O
o
- Jan 1, 1970
- 0
hi, a smt assembly question ..
assuming we are talking about a double sided boards , each side active
chips with .5mm spacing and 0805 resistors etc.
a local assembly house told me that they would make a solder stencil
for each side of the board ( $250 each is that ok? ) ... so they print
solder on the first side , p and p the components and run it on the IR
reflow belt , then repeat for the other side
my question #1 ... in the older days with bigger components i know
they used glue dots on the first side to hold the components so they
didn't fall off when they reflowed the second side ? do they still do
this today or won't the back side of the board get hot enough for the
solder to flow and the components to fall off ?
the reason i wonder .. is i thought the fine pitch parts need to self
center during reflow on side one and that wouldn't happen if they were
glued down ..
my question #2 ... i guess you can't batch oven relow 2 sided boards ?
( unless i guess everything is glued down .. is would seem tough to
have glue dots small enough for 0805 )
thanks for any insight ... o
assuming we are talking about a double sided boards , each side active
chips with .5mm spacing and 0805 resistors etc.
a local assembly house told me that they would make a solder stencil
for each side of the board ( $250 each is that ok? ) ... so they print
solder on the first side , p and p the components and run it on the IR
reflow belt , then repeat for the other side
my question #1 ... in the older days with bigger components i know
they used glue dots on the first side to hold the components so they
didn't fall off when they reflowed the second side ? do they still do
this today or won't the back side of the board get hot enough for the
solder to flow and the components to fall off ?
the reason i wonder .. is i thought the fine pitch parts need to self
center during reflow on side one and that wouldn't happen if they were
glued down ..
my question #2 ... i guess you can't batch oven relow 2 sided boards ?
( unless i guess everything is glued down .. is would seem tough to
have glue dots small enough for 0805 )
thanks for any insight ... o