Micro-machined temperature dependent one-shot valve and process for production thereof

Abstract

A micro-machined temperature dependent one-shot valve is provided which has an operation temperature adjustable readily, causing no leakage below the operation temperature even at a high pressure difference, being useful both in a liquid environment and in a gas environment, and being miniaturizable. The micro-machined temperature dependent one-shot valve comprises a silicon substrate 100 , a channel 101 penetrating the entire thickness of the silicon substrate, and a low melting point metal member 101 deposited on one face of the silicon substrate to obstruct the channel.

1 . A valve, comprising:
 a planar crystal substrate;   a channel penetrating an entire thickness of the planar crystal substrate; and   a low melting point metal member deposited on one face of the planar crystal substrate to obstruct the channel.   
     
     
         2 . The valve according to  claim 1 , wherein a metal layer is provided between the low melting point metal member and the planar crystal substrate so as to obstruct the channel. 
     
     
         3 - 5 . (canceled) 
     
     
         6 . The valve according to  claim 1 , wherein the low melting point metal member is formed from an alloy containing at least one element selected from a group that includes: Bi, Sn, Pb, In, and Cd. 
     
     
         7 . The valve according to  claim 1 , wherein a part of the low melting point metal member is allowed to intrude into the channel. 
     
     
         8 . The valve according to  claim 2 , wherein the metal layer formed from copper is covered by a photoresist layer, and a part of the low melting point metal member is allowed to intrude into the photoresist layer and is deposited on the metal layer formed from copper. 
     
     
         9 . The valve according to  claim 1 , wherein a trench is formed on a portion of the planar crystal substrate onto which the low melting point metal member is deposited. 
     
     
         10 . (canceled) 
     
     
         11 . The valve according to  claim 1 , wherein a heater component is placed between the low melting point metal member and the planar crystal substrate. 
     
     
         12 . A process for producing a valve comprised of a channel perforated through an entire thickness of a planar crystal substrate, and a low melting point metal member deposited on one face of the planar crystal substrate to obstruct the channel, the process comprising steps of:
 forming a channel through an entire thickness of a planar crystal substrate; and   depositing a low melting point metal member on a face of the planar crystal substrate to obstruct the channel.   
     
     
         13 . The process for producing a valve according to  claim 12 , wherein the step of forming the channel is conducted by reactive ion etching. 
     
     
         14 . The process for producing a valve according to  claim 12 , wherein the step of forming the channel is conducted by wet etching. 
     
     
         15 . The process for producing a valve according to  claim 12 , wherein the step of depositing the low melting point metal member is conducted by immersing the planar crystal substrate in a two-phase liquid bath that includes a low-melting metal as one of the two liquid phases. 
     
     
         16 . The process for producing a valve according to  claim 12 , further comprising steps of:
 forming a metal layer on one face of the planar crystal substrate;   patterning the metal layer;   forming the channel perforated through the entire thickness of the planar crystal substrate at a position where the metal layer has been patterned; and   depositing the low melting point metal member on the metal layer to obstruct the channel.   
     
     
         17 . The process for producing a valve according to  claim 12 , wherein the depositing the low melting point metal member includes forcing a part of the low melting point metal member to intrude into the channel by heating the planar crystal substrate up to a temperature higher than the melting temperature of the low-melting metal and applying a pressure difference between both ends of the channel. 
     
     
         18 . The process for producing a valve according to  claim 12 , further comprising steps of:
 forming a trench on one face of the planar crystal substrate;   forming the channel to be adjacent to the trench perforated through the entire thickness of the planar crystal substrate; and   depositing the low melting point metal member to cover the trench on the planar crystal substrate and to obstruct the channel.   
     
     
         19 . The process for producing a valve according to  claim 12 , further comprising steps of:
 forming a metal layer on one face of the planar crystal substrate;   patterning the metal layer for formation of the low melting point metal member and for formation of a heater component simultaneously;   forming the channel perforated through the entire thickness of the planar crystal substrate at a position where the metal layer has been patterned for the depositing of the low melting point metal member; and   depositing the low melting point metal member on the patterned metal layer to obstruct the channel.