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Submitted on 1 Jan 1983
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PHOTOTHERMAL EXAMINATION OF AN ADHESIVE BONDED PIEZOMEMBRANE FOR TELEPHONE APPLICATION - A SELF-TESTING
SAMPLE
R. Tilgner, J. Baumann
To cite this version:
R. Tilgner, J. Baumann. PHOTOTHERMAL EXAMINATION OF AN ADHESIVE BONDED
PIEZOMEMBRANE FOR TELEPHONE APPLICATION - A SELF-TESTING SAMPLE. Journal
de Physique Colloques, 1983, 44 (C6), pp.C6-469-C6-470. �10.1051/jphyscol:1983675�. �jpa-00223234�
JOURNAL DE PHYSIQUE
Colloque C6, suppl6ment au nO1O, Tome 44, octobre 1983 page C6- 469
PHOTOTHERMAL EXAMINATION OF AN ADHESIVE BONDED PIEZOMEMBRANE FOR
TELEPHONE APPLICATION
-
A SELF-TESTING SAMPLER . T i l g n e r and J . ~aurnann'
Reitmorstrasse 4 9 , 0-8000 Mnchen 22, F.R. G.
'siemens, Romerhofweg 51E, 0-8046 Garching, F.R. G.
Ri.sumi!
-
En b a l a y a n t u n e membrane d e t 6 l i l p h o n e p i 6 z o - c g r a m i q u e a v e c u n e t a c h e l u m i n e u s e o n o b t i e n ti
l ' a i d e d u s i g n a l p h o t o t h e r m i q u e u n e i m a g e c a r a c t i i r i s t i q u e d e l l i . c h a n t i l l o n q u i p e u t e t r e e v a l u e e e t u t i l i s e e comme r n e t h o d e d ' a n a l y s e n o n - d e s t r u c t i v e . A b s t r a c t - S c a n n i n g a p i e z o c e r a m i c d r i v e n t e l e p h o n e membrane b y a l i g h t s p o t r e s u l t s i n a n e v a l u a b l e p h o t o t h e r m a l s i g n a l p a t t e r n ,which may b e u s e d f o r n o n d e s t r u c t i v e t e s t i n g .
F o r t e l e p h o n e a p p l i c a t i o n an a l u m i n u m a l l o y membrane, a b o u t 250pm t h i c k , h a s b e e n a t t a c h e d t o a d r i v i n g p i e z o e l e c t r i c c e r a m i c f o i l o f 1 5 0 pm t h i c k n e s s b y means o f an a d h e s i v e l a y e r o f a d j u s t a b l e v a r i a b l e t h i c k n e s s / 1 / ( f i g . 1 ) . To c h e c k t h e q u a l i t y o f t h e b o n d i n g a
F i g . 1 . : A l - M e m b r a n e f o r t e l e p h o n e a p p l i c a t i o n d r i v e n b y a n a t t a c h e d p i e z o e l e c t r i c c e r a m i c w i t h a s t a n d a r d d e l a m i n a t i o n - ( P T F E - f o i 1 ) .
n o n d e s t r u c t i v e t e s t ( N D T ) was n e e d e d . We r e a l i z e d a s t a n d a r d d e l a m i - n a t i o n b y i n s e r t i n g a 5 pm t h i c k p o l y t e t r a f l u o r e t h y l e n e s t r i p b e t w e e n t h e c e r a m i c a n d t h e a d h e s i v e l a y e r . S t a n d a r d NDT m e t h o d s as X - r a y o r c o n v e n t i o n a l u l t r a s o n i c e x a m i n a t i o n w e r e n o t a p p l i c a b l e t o t h i s p r o b l e m . The c o n t r a s t o b t a i n e d i n a X - r a y p i c t u r e i s much t o o l o w f o r e v a l u a b l e p a t t e r n s . U n l i k e X - r a y e x a m i n a t i o n u l t r a s o n i c t e c h n i q u e i s a b l e t o t e s t t h e f u n c t i o n o f t h e b o n d i n g , b u t u l t r a s o n i c imagin.9 i s n o t r e a l l y f r e e o f m e c h a n i c a l c o n t a c t : t h e r e i s a c o u p l i n g f l u i d n e c e s s a r y t o g u i d e t h e a c o u s t i c w a v e s i n t o t h e s a m p l e . As t h e t e l e p h o n e membranes a r e f a b r i c a t e d b y an a u t o m a t i c p r o d u c t i o n l i n e , s u c h a t e s t w o u l d mean a c o n s i d e r a b l e c o m p l i c a t i o n o f t h e m a n u f a c t u - r i n g f l o w .
Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1983675
C6-470 JOURNAL DE PHYSIQUE
P h o t o t h e r m a l e x a m i n a t i o n may g i v e an e l e g a n t s o l u t i o n u s i n g t h e t e l e p h o n e membrane a s a s e l f - t e s t i n g s a m p l e 2 . S c a n n i n g t h e
Position on
the Sample
F i g . 2 . : D i a m e t r a l s c a n a c r o s s t h e s a m p l e c o n t a i n i n g
a
s t a n d a r d d e l a m i n a t i o n .aluminym f o i l w i t h t h e l i g h t s p o t o f a 50 W h a l o g e n lamp o r a 1 W A r - l a s e r r e s u l t s i n p h o t o t h e r m a l s i g n a l s , w h i c h may be c o n v e - n i e n t l y d e t e c t e d by t h e p i e z o c e r a m i c . F i g . 2 shows t h e a m p l i t u d e of t h e p h o t o t h e r m a l s i g n a l o b t a i n e d f r o m a d i a m e t r a l s c a n a c r o s s t h e s a m p l e . The s p a t i a l r e s o l u t i o n o f t h e method i s i n t h e o r d e r of t h e s a m p l e ' s t h e r m a l d i f f u s i o n l e n g t h , w h i c h i s i n a c c o r d a n c e w i t h o t h e r w o r k e r ' s o b s e r v a t i o n s / 3 / . As f a r we know, t h i s i s t h e f i r s t c o n c r e t e a p p l i c a t i o n of t h e r m a l waves f o r n o n d e s t r u c t i v e t e s t i n g i n i n d u s t r i a l qua1 i t y c o n t r o l .
/ 1 / K . W a l l i s e r ; F r e q u e n z 3 0 , 272 ( 1 9 7 6 )
/ 2 / R . T i l g n e r and J . B a u m z n ; J . N o n d e s t r . E v a l . 3 ( 2 1 , 1 1 3 ( 1 9 8 2 ) / 3 / R . L . Thomas e t a l . ; J . A p p l . P h y s . - 5 1 , 1152 ( 1 9 8 0 )
