| 摘要 |
PROBLEM TO BE SOLVED: To provide a substrate having low thermal expansion properties and good adhesiveness to a copper foil.SOLUTION: There is provided a method for producing a low thermal expandable substrate which comprises: a step of producing a prepreg containing a resin composition layer composed of a thermosetting resin composition and a pair of glass cloth layers containing glass cloth and holding the resin composition layer; and a step of bringing a copper foil into contact with both principal surfaces of the prepreg to press in a reduced-pressure atmosphere. The thermosetting resin composition used for the production of the prepreg contains 70-92 mass% of a filler. In the filler, the ratio of particles having a particle diameter of 1 μm or less is 40 mass% or less. The glass cloth used for the production of the prepreg has a thickness of 80-150 μm and an air permeability of 5 cm/(cms)or less.SELECTED DRAWING: Figure 4 |
