Thermal head
AssigneeKYOCERA Corporation
InventorsTakayuki Yamamoto, Shigenori Ota
Life of this patent
Estimating the term…
Abstract
The drive circuit elements mounted on a heat resistant substrate for composing a thermal head were covered with a protective layer made of epoxy resin in the prior art. This epoxy resin is greatly different from the heat resistant substrate in the coefficient of linear expansion and is relatively high in Young's modulus, and therefore due to rise or fall of temperature in the manufacturing process, the shrinkage of the protective layer is greater than the shrinkage of the heat resistant substrate, and hence the heat resistant substrate is warped. Such warp may be eliminated by selecting a resin having a coefficient of linear expansion almost same as the coefficient of linear expansion of the heat resistant substrate as the material for the protective layer.
Claims19
A thermal head composed by disposing a plurality of drive circuit elements for driving heating resistance elements on a substrate having a coefficient of linear expansion on which a plurality of heating resistance elements are arranged linearly, and covering the drive circuit elements with a resin having a coefficient of linear expansion, wherein the resin and the substrate possess a substantially similar coefficient of linear expansion.
An improved thermal head wherein a plurality of drive circuit elements for driving heating resistance elements are disposed on a substrate having a coefficient of linear expansion on which a plurality of heating resistance elements are arranged linearly, and the drive circuit elements are covered with a resin having a coefficient of linear expansion, wherein the improvement comprises:
- the resin and substrate posses a substantially similar coefficient of linear expansion.
Dependencies are inferred from the claim text.