BGA für HDI Leiterplatte

BGAs (Ball Grid Arrays) are SMD components with connections on the bottom of the component. Each pin is provided with a solder ball. All connections are distributed in a uniform surface grid or matrix on the component. Common grids are nowadays: 1.27 mm - 1.00 mm - 0.80 mm - 0.50 mm.

With several hundred component connections, the number of „routable" pins is limited per layer.  The inner pins of the BGA can only be connected through a via and routed to another layer > DogBone technology.

If the pitch is even smaller, or if traces between the solder pads are necessary, the via-in-pad technology is recommended: The vias are placed directly into the solder pads of the BGA.

Manufacturer's instructions must be followed carefully. These define the elementary connection distances, solder ball diameters and the housing geometries. Other technical details such as technology of the vias or trace -width and -spacing will be specified by the designer. For possible parameters check the following tables.

 

BGA - Design Recommendations

Pitch
[mm]

Ø BGA-Pad*

Ø Via-Pad
/ Via-Drill

Ø Via-Pad**
/ Via-Drill

Track-width
/ -spacing

Track-width
/ -spacing


BGA Pad Diameter

Dog-Bone
BGA Dogbone Via Pad Diameter

Via-in-Pad
BGA Via in Pad diameter

Inner layer
BGA Inner layer track-width

Inner layer
BGA Inner layer track-space

1,27

550µm

550µm/300µm

-

150µm/285µm

150µm/140µm

1,00

500µm

500µm/200µm

-

150µm/175µm

100µm/100µm

0,80

350µm

450µm/150µm

400µm/200µm

150µm/100µm

70µm/70µm

0,50

250µm

250µm/100µm

300µm/100µm

70µm/90µm

-

*plus 50µm annular solder-stop clearance
**plus 50µm annular solder-stop clearance, please order as filled & capped

BGA Dogbone - Detail

Printed Circuit BGA Parameter
 


Outer layers

Pitch =

1,27mm

1,00mm

0,80mm

0,50mm

a

Ø BGA Pad (solder pad)

550µm

500µm

350µm

250µm

b

Solder-stop (SS) clearance, annular

75µm

75µm

75µm

75µm

c

Ø Solder-stop clearance

700µm

650µm

500µm

400µm

d

Stringer length (approx.)

348µm

207µm

165µm

103µm

e

Ø Via Pad

550µm

500µm

450µm

250µm

f

Ø Via Pad drill (final)

300µm

200µm

150µm

100µm

g

Via Pad <> BGA Pad

348µm

207µm

165µm

103µm

h

Stringer width

250µm

250µm

200µm

150µm

i

SS clearance <> SS clearance

570µm

350µm

300µm

100µm

j

Via Pad <> Via Pad

720µm

500µm

350µm

250µm

 

Inner layers

Fan-Out with 1 conductor:

Pitch =

1,27mm

1,00mm

0,80mm

0,50mm

e

Ø Via Pad

BGA inner layers routing 1 track

670µm

550µm

425µm

260µm

b

Ø Via Pad Drill

300µm

250µm

150µm

100µm

k

Track Width

200µm

150µm

125µm

80µm

l

Track Space

200µm

150µm

125µm

80µm

 


Fan-Out with 2 conductors:

Pitch =

1,27mm

1,00mm

0,80mm

0,50mm

e

Ø Via Pad

BGA inner layers routing 2 tracks

620µm

485µm

300µm

-

b

Ø Via Pad Drill

300µm

250µm

150µm

-

k

Track Width

125µm

100µm

100µm

-

l

Track Space

125µm

100µm

100µm

-

 


Fan-Out with 3 conductors:

Pitch =

1,27mm

1,00mm

0,80mm

0,50mm

e

Ø Via Pad

BGA inner layers routing 3 tracks

550µm

460µm

275µm

-

b

Ø Via Pad Drill

250µm

200µm

100µm

-

k

Track Width

100µm

75µm

75µm

-

l

Track Space

100µm

75µm

75µm

-