<s>
A	O
ball	B-Algorithm
grid	I-Algorithm
array	I-Algorithm
(	O
BGA	O
)	O
is	O
a	O
type	O
of	O
surface-mount	O
packaging	O
(	O
a	O
chip	B-Algorithm
carrier	I-Algorithm
)	O
used	O
for	O
integrated	O
circuits	O
.	O
</s>
<s>
BGA	O
packages	O
are	O
used	O
to	O
permanently	O
mount	O
devices	O
such	O
as	O
microprocessors	B-Architecture
.	O
</s>
<s>
A	O
BGA	O
can	O
provide	O
more	O
interconnection	O
pins	O
than	O
can	O
be	O
put	O
on	O
a	O
dual	B-Algorithm
in-line	I-Algorithm
or	O
flat	B-Algorithm
package	I-Algorithm
.	O
</s>
<s>
The	O
BGA	O
is	O
descended	O
from	O
the	O
pin	B-Algorithm
grid	I-Algorithm
array	I-Algorithm
(	O
PGA	O
)	O
,	O
which	O
is	O
a	O
package	O
with	O
one	O
face	O
covered	O
(	O
or	O
partly	O
covered	O
)	O
with	O
pins	O
in	O
a	O
grid	O
pattern	O
which	O
,	O
in	O
operation	O
,	O
conduct	O
electrical	O
signals	O
between	O
the	O
integrated	O
circuit	O
and	O
the	O
printed	O
circuit	O
board	O
(	O
PCB	O
)	O
on	O
which	O
it	O
is	O
placed	O
.	O
</s>
<s>
In	O
a	O
BGA	O
the	O
pins	O
are	O
replaced	O
by	O
pads	O
on	O
the	O
bottom	O
of	O
the	O
package	O
,	O
each	O
initially	O
with	O
a	O
tiny	O
solder	B-Algorithm
ball	I-Algorithm
stuck	O
to	O
it	O
.	O
</s>
<s>
The	O
device	O
is	O
placed	O
on	O
a	O
PCB	O
with	O
copper	O
pads	O
in	O
a	O
pattern	O
that	O
matches	O
the	O
solder	B-Algorithm
balls	I-Algorithm
.	O
</s>
<s>
In	O
more	O
advanced	O
technologies	O
,	O
solder	B-Algorithm
balls	I-Algorithm
may	O
be	O
used	O
on	O
both	O
the	O
PCB	O
and	O
the	O
package	O
.	O
</s>
<s>
Also	O
,	O
in	O
stacked	O
multi-chip	B-Algorithm
modules	I-Algorithm
,	O
(	O
package	B-Algorithm
on	I-Algorithm
package	I-Algorithm
)	O
solder	B-Algorithm
balls	I-Algorithm
are	O
used	O
to	O
connect	O
two	O
packages	O
.	O
</s>
<s>
Pin	B-Algorithm
grid	I-Algorithm
arrays	I-Algorithm
and	O
dual-in-line	O
surface	O
mount	O
(	O
SOIC	B-Algorithm
)	O
packages	O
were	O
being	O
produced	O
with	O
more	O
and	O
more	O
pins	O
,	O
and	O
with	O
decreasing	O
spacing	O
between	O
the	O
pins	O
,	O
but	O
this	O
was	O
causing	O
difficulties	O
for	O
the	O
soldering	O
process	O
.	O
</s>
<s>
A	O
disadvantage	O
of	O
BGAs	O
is	O
that	O
the	O
solder	B-Algorithm
balls	I-Algorithm
cannot	O
flex	O
in	O
the	O
way	O
that	O
longer	O
leads	O
can	O
,	O
so	O
they	O
are	O
not	O
mechanically	O
compliant	O
.	O
</s>
<s>
X-ray	B-Library
machines	O
,	O
industrial	O
CT	O
scanning	O
machines	O
,	O
special	O
microscopes	O
,	O
and	O
endoscopes	O
to	O
look	O
underneath	O
the	O
soldered	O
package	O
have	O
been	O
developed	O
to	O
overcome	O
this	O
problem	O
.	O
</s>
<s>
Pre-configured	O
solder	B-Algorithm
balls	I-Algorithm
matching	O
the	O
array	O
pattern	O
can	O
be	O
used	O
to	O
reball	O
BGAs	O
when	O
only	O
one	O
or	O
a	O
few	O
need	O
to	O
be	O
reworked	O
.	O
</s>
<s>
Due	O
to	O
the	O
cost	O
of	O
visual	O
X-ray	B-Library
BGA	O
inspection	O
,	O
electrical	O
testing	O
is	O
very	O
often	O
used	O
instead	O
.	O
</s>
<s>
The	O
less	O
reliable	O
type	O
is	O
a	O
ZIF	B-General_Concept
socket	I-General_Concept
,	O
with	O
spring	O
pinchers	O
that	O
grab	O
the	O
balls	O
.	O
</s>
<s>
quad-flat	B-Algorithm
no-leads	I-Algorithm
package	I-Algorithm
)	O
or	O
BGA	O
packages	O
,	O
various	O
DIY	O
reflow	O
methods	O
have	O
been	O
developed	O
using	O
inexpensive	O
heat	O
sources	O
such	O
as	O
heat	O
guns	O
,	O
and	O
domestic	O
toaster	O
ovens	O
and	O
electric	O
skillets	O
.	O
</s>
<s>
CBGA	O
and	O
PBGA	B-Algorithm
denote	O
the	O
ceramic	O
or	O
plastic	O
substrate	O
material	O
to	O
which	O
the	O
array	O
is	O
attached	O
.	O
</s>
<s>
FBGA	B-Algorithm
:	O
fine	O
ball	B-Algorithm
grid	I-Algorithm
array	I-Algorithm
based	O
on	O
ball	B-Algorithm
grid	I-Algorithm
array	I-Algorithm
technology	O
.	O
</s>
<s>
It	O
has	O
thinner	O
contacts	O
and	O
is	O
mainly	O
used	O
in	O
system-on-a-chip	B-Architecture
designs	O
;	O
also	O
known	O
as	O
fine	O
pitch	O
ball	B-Algorithm
grid	I-Algorithm
array	I-Algorithm
(	O
JEDEC-Standard	O
)	O
or	O
fine	O
line	O
BGA	O
by	O
Altera	O
.	O
</s>
<s>
UFBGA	B-Algorithm
and	O
UBGA	B-Algorithm
and	O
ultra	O
fine	O
ball	B-Algorithm
grid	I-Algorithm
array	I-Algorithm
based	O
on	O
pitch	O
ball	B-Algorithm
grid	I-Algorithm
array	I-Algorithm
.	O
</s>
<s>
Effectively	O
also	O
the	O
flip	B-Device
chip	I-Device
methods	O
for	O
mounting	O
chip	O
dies	O
to	O
a	O
carrier	O
is	O
sort	O
of	O
a	O
BGA	O
design	O
derivate	O
with	O
the	O
functional	O
equivalent	O
of	O
the	O
balls	O
there	O
being	O
called	O
bumps	O
or	O
micro	O
bumps	O
.	O
</s>
<s>
To	O
make	O
it	O
easier	O
to	O
use	O
ball	B-Algorithm
grid	I-Algorithm
array	I-Algorithm
devices	O
,	O
most	O
BGA	O
packages	O
only	O
have	O
balls	O
in	O
the	O
outer	O
rings	O
of	O
the	O
package	O
,	O
</s>
<s>
Intel	O
used	O
a	O
package	O
designated	O
BGA1	O
for	O
their	O
Pentium	B-General_Concept
II	I-General_Concept
and	O
early	O
Celeron	B-Device
mobile	O
processors	O
.	O
</s>
<s>
BGA2	B-Algorithm
is	O
Intel	O
's	O
package	O
for	O
their	O
Pentium	B-General_Concept
III	I-General_Concept
and	O
some	O
later	O
Celeron	B-Device
mobile	O
processors	O
.	O
</s>
<s>
BGA2	B-Algorithm
is	O
also	O
known	O
as	O
FCBGA-479	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
"	O
micro-FCBGA	B-Algorithm
"	O
(	O
flip	B-Device
chip	I-Device
ball	B-Algorithm
grid	I-Algorithm
array	I-Algorithm
)	O
is	O
Intel	O
's	O
current	O
BGA	O
mounting	O
method	O
for	O
mobile	O
processors	O
that	O
use	O
a	O
flip	B-Device
chip	I-Device
binding	O
technology	O
.	O
</s>
<s>
It	O
was	O
introduced	O
with	O
the	O
Coppermine	O
Mobile	B-Device
Celeron	I-Device
.	O
</s>
<s>
Micro-FCBGA	B-Algorithm
has	O
479	O
balls	O
that	O
are	O
0.78mm	O
in	O
diameter	O
.	O
</s>
<s>
This	O
is	O
thinner	O
than	O
a	O
pin	B-Algorithm
grid	I-Algorithm
array	I-Algorithm
socket	O
arrangement	O
,	O
but	O
is	O
not	O
removable	O
.	O
</s>
<s>
The	O
479	O
balls	O
of	O
the	O
Micro-FCBGA	B-Algorithm
package	O
(	O
a	O
package	O
almost	O
identical	O
to	O
the	O
478-pin	O
socketable	O
micro-FCPGA	B-Device
package	O
)	O
are	O
arranged	O
as	O
the	O
6	O
outer	O
rings	O
of	O
a	O
1.27mm	O
pitch	O
(	O
20	O
balls	O
per	O
inch	O
pitch	O
)	O
26x26	O
square	O
grid	O
,	O
with	O
the	O
inner	O
14x14	O
region	O
empty	O
.	O
</s>
