JP2001076599A - Method of manufacturing for micro-reed switch, micro- reed switch body, and micro-reed switch member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a micro-reed switch further miniaturizable than the conventional reed switch, allowing mass production, and capable of improving switch responsiveness by applying the micromachining technique of silicon. SOLUTION: A recess 110 is formed on a silicon substrate 102, and an elastic cantilever 112 extended from one side face is arranged. A wiring pattern made of a magnetic thin film and a moving contact point 116 are formed on the cantilever 112. A glass substrate 101 connected to one side face of the silicon substrate 102 is provided with a fixed contact point (forming part of a second electrode section) 109 relatively separated from the moving contact point 116 invariably and brought into contact with the moving contact point 116 when the magnetic flux flows through the wiring pattern and moving contact point 116 and the contilever 112 is pulled as a magnet (external magnetic field) approaches.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a micro reed switch using a silicon substrate, a micro reed switch body, and a method for manufacturing a micro reed switch member.

[0002]

2. Description of the Related Art FIG. 18 is an exploded perspective view of a conventional reed switch 10, and FIG. 19 is a sectional view after assembly.
The conventional reed switch 10 includes a pair of magnetic tongue pieces 12 and 13 sealed in a glass tube 11, and the magnetic tongue pieces 12 and 13 are contact points whose tips are separated from each other. It is formed as a switch piece. When a magnet (not shown) approaches the reed switch 10, magnetic flux flows through both magnetic tongue pieces 12, 13, and the magnetic tongue pieces 12, 13 are attracted to each other to be in a closed state, and the magnet (not shown) Is reed switch 1
When it is away from zero, the contacts are separated by the elasticity of the magnetic tongue pieces 12 and 13 to be in an open state.

[0003]

However, the reed switch 10 as described above has a problem that it is difficult to mass-produce in a production process, and the cost is high. Also, the magnetic tongue piece 12,
Since 13 is formed by press working,
Not only is there a limit to the miniaturization of the movable part including the contacts,
It is difficult to further improve the responsiveness of the switch operation.

The magnetic tongue pieces 12 and 13 are connected to the lead wire portion 12.
a, 13a are formed integrally, that is, the magnetic tongue pieces 12, 13 and the lead wire portions 12a, 13a are formed of one magnetic material, and the lead wire portions 12a, 13a
Processing (bending, cutting, etc.) affects the characteristics of the reed switch, and adversely affects the glass tube sealing portion at the time of bending the lead wire portion. Moreover, since the glass tube is used bare when used, there is a problem of poor durability.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a first object of the present invention is to apply a microfabrication technique of silicon so that it can be made smaller than a conventional reed switch and can be mass-produced. It is another object of the present invention to provide a micro reed switch capable of improving the switch responsiveness.

A second object of the present invention is to provide a micro reed switch in which the movable portion and the lead wire portion are separated from each other, so that it is not necessary to consider an adverse effect on the characteristics due to the processing of the lead wire portion.

A third object is to provide a micro reed switch body which can improve the reliability as a switch by electrically connecting the micro reed switches in parallel.

A fourth object of the present invention is to provide a method for manufacturing a reed switch member capable of obtaining the above micro reed switch.

[0009]

According to a first aspect of the present invention, a recess is formed on one side of a silicon substrate, and the recess extends from the one side on the recess. The released elastic movable piece is arranged, and the movable piece includes
A first electrode portion including a magnetic thin film layer is formed, and the first electrode portion has a contact surface formed on a side surface opposite to a side surface facing the recess, and is joined to one side surface of the silicon substrate. The other members are always separated from the first electrode unit, and when a magnetic flux flows through the first electrode unit in response to a change in an external magnetic field, the first electrode unit is attracted. A second electrode portion is provided in contact with the contact surface of the first electrode portion. Wiring for connecting the first electrode portion and the second electrode portion to an external electric element is provided on the silicon substrate and other members. The gist of the present invention is the micro reed switch described above.

According to a second aspect of the present invention, in the first aspect, the second electrode portion provided on the other member includes a micro reed switch which is a fixed electrode portion. According to a third aspect of the present invention, in the first aspect, the silicon substrate is a first silicon substrate, the movable piece is a first movable piece, the recess is a first recess, and the magnetic thin film layer is a first magnetic thin film layer. 2. The micro reed switch according to claim 1, wherein the other member is formed of a second silicon substrate, a second recess is formed on one side surface of the second silicon substrate, and the second member is formed on the second recess. Is provided with a second movable piece having elasticity extending from the same side surface, a second electrode portion including a second magnetic thin film layer is formed on the second movable piece, and the second electrode portion is provided with a second electrode portion. The gist of the present invention is a micro reed switch in which a contact surface that is detachable from the contact surface of the first electrode portion is formed on a side surface opposite to a side surface facing the two concave portions.

According to a fourth aspect of the present invention, there is provided a micro reed switch according to the second aspect, wherein the other member is made of glass. Claim 5
The gist of the present invention is that in any one of the first to fourth aspects, the silicon substrate and the other members are made of a resin-molded micro reed switch.

According to a sixth aspect of the present invention, there is provided a micro reed switch body comprising a plurality of the micro reed switches according to any one of the first to fifth aspects connected in parallel with each other. It is.

According to a seventh aspect of the present invention, a p-type single-crystal silicon substrate has a p-type single crystal silicon
Forming a p-type silicon layer in the epitaxial growth layer by forming an epitaxial growth layer made of n-type single crystal silicon on the upper surface of the p-type single crystal silicon substrate; A step of forming a p-type silicon layer for forming an opening in the epitaxial growth layer by the addition, and a portion which is partitioned by the silicon layer for forming an opening and becomes a movable piece, and in which the movable piece extends Forming a magnetic thin film layer and a wiring pattern along, and after forming a wiring pattern connected to the magnetic thin film layer, excluding a portion corresponding to the p-type silicon layer for forming the opening, a protective film Forming each of the p-type silicon layers into a porous silicon layer by performing anodizing treatment with the protective film formed. A microreed switch member comprising: a step of removing the porous silicon layer by alkali etching to form a portion where the porous silicon layer has been formed, and a step of subsequently removing the protective film. Of the present invention.

(Operation) According to the first aspect of the present invention,
When a magnet (not shown) or the like approaches the movable piece that is always separated from the second electrode portion and the external magnetic field changes, magnetic flux flows through the first electrode portion in accordance with the change in the external magnetic field, and When the movable piece having one electrode is drawn, the contact surface of the first electrode portion comes into contact with the contact surface of the second electrode portion to be in a closed state.

Further, when the external magnetic field returns as in the state where the first electrode portion is separated from the second electrode portion, the movable piece returns due to its own elasticity, and the first electrode portion and the second electrode portion return. The electrodes are separated from each other to be in an open circuit state.

The micro reed switch according to the first aspect can be easily miniaturized and mass-produced by a silicon fine processing technique, and the switch responsiveness is improved. Further, the lead wire portion is electrically connected to the first electrode portion of the movable piece. Therefore, since the lead wire portion and the first electrode portion of the movable piece are separated from each other, it is not necessary to consider an adverse effect due to the processing of the lead wire portion.

According to the second aspect of the present invention, when the magnetic flux flows in response to a change in the external magnetic field and the movable piece having the first electrode is attracted to the first electrode portion of the movable piece, the first electrode portion of the first piece is moved. The contact surface of the electrode unit comes into contact with the contact surface of the fixed electrode as the second electrode unit to be in a closed state.

According to the third aspect of the present invention, the first movable piece having the first electrode portion is always separated from the second movable piece having the second electrode portion. When the magnetic flux flows through the first and second electrode portions in response to the change in the external magnetic field, the first and second movable pieces that have been separated from each other move when the two movable pieces having the respective electrode portions are attracted to each other. The contact surfaces of the two electrode portions come into contact with each other to be in a closed state.

When the external magnetic field returns as in the case where the two electrode parts are separated from each other, the first movable piece and the second movable piece return by their own elasticity, and the first electrode part and the second electrode part return. The parts are separated from each other.

According to the fourth aspect of the present invention, the other member is made of glass, so that the fixed electrode as the second electrode portion is provided on the surface of the same glass material, thereby realizing the function of the second aspect. .

According to the fifth aspect of the invention, the durability can be improved by resin-molding the silicon substrate and other members, unlike the case where a conventional glass tube is used.

According to the invention of claim 6, according to claim 1,
By connecting a plurality of the micro reed switches according to any one of claims 5 to 5 in parallel with each other,
Switch reliability can be improved.

According to the seventh aspect of the present invention, a p-type silicon layer is formed in a predetermined region on the surface side of the p-type single crystal silicon substrate by adding impurities. Next, the p-type silicon layer is embedded in the epitaxial growth layer by forming an epitaxial growth layer made of n-type single crystal silicon on the upper surface of the p-type single crystal silicon substrate.

Subsequently, a p-type silicon layer for forming an opening is formed in the epitaxial growth layer by adding an impurity, and then a portion which is partitioned by the silicon layer for forming the opening to become a movable piece. Then, a magnetic thin film layer is formed along the direction in which the movable piece extends.

Next, a protective film is formed except for a portion corresponding to the p-type silicon layer for forming the opening. continue,
By performing anodizing treatment with the protective film formed, each of the p-type silicon layers is changed to a porous silicon layer. Then, by removing the porous silicon layer by alkali etching, the portion where the porous silicon layer was located is hollowed out. Then, the protective film is removed.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described below in detail with reference to FIGS.

FIG. 1 schematically shows a configuration of a micro reed switch MS of the present embodiment. The micro reed switch MS includes a glass substrate 101 and a micro reed switch member M disposed on the glass substrate 101.
It comprises Sa, a glass substrate 101, a molded part 103 in which a micro reed switch member MSa is molded, and the like.

As shown in FIG. 3, a substantially rectangular concave portion 104 obtained by HF etching is formed at the center of a glass substrate 101 having a flat upper surface. As shown in FIG.
01 is a pair of bonding pads 1 on the upper surface in the longitudinal direction.
Reference numerals 05 and 106 are formed by a physical film forming method such as sputtering of Al, Au, or the like, or vacuum evaporation. Also, from one bonding pad 105 to the edge of the concave portion 104,
The wiring pattern 107 is formed by extending a nickel-iron alloy by a physical film forming method such as sputtering or vacuum evaporation. Also, the other bonding pad 106 can be
The wiring pattern 108 is formed by extending a nickel-iron alloy by a physical film forming method such as sputtering or vacuum evaporation to a substantially central portion of the bottom surface in the substrate 04. The wiring pattern 1
The nickel / iron alloy forming the layers 07 and 108 has magnetism, and therefore, the wiring patterns 107 and 108 constitute a magnetic thin film.

The tip of the wiring pattern 108 is
The fixed contact 109 is formed by a physical film forming method such as sputtering of u, Ag or the like or vacuum deposition. The fixed contact 109 forms a fixed electrode portion, and the fixed contact 109 and the wiring pattern 108 form a second electrode portion.

Next, the micro reed switch member MSa will be described. As shown in FIGS. 1 and 2, a p-type single crystal silicon substrate (hereinafter, simply referred to as a silicon substrate.
Unlike the manufacturing procedure described later, in the description of the configuration, a description will be given as a silicon substrate individually scribed from a wafer. ) 102 is made of a p-type silicon single crystal having a plane orientation of (110), and has a porous p-type
A substantially rectangular concave portion 110 obtained by subjecting a layer made of mold silicon to alkaline etching is formed. The recess 110 has a substantially U-shaped opening 111, and the opening edge when a cantilever 112 described later is temporarily omitted is formed to have substantially the same size as the recess 104.

FIG. 5 is an enlarged sectional view of the silicon substrate 102. As shown in FIG. An elastic cantilever 112 as a lever structure is disposed in the recess 110 so as to be vertically displaceable. As shown in FIG. 5, the cantilever 112 is mainly composed of an epitaxially grown layer 113 of n-type single crystal silicon, and extends beyond the center of the recess 110 in the longitudinal direction. The cantilever 112 constitutes a movable piece.

On the upper surface of the epitaxial growth layer 113,
A thin oxide film (SiO2 film) 114 is formed as an insulating layer. A wiring pattern 115 is formed on the upper surface (in FIG. 5) of the oxide film 114 by a physical film forming method such as sputtering or vacuum evaporation of a nickel-iron alloy. The wiring pattern 115 extends in the longitudinal direction from the tip of the cantilever 112 to one end of the silicon substrate 102. Therefore, the wiring pattern 11
The nickel-iron alloy forming 5 is magnetic and therefore
The wiring pattern 115 forms a magnetic thin film layer.

At the tip of the cantilever 112, a movable contact 116 is formed on the wiring pattern 115 by a physical film forming method such as sputtering of Au, Ag or the like or vacuum deposition.
Are formed and are electrically connected to the wiring pattern 115. Wiring pattern 115 and movable contact 116
Constitutes a first electrode portion. And the movable contact 1
Reference numeral 16 has a contact surface that contacts the fixed contact 109.

The silicon substrate 102 is a glass substrate 1
01, as shown in FIG.
The opening edges of 110 are correspondingly arranged and joined using anodic bonding technology. The wiring pattern 115 is in contact with the wiring pattern 107, that is, the two 115 and 107 are electrically connected. The movable contact 116 on the cantilever 112 is
It is always spaced apart so as to oppose the fixed contact 109 in the inside 04. The anodic bonding is performed in a vacuum chamber, and the space formed by the concave portions 104 and 110 is vacuum-sealed.

As shown in FIG. 1, the micro reed switch MS is formed by bonding the glass substrate 101 and the silicon substrate 102 of the micro reed switch member MSa to the bonding pad 105 of the glass substrate 101.
Leads 119 and 120 disposed on the opposite side to 106
Are electrically connected through wires 121 and 122. Also, the base ends of the leads 119 and 120 and the wire 12
The glass substrate 101 and the silicon substrate 102, including the components 1 and 122, are molded by a molding portion 103 made of a molding synthetic resin such as an epoxy resin.

The dimensions of each part of the micro reed switch member MSa in this embodiment are as follows.
That is, the thickness t and the width w of the silicon substrate 102 (including the epitaxial growth layer 113) are such that t = about 50.
0 μm, w = 500 μm to 1000 μm. The thickness, width and length of the cantilever 112 are each about 10 μm,
It is about 200 μm and about 300 μm. The clearance between the bottom of the cantilever 112 and the inner bottom of the recess 110 is about 1
0 μm. Oxide film 114 has a thickness of about 0.5 μm.

The size of the glass substrate 101 is large enough to support the silicon substrate 102. Further, when the magnet disposed outside the micro reed switch MS approaches, the concave portion 104 of the glass substrate 101 causes the magnetic flux to pass through the wiring patterns 108 and 115, so that the cantilever 112 is displaced to the fixed contact 109 side. , The movable contact 116 has a sufficient distance to contact the fixed contact 109.

When a magnet approaches the outside of the micro reed switch MS, the wiring pattern 10 which is a magnetic thin film
The magnetic flux passes through 8,115. As a result, FIG.
, The distal end of the cantilever 112 is displaced downward against the elastic force of the cantilever 112,
Contacts the fixed contact 109 side to close the circuit.

When the magnet approaching the outside of the micro reed switch MS is separated, the magnetic flux does not pass through the wiring patterns 108 and 115, which are magnetic thin films, so that the cantilever 112 itself is cantilevered in FIG. Beam 11
2 is displaced upward, that is, the movable contact 116
Is separated to the side opposite to the fixed contact 109 and is opened.

The operation and effect of the micro reed switch MS configured as described above will be described. (1) In the present embodiment, the concave portion 110 is formed on one side surface of the silicon substrate 102, and the elastic cantilever 112 (movable piece) extending from the one side surface is arranged in the concave portion 110. The cantilever 112 has the wiring pattern 11
5 (magnetic thin film layer) and a first electrode portion including the movable contact 116 were formed, and the movable contact 116 was formed as a contact surface located on the side opposite to the side facing the recess 110. Further, the glass substrate 101 (another member) bonded to one side surface of the silicon substrate 102 is always relatively separated from the movable contact 116 forming a part of the first electrode portion, When the magnetic flux flows through the wiring pattern 115 and the movable contact 116 according to the approach of the magnet (external magnetic field), when the cantilever 112 is drawn, the movable contact 1
A fixed contact 109 (which constitutes a part of the second electrode portion) that comes into contact with 16 was provided.

On the glass substrate 101, bonding pads 105 and 106 for connecting the wiring patterns 108 and 115 to an external electric element, and wires 12
1, 122 and leads 119 and 120 were provided.

As a result, the micro reed switch MS can be easily reduced in size and mass-produced by the silicon fine processing technology. Moreover, since the size and weight can be reduced, the switch responsiveness can be improved.

(2) The wiring pattern 115 constituting a part of the first electrode portion on the cantilever 112 is a glass substrate 101
It is electrically connected to the lead 119 via the upper wiring pattern 107 and the wire 121. Therefore, the lead 119 (corresponding to the lead wire portion) and the cantilever 112 are provided.
Of the lead 11
It is not necessary to consider the adverse effects of the processing of No. 9.

(Method of Manufacturing Micro Reed Switch Member MSa) Next, the micro reed switch M of the present embodiment will be described.
Micro reed switch member MSa constituting S
Will be described with reference to FIGS.

First, as shown in FIG. 6, a rectangular parallelepiped p-type single-crystal silicon substrate (110) (in this manufacturing procedure, for convenience of explanation, the silicon substrate 1
02 is described in a wafer state) 102, and a mask (not shown) is formed on the surface of the silicon substrate 102. Next, boron is implanted into the silicon substrate 102 by ion implantation or the like, and the boron is thermally diffused. As a result, as shown in FIG. 7, a p-type silicon layer 131 is formed substantially at the center of the silicon substrate 102.

Next, as shown in FIG. 8, on the upper surface of the silicon substrate 102 on which the p-type silicon layer 131 is formed,
An epitaxial growth layer 113 made of n-type single crystal silicon is formed by vapor phase growth. As a result, the p-type silicon layer 131 is buried in the epitaxial growth layer 113. Thereafter, the epitaxial growth layer 113
A mask (not shown) is formed on the surface of the silicon substrate 102 on which is formed. Further, a substantially U-shaped opening is formed in a predetermined region of the mask by photoetching.

Next, boron is implanted into the silicon substrate 102 by ion implantation or the like, and the boron is thermally diffused. As a result, as shown in FIG.
A substantially U-shaped p-type silicon layer 132 for forming an opening is formed in the epitaxial growth layer 113. This p-type silicon layer 132 reaches the depth of the buried p-type silicon layer 131.

Next, the silicon substrate 102 is heated in oxygen or air to form an oxide film 1 on the upper surface thereof.
14 is formed. Next, a wiring pattern 115 is formed by subjecting the silicon substrate 102 to sputtering or vacuum deposition of a nickel-iron alloy and then performing photolithography. Subsequently, the oxide film 115
A movable contact 116 is formed on the upper surface by performing sputtering, vacuum deposition, or the like of Au, Ag, or the like, and then performing photolithography.

Next, SiN or Si3 is deposited by CVD or the like.
By depositing N4 or the like, the wiring pattern 11 is formed on the upper surface of the silicon substrate 102 as shown in FIG.
5, passivation film 1 covering movable contact 116
33 are formed. In the passivation step,
A substantially U-shaped opening 13 is formed in the passivation film 133.
4 are formed. Then, the upper surface of the p-type silicon layer 132 is exposed by removing the oxide film 114 on the upper surface of the p-type silicon layer 132.

Next, the upper surface of the passivation film 133 is entirely covered with a metal protective film 1 made of tungsten (W) by a physical film forming method such as sputtering or vacuum evaporation.
Cover with 35. At this time, the metal protective film 13 is located immediately below the opening 134 (more precisely, the opening of the oxide film 114).
5 and epitaxial growth layer 113 of silicon substrate 102
W silicide is formed at the interface in contact with. W (tungsten) and W silicide forming the metal protective film 135 have HF resistance. After this,
As shown in FIG. 12, a substantially U-shaped opening 136 is formed in a portion corresponding to the upper surface of the p-type silicon layer 132 by photolithography.

Then, as shown in FIG. 13, a silicon substrate 102 is treated with a hydrofluoric acid aqueous solution 1 as a high-concentration HF-based solution.
Then, in this state, a current is made to flow using the silicon substrate 102 as an anode and the metal protective film 135 as a counter electrode.
That is, anodization is performed. Note that in FIG.
Represents a DC power supply. In this embodiment, a formation voltage of 0.6 V or more is not applied, and a most efficient voltage is applied.

By selectively making only the portions of the p-type silicon layers 131 and 132 porous by the anodization as described above, the portions are changed to the porous silicon layer 137. At this time, the portion covered with the metal protective film 135 is prevented from being eroded by the hydrofluoric acid aqueous solution by the metal protective film 135. In the opening 134, the metal protective film 13
5 and epitaxial growth layer 113 of silicon substrate 102
Since an HF-resistant W silicide is formed at the interface with, the hydrofluoric acid aqueous solution does not erode from the interface.

Next, the porous silicon layer 137 is anisotropically etched by performing alkali etching with TMAH (tetramethylammonium hydroxide). The p-type silicon layers 131 and 132 are easily dissolved in alkali by being made porous through anodization. As a result, a cavity 139 is easily formed in the portion where the porous silicon layer 137 was located (FIG. 14).
reference). Finally, the unnecessary metal protective film 135 is removed by etching such as plasma etching, and the passivation film 133 is removed by a known method, whereby the micro reed switch member MSa shown in FIG. 1 is obtained.

According to the method of manufacturing the micro reed switch member MSa of this embodiment, the following operation and effect can be obtained. (3) Micro reed switch member M in the present embodiment
According to the manufacturing method of Sa, the p-type silicon layer 131 is formed in a predetermined region on the surface side of the silicon substrate 102 by adding boron (impurity), and then the n-type silicon layer 131 is The p-type silicon layer 131 was embedded in the epitaxial growth layer 113 by forming the epitaxial growth layer 113 made of single crystal silicon.

Then, by boron (adding impurities),
Forming a p-type silicon layer 132 for forming an opening in the epitaxial growth layer 113;
And a wiring pattern 115 along the direction in which the movable piece extends.
(Magnetic thin film layer) was formed.

Next, the passivation film 1 is removed except for the portion corresponding to the p-type silicon layer 132 for forming the opening.
33, a metal protective film 135 (protective film) was formed. next,
With the passivation film 133 and the metal protection film 135 formed, anodization treatment is performed to form each p-type silicon layer 13.
1,132 was changed to a porous silicon layer 137. Then, the porous silicon layer 137 is removed by alkali etching.
The cantilever 112
Was formed.

By doing so, the micro reed switch member MSa can be manufactured easily and in large quantities. (4) The metal protective film 135 made of W (tungsten) in this embodiment has a high melting point and a thermal expansion coefficient of SiN.
The passivation film 133 of Si3N4 or the like and the epitaxial growth layer 113 of the silicon substrate 102 are close to and closely adhered to each other, so that they do not peel off.

(5) Since the p-type silicon layers 131 and 132 are formed in a predetermined area in advance and then anodized, the p-type silicon layers 131 and 132 are compared with the conventional method in which the surface of the silicon substrate 102 is directly anodized. Therefore, the shape and the depth of the anodized portion hardly vary.

(6) Since the epitaxial growth layer 113 is formed on the p-type silicon layer 131, the formation is not particularly difficult. (7) Since the anodization is performed after the completion of the passivation step, the metal protective film 135 can be formed in a state where the cavity 139 is not formed. Therefore, the formation of the metal protective film 135 is facilitated.

In other words, since the metal protective film 135 does not enter the cavity 139, there is no need to perform a complicated removal operation. Further, since the alkaline etching is also performed after the completion of the passivation step, there is no fear that the wiring pattern 115 is contaminated by the etchant. As described above, according to this manufacturing method, simplification of the process and simplification of the operation when manufacturing the micro reed switch member MSa can be achieved.

(8) Further, the porous silicon layer 137
With this manufacturing method for removing silicon, the silicon substrate 102
There is an advantage that the plane orientation is not particularly limited.
In addition, the manufacturing method of the present embodiment (including an anodizing method using W (tungsten) as the metal protective film 135)
Is basically similar to a manufacturing process of a bipolar IC using, for example, W (tungsten) as a gate material of the IC. Therefore, there is an advantage that the micro reed switch member MSa can be easily reduced in size, weight, and mass-produced. This is advantageous in realizing miniaturization and high speed of the micro reed switch MS. (Second Embodiment) Next, a second embodiment of a micro reed switch MS will be described with reference to FIGS. Note that the same or corresponding components as those of the first embodiment are denoted by the same reference numerals, detailed description thereof will be omitted, and different portions will be mainly described.

In this embodiment, a micro reed switch member MSb is used instead of the glass substrate 101 of the first embodiment.
Are bonded via an insulating spacer 140 such as glass. That is, the micro reed switch MS of the present embodiment includes the micro reed switch member MSa and the micro reed switch member MSb of the first embodiment, the spacer 140, the molded portion 103, and the like.

Since the micro reed switch member MSb is formed by the same manufacturing method as the micro reed switch member MSa of the first embodiment, the micro reed switch member MSb is provided at a position corresponding to each part constituting the micro reed switch member MSa. Will be described simply by adding the symbol “a” to the symbol of each member of the micro reed switch member MSa.

As shown in FIG. 15, the cantilever 112a of the micro reed switch member MSb is formed to extend from the side opposite to the direction in which the cantilever 112 of the micro reed switch member MSa extends. . The movable contacts 116, 116a of the cantilever beams 112, 112a are always spaced apart from each other and arranged to face each other.

The wiring pattern 115a is formed on the silicon substrate 1
Pad 10 provided on the upper surface of the end portion 02a
6 is connected. The silicon substrate 102a of the micro reed switch member MSb has both ends in the longitudinal direction extending longer than the silicon substrate 102 of the micro reed switch member MSa.

The insulating spacer 140 is formed on the silicon substrate 102
a. The upper surface is joined using an anodic bonding technique. The insulating spacer 140 is formed in a flat rectangular parallelepiped shape,
One end is shorter than the silicon substrate 102a so that the bonding pad 106 is exposed.
The silicon substrate 102 of the micro reed switch member MSa is bonded to the upper surface of the insulating spacer 140 using an anodic bonding technique.

In the insulating spacer 140, each recess 110, 1 of both micro reed switch members MSa, MSb
A rectangular through hole 141 is formed corresponding to 10a,
The two concave portions 110 and 110a communicate with each other. The recess 11
0, 110a and the through hole 141 are vacuum-sealed by joining the insulating spacer 140 to both micro reed switch members MSa, MSb.

A bonding pad 105 is provided at an end of the insulating spacer 140 opposite to the position of the bonding pad 106 with the through hole 141 interposed therebetween, and is provided between the bonding pad 105 and the edge of the through hole 141. Has a wiring pattern 107 formed thereon. The wiring pattern 107 is in contact with and electrically connected to the wiring pattern 115 of the micro reed switch member MSa.

In this embodiment, the silicon substrate 102 corresponds to a first silicon substrate, and the silicon substrate 102a corresponds to a second silicon substrate. The cantilever 112 corresponds to a first movable piece, and the cantilever 112a corresponds to a second movable piece. The recess 110 corresponds to a first recess, and the recess 110a corresponds to a second recess. The wiring pattern 115 is a first magnetic thin film layer, a wiring pattern 115a.
Corresponds to the second magnetic thin film layer. The second electrode portion includes the wiring pattern 115a and the movable contact 116a, and the movable contact 116a corresponds to a contact surface that comes into contact with and separates from the movable contact 116.

In this embodiment, when the magnet approaches the outside of the micro reed switch MS, the magnetic flux passes through the wiring patterns 115 and 115a, which are magnetic thin films. As a result, in FIG. 15, the respective distal ends of the cantilevers 112, 112a are displaced toward each other in opposition to each other against the elastic force of the cantilevers 112, 112a. As a result, the movable contacts 116, 1
16a contact each other and close.

When the magnet approaching the outside of the micro reed switch MS is separated, the magnetic flux does not pass through the wiring patterns 115 and 115a, which are magnetic thin films. The tip portions of the cantilevers 112 and 112a are displaced upward,
That is, the movable contacts 116 and 116 a
It is separated in the opposite direction and opens.

(9) In the present embodiment, since the micro reed switch member MSa and the micro reed switch member MSb can be formed by the same manufacturing method, mass production is possible as compared with the first embodiment. Cost can be reduced. Moreover, also in the micro reed switch MS of the present embodiment, the size and weight can be easily reduced by the microfabrication technology of silicon, so that the switch responsiveness can be improved.

(10) In the present embodiment, the wiring pattern 115 constituting a part of the first electrode portion on the cantilever 112 is electrically connected to the lead 119 via the wiring pattern 107 and the wire 121. , On the other hand, cantilever 11
Wiring pattern 11 constituting a part of the second electrode unit on 2a
5a is electrically connected to the lead 120 via the wire 122. Therefore, leads 119 and 120
(Corresponding to a lead wire portion) and cantilever beams 112, 112
Since the wiring patterns 115 and 115a are separated from each other, it is not necessary to consider the adverse effects of processing the leads 119 and 120.

The embodiment of the present invention can be modified as follows, for example. (1) In the above embodiment, a single micro reed switch MS is configured. However, a plurality of micro reed switches MS connected in parallel may be molded in the molding unit 103 to form a micro reed switch body.

Since this micro reed switch body is constituted by a plurality of micro reed switches MS electrically connected in parallel, even if one or a plurality of micro reed switches MS fail, the remaining micro reed switches MS remain. Since the other micro reed switch MS operates normally, the reliability of the function as the micro reed switch body can be improved.

Also, originally, the micro reed switch MS
Is smaller, so that even a configuration in which a plurality of components are connected in parallel does not become so large. (2) A substrate having a plane orientation other than (110), such as a (111) substrate or a (10)
0) A substrate or the like may be used. If the (100) substrate is used in the first embodiment, higher sensitivity can be obtained.

(3) As an alkaline etchant other than TMAH, for example, KOH, hydrazine, EPW (ethylenediamine-pyrocatechol-water) and the like may be used.

(4) Micro reed switch member MS
When a and MSb are manufactured, for example, an n-type polycrystalline silicon layer, an amorphous silicon layer, or the like may be formed instead of the n-type single crystal silicon epitaxial growth layer 113.

(5) In the first embodiment, W (tungsten) is used as the metal protective film, but Mo (molybdenum) may be used. Also, the metal protective film made of Mo (molybdenum) has a high melting point like W (tungsten) and a thermal expansion coefficient close to that of the passivation film 133 such as SiN or Si3 N4 and the epitaxial growth layer 113 of the silicon substrate 102. It does not peel off because of its adhesion to

(6) In the above embodiment, the counter electrode was used when the metal protective film was anodized. Instead, an anodization was performed using a noble metal plate such as Pt as the counter electrode as in the related art. Of course, it is also possible.

Here, in addition to the technical ideas described in the claims, the technical ideas grasped by the above-described embodiments are listed below together with their effects. (1) The micro reed switch according to claim 4, wherein the glass is formed with a concave portion into which the movable piece can be engaged.
In this way, the displacement of the movable piece can be allowed.

The technical terms used in this specification are defined as follows. “Lever structure: means a portion that is displaced when a magnetic flux passes through a magnetic thin film formed on the surface, and refers to, for example, a structure having one or more beams.” “Anodic formation: a substrate in an electrolytic solution Is a collective reforming process that forms a porous layer on the substrate by passing a current with the substrate as an anode. "

[0083]

As described above in detail, according to the first to seventh aspects of the present invention, by applying the microfabrication technology of silicon, it is possible to reduce the size of the conventional reed switch and to mass-produce it. It is possible, and the switch responsiveness can be improved. Further, since the movable piece and the lead wire portion are separated from each other, there is an effect that it is not necessary to consider the adverse effect of the characteristics due to the processing of the lead wire portion.

According to the third aspect of the present invention, since the other members can have the same structure as the structure on the silicon substrate side, they can be formed by the same manufacturing method, and mass production can be performed. And cost can be reduced.

According to the fifth aspect of the invention, since the resin molding is performed, the durability can be improved.
According to the invention described in claim 6, by electrically connecting the micro reed switches in parallel, the reliability of the micro reed switch body can be improved.

According to the seventh aspect of the invention, there is an effect that the micro reed switch can be easily manufactured.

[0087]

[Means for Solving the Problems] [Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a micro reed switch according to a first embodiment.

FIG. 2 is a schematic bottom view of the micro reed switch member MSa.

FIG. 3 is a plan view of the same glass substrate.

FIG. 4 is a sectional view of the micro reed switch member.

FIG. 5 is an enlarged sectional view of a micro reed switch member.

6A is a schematic cross-sectional view showing a manufacturing procedure of a micro reed switch member, and FIG. 6B is a schematic plan view thereof.

7A is a schematic sectional view, and FIG. 7B is a schematic plan view.

8A is a schematic sectional view, and FIG. 8B is a schematic plan view.

9A is a schematic sectional view, and FIG. 9B is a schematic plan view.

10A is a schematic sectional view, and FIG. 10B is a schematic plan view.

FIG. 11 is a schematic sectional view of the same.

FIG. 12 is a schematic sectional view of the same.

FIG. 13 is an explanatory view showing an anodizing method.

FIG. 14 is a schematic sectional view of the same.

FIG. 15 is a schematic sectional view of a micro reed switch according to a second embodiment.

FIG. 16 is a schematic plan view of one micro reed switch member.

FIG. 17 is a schematic plan view of the other micro reed switch member.

FIG. 18 is an exploded perspective view of a conventional reed switch before assembling.

FIG. 19 is a sectional view of a conventional reed switch.

[Explanation of symbols]

MS: micro reed switch, MSa, MSb: micro reed switch member 101: glass substrate, 102,
102a: p-type single-crystal silicon substrate, 103: molded part, 104: concave part, 107: wiring pattern, 108: wiring pattern (magnetic thin film layer), 109: fixed contact, 11
0, 110a: recess, 115, 115a: wiring pattern (magnetic thin film layer), 112, 112a: cantilever (movable piece), 113: epitaxial growth layer, 115, 115
a: wiring pattern, 116, 116a: movable contact, 13
1, 132: p-type silicon layer; 133: passivation film (protective film); 135: metal protective film (protective film).

Continued on the front page (72) Inventor Koichi Itoigawa 3-260 Toyota, Oguchi-cho, Niwa-gun, Aichi Prefecture F-term in Tokai Rika Electric Works, Ltd. (reference) 5G023 AA12 AA20 BA32 BA34 CA29 CA41 5G046 CA01 CA06 CD05

Claims (7)

[Claims] A concave portion is formed on one side surface of a silicon substrate, and an elastic movable piece extending from the one side surface is disposed on the concave portion, and the movable piece includes a magnetic thin film layer. A first electrode portion is formed, and the first electrode portion has a contact surface formed on a side surface opposite to a side surface facing the concave portion, and is provided on another member joined to one side surface of the silicon substrate. Is always separated from the first electrode portion, and when a magnetic flux flows through the first electrode portion in response to a change in an external magnetic field, and the movable piece having the first electrode portion is drawn, the first A second electrode portion is provided in contact with the contact surface of the one electrode portion. At least one of the silicon substrate and another member connects the first electrode portion and the second electrode portion to an external electric element. Microleads characterized by wiring of Pitch. 2. The micro reed switch according to claim 1, wherein the second electrode portion provided on the other member is a fixed electrode portion. 3. The method according to claim 1, wherein the silicon substrate is a first silicon substrate,
The micro reed switch according to claim 1, wherein the movable piece is a first movable piece, the recess is a first recess, and the magnetic thin film layer is a first magnetic thin film layer. A second concave portion is formed on one side surface of the second silicon substrate, and an elastic second movable piece extending from the same side surface is disposed on the second concave portion; A second electrode portion including the second magnetic thin film layer is formed on the piece, and the second electrode portion is
A micro reed switch in which a contact surface that can contact and separate from the contact surface of the first electrode portion is formed on a side surface opposite to a side surface facing the recess. 4. The micro reed switch according to claim 2, wherein the other member is formed from glass. 5. The micro reed switch according to claim 1, wherein the silicon substrate and another member are resin-molded. 6. A micro reed switch body comprising a plurality of the micro reed switches according to claim 1 connected in parallel with each other. 7. A step of forming a p-type silicon layer (131) in a predetermined region on the surface side of the p-type single crystal silicon substrate (102) by adding an impurity, and an upper surface of the p-type single crystal silicon substrate (131). Epitaxial growth layer (113) made of n-type single crystal silicon
To form the epitaxial growth layer (1).
13) embedding the p-type silicon layer (131) in the epitaxial growth layer (11) by adding impurities.
3) forming a p-type silicon layer (132) for forming an opening in (3); and forming a movable piece partitioned by the silicon layer (132) for forming an opening. Forming a magnetic thin film layer (115) along the extending direction; and, after forming the magnetic thin film layer (115), excluding a portion corresponding to the p-type silicon layer (132) for forming the opening. Forming a protective film (133, 135); and performing anodizing treatment with the protective film (133, 135) formed, thereby forming each of the p-type silicon layers (1).
(31, 132) into a porous silicon layer (137); and removing the porous silicon layer (137) by alkali etching to form the porous silicon layer (1).
37) A method for manufacturing a micro reed switch member, comprising: a step of hollowing out a portion where there was, and a step of subsequently removing the protective film (133, 135).