JP3312158B2 - Semiconductor physical quantity sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor physical quantity sensor. Specifically, the present invention relates to an electrode extraction structure of a semiconductor physical quantity sensor that detects physical quantities such as pressure and acceleration.

[0002]

FIG. 13 is a sectional view showing a conventional capacitance type pressure sensor 51. As shown in FIG. In this pressure sensor 51, an elastically deformable thin-film diaphragm 52 is formed substantially at the center of a frame 53, and a cover 55 is overlaid on the frame 53.
Is joined to. A movable electrode 56 is formed on the upper surface of the diaphragm 52, and the movable electrode 56 is electrically connected to an electrode pad (not shown) on the upper surface of the frame 53. A depression 54 is formed on the upper surface of the diaphragm 52, and a fixed electrode 57 is formed on the inner surface of the cover 55 with a small gap from the movable electrode 56. The fixed electrode 57 is pulled out by an electrode lead-out portion 58 provided on the inner surface of the cover 55, and the crimp pad 5 provided at an end of the electrode lead-out portion 58 is provided.
9 and the crimping pad 61 on the upper surface of the frame 53 are connected by crimping, and the crimping pad 61 is further pulled out by a lead wire 60 on the upper surface of the frame 53, whereby the fixed electrode 57 is connected to another electrode pad 62 at the end of the lead wire 60. Connected.

[0003]

The draw-out wiring 60
The insulating film 6 is formed in a groove-shaped wiring portion 63 formed on the upper surface of the frame 53 from the depression 54 to the side end of the frame 53.
4 are provided. Further, the crimp pads 59 of the electrode lead portions 58 and the crimp pads 61 of the lead wires 60 were each formed in a flat plane as shown in FIG. For this reason, when the crimp pads 59 and 61 are formed, the thickness thereof varies, and when the crimp pads 59 and 61 become thinner than the specified thickness, the two crimp pads 59 and 61 are not sufficiently crimped and the electrical connection is poor. There was a problem of generating.

Further, when the pressure bonding pads 59 and 61 are thicker than the specified thickness, the overlapping thickness of the pressure bonding portions becomes large, and a gap is generated between the frame 53 and the cover 55, so that the bonding cannot be performed sufficiently. As a result, there is a problem that the frame 53 and the cover 55 are peeled off when heat is applied to the pressure sensor 51 or during a manufacturing process such as dicing.

The present invention has been made in view of the above-mentioned drawbacks of the conventional example, and has as its object to join the frame and the cover without gaps and to reliably draw out the fixed electrodes to the electrode pads on the frame. It is in.

[0006]

A semiconductor physical quantity sensor according to the present invention comprises a substrate provided with a physical quantity detecting portion, and a substrate bonded to at least one surface of the substrate. A connection wiring for electrical connection with the other substrate, an electrode for detecting a physical quantity and a connection wiring connected to the electrode are provided on the other substrate, and the two connection wirings are crimped to form the two connection wirings. Surface and side of connection wiring
The semiconductor physical quantity sensor in contact electrically connects the door, the crimping portion of at least one of the connecting wires, pressure
A conductive portion that is electrically connected to the other of the connection wires by attachment
And an escape portion that allows the conductive portion rolled by crimping to escape is provided , and the conductive portion and the escape by crimping are provided .
The conducting portion of the connection wiring provided with
In the blurred state, it is electrically connected to the other connection wiring.
It is characterized in that that.

At this time, it is preferable that at least a part of the crimping portion is made of Au.

In addition, the relief portion is provided in each of the crimping portions of the connection wiring provided on the two substrates, and the connection wiring of the crimping portion of one of the substrates is press-fitted into the relief portion of the other substrate. Alternatively, the connection wires of the two crimping portions may intersect.

The relief portion may be provided in a crimping portion of the connection wiring provided on one of the substrates, and the crimping portion of the connection wiring provided on the other substrate may be formed flat.

For example, the crimping portion provided with the relief portion may have a comb-like, island-like, lattice-like, spiral, concentric or radial pattern.

Further, the connection wiring is formed in a convex shape in a plan view at one of the crimping portions, and a relief portion is provided on the tip side from the leading edge of the connection wiring, and the connection wiring is formed in a concave shape in a plan view at the other crimping portion. And a relief portion is provided on the distal end side from the distal end edge of the connection wiring, and the distal end edge of the connection wiring of the crimping portion having a convex shape in plan view and the distal end edge of the connection wiring of the crimping portion having a concave shape in plan view. May be overlapped and connected.

These semiconductor physical quantity sensors can be capacitance type sensors that take out the change of the detection section as a capacitance change, and can be used as a pressure sensor or an acceleration sensor.

[0013]

In the semiconductor physical quantity sensor according to the present invention, when pressure is applied to the crimping portions, the connection wiring of the rolled crimping portion spreads to the escape portion and escapes. Since the connection wiring of the crimping part is crushed and escapes to the relief part, the crimping parts can be crushed and crimped with a small force, the crimping part can be sufficiently crushed by the pressing force joining the substrates, and the crimping part There is no gap between the two substrates due to being hindered, and the substrates can be securely joined together. In addition, since the connection wires of the crimping portion are crushed, the crimping portions are securely joined to each other, and the two connection wires can be reliably connected without causing a contact failure.

Since Au is soft and easy to be rolled, if at least a part of the crimping portion, for example, the surface of the crimping portion is formed of Au, the crimping portion can be more securely crimped. Further, since Au has a small sheet resistance, it is preferable to use Au for at least a part of the crimping portion.

[0015] Further, a relief portion is provided in each of the crimping portions of the two connection wires, and the connection wire of the crimping portion is press-fitted into the other relief portion so that the two crimping portions are engaged with each other.
The crimping portion can be more securely crimped. Alternatively, even if two crimping portions are crossed, the crimping portion can be more securely crimped.

Further, if one of the crimping portions is formed flat, the crimping can be performed at any place of the flat crimping portion, so that the requirement regarding the alignment accuracy of the crimping portion can be relaxed. it can.

These structures are particularly effective for a capacitance type sensor that takes out a change in a detecting portion as a change in capacitance, and can be applied to a pressure sensor, an acceleration sensor, and the like.

[0018]

FIG. 1 is an exploded perspective view of a capacitance type pressure sensor 1 according to an embodiment of the present invention, with a part cut away. The pressure sensor 1 has a substantially circular, elastically deformable thin-film diaphragm 2 disposed substantially at the center of a frame 3, and the frame 3 and the diaphragm 2 are integrally made of a silicon wafer. The detected pressure is introduced to the lower surface of the diaphragm 2. A glass cover 5 is overlaid on the upper surface of the frame 3, and the periphery thereof is joined to the frame 3 by an anodic bonding method or the like. A depression 4 is formed in the frame 3 so that the diaphragm 2 can be displaced in the thickness direction, and a pressure introduction passage 8 is formed to extend from the side end of the frame 3 to the depression 4. The upper surface of the diaphragm 2 is a movable electrode 6 having conductivity.
It is electrically connected to the electrode pad 9 formed on the exposed portion of the upper surface of the frame 3.

On the inner surface of the cover 5, a fixed electrode 7, an electrode lead-out part (connection wiring) 10 and a crimping part 11 are formed. The fixed electrode 7, the electrode lead-out part 10 and the crimping part 11
For example, it can be integrally formed by sputtering aluminum, Au, or the like. A drawing groove 13 is formed in the upper surface of the frame 3 from the depression 4 to the outer peripheral surface.
It is covered with 2. On the insulating film 12, a crimping portion 14, an electrode pad 15, and a lead wiring (connection wiring) 16 for electrically connecting them are formed. The crimping portion 14, the lead wiring 16, and the electrode pad 15 are integrally formed by, for example, sputtering aluminum or Au.

FIG. 2 is a perspective view of the crimping portion 11 on the cover 5 side and the crimping portion 14 on the frame 3 side of the pressure sensor 1. The crimping portion 11 is a linear conductive portion (connection wiring).
11 a is formed in a comb-like shape, and is formed so as to slightly protrude from the surface of the electrode lead portion 10. A gap is formed between the conductive portion 11a and the conductive portion 11a to serve as a relief portion 11b. The conductive portion 11a is formed, for example, by using a mask having a comb-like pattern during sputtering, or by etching later. On the other hand, the crimping portion 14 on the frame 3 side also has a linear conductive portion (connection wiring) 14 a formed in a comb-like shape, and is formed so as to slightly protrude from the surface of the extraction wiring 16. A gap is formed between the conductive portion 14a and the conductive portion 14a to serve as the escape portion 14b.

When the cover 5 and the frame 3 are joined by pressing the crimping portion 11 and the crimping portion 14 so as to face each other,
As shown in FIG. 3, the conducting portion 11 a of the crimping portion 11 is press-fitted so as to mesh with the relief portion 14 b of the crimping portion 14.
The conducting portion 14a of the crimping portion 14 is a relief portion 14 of the crimping portion 11.
Press-fit so as to mesh with b. At this time, the conductive portion 11a and the conductive portion 14a crushed by the crimping are pushed out to the relief portion 11b between the conductive portions 11a and the relief portion 14b between the conductive portions 14a, and are crushed and crimped to each other. Are joined. Therefore, the extra thickness of the crimping portions 11 and 14 is reduced by the conduction portions 11a and 14a,
The protrusion 3b is absorbed by the protrusion, and as a result, a gap is not generated between the frame 3 and the cover 5 due to being hindered by the crimping portions 11 and 14, so that the frame 3 and the cover 5 can be securely joined. In addition, the crimping portion 11 and the crimping portion 14 are reliably electrically connected to each other by the conductive portions 11a and 14a being crushed and crushed. Therefore, the fixed electrode 7 is not hindered from joining the frame 3 and the cover 5.
Can be reliably drawn out to the electrode pad 15 and connection failure of the capacitance type sensor can be prevented. Also,
The cover 5 does not peel off during the manufacturing process, and the yield of the pressure sensor 1 can be increased, and the pressure sensor 1 with high reliability can be provided. Furthermore, since the crimping portions 11 and 14 do not need to have high thickness accuracy, the manufacturing process can be simplified.

FIG. 4 is a front view showing the structure of the crimping portion 11 according to another embodiment of the present invention. As in this example,
If the crimping portion 11 has a two-layer structure of the chromium layer 18 and the Au layer 17, and the Au layers 17 are crimped together, it is possible to further enhance the crimpability due to its softness.
A similar effect can be obtained by mixing Au (for example, fine Au particles) into the conductive portion 11a or the conductive portion 14a. The crimping portion 14 may have the same electrode structure.

Although not shown, a similar effect can be obtained by a three-layer structure of a chromium layer, a nickel layer, and an Au layer. ,

FIG. 5 is a perspective view showing the structure of the crimping portion 11 and the crimping portion 14 in still another embodiment of the present invention. In the crimping portion 11, the conducting portion 11a is formed in a vertical comb shape, and in the crimping portion 14, the conducting portion 14a is formed in parallel in the horizontal direction. The conducting parts 11a, 14 crimped so that the parts 11a, 14b cross each other and crimped to each other
a is a relief portion 11b or a conduction portion 14a between the conduction portions 11a.
Is crushed by the escape portion 14b. By forming the conductive portions 11a and the conductive portions 14a so as to intersect with each other, the conductive portions 11a and the conductive portions 14a are reliably connected to each other, and connection failures are further reduced. The separated conductive portions 14a are electrically connected via the conductive portion 11a after the pressure bonding.

FIGS. 6 (a) and 6 (b) respectively show
It is a top view of the crimping part 11 and the crimping part 14 in another Example of this invention. The crimping portion 11 on the cover 5 side is formed in a flat planar shape, and the crimping portion 14 on the frame 3 side.
In this case, the conducting portions 14a are formed in a lattice shape. Crimping part 1
When the crimping portion 1 and the crimping portion 14 are crimped, the conductive portion 14a is crushed and spreads to the escape portions 14b scattered in an opening shape, and the crimping portion 14 becomes thin, so that the cover 5 and the frame 3 can be joined without gaps. . Of course, the crimping portion 14 on the frame 3 side is formed in a flat planar shape, and the crimping portion 1 on the cover 5 side is formed.
1 may be formed with a grid-like conductive portion 11a. Thus, the crimping portion 11 of the cover 5 or the frame 3
Of one of the crimping portions 14 of the contact hole 11a
Alternatively, by forming 14a and making the remaining one a flat planar shape, it is not necessary to strictly align the crimping portion 11 and the crimping portion 14, and the requirement for alignment accuracy can be eased.

FIGS. 7A and 7B are plan views showing a crimping portion 11 and a crimping portion 14 according to still another embodiment of the present invention. The crimping portion 11 on the cover 5 side is formed in a flat planar shape, and the crimping portion 14 on the frame 3 side is connected to the island-shaped conductive portion 1.
4a are scattered, and a lattice-shaped relief portion 14b is formed therebetween. After the separated conducting portions 14a are crimped, the conducting portions 14a are crushed and come into contact with each other to be electrically connected.

In addition to the above-mentioned patterns, various shapes are possible for the shape of the crimping portions 11 and 14. Some of the patterns are shown below.

FIG. 8 shows a crimping portion 14 on the frame 3 side in which a spiral conducting portion 14a is formed and a spiral relief portion 14b is formed therebetween.

9 (a) and 9 (b), a circular or semicircular flat crimping portion 1 is attached to the tip of an electrode lead-out portion 10.
1 is provided. The crimping portion 14 includes a conducting portion 14a having a circular shape and a radial shape (a cross shape), and a relief portion 14b surrounded by the conducting portion 14a. Although not shown, a radial conductive portion 14a except for the annular portion may be used, or a conductive portion 14a having a concentric pattern may be used.

Although not shown, one conductive portion is formed in an island shape, the other conductive portion is formed in a grid shape, and one island-shaped conductive portion is formed in the other grid-shaped conductive portion. The crimping area can be widened if it fits into the island-shaped relief portion and is press-fitted.

In the example shown in FIGS. 10 (a) and 10 (b), on the cover 5 side, the conducting portion 11a of the crimping portion 11 is formed in a convex pattern in plan view, and is closer to the distal end than the leading edge of the conducting portion 11a. A relief portion 11b is provided along the edge of the conduction portion 11a. Also, on the frame 3 side, the crimping portion 1
4 are formed in a concave pattern in plan view,
A relief portion 14b is provided along the edge of the conductive portion 14a on the distal end side of the distal end edge of the conductive portion 14a. here,
The width of the convex portion protruding to the center of the conductive portion 11a on the cover 5 side is larger than the inner width of the concave portion recessed at the center of the conductive portion 14a on the frame 3 side. Therefore, the crimping part 1
At the time of crimping of the first and the 14th, as shown in FIG. 11, the leading edges of the two conducting portions 11a and 14a can be crimped over the entire length (or a part of the leading edge) so as to be electrically connected. Can be. At this time, the crushed conductive portions 11a and 14a can spread to the escape portions 11b and 14b on the distal end side of the conductive portions 11a and 14a, and thus are easily crushed by a small pressing force.

FIG. 12 is a sectional view showing an acceleration sensor 21 according to still another embodiment of the present invention. In this acceleration sensor 21, a beam 23 having a resilient mass portion 23 is provided substantially at the center of a rectangular frame 22.
And the mass portion 23 can be freely displaced in its thickness direction. On the upper surface of the mass portion 23, a recess 25 is formed in the frame 23. The mass portion 23, the beam 24 and the frame 22 are integrally formed from a silicon wafer. A movable electrode 26 is formed on the upper surface of the mass portion 23, and is electrically connected to an electrode pad (not shown) on the upper surface of the frame 22. Have been allowed. A glass cover 27 is overlaid on the upper surface of the frame 22, and its peripheral portion is
Is joined to. The movable electrode 26 is provided on the inner surface of the cover 27.
A fixed electrode 28 is provided with a small gap therebetween, and a crimping portion 29 is provided at an end of an electrode lead-out portion 30 drawn from the fixed electrode 28. Also, the frame 22
On the upper surface of the groove is formed a groove 31 extending from the depression 25 to the outer peripheral surface of the frame 22, and the bottom surface of the groove 31 is covered with an insulating film 32. Also, the drawing groove 31
A crimping part 33 and an electrode pad 34 are formed in the inside,
The crimping part 33 and the electrode pad 34 are electrically connected by a lead-out wiring 35 formed integrally with them.

The crimping portion 29 and the crimping portion 33 of the acceleration sensor 21 are formed with the same conducting portions and relief portions as those described in various ways with respect to the crimping portion 11 and the crimping portion 14 of the pressure sensor 1. The cover 27 and the frame 23 can be securely joined without any gap. Further, the crimping portions 29 and 33 are also securely connected. When the acceleration sensor 21 senses acceleration, the mass portion 23 is displaced in the thickness direction, the gap between the movable electrode 26 and the fixed electrode 28 changes, and the capacitance between the electrodes 26, 28 changes. Therefore, by detecting the change in the capacitance, the magnitude of the acceleration applied to the acceleration sensor 21 can be detected. The acceleration sensor 21 can also be used as a vibration sensor for detecting vibration.

In the above embodiment, the case where the silicon substrate (frame) and the glass substrate (cover) are joined has been described, but the material of the substrate is not limited to silicon or glass. For example, the present invention can be applied to a case where a silicon cover is joined to a silicon frame or a case where a glass cover is joined to a frame made of a compound semiconductor such as GaAs. Of course, as a bonding method between the substrates, in addition to the anodic bonding method, a direct bonding method between the silicon substrate and the silicon substrate, a method for bonding the substrates using water glass, and the like can also be used.

The present invention is not limited to a pressure sensor or acceleration sensor having a two-layer structure in which a cover is joined to the upper surface of the frame as in the above embodiment. For example, a glass cover is joined to both upper and lower surfaces of a silicon frame. Needless to say, the present invention can be applied to a pressure sensor or an acceleration sensor having a layer structure, or a pressure sensor or an acceleration sensor having a three-layer structure in which a silicon frame is joined to upper and lower surfaces of a glass cover.

[0036]

According to the present invention, the two substrates can be securely joined without any gap, and the crimping portion provided on one of the substrates and the crimping portion provided on the other substrate can be securely connected. Can be connected to

At this time, a part of the crimping portion of the connection wiring is Au
If it is formed from, the crimping portion can be more securely crimped. The occurrence rate of defective semiconductor physical quantity sensors can be reduced, and a highly reliable sensor can be manufactured.

Further, the two crimping portions can be pressed into each other so as to mesh with each other so that the crimping portions can be more securely crimped, or the two crimping portions can be crossed to more securely crimp the crimping portions.

If one of the crimping portions is formed flat,
The alignment accuracy of the crimping portion can be reduced.

These structures are particularly effective for a capacitance type sensor in which a change in the detection section is extracted as a capacitance change, and can be applied to a pressure sensor, an acceleration sensor, and the like.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view in which a pressure sensor according to an embodiment of the present invention is partially broken.

FIG. 2 is a perspective view showing a crimping portion on a cover side and a frame side of the pressure sensor.

FIG. 3 is a schematic cross-sectional view showing a state when the above-mentioned crimping portions are crimped together.

FIG. 4 is a front view showing a crimping portion on a cover side of a pressure sensor according to another embodiment of the present invention.

FIG. 5 is a perspective view showing a crimping portion on a cover side and a frame side of a pressure sensor according to still another embodiment of the present invention.

FIG. 6A is a plan view showing a crimping portion on a cover side of a pressure sensor according to still another embodiment of the present invention, and FIG. 6B is a plan view showing a crimping portion on a frame side.

FIG. 7A is a plan view showing a crimping portion on a cover side of a pressure sensor according to still another embodiment of the present invention, and FIG. 7B is a plan view showing a crimping portion on a frame side.

FIG. 8 is a plan view showing a crimping portion on a frame side of a pressure sensor according to still another embodiment of the present invention.

FIG. 9A is a plan view showing a crimping portion on a cover side of a pressure sensor according to still another embodiment of the present invention, and FIG. 9B is a plan view showing a crimping portion on a frame side.

FIG. 10A is a plan view illustrating a cover-side crimping portion of a pressure sensor according to yet another embodiment of the present invention, and FIG. 10B is a plan view illustrating a frame-side crimping portion.

FIG. 11 is an explanatory view showing a crimping state of the crimping portion on the cover side and the crimping portion on the frame side in the same.

FIG. 12 is a sectional view showing an acceleration sensor according to still another embodiment of the present invention.

FIG. 13 is a cross-sectional view showing a conventional pressure sensor.

FIG. 14 is a perspective view showing a crimping portion on a cover side and a frame side of the pressure sensor.

[Explanation of symbols]

 3 Frame 4 Movable electrode 5 Cover 7 Fixed electrode 8 Pressure inlet 10 Electrode lead-out part 11, 14 Crimping part 11a, 14a Conducting part 11b, 14b Relief part 12 Leading groove 13 Insulating film 16 Leading wiring

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-138141 (JP, A) JP-A-6-120290 (JP, A) JP-A-4-196450 (JP, A) JP-A-5-196450 180868 (JP, A) JP-A-4-116465 (JP, A) JP-A-1-176932 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01P 15/00-15 / 13 G01L 9/00-9/12 G01L 1/14 H01L 29/84 H01L 21/60

Claims (6)

(57) [Claims] 1. A substrate provided with a physical quantity detection unit, and a substrate bonded to at least one surface of the substrate, and one of the substrates is provided with connection wiring for electrical connection to the outside. An electrode for detecting a physical quantity and a connection wiring connected to the electrode are provided on the other substrate, and the two connection wirings are crimped to make the surfaces of the two connection wirings come into contact with each other to make electrical connection. the semiconductor physical quantity sensor which is connected to the crimping portion of at least one of the connecting wires, the crimp
A conductive portion electrically connected to the other connection wiring and a relief portion where the conductive portion rolled by crimping can be provided , and the conductive portion and the relief portion are provided by crimping.
The connecting portion of the connecting wire is crushed by rolling.
A semiconductor physical quantity sensor electrically connected to the other connection wiring in a state . 2. The relief portion is provided in each of the crimped portions of the connection wires provided on the two substrates, and the connection wire of the crimped portion of one of the substrates is press-fitted into the relief portion of the other substrate. The semiconductor physical quantity sensor according to claim 1, wherein: 3. The semiconductor physical quantity according to claim 1, wherein the relief portions are provided at crimping portions of the connection wires provided on the two substrates, respectively, and the connection wires of the two crimping portions cross each other. Sensor. 4. The crimping portion of the connection wiring provided on one of the substrates is provided with the relief portion, and the crimping portion of the connection wiring provided on the other substrate is formed flat.
4. A semiconductor physical quantity sensor according to claim 1. 5. The crimping portion provided with the relief portion has a comb-like, island-like, lattice-like, spiral, concentric, or radial pattern.
Or the semiconductor physical quantity sensor according to 4. 6. A connecting wire is formed in a convex shape in a plan view at one of the crimping portions, and a relief portion is provided on a tip side from a leading edge of the connecting wire, and the connecting wire is formed in a concave shape in a plan view at the other crimping portion. Forming and providing a relief portion on the distal end side from the distal end edge of the connection wiring, the distal end edge of the connection wiring of the crimping portion having a convex shape in plan view and the distal end edge of the connection wiring of the crimping portion having a concave shape in plan view. The semiconductor physical quantity sensor according to claim 1, wherein the semiconductor physical quantity sensor is connected by overlapping.