Background technology
By the laminate structure that different materials constitutes, promptly the film-substrate structure has obtained application more and more in many advanced technologies.In P.e.c. and encapsulation field, exist a large amount of ultra-thin coating film-substrate structures, adhesion strength between film and the basic unit can be with the adhesion energy evaluation on the unit area, and adhesion energy is not convenient for measurement, therefore, usually the reliability of film-based structures adopts an index evaluation that is referred to as " energy release rate ", promptly allows film on the unit area, breaks away from basic unit's energy needed (being energy to failure).
The measurement of energy release rate is calculated, and adopt static load bubble test (perhaps bloating test) and axle to carry bubble test usually and realize: opening a radius in the basic unit of film-based structures is
Aperture, by aperture laminate structure is loaded, thereby makes film and basic unit's layering, and form a bubbling, record the displacement (degree of disturbing) of film
And corresponding load
With the bubbling radius
Calculate external work
,, calculate the elastic strain energy of film then by the Elasticity response of laminate structure
External work
Deduct the elastic strain energy of film
Then break away from the energy to failure of basic unit for film, the energy to failure on the unit area is energy release rate.Because the static load bubble test is difficult to control well in test pressure, bubbling radius and bubbling height, therefore axle carries a bubble test and is advocated.
Because the coating film-substrate structure belongs to the superthin layer structure, finding the solution of its mechanical response belongs to the nonlinear mechanics answer usually, in most cases can only provide approximate solution, is difficult to try to achieve accurate analytic solution.Therefore, the testing program that is used for energy release rate measurement calculating is determined, should consider the operability in the test, takes into account the degree of accuracy that the response of superthin layer structural mechanics is found the solution again.This difficulty is perplexing the worldwide scholars in this field always, up to now, does not see one as yet and measures numerical procedure comparatively accurately.
Summary of the invention
In order to overcome the weak point in the existing measurements and calculations, the present invention has provided the accurately technical scheme of measurements and calculations coating film-substrate structural interface energy release rate of a cover.This technical scheme, easy and simple to handle feasible, measurement parameter is few, precision is high.
The object of the present invention is achieved like this: a kind of interfacial energy release rate accurate measurement method of coating film-substrate structure comprises the steps: to open a radius and is in the basic unit of coating film-substrate structure
Aperture, at the opening area core, utilize a radius to be
" circular clamping plate " film is clamped, make the film of clamped region can not produce distortion, by " circular clamping plate " film is slowly applied external force
, make coating film break away from basic unit, and form a radius and be
, highly be
Bubbling, strengthen density measurement, as often as possible record the bubbling height
And corresponding external force value
, with the following formula of measurement data substitution, calculating coating film (is that radius is in the disengaging base layer region
Annulus in) the interfacial energy release rate
(1)
Wherein,
Be energy release rate,
Be the bubbling radius,
Be the radius of the aperture of opening in basic unit,
Be coating film thickness,
Be elastic modulus,
Be Poisson ratio,
,
For the radius of circular clamping plate (
),
Be calculating parameter (can pass through the analytical method accurate Calculation, also can check in roughly) by accompanying drawing provided by the present invention,
For corresponding to external force
The bubbling height value,
,
,
,
,
Unit be the millimeter (mm),
Unit be MPa (MPa),
Unit be newton (N),
Unit be 10
-3Joule/square millimeter (10
-3J/mm
2) or Newton/millimeter (N/mm).
" circular clamping plate " in the above constitutes by clamping disk cap (" 1 " among Fig. 1) and loading cylinder punching pin (" 2 " among Fig. 1), also claims by " clamping punching pin ".By " clamping punching pin " film is applied external force
The time, slow down external force as far as possible
The speed that applies (per minute is less than 1 millimeter), produce fracture to avoid film.Make like this related parameter (external force is arranged
, the bubbling radius
, the bubbling height
) measurement conveniently realized.
In order to improve computational accuracy, adopt the surveying instrument of degree of precision as far as possible, accurately measure corresponding to external force
The bubbling height
, wherein,
, and strengthen density measurement (promptly as far as possible
Enough big), to guarantee adopting trapezoidal method to calculate the precision of definite integral.So external force
Institute's work
, can calculate by following formula:
Thin flexible film strain energy in the existing method
Calculating inaccurate.The present invention is (Jun-yi Sun on the basis of previous research work, Jian-li Hu, Xiao-ting He, Zhou-lian, Zheng, 2010. A theoretical study of a clamped punch-loaded blister configuration:the quantitative relation of load and deflection. International Journal of Mechanical Sciences. 52 (7), 928-936.), the accurate Analysis of the circular membrane that the periphery that utilizes a center to have hard-core clamps is separated, and has tried to achieve the thin flexible film strain energy of loading structure shown in Figure 1
Precise calculation.Specific as follows: as to make film produce the external force of distortion
Maximum degree of disturbing with the film generation
Between, should satisfy following formula
(see Jun-yi Sun for details, Jian-li Hu, Xiao-ting He, Zhou-lian, Zheng, 2010. A theoretical study of a clamped punch-loaded blister configuration:the quantitative relation of load and deflection. International Journal of Mechanical Sciences. 52 (7), 928-936.) therefore, the thin flexible film strain energy
Can obtain by following formula
Like this, our the interfacial energy release rate computing formula that can finally obtain the coating film-substrate structure is:
By as can be seen above, energy release rate of the present invention
Computational accuracy, depend primarily on the precision of surveying instrument.As long as surveying instrument has enough measuring accuracy, strengthen density measurement, just can guarantee the external force that formula (2) calculates
Institute's work
Enough computational accuracies are arranged, and the thin flexible film strain energy
Computing formula (4) be accurate analytic solution, do not have the error of calculation, therefore, this has just guaranteed the computational accuracy of energy release rate.
Description of drawings
Fig. 1 loads organigram for bubble test, and among the figure, 1-clamps the disk cap, 2-loads basic unit, 4-coating film in cylinder punching pin, the 3-film based structures.1 and 2 constitute " clamping punching pin ".
Be the bubbling radius,
Be the radius of clamping disk and cylinder punching pin,
Be the radius of the aperture of opening in basic unit,
Be the thickness of coating film,
Maximum degree of disturbing for deformation of thin membrane.Wherein
Fig. 2 is a calculating parameter
With Poisson ratio
With
Graph of a relation, promptly
Parameter Map.Among the figure,
Be respectively 0.0001,0.001,0.01,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9, arrange in the direction of the clock.
Embodiment
Measuring samples is made
Opening a radius in the basic unit of test specimen to be measured (being the coating film-substrate structure) is
Aperture.
Install by " clamping punching pin "
To clamp disk cap and cylinder punching pin firm grip, and make the film of clamped region can not produce distortion.
Film is loaded as far as possible slowly, rupture to avoid film, loading velocity is controlled at per minute less than in 1 millimeter, makes radius of the final formation of film be
, highly be
Bubbling, and circle ring area should have certain big radius
, to guarantee the validity of surveying work.
The present invention does not do specific requirement to surveying instrument, mainly stresses to provide a method, and according to test condition, the measurement of correlation instrument in this field can be selected for use to the greatest extent.Adopt surveying instrument as far as possible, accurately record the thickness of coating film with degree of precision
, basic unit's perforate radius
, the final bubbling radius that forms of film
, and in the loading procedure corresponding to external force
The bubbling height
Strengthen density measurement, to guarantee adopting trapezoidal method to calculate the precision of definite integral as far as possible.
Energy release rate
Calculating
According to the bubbling radius
Calculate
, by Poisson ratio
With
Value, according to our previous research work (Jun-yi Sun, Jian-li Hu, Xiao-ting He, Zhou-lian, Zheng, 2010. A theoretical study of a clamped punch-loaded blister configuration:the quantitative relation of load and deflection. International Journal of Mechanical Sciences. 52 (7), 928-936.), adopt analytical method accurately to determine calculating parameter
, also can check in calculating parameter roughly by accompanying
drawing 2 provided by the invention
Utilize elastic modulus
And measurement data
And
With the bubbling radius
, basic unit's perforate radius
, coating film thickness
, calculate energy release rate by following formula:
Wherein,
With
Be known parameter,
,
,
,
,
Unit be the millimeter (mm), elastic modulus
Unit be MPa (MPa), external force
Unit be newton (N), energy release rate
Unit be 10
-3Joule/square millimeter (10
-3J/mm
2) or Newton/millimeter (N/mm).