Several types of Ag powder were used as electrode paste for a multilayer ceramic substrate. The shrinkage behavior of the silver powders was investigated during the sintering. Bending and cracking were frequently observed on the substrate when coarse powders that show a broad size distribution and aggregation were used. The shrinkage curve of the Ag paste obtained by spray pyrolysis agreed well with that of the substrate. Furthermore, the electrical properties of the Ag paste were also determined. The resistivity of a silver electrode sintered at 900°C was about 2.00×10-6 Ω･cm.

Several types of Ag powder were used as electrode paste for a multilayer ceramic substrate. The shrinkage behavior of the silver powders was investigated during the sintering. Bending and cracking were frequently observed on the substrate when coarse powders that show a broad size distribution and aggregation were used. The shrinkage curve of the Ag paste obtained by spray pyrolysis agreed well with that of the substrate. Furthermore, the electrical properties of the Ag paste were also determined. The resistivity of a silver electrode sintered at 900 C was about 2.00×10 -6 Ω･cm.Key words: Electrode, Silver, Paste, Sintering, Substrate . I N T R O D U C T I O NT h e a d v a n t a g e o f l o w -t e m p e r a t u r e c o -f i r e d c e r a m i c s ( L T C C ) w h i c h e n a b l e s s i n t e r i n g a t l e s s t h a n 1 0 0 0 C i s t h e p o s s i b i l i t y t o u s e t h e c o n d u c t i v e m a t e r i a l s w i t h l o w r e s i s t i v i t y . M e t a l s s u c h a s A g , P d , A g -P d a l l o y , a n d N i h a v e b e e n u s e d a s c o n d u c t i v e m a t e r i a l s b e c a u s e t h e i r s i n t e r i n g t e m p e r a t u r e s a r e c l o s e t o t h a t o f c o n v e n t i o n a l l y u s e d s u b s t r a t e s . S o f a r , s e v e r a l t y p e s o f A g p o w d e r h a v e be e n u s e d a s e l e c t r o d e p a s t e f o r L T C C s u b s t r a t e s [ 1 -4 ] . T h e p a r t i c l e c h a r a c t e r i s t i c s o f A g p o w d e r s a f f e c t t h e i r s h r i n k a g e b e h a v i o r d u r i n g t h e s i n t e r i n g , a n d w h e n c o a r s e A g p o w d e r s w i t h a b r o a d s i z e d i s t r i b u t i o n a n d a g g r e g a t i o n a r e u s e d , t h e y f r e q u e n t l y s h o w b e n d i n g a n d c r a c k i n g o n t h e s u b s t r a t e . F o r t h e s e c o a r s e A g p o w d e r s , s u r f a c e t r e a t m e n t i s c a r r i e d o u t u s i n g v a r i o u s a d d i t i v e s . T h e r e f o r e , i t i s i m p o r t a n t t o u n d e r s t a n d t h e s i n t e r i n g b e h a v i o r o f A g p a r t i c l e s o f s u b m i c r o n s i z e a n d n a r r o w s i z e d i s t r i b u t i o n i n o r d e r t o s o l v e s u c h p r o b l e m s . I n t h i s w o r k , v a r i o u s t y p e s o f s i l v e r p o w d e r w e r e p r e p a r e d b y c h e m i c a l r e d u c t i o n a n d s p r a y p y r o l y s i s a n d t h e nt h e i r s i n t e r i n g b e h a v i o r w a s i n v e s t i g a t e d i n d e t a i l .T h e e l e c t r i c a l p r o p e r t i e s o f A g p a s t e w e r e a l s o d e t e r m i n e d . , ( e ) ) , a n d 5 m ( F i g . 1 ( a ) , ( d ) ) , r e s p e c t i v e l y . T h e i r s p e c i f i c s u r f a c e a r e a w a s l e s s t h a n 1 m 2 / g a n d t a p d e n s i t i e s r a n g e d f r o m 3 . 9 t o 4 . 9 g / c m 3 . . E X P E R I M E N T A L . 1 S t a r t i n g m a t e r i a l s T h e p a r t i c l e c h a r a c t e r i s t i c s o f A g p o w d e r s o b t a i n e d b y c h e m i c a l r e d u c t i o n a n d s p r a y T h e t ...