JP2008218023A - Switching device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a switching device and its manufacturing method capable of preventing adhesion of contacts without increasing junction resistance. <P>SOLUTION: The switching device has a metallic contact comprising metallic fixed contacts 10, 10 formed on the upper surface of a first substrate 1 made of a glass material; and a metallic movable contact 20 formed on the lower surface of a second substrate 2 made of the glass material and disposed in face to face with the first substrate 1, and set opposite to the fixed contacts 10, 10. A shot-peening treatment is conducted to spray a lot of fine metallic and spherical particles onto the upper surface of the first substrate 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a switching element such as a micro relay and a manufacturing method thereof.

2. Description of the Related Art Conventionally, a micro relay that is formed on a silicon substrate by using a micromachining technique and performs switching of an electric circuit is known. For example, as shown in FIG. 4, this type of microrelay includes a pair of metal fixed contacts 101, 101 formed on the surface of the first silicon substrate 100 (the upper surface in FIG. 4), and the first silicon There is a metal contact portion formed on the surface (the lower surface in FIG. 4) of the second silicon substrate 102 disposed so as to face the substrate 100 and composed of the fixed contacts 101 and the metal movable contact 103 facing the 101. Then, the fixed contacts 101, 101 and the movable contact 103 are brought into and out of contact with each other by electromagnetic force or electrostatic attraction, thereby switching between conduction / non-conduction between the fixed contacts 101, 101 to open / close the contacts.
JP 2003-249157 A

  However, in the above conventional example, when the contact surfaces contacting and separating each other in each of the fixed contacts 101 and 101 and the movable contact 103 are soft, there is a possibility that the contacts adhere to each other when the contacts are opened and closed repeatedly. In order to solve this problem, it is conceivable to harden the contact surfaces of the fixed contact 101 and the movable contact 103. In this case, the contact area is reduced due to unevenness on the contact surface, and the contact surface is opened and closed several million times. There is a problem that the contact resistance is high until the unevenness is reduced.

  The present invention has been made in view of the above points, and it is an object of the present invention to provide a switching element that can prevent contact points from sticking without increasing contact resistance and a method for manufacturing the same.

  In order to achieve the above object, a first aspect of the present invention is a method of manufacturing a switching element having a metal contact portion composed of a fixed contact and a movable contact, and opening and closing the contact by moving the fixed contact and the movable contact. A first step of forming a metal contact portion, and injecting countless fine metal spherical particles onto any surface of the formed metal contact portion facing each other of the fixed contact and the movable contact. And a second step.

  The invention of claim 2 is the invention of claim 1, wherein the first step is a step of forming a metal contact portion on the wafer.

  According to a third aspect of the present invention, in the second aspect of the present invention, between the first step and the second step, a resist is formed on the entire surface excluding the metal contact portion on one surface of the wafer on which the metal contact portion is formed. The third step is provided.

  The invention of claim 4 is the invention of any one of claims 1 to 3, characterized in that the spherical particles are made of a metal material that is difficult to form an alloy with the metal material used for the metal contact portion. To do.

  A fifth aspect of the invention is characterized in that, in the invention of any one of the first to third aspects, the spherical particles are made of a metal material used for a contact to which the spherical particles are to be injected.

  The invention of claim 6 is the invention according to any one of claims 1 to 3, wherein the spherical particles are made of a metal material used for a contact point opposite to a contact point to which the spherical particles are to be injected. .

  The invention of claim 7 is the invention of any one of claims 1 to 3, characterized in that the spherical particles are made of a metal material having high hardness and high specific gravity.

  The invention according to claim 8 is manufactured using the method for manufacturing a switching element according to any one of claims 1 to 7.

  According to the first aspect of the present invention, since the step of injecting countless fine metal spherical particles onto any one of the surfaces of the fixed contact and the movable contact facing each other is provided, the surface of the contact is cured and the contact surface The unevenness of the contacts can be reduced, and therefore, contact between the contacts can be prevented without increasing the contact resistance.

  According to the invention of claim 3, since the resist is formed on the entire surface of the wafer where the metal contact portion is formed except for the metal contact portion, spherical particles can be sprayed only on the metal contact portion, which is unnecessary. Can be prevented from being processed.

  According to invention of Claim 4, since spherical particle | grains consist of a metal material which cannot form an alloy easily with the metal material used for a metal contact part, the increase in contact resistance by alloying with spherical particle | grains and a contact is prevented. be able to.

  According to the fifth aspect of the present invention, since the spherical particles are made of the metal material used for the contact to which the spherical particles are to be injected, an increase in contact resistance due to alloying of the spherical particles and the contacts can be prevented.

  According to the sixth aspect of the present invention, since the spherical particles are made of a metal material used for the contact opposite to the contact for which the spherical particles are to be ejected, the contact surface unevenness is opened and closed a predetermined number of times. It can be close to the uneven state of the case.

  According to the invention of claim 7, since the spherical particles are made of a metal material having a high hardness and a large specific gravity, the kinetic energy necessary for processing can be sufficiently obtained even if the diameter of the spherical particles is reduced, Therefore, the unevenness of the contact surface can be further reduced.

  According to invention of Claim 8, the switching element which has an effect of any one of Claims 1 thru | or 7 can be provided.

  Hereinafter, embodiments of a switching element according to the present invention will be described with reference to the drawings. However, in the following description, the vertical direction in FIG. 1 is defined as the vertical direction. In the present embodiment, like the conventional example, a pair of metal fixed contacts 10 and 10 formed on the upper surface of the first substrate 1 made of a glass material are disposed so as to face the first substrate 1. Formed on the lower surface of the second substrate 2 and having a metal contact portion composed of a metal movable contact 20 facing the fixed contacts 10, 10 and movable with the fixed contacts 10, 10 by electromagnetic force or electrostatic attraction. The contact 20 is opened and closed by switching between conduction and non-conduction between the fixed contacts 10 and 10 by bringing the contact 20 into and out of contact with each other. The metal layer on the first substrate 1 side of the fixed contacts 10 and 10 of the present embodiment is made of, for example, gold, and the outermost layer 10a is made of rhodium. Further, the outermost layer (the lower surface in FIG. 1) of the movable contact 20 is made of ruthenium.

  In this embodiment, the technical idea of the present invention is applied to the microrelay described in the prior art, and the basic structure thereof is well known, so detailed description thereof is omitted here. However, it goes without saying that the technical idea of the present invention can be applied to switching elements other than micro relays. Below, the manufacturing method of the switching element which is the summary of this invention is demonstrated.

  First, as shown in FIG. 2A, the lower surface of the first substrate 1 is processed by sandblasting to penetrate the through hole 11 in the thickness direction, and the inner surface of the through hole 11 is subjected to, for example, copper plating. After that, the fixed contacts 10 and 10 are formed on the upper side of the through hole 11. Next, as shown in FIG. 2B, a resist 12 is formed on the entire top surface of the first substrate 1 except for the fixed contacts 10 and 10 so that only the fixed contacts 10 and 10 are exposed. The thickness dimension of the first substrate 1 is preferably about several hundred μm to several mm, and the diameter of the through hole 11 is preferably about several tens μm to several hundred μm.

  Thereafter, as shown in FIG. 2 (c), so-called shot peening is performed on the upper surface of the first substrate 1 on which the resist 12 is formed, by spraying countless fine metal spherical particles 3. Thus, the surfaces of the fixed contacts 10 and 10 are modified and cured, and the surface irregularities are reduced. Here, the shot peening process is a modification of the surface of an object by accelerating fine metal spherical particles 3 called a shot material with a shot accelerator (not shown) and injecting the object onto the object. A processing method for curing. In the present embodiment, the spherical particles 3 that are shot materials are accelerated by using air pressure, and the air pressure is about 1.5 atm to 5 atm. The spherical particles 3 of the present embodiment are made of rhodium and have a diameter of about several hundred nm to several tens of μm.

  As described above, by injecting countless fine metal spherical particles 3 onto the surfaces of the fixed contacts 10 and 10, the surfaces of the fixed contacts 10 and 10 can be cured and the surface irregularities can be reduced. It is possible to prevent the contacts from sticking without increasing the contact resistance. Further, since the metal material constituting the spherical particles 3 is rhodium constituting the outermost layer 10a of the fixed contacts 10, 10, it is possible to prevent the spherical particles 3 and the outermost layer 10a of the fixed contacts 10, 10 from being alloyed. And increase in contact resistance can be prevented. Further, since the resist 12 is formed on the entire surface of the first substrate 1 except for the fixed contacts 10, 10, only the fixed contacts 10, 10 can be subjected to shot peening so that unnecessary processing is not performed. can do.

  By the way, the spherical particles 3 of the present embodiment are formed of the same metal material as that of the outermost layer 10a of the fixed contacts 10, 10, but are difficult to alloy with the outermost layer 10a of the fixed contacts 10, 10. It may be formed of any metal material. Further, the spherical particles 3 may be formed of the same metal material as the outermost layer metal material (here, ruthenium) of the movable contact 20, and in this case, the surface of the fixed contacts 10, 10 can be opened and closed. It can be close to the uneven state when it is performed a predetermined number of times (for example, several million times).

  Furthermore, the spherical particles 3 may be formed of a metal material having high hardness and high specific gravity, such as iridium. In this case, as shown in FIG. 3, even if the diameter of the spherical particles 3 is reduced, sufficient kinetic energy required for the shot peening process can be obtained. The unevenness on the surface of 10 can be further reduced.

  In this embodiment, the case where the fixed contacts 10 and 10 are subjected to shot peening is described. However, the movable contact 20 may be subjected to the above-described shot peening, and the fixed contacts 10 and 10 may be processed. The same effect as that of the case can be obtained.

It is sectional drawing which shows embodiment of the switching element of this invention. It is explanatory drawing which shows a manufacturing method same as the above, (a) is sectional drawing which shows the state before forming a resist, (b) is sectional drawing which shows the state which formed the resist, (c) is injection of a spherical particle. It is sectional drawing which shows time. It is sectional drawing which shows the case where a different spherical particle is used in the manufacturing method same as the above. It is sectional drawing which shows the conventional switching element.

Explanation of symbols

1 First substrate (wafer)
10 Fixed contact 2 Second substrate (wafer)
20 Moving contact 3 Spherical particles

Claims (8)

  A method of manufacturing a switching element that has a metal contact portion composed of a fixed contact and a movable contact, and opens and closes the contact by moving the fixed contact and the movable contact, and the first step of forming the metal contact portion; And a second step of injecting countless fine metal spherical particles onto any one of the surfaces of the fixed contact and the movable contact facing each other in the formed metal contact portion. Production method.   2. The method of manufacturing a switching element according to claim 1, wherein the first step is a step of forming a metal contact portion on a wafer.   Between the first step and the second step, there is provided a third step of forming a resist on the entire surface excluding the metal contact portion on one surface of the wafer on which the metal contact portion is formed. The manufacturing method of the switching element of Claim 2.   4. The method of manufacturing a switching element according to claim 1, wherein the spherical particles are made of a metal material that hardly forms an alloy with a metal material used for the metal contact portion. 5.   The method for manufacturing a switching element according to any one of claims 1 to 3, wherein the spherical particles are made of a metal material used for a contact to which the spherical particles are jetted.   4. The method of manufacturing a switching element according to claim 1, wherein the spherical particles are made of a metal material used for a contact point opposite to a contact point to which the spherical particles are jetted. 5.   The method for manufacturing a switching element according to claim 1, wherein the spherical particles are made of a metal material having high hardness and high specific gravity.   A switching element manufactured using the method for manufacturing a switching element according to claim 1.

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