Unitek UNIBOND 2, User Manual

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5 . 11 . F i g u r e 1 8 i l l u s t r a t e s t h e r e l a t i o n s h i p o f contact r e s i s t a n c e and e l e c t r o d e
force. T h i s d a t a was obtained b y c a r e f u l l y a p p l y i n g a l o w f o r c e t o t h e p a r t s . and
reading t h e Milliohmmeter a s t h e f o r c e was increased b y simultaneously t u r n i n g t h e
Force Adjustment Knob on t h e weld head and i n c r e a s i n g t h e f o r c e a p p l i e d t o t h e Foot-
pedal. N o t i c e t h e s t e e p slope o f moly e l e c t r o d e s o n copper r i b b o n combination. C o m -
pare t h e d i f f e r e n c e between copper and moly e l e c t r o d e s o n gold p l a t e d Kovar.
copper t r a c e :
MODE
V V+I V+I V+I
AMPLITUDE ( v o l t s )
0.75 0.75
0.88
0.50
DURATION (ms)
4
4 4 4
ELECTRODES EU1000 EU1000 EU1000
EU1000
ELECTRODE FORCE ( o z )
35
35 35 35
ELECTRODE GAP ( i n c h )
.012
.012 .012 .012
OUTPUT RESISTANCE -
3.75
5 1
RESISTANCE RANGE -
X 1
X 1 X 1
Figure 1 8 - Contact Resistance o f : ( a )
EU1001, Moly Electrodes on copper rib b on
on an unplated copper t r a c e ; ( b ) EU1000,
Copper Electrodes on g o l d p l a t e d Kovar o n
a t i n n e d copper t r a c e ; ( c ) EU1001, Moly
Electrodes on gold p l a t e d Kovar o n a gold
plated copper t r a c e ; a n d ( d ) EU1000, Cop-
per Electrodes on g o l d p l a t e d Kovar o n a
gold p l a t e d copper t r a c e .
1'3'12
to
10
5
( b )
10 5 0 1 0 0 1 5 0
Force (ounces)
200
5.12. T h e Unibond should remain i n t h e VOLTAGE Mode. S e t t h e Amplitude, D u r a t i o n ,
Force and Gap so t h a t a s a t i s f a c t o r y weld i s made. P l a c e t h e weldments under t h e
electrodes. A l l measurements must b e made u s i n g t h e e x a c t e l e c t r o d e c o n f i g u r a t i o n and
Electrode Force which would b e used on t h e production l i n e . A p p l y enough f o r c e , w i t h
the Footpedal, t o h o l d t h e p a r t s i n p o s i t i o n . P r e s s t h e Meter Switch on t h e r e a r o f
the Unibond. P r e s s t h e Cable Pedal u n t i l t h e Meter a u d i b l e alarm sounds. R e c o r d t h e
value o f t h e Meter Reading.
5.13. R e l e a s e t h e Meter Switch and t h e Unibond w i l l make t h e weld. B e c a r e f u l n o t
to increase t h e f o r c e on t h e Footpedal. D o n o t b e concerned i f t h e Overload I n d i c a t o r
l i g h t s . C a r e f u l l y c o n t r o l t h e Footpedal so t h a t t h e f o r c e a p p l i e d by t h e e l e c t r o d e s
does n o t change. P r e s s t h e Meter Switch and r e c o r d t h e Meter Reading. T h i s value
should b e lower t h a n t h e v a l u e obtained i n 5 . 1 2 . R e p e a t t h i s process f i v e o r t e n
times. S e t t h e Weld Resistance S e l e c t o r and Control t o a v a l u e which corresponds t o
the average o f t h e " b e f o r e " and " a f t e r " weld r e s i s t a n c e s .
5.14. P l a c e t h e Unibond i n t h e VOLTAGE + CURRENT Mode. I n a l l p r o b a b i l i t y i t w i l l
be necessary t o increase t h e AMPLITUDE i n order t o o p t i m i z e t h e weld schedule. T h e
following i s a comparision showing t h e e f f e c t o f various Output Resistance s e t t i n g s
for welding . 0 0 3 x . 0 1 5 i n c h g o l d p l a t e d Kovar r i b b o n and a . 0 1 5 i n c h , 1 o z unplated
- 1 7 -