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US 7,395,722 B2Granted
Mechanical property measurement of thin films by micro plane-strain compression
AssigneeE.I. du Pont de Nemours and Company
InventorLi Lin
Life of this patent
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Abstract
This invention is directed to the measurement of stress-strain relationships in thin films using substantially flat, parallel test surfaces with minimal width. This invention is further directed to the measurement of stress-strain relationships in thin films at controlled temperatures and at high strain rates above 100% per second.
Claims12
A testing apparatus for determining the stress-strain relationship in a film comprising:
- (a) a first and a second substantially flat test surfaces between which the film is placed for testing, the flat test surfaces each having a substantially linear configuration and in substantially complete alignment and wherein the width of each test surface is at least equal to the thickness of the film and no greater than twice the thickness of the film;
- (b) a position means for positioning the test surfaces substantially parallel to each other;
- (c) a displacement means for moving one of the test surfaces with respect to the second test surface;
- and
- (d) a thermal control means for modulating temperatures of the film and the test surfaces comprise a heating surface and a cooling surface having a thermoelectric component positioned between said surfaces;
- wherein the position means for positioning at least one of the test surfaces is a double cantilever structure onto which one test surface is attached.
3 more elements
A method for determining the stress-strain relationship in a film of comprising the steps of:
- (a) placing the film between a first and a second substantially flat test surfaces for testing, the flat test surfaces each having a substanstially linear configuration and wherein the width of each test surface is at least equal to the thickness of the film and no greater than twice the thickness of the film;
- (b) positioning the test surfaces substantially parallel to each other;
- (c) modulating temperatures of the film and the test surfaces by a heating surface and a cooling surface of thermal control means having a thermoelectric component postioned between said surfaces;
- (d) moving one of the test surfaces toward second test surface to compress the film;
- and
- (e) measuring the force required to compress the film;
- wherein the test surfaces are positioned substantially parallel by means of a double cantilever structure onto which one test surface is attached.
4 more elements
Dependencies are inferred from the claim text.