Patent ID: 8263908

Claim:
A heater plate manufactured by receiving a sheath heater within a groove portion formed in a base member made of aluminum or aluminum alloy, placing at least one joint member made of aluminum or aluminum alloy into said groove portion so as to fix said sheath heater in the groove portion, wherein said joint member has two correspondingly tapered portions facing each other which extend toward a lower end in a direction of gravity thereof in a manner that a distance between said two tapered portions becomes narrower, and a width of a surface portion contacting with said sheath heater in said joint member is larger than a width of said sheath heater and metal bonding said base member to said joint member by forge-pressing, in a manner that a force is added from an upper surface of said base member toward said sheath heater direction, with said sheath heater fixed in place therebetween and hermetically sealed thereby; wherein said forge-pressing comprises applying said force while heating said joint base member and said joint member at an elevated temperature in order to perform a solid-state welding of said base member and said joint member at said tapered portions; wherein metallurgical continuity exists across a bond interface between said metal bonded base member and said metal bonded joint member, thus providing a hermetical seal of said sheath heater.