2001 Nov 21

25

Philips Semiconductors

Product specification

Dual-band power amplifier controller for

GSM, PCN and DCS

PCF5079

15 SOLDERING (HVSON10)

15.1

Soldering information

Information contained within this chapter is of a preliminary

nature and may change without notice.

15.2

PCB design guidelines

These guidelines are to help the user in developing the

proper PCB design. For the surface mount process refer to

“Data Handbook IC26; Integrated Circuit Packages”

(document order number 9398 652 90011).

15.2.1

Referring to Fig.20, dimensions Z and G are respectively

the outside to outside and the inside to inside pad

dimensions.

The dimensions X and Y indicate respectively the width

and the length of the pad. Note that the calculated

X dimension is the maximum value in order to avoid solder

bridging between adjacent pads.The calculated

Y dimension is the minimum value and therefore pad

design should start with this value and the pad length at

the outside be extended if more solder joint fillets are

required.

The dimension ‘Cpl’ defines the minimum distance

between the inner tip of the pad and the outer edge of the

thermal pad. It is suggested that this dimension be fixed at

0.15 mm to avoid solder bridging issues between the

thermal pad and the perimeter pads.

handbook, full pagewidth

MGW498

Cpl = 0.15

0.33

0.30

thermal via

Z =

3.46

3.27

Y =

0.69

0.55

G =

2.09

1.20

1.00

X = 0.28

0.50

TYP

2.00 REF

1.20

1.00

Fig.20 HVSON10 PCB pattern.

Dimensions in mm.

The solder mask opening dimension should be larger than the pad dimension by 125 to 150

µm.

15.2.2

The size of the thermal pad should at least match the size

of the exposed die-attach paddle. However, in some

cases, the die-attach paddle size may need to be modified

to avoid solder bridging between the thermal pad and the

perimeter pads. In order to effectively transfer heat from

the top metal layer to the inner or bottom layers of the

PCB, thermal vias should be incorporated into the thermal

pad design. The number of thermal vias will depend on the

application and on the power dissipation and electrical

requirements. It is recommended to incorporate an array

of thermal vias at a pitch of 1.0 to 1.2 mm with the via

diameter between 0.3 and 0.33 mm.