Electronic control apparatus and method for connecting substrate of electronic control apparatus
In a configuration that a thermal grease is applied between a circuit board having an electronic component mounted thereon and a case body containing the board to thermally connect both by the thermal grease, the application has not been easy since the thermal grease is high in initial viscosity. A thermal grease is made of a material that has a viscosity not impeding applicability at the initial stage (before application), for example, a viscosity of about 50-400 (Pa·s), and that increases to about 600-3,000 (Pa·s) in viscosity after application.
1. A method for producing an electronic control apparatus, the electronic control apparatus comprising:
a circuit board having an electronic component mounted thereon;
a case body including a case and a cover;
a waterproof seal material to join the cover and the case; and
a heat conductive material arranged at a position between an inner surface of the case or the cover and the electric component,
wherein the method comprises providing, as the heat conductive material, a thermal grease that increases in viscosity by heat, and applying the thermal grease to at least one side of the inner surface of the case or the cover and the electric component so as to be arranged in the position; and
wherein the waterproof seal material, which is formed of a thermosetting resin, is applied to a connecting position between the case and the cover, and after the thermal grease and the waterproof seal material are applied, the thermal grease and the waterproof seal material are heated at a state such that the circuit board is contained in the case body, thereby causing the thermal grease to increase in viscosity and curing the waterproof material.
2. The method for producing the electronic control apparatus as claimed in claim 1 , wherein the thermal grease contains an adhesive assistant, and the thermal grease after heated is made to adhere to the electric component and the case body.
3. The method for producing the electronic control apparatus as claimed in claim 2 , wherein a clearance between the case and the circuit board gets narrower toward a fixing part side of the circuit board.
4. The method for producing the electronic control apparatus as claimed in claim 1 , wherein a clearance between the case and the circuit board gets narrower toward a fixing part side of the circuit board.