VBUS05A1-SD0 Datasheet, PDF (6/10 Pages) Vishay Siliconix – Low Capacitance Bidirectional Symmetrical (BiSy) Single Line ESD-Protection Diode in Silicon Package

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APPLICATION NOTE
1. PCB FOOTPRINT DESIGN
Verified by internal tests, Vishay recommends the soldering
pad and solder mask opening design as shown in fig. 1. We
recommend using a non-solder mask defined (NSMD)
design, as shown below. The reason is that with a NSMD
design, the size of the actual solder pad is more accurate
(tolerances for copper etchings are smaller compared to a
solder mask defined process).
0.75
0.05
VBUS05A1-SD0
Vishay Semiconductors
0.28
0.28
soldering mask opening
solder pad
Fig. 1 - Recommended Soldering Pad Design
2. PCB SOLDERING PAD METALLIZATION
There are several common pad metallization/finishes,
including OSP (Organic Solderability Protectant), HASL (Hot
Air Solder Level), and ENiAu. Because of the CLP0603’s
extremely small size, Vishay only recommends using the
electroless Ni/immersion gold over copper pad plating.
3. SCREEN PRINT PROCESS
The solder paste is applied to the PCB by using a screen
print process. The recommended stencil thickness for the
CLP0603 package is 80 μm (the absolute maximum is
100 μm). The recommended dimensions for the stencil
openings are 12 mil (300 μm) by 8 mil (200 μm) for both
pads. The side wall of the stencil openings should be
tapered approximately 5 degrees. An electro-polished finish
will support a better release of the paste.
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Fig. 2 - Maximum Stencil Openings -
for a Stencil Thickness of 80 μm
Note
• A wider stencil opening will result in a better solder paste release
from the stencil. So the best quality can be obtained by using the
optimum between the stencil quality, thickness, and opening.
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If a tilting of the package is observed, the amount of solder
paste should be reduced slightly. Please also take into
consideration the direct relation between the amount of
solder paste and the package shear strength.
4. SOLDER PASTE TYPE
Type 4 solder pastes (or smaller powder sizes) are
recommended. In our evaluation we used the Cookson
Electronics’ Alpha OM-338 CSP (96.5 % Sn/3 % Ag/0.5 %
Cu) solder paste.
5. REFLOW SOLDERING PROCESS
A standard surface-mount reflow soldering process can be
used (reference: JPC/JEDEC J-STD-020D).
However, for an optimum process, recommendations from
the solder paste supplier should be considered. Variations in
chemistry and viscosity of the fluxer may require small
adjustments to the soldering profile.
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Rev. 1.0, 09-Jul-13
6
Document Number: 85245
For technical questions, contact: [e-mail]
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000