Socket Mounting Recommendations and Reflow Profile
Stencil
Table 1 shows the recommended stencil dimensions. A laser-cut, electro-polished and Ni-plated
stainless steel stencil is recommended to give the most consistent paste release. The apertures
can be made round except for smaller pitches, where square apertures are recommended.
Remember to keep the stencil small enough to fit within the keep-out area of the socket, but yet
have provisions to remove it from the PCB once the paste has been applied.
Table 1: Recommended stencil dimensions.
Device Pitch
(mm)
1.27
PCB Pad Diameter
(mm / in)
Stencil Thickness
(mm/in)
Stencil Aperture
(mm/in)
min. 0.60 / 0.023
min. 0.50 / 0.019
min. 0.40 / 0.016
min. 0.35 / 0.014
min. 0.35 / 0.014
min. 0.30 / 0.012
0.15 / 0.006
0.15 / 0.006
0.13 / 0.005
0.13 / 0.005
0.13 / 0.005
0.13 / 0.005
round 0.66 / 0.026
round 0.55 / 0.022
round 0.44 / 0.017
square 0.39 / 0.015
square 0.39 / 0.015
square 0.33 / 0.013
1.00
0.80
0.75
0.65
0.50
Solder Paste
E-tec recommends using solder paste without ( or <0.5%) silver (Ag) to reduce the solder’s
wetting ability and prevent the paste from running up the pins, thus maximizing the volume of
solder left on the pads. Brands such as Qualitek (www.qualitek.com) or Alpha Metals
(www.alphametals.com) produce such solder paste on customer request. For Sn/Pb solder paste
we recommend Ecorel 803S offered by Avantec (www.avantec.dehon.com).
Reflow Profile
Both standard Sn-Pb eutectic and Pb-free reflow profiles are shown below.
E-tec Interconnect Ltd, Industrial Zone C, CH-1072 Forel (Lavaux), Switzerland
Phone +41-21-781 08 10 · www.e-tec.com · info@e-tec.com
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E-tec Socket Mounting Recommendations
PRELIMINARY