BGA - Ball Grid Array

BGA for HDI PCB

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 proposal

The values given are design proposals, values of component data sheets are always preferable.

Pitch Ø BGA-Pad* Ø Via-Pad / Via-Drill Ø Via-Pad**/ Via-Drill Track-width / -space Track-width / -space
Pitch Ø BGA-Pad* 
BGA Pad diameter
Ø Via-Pad / Via-DrillDog-Bone BGA Dogbone Via Pad diameterØ Via-Pad**/ Via-DrillVia-in-Pad BGA Via in Pad diameterTrack-width / -spaceInner layer BGA Inner layer track-widthTrack-width / -spaceInner layer BGA Inner layer conductor width
Pitch1,27mmØ BGA-Pad*550µmØ Via-Pad / Via-Drill550µm/300µmØ Via-Pad**/ Via-Drill-Track-width / -space150µm/285µmTrack-width / -space150µm/140µm
Pitch1,00mmØ BGA-Pad*500µmØ Via-Pad / Via-Drill500µm/200µmØ Via-Pad**/ Via-Drill-Track-width / -space150µm/175µmTrack-width / -space100µm/100µm
Pitch0,80mmØ BGA-Pad*350µmØ Via-Pad / Via-Drill450µm/150µmØ Via-Pad**/ Via-Drill400µm/200µmTrack-width / -space150µm/100µmTrack-width / -space70µm/70µm
Pitch0,50mmØ BGA-Pad*250µmØ Via-Pad / Via-Drill250µm/100µmØ Via-Pad**/ Via-Drill300µm/100µmTrack-width / -space70µm/90µmTrack-width / -space-

*plus 50µm circumferential solder-stop clearance
**plus 50µm circumferential solder-stop clearance, please order as IPC 4761 Type VII: Filled & Capped Vias

BGA Dogbone - Detail

Outer layers

Leiterplatte BGA Parameter
 
Pitch =
1,27mm 1,00mm 0,80mm 0,50mm
 a
Pitch =
Ø BGA Pad (solder pad)1,27mm550µm1,00mm500µm0,80mm350µm0,50mm250µm
 b
Pitch =
Solder-stop (SS) clearance, circumferential1,27mm75µm1,00mm75µm0,80mm75µm0,50mm75µm
 c
Pitch =
Ø Solder-stop clearance1,27mm700µm1,00mm650µm0,80mm500µm0,50mm400µm
 d
Pitch =
Stringer length (approx.)1,27mm348µm1,00mm207µm0,80mm165µm0,50mm103µm
 e
Pitch =
Ø Via Pad1,27mm550µm1,00mm500µm0,80mm450µm0,50mm250µm
 f
Pitch =
Ø Via Pad drill (final)1,27mm300µm1,00mm200µm0,80mm150µm0,50mm100µm
 g
Pitch =
Via Pad <> BGA Pad1,27mm348µm1,00mm207µm0,80mm165µm0,50mm103µm
 h
Pitch =
Stringer width1,27mm250µm1,00mm250µm0,80mm200µm0,50mm150µm
 i
Pitch =
SS clearance <> SS clearance1,27mm570µm1,00mm350µm0,80mm300µm0,50mm100µm
 j
Pitch =
Via Pad <> Via Pad1,27mm720µm1,00mm500µm0,80mm350µm0,50mm250µm

The values given are design proposals, values of component data sheets are always preferable.


BGA inner layer 1 fan out

Inner layers

Fan-Out with 1 track

 
Pitch =
1,27mm 1,00mm 0,80mm 0,50mm
 e
Pitch =
Ø Via Pad1,27mm670µm1,00mm550µm0,80mm425µm0,50mm260µm
 b
Pitch =
Ø Via Pad Drill1,27mm300µm1,00mm250µm0,80mm150µm0,50mm100µm
 k
Pitch =
Track Width1,27mm200µm1,00mm150µm0,80mm125µm0,50mm80µm
 l
Pitch =
Track Space1,27mm200µm1,00mm150µm0,80mm125µm0,50mm80µm

BGA Innenlagen 2 fan out

Inner layers

Fan-Out with 2 tracks

 
Pitch =
1,27mm 1,00mm 0,80mm 0,50mm
 e
Pitch =
Ø Via Pad1,27mm620µm1,00mm485µm0,80mm300µm0,50mm-
 b
Pitch =
Ø Via Pad Drill1,27mm300µm1,00mm250µm0,80mm150µm0,50mm-
 k
Pitch =
Track Width1,27mm125µm1,00mm100µm0,80mm100µm0,50mm-
 l
Pitch =
Track Space1,27mm125µm1,00mm100µm0,80mm100µm0,50mm-

BGA Innenlagen 3 fan out

Inner layers

Fan-Out with 3 tracks

 
Pitch =
1,27mm 1,00mm 0,80mm 0,50mm
 e
Pitch =
Ø Via Pad1,27mm550µm1,00mm460µm0,80mm275µm0,50mm-
 b
Pitch =
Ø Via Pad Drill1,27mm250µm1,00mm200µm0,80mm100µm0,50mm-
 k
Pitch =
Track Width1,27mm100µm1,00mm75µm0,80mm75µm0,50mm-
 l
Pitch =
Track Space1,27mm100µm1,00mm75µm0,80mm75µm0,50mm-