) function for displaying user position information. In addition to this GPS function, by providing a function for accurately detecting geomagnetism and a function for detecting acceleration, it is possible to detect the azimuth, direction, or movement direction in the three-dimensional space of the mobile terminal device carried by the user. it can.
In order to provide the mobile terminal device with the functions described above, it is necessary to incorporate a physical quantity sensor such as a magnetic sensor or an acceleration sensor in the mobile terminal device. Further, in order to be able to detect the orientation and acceleration in the three-dimensional space by such a physical quantity sensor, it is necessary to incline the installation surface of the physical quantity sensor chip.

Here, various types of physical quantity sensors described above are currently provided. For example, a magnetic sensor that detects magnetism and does not tilt the installation surface is known as one of them. This magnetic sensor is mounted on the surface of a substrate and is one magnetic sensor chip (physical quantity sensor chip) that is sensitive to magnetic components of external magnetic fields in two directions (X and Y directions) orthogonal to each other along the surface. And the other magnetic sensor chip that is placed on the surface of the substrate and is sensitive to the magnetic component of the external magnetic field in the direction perpendicular to the surface (Z direction).
This magnetic sensor measures the geomagnetic component as a vector in a three-dimensional space using the magnetic component detected by the pair of magnetic sensor chips.

  However, this magnetic sensor has the disadvantage that the thickness (height relative to the Z direction) increases because the other magnetic sensor chip is placed in a state of being perpendicular to the surface of the substrate. Therefore, in order to reduce the thickness as much as possible, a physical quantity sensor (see, for example, Patent Documents 1 to 3) in which the installation surface is inclined as described above is preferably used.

  Further, as this type of physical quantity sensor, there is an acceleration sensor as described in Patent Document 1. In this one-side beam structure acceleration sensor, the acceleration sensor chip (physical quantity sensor chip) is inclined in advance with respect to the mounting substrate, so that even if the sensor packaging is placed on the surface of the mounting substrate, it depends on the inclination direction. In addition, the sensitivity in the predetermined axis direction can be kept high, and the sensitivity in the other axis direction including the direction along the surface of the substrate can be reduced.

  As described above, the physical quantity sensor in which the physical quantity sensor chips are tilted with respect to each other can be reduced in thickness by reducing the thickness as much as possible, and has various advantages associated with the tilting, and thus will become the mainstream in the future. .

For example, as shown in FIG. 13, this type of physical quantity sensor includes physical quantity sensor chips 81 and 82, a plurality of leads 83 for electrically connecting the physical quantity sensor chips 81 and 82 to the outside, and these. It consists of the resin mold part 84 fixed integrally. The physical quantity sensor chips 81 and 82 are disposed to be inclined with respect to the lower surface (bottom surface) 84 a of the resin mold portion 84.
When manufacturing the physical quantity sensor 80 described above, for example, the stage portions 85 and 86 of the lead frame are inclined by press working or the like, and then the physical quantity sensor chips 81 and 82 are mounted on the stage portions 85 and 86. . Thereafter, a wire 87 for electrically connecting the pads formed on the surfaces of the physical quantity sensor chips 81 and 82 and the leads 83 by wire bonding is disposed. In addition, since the process of inclining the stage parts 85 and 86 and the process of mounting the physical quantity sensor chips 81 and 82 on the stage parts 85 and 86 are performed using separate apparatuses, the stage parts 85 and 86 are inclined. After the step of making the lead frame, it is necessary to transport the lead frame between the devices.
JP-A-9-292408 JP 2002-156204 A JP 2004-128473 A

However, when the lead frame is transported after the stage portion is tilted, the tilt angle of the stage portion may change.
In addition, when the tilt angle of the stage portion changes when manufacturing the physical quantity sensor, the accuracy of the tilt angle of the physical quantity sensor is lowered, and there is a problem that it is impossible to accurately detect the azimuth and acceleration in the three-dimensional space.
An object of this invention is to provide the manufacturing method of the physical quantity sensor which can detect the azimuth | direction and acceleration in a three-dimensional space with high precision, and the lead frame used for this.

In order to solve the above problems, the present invention proposes the following means.
The present invention is a lead frame made of a metal thin plate having a stage portion, a frame portion having leads arranged around the stage portion, and a connecting portion for mutually connecting the stage portion and the frame portion, A part of the connecting portion is made of a shape memory alloy and stored in advance so that the stage portion is inclined at a predetermined angle with respect to the frame portion, and is heated to a restoring temperature of the shape memory alloy. Thus, a lead frame is proposed in which the stage portion is deformed to be inclined at the stored predetermined angle.

When manufacturing a physical quantity sensor using the lead frame according to the present invention, first, in a state where the connecting portion is cooled to a temperature lower than the restoration temperature, the connecting portion is plastically deformed by press working or the like, and the stage portion is thus formed. It arrange | positions flat with respect to a flame | frame part. Then, the physical quantity sensor chip is arranged on the surface of the stage portion, and the physical quantity sensor chip and the lead are electrically connected.
Thereafter, when the connecting portion is heated again to the recovery temperature of the shape memory alloy, the connecting portion is deformed and the stage portion and the physical quantity sensor chip are inclined at the aforementioned inclination angle with respect to the frame portion. Finally, the production of the physical quantity sensor is completed by fixing the stage portion, the physical quantity sensor chip, and the lead integrally with a resin, or housing the stage part, the physical quantity sensor chip, and the lead in a predetermined case.

As described above, by configuring the connecting portion from a shape memory alloy, the physical quantity sensor chip is arranged on the stage portion, or the physical quantity sensor chip and the lead are electrically connected, and then the connecting portion is heated to the restoration temperature. Only the stage part and the physical quantity sensor chip can be inclined at the aforementioned inclination angle. For this reason, when the physical quantity sensor chip is placed on the stage part or until the electrical connection between the physical quantity sensor chip and the lead is completed, for example, when the lead frame is transported, an external force is applied to the stage part. Even if the inclination angle of the stage portion with respect to the frame portion is changed, the accuracy of the inclination angle of the physical quantity sensor chip can be easily improved.
In addition, the stage portion may be arranged flat with respect to the frame portion after the inclination angle of the stage portion is set and before the placement of the physical quantity sensor chip and the electrical connection of the physical quantity sensor chip is completed. Therefore, the physical quantity sensor chip can be arranged and the electrical connection between the physical quantity sensor chip and the lead can be easily performed.

Further, the present invention is characterized in that the stage portion is disposed flat with respect to the frame portion by plastically deforming a part of the connecting portion in a state below the restoration temperature of the shape memory alloy. Proposal of lead frames to be used.

Furthermore, the present invention provides a metal having a stage portion on which a physical quantity sensor chip is placed on the surface, a frame portion having leads arranged around the stage portion, and a connecting portion that connects the stage portion and the frame portion to each other. A lead frame made of a thin plate is prepared, and at least a part of the connecting part is made of a shape memory alloy, and a part of the connecting part is deformed in a state of being heated to a temperature higher than the restoring temperature of the shape memory alloy. A stage tilting step for tilting and storing the stage portion at a predetermined tilt angle with respect to the frame portion, an adhesion step for bonding the physical quantity sensor chip to the stage portion, and the physical quantity sensor chip and the lead. A wiring step of electrically connecting; heating the connecting portion to the restoring temperature; and tilting the stage portion with respect to the frame portion to the stored inclination. Proposes a method for manufacturing a physical quantity sensor, characterized in that it comprises a re-gradient step tilting angle.
According to the physical quantity sensor manufacturing method of the present invention, the stage portion and the physical quantity sensor chip are tilted in the stage tilt process only by performing a re-tilt process for heating the connecting part to the restoration temperature after the bonding process and the wiring process. Can be tilted. For this reason, even when the lead frame is transported, for example, when the lead frame is transported, even if the external force is applied to the stage portion and the inclination angle of the stage portion with respect to the frame portion changes, the physical quantity sensor The accuracy of the tilt angle of the chip can be easily improved.

Further, according to the present invention, between the stage tilting step and the bonding step, a part of the connecting portion is plastically deformed at a temperature equal to or lower than the restoration temperature of the shape memory alloy, and the stage portion is moved with respect to the frame portion A method of manufacturing a physical quantity sensor is provided, which includes a flat step for flatly arranging the physical quantity sensor.
According to the physical quantity sensor manufacturing method according to the present invention, in the bonding process and the wiring process, the stage part is arranged flat with respect to the frame part, thereby arranging the physical quantity sensor chip and the physical quantity sensor chip and the lead. Electrical connection can be made easily.

Furthermore, the present invention provides the above physical quantity sensor manufacturing method, wherein after the wiring step, the lead frame is sandwiched from above and below by a pair of molds, and the resin is defined in the resin forming space defined by the pair of molds. The stage portion is accommodated, and the molten resin is injected into the resin forming space, and the physical quantity sensor chip, the stage portion, a part of the lead frame, and the lead are embedded in the resin and fixed integrally. A step of forming a resin mold portion, and the re-tilting step is performed when the lead frame is sandwiched from above and below by a pair of molds, and the lead frame is heated by the molds during the sandwiching. Thus, a method of manufacturing a physical quantity sensor is proposed in which the stage portion is inclined at the stored inclination angle.
According to the present invention, in the method of manufacturing a physical quantity sensor, a lid that covers the lead frame is bonded to a surface of a plate-like base member on which the lead and the lead frame are placed via low-melting glass. The stage member is stored in the process using the heat that melts the low-melting glass in the process. Has proposed a method of manufacturing a physical quantity sensor characterized by tilting at a tilt angle.

As described above, according to the present invention, at least the connecting portion for inclining the stage portion is formed of the shape memory alloy, so that the inclination angle of the stage portion is set and then the physical quantity sensor chip is mounted. Even if the external force is applied to the stage part and the inclination angle of the stage part changes until the electrical connection of the device or the physical quantity sensor chip is completed, the accuracy of the inclination angle of the physical quantity sensor chip can be easily improved. it can. Therefore, it is possible to provide a physical quantity sensor that can accurately detect the azimuth and acceleration in the three-dimensional space.

Further, according to the present invention, after setting the inclination angle of the stage portion, the stage portion is placed flat with respect to the frame portion when the physical quantity sensor chip is mounted or the physical quantity sensor chip is electrically connected. Therefore, the physical quantity sensor chip can be arranged and the electrical connection between the physical quantity sensor chip and the lead can be easily performed.

1 to 8 show an embodiment of the present invention. A magnetic sensor (physical quantity sensor) according to this embodiment has a direction and a magnitude of an external magnetic field by two magnetic sensor chips inclined with respect to each other. It is manufactured using a lead frame formed by subjecting a thin metal plate made of a Ti—Ni alloy (shape memory alloy) to pressing and etching.
As shown in FIGS. 1 and 2, the lead frame 1 includes two stage portions 7 and 9 for placing magnetic sensor chips (physical quantity sensor chips) 3 and 5 formed in a rectangular plate shape in plan view, and a stage portion. 7 and 9 and a connecting lead (connecting portion) 13 for connecting the stage portions 7 and 9 and the frame portion 11 to each other. The stage portions 7 and 9, the frame portion 11 and the frame portion 11 The connecting lead 13 is integrally formed.

The frame portion 11 includes a rectangular frame portion 15 that is formed in a substantially rectangular frame shape so as to surround the stage portions 7 and 9, and a plurality of frames that protrude inward from the sides 15 a to 15 d of the rectangular frame portion 15. Lead 17.
A plurality of leads 17 are provided on each of the sides 15a to 15d of the rectangular frame portion 15, and are intended to be electrically connected to bonding pads (not shown) of the magnetic sensor chips 3 and 5. .
The two stage portions 7 and 9 are formed in a substantially rectangular shape in plan view so that the magnetic sensor chips 3 and 5 are placed on the surfaces 7a and 9a, respectively, and a pair of sides 15b and 15d of the rectangular frame portion 15 is formed. Are arranged side by side along the longitudinal direction.

The connecting lead 13 protrudes from the sides 15 a to 15 d of the rectangular frame portion 15 toward the one end portions 7 b and 9 b of the stage portions 7 and 9. One end portion of the connecting lead 13 is connected to side end portions located at both ends on the one end portions 7b and 9b side of the stage portions 7 and 9, respectively. Here, the side end portions of the stage portions 7 and 9 indicate end portions in the width direction of the stage portions 7 and 9 orthogonal to the arrangement direction of the two stage portions 7 and 9.
A twisted portion 19 is formed at one end of the connecting lead 13. The twisted portion 19 is formed so as to be easily deformable in order to change the direction of the stage portions 7 and 9 with respect to the frame portion 11 around the axis L1 orthogonal to the thickness direction of the rectangular frame portion 15. Here, each axis L1 is orthogonal to the arrangement direction of the two stage portions 7 and 9.
The twisted portion 19 is formed with, for example, a concave groove that is recessed in the thickness direction of the lead frame 1 by photoetching in advance, a notch portion that is cut out from the width direction of the connecting lead 13, and the like. The twisted portion 19 can be easily deformed. These grooves, notches, etc. may be simultaneously formed when the lead frame 1 is formed on a thin metal plate, for example.

Next, a method for manufacturing a magnetic sensor using the lead frame 1 will be described.
First, a metal thin plate 25 having a plurality of the lead frames 1 described above is prepared (preparation process), and the lead frame 1 is pressed into each lead frame 1 in a state where the lead frame 1 is heated to a Ti-Ni alloy restoration temperature of 300 ° C. or higher. As shown in FIG. 3, the direction of the stage parts 7 and 9 is changed around the axis L1 to incline the frame part 11 at a predetermined inclination angle (stage inclination process). In this stage tilting step, the twisted portion 19 of the connecting lead 13 is deformed, so that the direction of the stage portions 7 and 9 changes to a predetermined tilt angle about the axis L1.

Next, in a state in which the lead frame 1 is cooled to a temperature lower than the restoration temperature of 300 ° C. of the Ti—Ni alloy, the twisted portion 19 is plastically deformed by press working or the like, and as shown in FIG. Are arranged flat with respect to the frame portion 11 (flat step). After this flattening step, the magnetic sensor chips 3 and 5 are bonded to the surfaces 7a and 9a of the stage portions 7 and 9 via silver paste, respectively (bonding step). In this bonding step, the lead frame 1 is heated to 150 to 200 ° C. in order to heat the silver paste.
Then, by wire bonding, wires 21 are arranged between the bonding pads formed on the surfaces 3a and 5a of the magnetic sensor chips 3 and 5 and the leads 17, and the magnetic sensor chips 3 and 5 and the leads 17 are connected. Electrical connection (wiring process). In this wiring process, the lead frame 1 is heated to 230 ° C. to 250 ° C.
Since the heating in the bonding process and the wiring process is lower than the recovery temperature of the Ti—Ni alloy, which is 300 ° C., the twisted portion 19 is not deformed in these processes.

After completion of the wiring process, the twisted portion 19 is deformed by heating the Ti—Ni alloy to a restoring temperature of 300 ° C., so that the stage portions 7 and 9 and the magnetic sensor chips 3 and 5 are framed as shown in FIG. It inclines to the predetermined inclination angle mentioned above with respect to the part 11 (re-inclination process). In this re-tilting step, the lead frame 1 may be heated to 300 ° C. for 5 seconds.
Thereafter, as shown in FIG. 6, the lead frame 1 is sandwiched between the pair of molds E and F from above and below. One mold E has a flat surface E1, and a rectangular frame portion 15 and leads 17 are arranged on the flat surface E1. The other mold F has a recess F2 that is recessed from the surface F1. In a state where the rectangular frame portion 15 is sandwiched between the flat surface E1 and the surface F1 of the pair of molds E and F, the inclined magnetic sensor chips 3 and 5 and the stage portions 7 and 9 are accommodated in the recess F2. Become.

Then, the molten resin is injected into the resin forming space defined by the recesses F2 and the flat surface E1 of the molds E and F, and the magnetic sensor chips 3 and 5, the stage portions 7 and 9, the connecting leads 13 and the leads 17 are resinated. A resin mold part that is buried in and fixed integrally is formed (molding process). In this molding step, a molten resin at 175 ° C. is injected into the resin forming space in 1 minute, and then the resin is cured (cured) in 4 hours while maintaining 175 ° C. That is, since the temperature of the resin in the molding process is also lower than the restoration temperature of 300 ° C. of the Ti—Ni alloy, the twisted portion 19 is not deformed even in the molding process.
Therefore, by performing this molding step, as shown in FIGS. 7 and 8, the magnetic sensor chips 3 and 5 are fixed inside the resin mold portion 25 in a state of being inclined at a predetermined inclination angle. . The resin used here is more preferably a material having high fluidity so that the inclination angle of the magnetic sensor chips 3 and 5 is not changed by the flow of the resin.

Finally, the rectangular frame portion 15 is cut off to cut the connecting lead 13 and the lead 17 individually, and the manufacture of the magnetic sensor 27 is completed.
The resin mold portion 25 of the magnetic sensor 27 manufactured as described above is formed in a substantially rectangular shape in plan view similar to the rectangular frame portion 15 described above. Each lead 17 is electrically connected to the magnetic sensor chips 3 and 5 by metal wires 21, and the back surface 17 b is exposed to the lower surface 25 a side of the resin mold portion 25.

  The magnetic sensor chips 3 and 5 are embedded in the resin mold portion 25 and are inclined with respect to the lower surface 25 a of the resin mold portion 25. Further, the one end portions 3b, 5b of the magnetic sensor chips 3, 5 facing each other face the upper surface 25c side of the resin mold portion 25, and the surfaces 3a, 5a are inclined at an acute angle. Here, the acute angle indicates an angle θ formed between the front surface 7 a of the stage portion 7 and the back surface 9 c of the stage portion 9.

The magnetic sensor chip 3 is sensitive to magnetic components in two directions of an external magnetic field, and these two sensitive directions are directions orthogonal to each other along the surface 3a of the magnetic sensor chip 3 (A direction and B). Direction).
The magnetic sensor chip 5 is sensitive to magnetic components in two directions of an external magnetic field, and these two sensitive directions are directions orthogonal to each other along the surface 5a of the magnetic sensor chip 5 (C direction and D direction).
Here, the A and C directions are parallel to the axis L1 of the stage portions 7 and 9, and are opposite to each other. The B and D directions are orthogonal to the axis L1 and are opposite to each other.

Furthermore, a plane defined by the A and B directions along the surface 3a of the magnetic sensor chip 3 (AB plane) and a plane defined by the C and D directions along the surface 5a of the magnetic sensor chip 5 (C -D plane) intersect each other at an acute angle θ.
Note that the angle θ formed by the AB plane and the CD plane is greater than 0 ° and not greater than 90 °. Theoretically, if the angle is greater than 0 °, the orientation of the three-dimensional geomagnetism Can be measured. However, in order to detect the geomagnetic vector component in the direction perpendicular to the AB plane or the CD plane with a sensitivity of a minimum level or more and to calculate the geomagnetic vector so as to reduce the error, the angle θ is set to 20 ° or more. It is preferable to set the angle to 30 ° or more in order to further reduce the error.
For example, the magnetic sensor 27 is mounted on a substrate in a mobile terminal device (not shown). In this mobile terminal device, the direction of geomagnetism measured by the magnetic sensor 27 is shown on the display panel of the mobile terminal device.

According to the manufacturing method of the lead frame 1 and the magnetic sensor 27 described above, the re-tilting step of heating the lead frame 1 to the recovery temperature of the Ti—Ni alloy is performed after the bonding step and the wiring step, particularly before the molding step. As a result, the stage portions 7 and 9 and the magnetic sensor chips 3 and 5 can be inclined at an inclination angle in the stage inclination step. For this reason, for example, when the lead frame is transported between the completion of the bonding process and the wiring process and the molding process, an external force is applied to the stage parts 7 and 9, and the stage part 7 Even if the inclination angle 9 changes, the accuracy of the inclination angle of the magnetic sensor chips 3 and 5 can be easily improved. Therefore, it is possible to provide the magnetic sensor 27 that can accurately detect the orientation in the three-dimensional space.
In addition, since the stage portions 7 and 9 can be placed flat with respect to the frame portion 11 in the bonding step and the wiring step after the inclination angle of the stage portions 7 and 9 is set in the stage tilting step, the magnetic The arrangement of the sensor chips 3 and 5 and the electrical connection between the magnetic sensor chips 3 and 5 and the lead 17 can be easily performed.

In the above embodiment, the re-inclination step is performed before the lead frame 1 is sandwiched between the two molds E and F. However, the present invention is not limited to this. For example, the two molds E and It may be performed when the lead frame 1 is sandwiched by F. That is, the lead frame 1 may be heated to the restoration temperature of the Ti—Ni alloy by the two molds E and F.
In addition, the lead frame 1 is made of a Ti—Ni alloy, but is not limited to this, and may be made of at least a shape memory alloy. However, when the recovery temperature of the shape memory alloy is lower than the heating temperature of the lead frame 1 in the bonding process or the wiring process, the stage parts 7, 9 are not tilted in the bonding process or the wiring process. It is preferable to hold 9 with a pin or the like.

Further, the entire lead frame 1 is made of a shape memory alloy. However, the present invention is not limited to this, and a twisted portion 19 for tilting at least the stage portions 3 and 5 with respect to the frame portion 11 is made of a shape memory alloy. Just do it.
That is, for example, as shown in FIG. 9, a thin metal plate constituting the lead frame 31 is formed by alternately arranging a shape memory alloy plate 37 and plates 33, 35 made of other metals such as copper in a stripe pattern. It may be done. However, in the case of this configuration, it is necessary to manufacture the lead frame 31 by pressing or punching so that the twisted portion 19 is formed on the shape memory alloy plate.

Further, for example, a shape memory alloy plate material may be fixed only to the twisted portion 19. That is, as shown in FIG. 10, a shape memory alloy plate material 39 may be disposed in the recess 19 b that is recessed from the surface 19 a of the twisted portion 19. In this configuration, when forming the lead frame from a thin metal plate made of another metal such as copper, the recess 19b is formed by pressing or etching, and then the shape memory alloy is formed in the recess 19b. A plate material 39 may be provided. Further, as shown in FIG. 11, a shape memory alloy plate 41 may be bonded to the surface 19 a of the twisted portion 19.
In the case of these configurations, since it is not necessary to form the entire lead frame from a shape memory alloy, the lead frame can be manufactured at low cost.

Furthermore, the magnetic sensor chips 3 and 5, the leads 17, and the stage portions 7 and 9 are integrally fixed by the resin mold portion 25. However, the present invention is not limited to this, for example, as shown in FIG. It may be accommodated in the internal space of the box 51 as a ceramic package. Here, the box 51 includes a plate-like base member 55 on which the lead frame 53 is placed and a lid 57 that covers the lead frame 53 placed on the base member 55.
In the case of this configuration, for example, the lead frame 53 may be bonded to the surface 55a of the base member 55 in advance via a low melting point glass 59 or the like, and at this time, the stage tilting process of the above embodiment may be performed simultaneously. good. That is, if the heat for melting the low melting point glass 59 for bonding the lead frame 53 is equal to or higher than the recovery temperature of the shape memory alloy, the stage portions 7 and 9 may be inclined using this heat.

In the case of this configuration, for example, as in the above-described embodiment, after performing the flattening process, the bonding process, and the wiring process, the periphery of the surface 55a of the lead 17 and the base member 55 through the low melting point glass 61 or the like The lid body 57 may be adhered to this, and at this time, the re-inclination step of the above embodiment may be performed simultaneously. That is, the stage portions 7 and 9 and the magnetic sensor chips 3 and 5 may be inclined again by using heat for melting the low melting point glass 61.
In the case of the above-described configuration, the stage tilting process and the re-tilting process can be performed simultaneously with the process of attaching the lead frame 53 to the box body 51 and housing the lead frame 53 in the box body 51. Efficiency can be improved easily.

Furthermore, in the bonding process, the magnetic sensor chips 3 and 5 are bonded to the surfaces 7a and 9a of the stage portions 7 and 9 via the silver paste. However, the present invention is not limited to this. 9 may be adhered.
In the above embodiment, the lead frames 1, 31, 53 including the two stage portions 7 and 9 have been described. However, the present invention is not limited thereto, and the lead frame including one or three or more stage portions is used. You may apply.

Furthermore, although the frame portion 11 includes the rectangular frame portion 15 formed in a substantially rectangular frame shape in plan view, the frame portion is not limited to this, and the frame body portion projects the lead 17 at least inward. As long as it has. That is, this frame part may be formed in a circular shape in a plan view, for example, and may have a three-dimensional structure.
Further, the stage portions 7 and 9 are formed in a substantially rectangular shape in plan view, but the present invention is not limited to this, and at least the magnetic sensor chips 3 and 5 are formed so as to be capable of being bonded to the surfaces 7a and 9a. That's fine. That is, the stage portions 7 and 9 may be formed in, for example, a circular shape or an oval shape in a plan view, or may be provided with holes penetrating in the thickness direction or formed in a mesh shape. .

  In the embodiment of the present invention, the description is applied to a magnetic sensor that detects a magnetic direction in a three-dimensional space. However, the present invention is not limited to this, and a physical quantity sensor that measures at least the azimuth and orientation in a three-dimensional space. If it is. Here, the physical quantity sensor may be, for example, an acceleration sensor equipped with an acceleration sensor chip that detects the magnitude and direction of acceleration instead of the magnetic sensor chip.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

It is a top view showing a lead frame concerning one embodiment of the present invention. FIG. 2 is a side sectional view of the lead frame of FIG. 1. FIG. 5 is a side cross-sectional view illustrating a method for manufacturing a physical quantity sensor using the lead frame of FIG. 1. FIG. 5 is a side cross-sectional view illustrating a method for manufacturing a physical quantity sensor using the lead frame of FIG. 1. FIG. 5 is a side cross-sectional view illustrating a method for manufacturing a physical quantity sensor using the lead frame of FIG. 1. FIG. 5 is a side cross-sectional view illustrating a method for manufacturing a physical quantity sensor using the lead frame of FIG. 1. It is a top view which shows the magnetic sensor manufactured with the lead frame of FIG. It is a sectional side view of the magnetic sensor of FIG. The lead frame which concerns on other embodiment of this invention is shown, (a) is a schematic plan view, (b) is GG arrow sectional drawing of (a). In the lead frame concerning other embodiments of the present invention, it is an expanded sectional view showing a twist part. In the lead frame concerning other embodiments of the present invention, it is an expanded sectional view showing a twist part. It is a schematic sectional drawing which shows the method of manufacturing a magnetic sensor using the lead frame which concerns on other embodiment of this invention. It is a side view which shows the outline of the conventional magnetic sensor.

Explanation of symbols

1, 31, 53 ... lead frame, 3, 5 ... magnetic sensor chip (physical quantity sensor chip), 7, 9 ... stage portion, 7a, 9a ... surface, 11 ... frame portion, 13 ... Connection lead (connection part), 17 ... Lead, 39, 41 ... Plate material, 27 ... Magnetic sensor (physical quantity sensor)

Claims (6)

A lead frame made of a thin metal plate having a stage part, a frame part including leads arranged around the stage part, and a connecting part that interconnects the stage part and the frame part,
At least a part of the connecting portion is made of a shape memory alloy, and the stage portion is stored in advance so as to be inclined at a predetermined angle with respect to the frame portion, and is heated to the restoring temperature of the shape memory alloy. Thus, the stage portion is deformed so as to be inclined at the stored predetermined angle. 2. The stage portion is arranged flat with respect to the frame portion by plastically deforming a part of the connecting portion in a state below the restoration temperature of the shape memory alloy. Lead frame.
A lead frame comprising a metal thin plate having a stage portion on which a physical quantity sensor chip is placed on the surface, a frame portion including leads disposed around the stage portion, and a connecting portion that interconnects the stage portion and the frame portion. Preparing at least a part of the connecting portion with a shape memory alloy; and
A stage tilting step in which a part of the connecting part is deformed in a state of being heated to a temperature equal to or higher than the restoring temperature of the shape memory alloy, and the stage part is tilted with respect to the frame part at a predetermined tilt angle and stored
Bonding step of bonding the physical quantity sensor chip to the stage part;
A wiring step of electrically connecting the physical quantity sensor chip and the lead;
A physical quantity sensor manufacturing method comprising: a re-inclination step of heating the connecting portion to the restoring temperature and inclining the stage portion to the stored inclination angle with respect to the frame portion. Between the stage tilting step and the adhering step, a flat step of plastically deforming a part of the connecting portion below the restoring temperature of the shape memory alloy and arranging the stage portion flat with respect to the frame portion The method of manufacturing a physical quantity sensor according to claim 3, further comprising: After the wiring step, the lead frame is sandwiched from above and below by a pair of molds, the stage portion is accommodated in a resin formation space defined by the pair of molds, and further melted in the resin formation space A step of injecting the formed resin and forming the physical quantity sensor chip, the stage portion, a part of the lead frame, and a resin mold portion that embeds the lead inside the resin and integrally fixes the resin,
The re-inclination step is performed when the lead frame is sandwiched from above and below by a pair of molds,
5. The method of manufacturing a physical quantity sensor according to claim 3, wherein the lead frame is heated by the mold during the sandwiching to incline the stage portion at the stored inclination angle. 6. . In the re-tilting step, a lid that covers the lead frame is bonded to a surface of a plate-like base member on which the lead and the lead frame are placed via a low melting point glass, and the base member and the lid Is performed simultaneously with the step of forming a ceramic package containing the lead frame,
5. The method of manufacturing a physical quantity sensor according to claim 3, wherein the stage portion is inclined at the stored inclination angle by utilizing heat for melting the low-melting glass in the step.

Images