WO2008038339A1 - Bimorph switch - Google Patents

Abstract

Bimorph switch (1A) comprising substrate (10) equipped with fixed contact (11) and bimorph beam (20A) equipped at its distal end (43) with traveling contact (44), wherein the bimorph beam (20A) includes first bimorph part (40) furnished with Si layer (30) and first Cu layer (41) and, interposed between the two layers (30,41), thin-film heater (42); second bimorph part (50) furnished with Si layer (30) and second Cu layer (51) having no heater interposed between the two layers (30,51); and third bimorph part (60) furnished with Si layer (30) and third Cu layer (61) having no heater interposed between the two layers (30,61).

Description

 Specification

 Bimorph switch

 Technical field

 The present invention relates to a bimorph switch that electrically connects a fixed contact provided on a substrate and a movable contact provided on a bimorph beam.

 Background art

 [0002] By changing the heater on / off control of a bimorph beam composed of two layers with different thermal expansion coefficients and also having a material force, the shape of the nanomorph beam is changed. Conventionally, a bimorph switch that electrically connects contacts is also known (see, for example, Patent Document 1). Since these bimorph switches are constructed using MEMS (Micro Electro Mechanical Systems) technology, the switch can be made much smaller.

 On the other hand, in the manufacturing process of various electronic components such as semiconductor integrated circuit elements, an electronic component testing apparatus is used to test the performance and function of the electronic components. In this electronic component testing apparatus, a test head electrically relays between a tester that actually executes a test and an electronic component to be tested, and this test head is a pin electronic circuit composed of an electric circuit board. -Have a tas. There are thousands of switching relays in pin electronics, but when handling high-frequency signals, the larger the relay size, the more noise is generated. For this reason, when a high-frequency signal is used as a test signal, it is necessary to reduce the size of the relay, and the bimorph switch as described above may be used as a pin electronics relay of the test head.

 [0004] By the way, since the electronic component test apparatus applies a high-temperature thermal stress of the electronic component under test during the test, the temperature inside the test head may also increase. Also, the temperature inside the test head may increase due to self-heating of the devices on the pin electronics during the test. Due to these factors, the ambient temperature in the test head varies from before and after 20 ° C to about 90 ° C.

[0005] On the other hand, in bimorph beams, due to the creep strength and fatigue strength of the metal layer, The upper limit temperature of heat is limited to about 200 ° C. Therefore, the change in ambient temperature in the test head as described above cannot be ignored. Depending on the change in ambient temperature, the contact gap between the movable contact and the fixed contact may change, or the movable contact may change. When the contact with the fixed contact is overloaded, it may be difficult to ensure stable contact.

[0006] Also, in order to maintain the pressing force [mN] between the contacts constant, it is necessary to increase / decrease the power applied to the heater in response to changes in the ambient temperature, and it is difficult to control the heater temperature. There was a problem.

 [0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2004-55410

 Disclosure of the invention

 [0008] An object of the present invention is to provide a nomorph switch capable of ensuring stable contact by suppressing changes in contact gap and overload during contact.

 In order to achieve the above object, according to the present invention, there is provided a bimorph switch for electrically connecting a movable contact and a fixed contact, the substrate provided with the fixed contact, and the movable contact provided. A bimorph beam, the bimorph beam having two layers made of materials having different coefficients of thermal expansion, and a first bimorph section having a heater for heating the two layers, and a heat A second bimorph portion connected to the first bimorph portion at least at a part of one side adjacent to the first bimorph portion; and having two layers composed of materials having different expansion coefficients. A bimorph switch is provided (see claim 1).

 [0010] The present invention includes a first bimorph portion having a bimorph beam force heater and a second bimorph portion having no heater. Because the bimorph beam has these two types of bimorph parts, even if the ambient temperature around the bimorph switch changes, it is possible to cancel the changes that occurred in the first bimorph part with the second bimorph part. . As a result, changes in the contact gap caused by changes in the ambient temperature and overloading during contact can be suppressed, and stable contact can be ensured. In addition, since the heating temperature of the heater can be set without depending on the change in the ambient temperature, the heater temperature can be easily controlled.

[0011] Although not particularly limited in the above invention, the movable contact is opposed to the fixed contact. Preferably, it is provided at one end of the first bimorph part or the second bimorph part U, so that it faces (see claim 2).

 [0012] Although not particularly limited in the above invention, the two layers of the first bimorph portion include a first layer constituted by a first material force and a coefficient of thermal expansion higher than that of the first material. A second layer made of a relatively large second material, and the heater is interposed between the first layer and the second layer, and the second layer It is preferable that the two layers of the bimorph portion include a first layer constituted by the first material force and a second layer constituted by the second material force. 3).

 [0013] In the above invention, although not particularly limited, it is preferable that the first material includes silicon and the second material includes copper (see claim 4).

 [0014] In the above invention, although not particularly limited, the first morph portion is provided on a distal end side of the bimorph beam, and the second morph portion is generated by a change in ambient temperature. Preferably, the bimorph beam is provided on the rear end side of the bimorph beam so as to cancel the change of the first bimorph portion, and the bimorph beam is fixed to the substrate at the rear end (see claim 5). ).

 [0015] Although not particularly limited in the above invention, the bimorph beam has a shape that is bent from the front end toward the rear end, and in the first bimorph portion, the first bimorph portion has the first main surface on the first main surface side. And the second layer is provided on the other main surface side, and the first layer is provided on one main surface side in the second nomorph portion. In addition, it is preferable that the second layer is provided on the other main surface side (see claim 6).

 [0016] In the above invention, although not particularly limited, the bimorph beam has a shape extending substantially linearly from the rear end toward the tip, and in the first bimorph portion, The first layer is provided on the main surface side, and the second layer is provided on the other main surface side. In the second bimorph portion, the first layer is provided on the one main surface side. It is preferable that two layers are provided and the first layer is provided on the other main surface side (see claim 7).

[0017] In the above invention, although not particularly limited, the first nomorph portion is the bi-axial portion. The second bimorph portion is provided at the center of the morph beam, and the second bimorph portion is provided at both ends of the bimorph beam so as to cancel out the change in the first bimorph portion caused by the change in ambient temperature. (See claim 8).

[0018] Although not particularly limited in the above invention, the bimorph beam is fixed to the substrate at both ends thereof, and the second layer is provided on one main surface side in the first bimorph portion. The first layer is provided on the other main surface side, and the first bilayer portion is provided with the first layer on one main surface side, and the other main surface side. It is preferable that the second layer is provided on the substrate (see claim 9). Brief Description of Drawings

 FIG. 1 is a plan view showing an overall configuration of a bimorph switch according to a first embodiment of the present invention.

 [FIG. 2] FIG. 2 is a sectional view taken along the line Π-Π in FIG.

 FIG. 3 is a cross-sectional view taken along the line ΙΠ-ΙΙΙ in FIG.

 [FIG. 4A] FIG. 4A is a schematic view of the bimorph beam according to the first embodiment of the present invention as viewed from the side, and shows a state where the heater is turned off at an ambient temperature of 25 ° C.

 [FIG. 4B] FIG. 4B is a schematic view of the bimorph beam according to the first embodiment of the present invention in which the side force is also viewed, and shows a state where the heater is turned off at an ambient temperature of 90 ° C.

 [FIG. 4C] FIG. 4C is a schematic view of the bimorph beam in the first embodiment of the present embodiment as viewed from the side, and shows a state where the heater is turned on at an ambient temperature of 25 ° C.

 [FIG. 4D] FIG. 4D is a schematic view of the bimorph beam in the first embodiment of the present invention as seen from the side, and shows a state in which the heater is turned on at an ambient temperature of 90 ° C.

 FIG. 5A is a graph showing an operation line of the bimorph switch according to the first embodiment of the present invention.

 FIG. 5B is a graph showing an operation line of a conventional cantilever type bimorph switch.

 FIG. 6 is a plan view showing a bimorph switch according to a second embodiment of the present invention.

FIG. 7A is a plan view showing a bimorph switch according to a third embodiment of the present invention. FIG. 7B is a cross-sectional view taken along line VIIB-VIIB in FIG. 7A.

 FIG. 8A is a plan view showing a bimorph switch according to a fourth embodiment of the present invention.

 FIG. 8B is a cross-sectional view taken along line VIIIB-VIIIB in FIG. 8A.

Explanation of symbols

 1 A ~: LD ... Bimorph switch

 10 ... Board

 11, 12 ... fixed contact

 20A ~ 20D '·' Nimo / Ref beam

 30 "'Si layer

 31 ... Protective layer

 40… First bimorph part

 41 ... 1st Cu layer

 42 ... Heater

 43 ··· Movable end

 44

 45 ··· Continuous part

 46 ... Notch

 50 ··· 2

 51 ... Second Cu layer

 52 ... Fixed end

 53 ... Support part

 60… The third bimorph section

 61 ... Third Cu layer

 62 ... Fixed end

 63 ... Support part

 70 ... Reference line

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

 [0022] <First embodiment>

 FIG. 1 is a plan view showing the overall configuration of the bimorph switch according to the first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line Π-Π in FIG. 1, and FIG. 3 is a cross-sectional view taken along line ΠΙ-ΠΙ It is.

 As shown in FIGS. 1 to 3, the bimorph switch 1A according to the first embodiment of the present invention includes a substrate 10 having fixed contacts 11 and 12 provided on the surface, and a movable contact 44 provided at the tip. In addition, the bimorph beam 20A is bent by the heating of the heater 42 so that the movable contact 44 electrically connects the fixed contacts 11 and 12 to each other. This bimorph switch 1A is a MEMS switch with a size of about 1840 ^ m X HOO ^ m. For example, it should be mounted as a switching relay on the pin electronics provided in the test head of the electronic component test equipment. Can do.

 The substrate 10 is made of, for example, a glass substrate having a borosilicate glass isotropic force. On this substrate 10, fixed terminals 11 and 12 having, for example, gold (Au) isotropic force are formed by a plating process or an etching process. The fixed terminals 11 and 12 are electrically connected to an electric circuit constituting pin electronics (not shown).

 [0025] The bimorph beam 20A in the present embodiment includes three bimorph portions 40 to 60 as shown in FIG. It is bent toward the rear ends 52 and 62 of both the Nomonoreflex beam 20 mm and the tip 43 force, and has a generally letter shape as a whole.

 [0026] The first bimorph portion 40 and the second bimorph portion 50 and the third bimorph portion 40 are arranged such that the tip 43 (hereinafter also simply referred to as the movable end 43) faces the fixed contacts 11 and 12 on the substrate 10. The second and third bimorph sections 50 and 60 are positioned at the end 45 (hereinafter simply referred to as a continuous section 45) opposite to the movable end 43. The first bimorph section 40 and the second bimorph sections 50 and 60 are integrated together! /.

 The second bimorph portion 50 extends from the continuous portion 45 so as to return toward the tip 43 side, and is an end portion 52 in the vicinity of the movable end 43 (hereinafter simply referred to as a fixed end 52). The substrate 10 is fixed to the substrate 10 via the support portion 53.

The third bimorph portion 60 also extends from the continuous portion 45 so as to return toward the tip 43 side, and is an end 62 in the vicinity of the movable end 43 (hereinafter simply referred to as a fixed end 62). , Support part 63 Via the substrate 10.

 [0029] Note that the first bimorph section 40 in the present embodiment corresponds to the first bimorph section in the present invention, and the second and third neomorph sections 50, 60 in the present embodiment correspond to the present application. This corresponds to the second bimorph portion in the invention.

 As shown in FIG. 2, the first bimorph section 40 has a Si layer 30 composed of silicon force and a first Cu layer 41 composed of copper force. A first Cu layer 41 is formed thereon. Further, the first bimorph section 40 has a thin film heater 42 interposed between the Si layer 30 and the first Cu layer 41. The heater 42 is connected to a power source (not shown), and generates heat in the first bimorph section 40 when electric power is supplied. In the present invention, the position of the thin film heater 42 is not limited to between the Si layer 30 and the first Cu layer 41, and the thin film heater 42 is placed on the upper layer portion, the lower layer portion, or both surfaces of the first bimorph portion 40. You may arrange in.

 The thin film heater 42 is formed to meander on the Si substrate 30 by, for example, etching the platinum (Pt) on the upper surface of the Si substrate 30. On the Si substrate 30 on which the thin film heater 42 is formed, a first Cu layer 41 is formed by vacuum deposition, sputtering, or the like. Further, the entire first bimorph portion 40 is coated with a protective layer 31 made of an oxide silicon (ie, silicon) using a method such as CVD. And protective layer 31

 2

 A movable contact 44 made of gold (Au) is formed on the lower surface of the movable end 43 of the first bimorph portion 40 coated with (1) by sputtering or the like.

[0032] It is ideal that only the first bimorph portion 40 is heated by the thin film heater 42, and it is preferable that the second bimorph portion 50 is not heated as much as possible. Therefore, the first bimorph portion 40 and the second bimorph portion are within a range in which the first bimorph portion 40 can be supported.

It is preferable to provide many notches 46 between 50.

[0033] Further, the thickness and shape of the first bimorph section 40 and the second bimorph sections 50, 60 are set so that the ONZOFF operation of the fixed contacts 11, 12 and the movable contact 44 can be performed in several tens of milliseconds or less. It is preferable to configure.

[0034] The thermal expansion coefficient of the first Cu layer 41 is relatively larger than the thermal expansion coefficient of the Si layer 30.

. Therefore, when the thin film heater 42 is heated, the first Cu layer 41 is larger than the Si layer 30. As a result, the first bimorph section 40 is bent downwardly so that the movable contact 44 contacts the fixed contacts 11 and 12 (see the dotted line in FIG. 2). .

As shown in FIG. 3, the second bimorph section 50 includes a Si layer 30 configured with a silicon force and a second Cu layer 51 configured with a copper force. Unlike the first bimorph section 40, the second bimorph section 50 does not have a thin film heater 42 formed between the Si layer 30 and the second Cu layer 41.

 [0036] The second Cu layer 41 is formed on the Si substrate 30 by vacuum deposition, sputtering, or the like. Further, like the first bimorph section 40, the entire second bimorph section 50 is coated with a protective layer 31 made of silicon oxide (SiO 2) using a technique such as CVD.

 2

 Yes.

 [0037] The fixed end 52 of the second bimorph portion 50 is provided with a support portion 53 constituted by S, and the support portion 53 is bonded to the substrate 10 by anodic bonding or the like.

 [0038] The third bimorph portion 60 has a structure similar to that of the second bimorph portion 50, although not particularly shown, and a third Cu layer that also has copper force on the Si substrate 30 that also has silicon force. 61 is formed, and the third bimorph portion 60 is made entirely of silicon oxide (SiO 2).

 2 Coated with protective layer 31. Further, the fixed end 62 of the third nomorph part 60 is provided with a support part 63 constituted by S, and the support part 63 is joined to the substrate 10.

 In the second and third bimorph parts 50, 60, the thermal expansion coefficient of the Cu layers 51, 61 is relatively larger than the thermal expansion coefficient of the Si layer 30. For this reason, when the ambient temperature in the test head rises, the Cu layers 51 and 61 expand more greatly than the Si layer 30.

 [0040] It should be noted that the Si layers 30 of the first to third bimorph portions 40 to 60 are all composed of the same Si substrate, and the Si substrate 30 is subjected to a predetermined process such as etching or sputtering. By applying the treatment, the first to third bimorph portions 40 to 60 are formed!

In the present embodiment, the force exemplified by the silicon layer as the insulating layer 30 is not particularly limited in the present invention, and may be constituted by an insulating substrate having an insulating material force other than silicon. In the present embodiment, the force described by exemplifying the Cu layer as the metal layer is not particularly limited in the present invention. For example, an aluminum layer, a nickel layer, a titanium layer, etc. A metal layer having a coefficient of thermal expansion different from that of the insulating layer can be applied.

 Next, the operation will be described.

 [0043] FIGS. 4A to 4D are schematic views of the bimorph beam according to the first embodiment of the present invention in which the side force is also viewed.

 [0044] When the ambient temperature in the test head is about 25 ° C and no power is supplied to the heater 42, as shown in FIG. 4A, the second and third bimorph sections 50, 60 Are bent from the fixed ends 52 and 62 so that the continuous portion 45 is located at a height h above the reference line 70.

 [0045] The first bimorph portion 40 is warped so that the continuous portion 45 is located at a height h above the reference line 70 and the movable end 44 is located at a height h above the reference line 70. This state

 2

 In this state, the movable contact 44 and the fixed contact 11 are not in contact with each other. The height h is a number

 It is a value approximating zero of about 2 m. Further, the reference line 70 is a virtual line indicating the flat first to third bimorph portions 40 to 60 in which no warpage occurs.

[0046] On the other hand, when the ambient temperature in the test head rises to about 90 ° C due to self-heating of the pin electronics device without supplying power to the heater 42, as shown in FIG. 4B The second and third Cu layers 51 and 61 have a larger coefficient of thermal expansion than the Si layer 30, so the warpage of the second and third bimorph portions 50 and 60 is weakened, and the continuous portion 45 is based. The height h is located above the quasi-line 70 (h> h).

 3 1 3

 [0047] Further, since the first Cu layer 41 has a higher coefficient of thermal expansion than the Si layer 30, the first bimorph portion 40 also has less warpage, and the continuous portion 45 is higher above the reference line 70. Is located at h

 Three

 At the same time, the movable end 44 is positioned substantially on the reference line 70, and the non-contact state between the movable contact 44 and the fixed contact 11 is maintained.

[0048] Thus, in the bimorph switch 1A according to the present embodiment, even if the ambient temperature in the test head changes greatly, for example, between 25 ° C and 90 ° C, it occurs in the first bimorph section 40. The bending change is offset by the bending change of the second and third bimorph parts 50 and 60, and the position of the movable end 44 of the bimorph beam 20A is maintained almost constant, so that the variation in the ambient temperature in the test head can be avoided. Without depending on this, the movable contact 44 and the fixed contact 11 can stably maintain a non-contact state (off state). [0049] Further, when electric power is supplied to the heater 42 in a state where the ambient temperature in the test head is about 25 ° C, as shown in FIG. The Cu layer 41 is thermally expanded more than the Si layer 30, and the movable end 44 of the first bimorph section 40 is lowered below the reference line 70 by the height h, so that the movable contact 43 and the fixed contact 11 are connected. Will be in contact

 Four

 . Since the ambient temperature in the test head is constant at 25 ° C, the second and third bimorph parts 50 and 60 maintain a state where the height h of the reference line 70 is warped upward.

[0050] Further, when the ambient temperature in the test head is raised to 90 ° C with the heater 42 turned on, the second and third layers are higher than the Si layer 30 as shown in FIG. 4D. Since the Cu layers 51 and 61 have a higher coefficient of thermal expansion, the warpage of the second and third bimorph parts 50 and 60 is weakened, and the second and third bimorph parts 50 and 60, as in FIG. 60 is warped by a height h above the reference line 70 with the fixed ends 52 and 62 as base points (h> h).

 3 1 3

 [0051] In addition, since the first bimorph portion 40 has a higher coefficient of thermal expansion in the first Cu layer 41 than in the Si layer 30, the continuous portion 45 has a height h above the reference line 70. Located with movable end 4

 Three

 3 is located at a height h below the reference line 70, so that the movable contact 44 and the fixed contact 1

 Four

 The contact state with 1 is maintained.

 [0052] Thus, in the bimorph switch 1A according to the present embodiment, even if the ambient temperature in the test head changes greatly, for example, between 25 ° C and 90 ° C, it occurs in the first bimorph section 40. Since the change is canceled out by the change in the second and third bimorph parts 50, 60, the movable contact 44 and the fixed contact 11 are in a stable contact state without depending on the change in the ambient temperature in the test head ( ON state) can be maintained.

 As described above, in the bimorph switch 1A according to the present embodiment, the change caused by the first bimorph section 40 due to the temperature change of the atmosphere in the test head (atmosphere around the bimorph switch 1A). Since the second and third morphs 50 and 60 cancel each other, changes in the contact gap caused by changes in the ambient temperature and overload during contact can be suppressed, and stable contact can be ensured. It becomes possible.

FIG. 5A is a graph showing the operation line of the bimorph switch according to the first embodiment of the present invention, and FIG. 5B is a graph showing the operation line of the conventional cantilever type bimorph switch. Note that the vertical axis in FIGS. 5A and 5B indicates that the movable contact 44 and the fixed contact 11 Indicates the clearance [/ zm] in the separated state, and indicates the pressing force [mN] between the fixed contact 11 and the movable contact 44 in the contact state above zero.

 [0055] In the bimorph switch 1A according to the present embodiment, as shown in FIG. 5A, a substantially constant clearance [m] does not depend on the ambient temperature fluctuation (25 ° C to 90 ° C) in the test head. Or, a substantially constant pressing force [mN] can be maintained. Therefore, in the bimorph switch 1A according to the present embodiment, it is possible to easily perform stable on / off control of the switch without being affected by the ambient temperature.

 [0056] On the other hand, as shown in FIG. 5B, in the conventional cantilever type bimorph switch, the clearance [m] and the pressing force [m N] fluctuate in proportion to the change in the ambient temperature in the test head. ing. For this reason, there is a difficulty that the on / off operation of the switch becomes unstable or that the applied power of the thin film heater 42 is controlled to increase / decrease in accordance with the ambient temperature.

 [0057] As described above, in this embodiment, the movable contact 43 and the fixed contact 11 can be stably brought into electrical contact without depending on the ambient temperature in the test head, and the force can be increased. Since the required pressing force [mN] can be obtained with a constant applied power, the temperature control of the heater 42 becomes easy.

 <Second Embodiment>

 FIG. 6 is a plan view showing a bimorph switch according to a second embodiment of the present invention.

 [0059] The bimorph switch 1B according to the second embodiment of the present invention is different from the bimorph switch 1A according to the first embodiment in that the third bimorph section 60 is not provided. If sufficient mechanical strength can be secured when the movable contact 4 4 and the fixed contact 11 are in contact, as shown in FIG. 6, the bimorph beam 20B is connected to the first bimorph section 40 and the first The first bimorph part 40 may be supported by only one bimorph part 50 without heater.

 [0060] <Third embodiment>

 FIG. 7A is a plan view showing a bimorph switch according to a third embodiment of the present invention, and FIG. 7B is a cross-sectional view taken along line VIIB-VIIB in FIG. 7A.

[0061] A bimorph switch 1C according to a third embodiment of the present invention is as shown in FIGS. 7A and 7B. In addition, a bimorph beam 20C extending substantially linearly from the fixed end 52 to the movable end 43 is provided. The bimorph beam 20C includes a first bimorph portion 40 on the movable end 43 side and a second bimorph portion 50 on the fixed end 52 side.

 [0062] In the first bimorph section 40, the first Cu layer 41 is formed on the Si substrate 30 as in the first embodiment. In contrast, the second bimorph portion 50 in the present embodiment is different from the first embodiment in that the second Cu layer 41 is formed on the lower surface of the Si substrate 30 and the second nanomorph portion is formed. 50 has a layer configuration opposite to the layer configuration of the first bimorph section 40.

 Note that the thin film heater 42 may be provided on the upper layer portion, the lower layer portion, or both surfaces of the first nanomorph portion 40. In addition, it is ideal to heat only the first bimorph portion 40 by the thin film heater 42, and it is preferable that the second bimorph portion 50 is not heated as much as possible, and therefore the range in which the first bimorph portion 40 can be supported. A notch between the first bimorph portion 40 and the second bimorph portion 50 may be provided.

 [0064] Due to such a layer structure, the second bimorph section 50 cancels out the change generated in the first bimorph section 40 due to the temperature change of the atmosphere in the test head (atmosphere around the bimorph switch 1C). Therefore, it is possible to suppress a change in contact gap caused by a change in ambient temperature and an overload at the time of contact, and to secure a stable contact.

 [0065] <Fourth embodiment>

 FIG. 8A is a plan view showing a bimorph switch according to a fourth embodiment of the present invention, and FIG. 8B is a cross-sectional view taken along line VIIIB-VIIIB of FIG. 8A.

 In the bimorph switch 1D according to the fourth embodiment of the present invention, as shown in FIGS. 8A and 8B, the bimorph beam 20D is fixed to the substrate 10 at both ends 52, 62 via the support portions 53, 63. It has a double-supported beam structure. Therefore, unlike the other embodiments, the movable contact 44 is provided at a substantially central portion of the bimorph beam 20D.

 [0067] The bimorph beam 20D in the present embodiment includes a first bimorph section 40 at the center thereof and second and third bimorph sections 50 and 60 at both ends thereof.

[0068] Unlike the first embodiment, the first bimorph section 40 has a first Cu layer 41 formed on the lower surface of the Si substrate 30. On the other hand, the second bimorph portion 50 in the present embodiment is Similar to the first embodiment, a second Cu layer 51 is formed on the upper surface of the Si substrate 30. In the third bimorph portion 60, a third Cu layer 61 is formed on the upper surface of the Si substrate 30 as in the first embodiment. That is, in the present embodiment, the second and third bimorph portions 50 and 60 have a layer configuration opposite to the layer configuration of the first bimorph portion 40. The first bimorph section 40 in the present embodiment corresponds to the first bimorph section in the present invention, and the second and third bimorph sections 50, 60 in the present embodiment are the second bimorph sections in the present invention. Corresponds to the bimorph part.

[0069] Due to such a layer structure, the change in the first bimorph part 40 due to the temperature change of the atmosphere in the test head (atmosphere around the bimorph switch 1D) is changed to the second and third bimorph parts. Since it can be offset by 50 and 60, changes in the contact gap caused by changes in the ambient temperature and overload during contact can be suppressed, and stable contact can be secured.

 [0070] The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment includes all design changes and equivalents belonging to the technical scope of the present invention.

 For example, in the above-described embodiment, when the first bimorph portion 40 is positioned on the front end side, the second bimorph portion 50 is positioned on the rear end side, and is movable to the front end of the first bimorph portion 40. Although the contact 44 is provided and the second bimorph portion 50 is fixed to the substrate 10 in the present invention, the present invention is not particularly limited to this. For example, the second bimorph portion 50 is positioned on the front end side, the first bimorph portion 40 is positioned on the rear end side, the movable contact 44 is provided at the front end of the second neomorph portion 50, and the first bimorph portion 40 is provided. The part 50 may be fixed to the substrate 10.

In addition, a second thin film heater (not shown) for heating and bending the second bimorph portion 50 may be added to the second bimorph portion 50 side. When the thin film heater 42 is heated, the second thin film heater is controlled to be in an unheated state, and when the thin film heater 42 is in an unheated state, the second thin film heater is heated. As a result, the moving stroke of the movable end 43 can be almost doubled, and as a result, the allowable range for the production variation of the bimorph switch can be increased. In addition, the contact capacity can be reduced by widening the contact gap. Suitable for high frequency relays.

Claims

The scope of the claims  [1] A bimorph switch for electrically connecting a movable contact and a fixed contact,  A substrate provided with the fixed contact;  A neomorph beam provided with the movable contact,  The bimorph beam is  A first bimorph section having two layers composed of material forces having different coefficients of thermal expansion and a heater for heating the two layers;  A second bimorph portion having two layers having different material expansion coefficients of thermal expansion and connected to the first bimorph portion at least at a part of one side adjacent to the first bimorph portion. And, equipped with! /, A bimorph switch. 2. The bimorph switch according to claim 1, wherein the movable contact is provided at one end of the first bimorph portion or the second bimorph portion so as to face the fixed contact. [3] The two layers of the first bimorph section include a first layer constituted by a first material force, and a second material having a relatively larger coefficient of thermal expansion than the first material. And the heater is interposed between the first layer and the second layer, and the two layers included in the second bimorph portion are: The bimorph switch according to claim 1 or 2, further comprising a first layer made of the first material and a second layer made of the second material force. 4. The bimorph switch according to claim 3, wherein the first material includes silicon and the second material includes copper.  [5] The first bimorph portion is provided on a tip side of the bimorph beam,  The second bimorph portion is provided on the rear end side of the bimorph beam so as to cancel out the change in the first bimorph portion caused by the change in ambient temperature.  The bimonoref switch according to claim 3 or 4, wherein the bimorph beam is fixed to the substrate at a rear end thereof. [6] The bimorph beam has a shape bent toward the rear end of the tip force, In the first bimorph part, the first layer is provided on one main surface side! /, And the second layer is provided on the other main surface side,  In the second bimorph portion, the first layer is provided on one main surface side, and the second layer is provided on the other main surface side. 5. Bimorph switch according to 5.  [7] The bimorph beam has a shape in which the rear end force also extends substantially linearly toward the front end.  In the first bimorph part, the first layer is provided on one main surface side! /, And the second layer is provided on the other main surface side,  6. The second bimorph portion, wherein the second layer is provided on one main surface side, and the first layer is provided on the other main surface side. Bimorph switch.  [8] The first bimorph portion is provided in the center of the bimorph beam,  5. The bimorph switch according to claim 3, wherein the second bimorph portion is provided on both ends of the bimorph beam so as to cancel out the change of the first bimorph portion caused by a change in ambient temperature. [9] The bimorph beam is fixed to the substrate at both ends thereof.  In the first bimorph portion, the second layer is provided on one main surface side, and the first layer is provided on the other main surface side,  In the second bimorph portion, the first layer is provided on one main surface side, and the second layer is provided on the other main surface side. 8. The bimorph switch described in 8.