Electronic device and thermal type flow meter on vehicle

Abstract

An airtight configuration for keeping down the permeation of corrosive gas from silicone adhesive, and for preventing corrosive gas from entering the case. An electronic device mounted on vehicle. the electronic device has at least one of a portion connecting components, and a portion sealing the clearance or hole where exists in the electronic device. The at least one of the connection portion and the seal portion is constituted by using adhesive or sealant which has at least one of a function adsorbing corrosive gas and a function trapping corrosive gas with chemical reaction. A car-mounted electronic device characterized by reduced permeation of corrosive gas into a case and high reliability.

1 . A vehicle-mounted electronic device comprising: 
 a case for installing a circuit board,    a silicone gel being filled inside the case,    wherein said silicone gel contains a trap agent for trapping at least one of a sulfur gas and a sulfur compound gas.    
     
     
         2 . The vehicle-mounted electronic device according to  claim 1 , wherein said trap agent is an impalpable powder with at least one of the amorphous bulk shape and a flake shape.  
     
     
         3 . The vehicle-mounted electronic device according to  claim 1 , wherein said trap agent is an impalpable powder with resin being coordinated on the surface of the powder.  
     
     
         4 . The vehicle-mounted electronic device according to  claim 1 , wherein said trap agent is made of silver or silver alloy.  
     
     
         5 . The vehicle-mounted electronic device according to  claim 1 , wherein said case is provided with an opening being closed by a cover, and said silicone gel is poured into said case through said opening.  
     
     
         6 . The thermal type air flow meter comprising: 
 an intake air passage for an internal combustion engine;    a heating resister arranged in a sub-path of said intake air passage;    a circuit board on which an electronic circuit for controlling the temperature of said heating resister is formed; and    a case for installing said circuit board,    wherein said case is filled with a silicone gel containing a trap agent for trapping at least one of a sulfur gas and a sulfur compound gas.    
     
     
         7 . The thermal type air flow meter according to  claim 6 , wherein said trap agent is an impalpable powder with at least one of an amorphous bulk shape and a flake shape.  
     
     
         8 . The thermal type air flow meter according to  claim 6 , wherein said trap agent is an impalpable powder with resin being coordinated on the surface of the powder.  
     
     
         9 . The thermal type air flow meter according to  claim 6 , wherein said trap agent is made of silver or silver alloy.  
     
     
         10 . The thermal type air flow meter according to  claim 6 , wherein said case is provided with an opening being closed by a cover, and said silicone gel is poured into said case through said opening.