Electronic component-mounting substrate and electronic device
An electronic component-mounting substrate including a peeling or falling prevention layer that has excellent adhesion and scratch resistance, can increase smoothness of corner parts of components after processing, and firmly covers a substrate and electronic components provided on the substrate, so that the electronic component-mounting substrate can prevent human nails or other components from getting caught between electronic components that are mounted during a process of mounting the electronic components, preventing the electronic components from peeling off or falling off from the substrate due to an external damage. The electronic component-mounting substrate includes a substrate, an electronic component, and a peeling or falling prevention layer, in which the peeling or falling prevention layer satisfies (1) a rate of change X of a coefficient of static friction is −50% or greater and 200% or smaller, and (2) an index Y is 0.8 or greater and 20.0 or smaller.
1. An electronic component-mounting substrate comprising:
a substrate;
an electronic component mounted on at least one surface of the substrate; and
a peeling or falling prevention layer that coats the substrate and the electronic component, wherein
the peeling or falling prevention layer satisfies both the following (1) and (2):
(1) a rate of change X of a coefficient of static friction obtained in the following [Formula 1] is −50% or greater and 200% or smaller:
X =(μ k 300 −μk 100 )/μ k 100 ×100 [Formula 1]
wherein μk 100 is a coefficient of static friction at a 100-th reciprocating wear test of the peeling or falling prevention layer, and μk 300 is a coefficient of static friction at a 300-th reciprocating wear test of the peeling or falling prevention layer; and
(2) an index Y obtained in the following [Formula 2] is 0.8 or greater and 20.0 or smaller:
Y=R 2 /( R 1 +A 1 ) [Formula 2]
wherein R 1 is a radius of curvature of a curved surface of a corner part of the electronic component in a cross section of the electronic component-mounting substrate, R 2 is a radius of curvature of a corner part of the peeling or falling prevention layer in the cross section of the electronic component-mounting substrate, and A 1 is a thickness of the corner part of the peeling or falling prevention layer in the cross section of the electronic component-mounting substrate.
2. The electronic component-mounting substrate according to claim 1 , wherein
the peeling or falling prevention layer includes a binder (A) and a filler (B), and
a product of a BET specific surface area [m 2 /g] of the filler (B) and a content rate [mass %] of the filler (B) in 100 mass % of the peeling or falling prevention layer is 0.01 to 15 [mass %·m 2 /g].
3. The electronic component-mounting substrate according to claim 1 , wherein a thickness A 2 of the peeling or falling prevention layer is 5 to 300 μm.
4. An electronic device on which the electronic component-mounting substrate according to claim 1 is mounted.
5. The electronic component-mounting substrate according to claim 2 , wherein a thickness A 2 of the peeling or falling prevention layer is 5 to 300 μm.
6. An electronic device on which the electronic component-mounting substrate according to claim 2 is mounted.
7. An electronic device on which the electronic component-mounting substrate according to claim 3 is mounted.
8. An electronic device on which the electronic component-mounting substrate according to claim 5 is mounted.