7.
Assembly and Storage Information
7.1
Storage Condition
7.1.1
Moisture Barrier Bag Before Opening
A moisture barrier bag must be stored at a temperature of less than 30°C with humidity under 85% RH.
The calculated shelf life for the dry-packed product is 12 months from the date the bag is sealed.
7.1.2
Moisture Barrier Bag Open
Humidity indicator cards must be blue, RH < 30%.
7.2
Motherboard Solder Paste
The SnAgCu eutectic solder with melting temperature of 217°C is most commonly used for lead-free solder reflow
application. This alloy is widely accepted in the semiconductor industry due to its low cost, relatively low melting
temperature, and good thermal fatigue resistance. Some recommended pastes include NC-SMQ
®
230 flux and
Indalloy
®
241 solder paste made up of 95.5 Sn/3.8 Ag/0.7 Cu or SENJU N705-GRN3360-K2-V Type 3, or SENJU
M705-GRN360-K-V, no clean paste.
7.3
Motherboard Stencil Design
The recommended stencil is a laser-cut, stainless-steel type with thickness of 100 μm to 130 μm and an approximate
ratio of 1:1 for stencil opening to pad dimension. To improve paste release, a positive taper with bottom opening 25
μm larger than the top is utilized. Local manufacturers may find other combinations of stencil thickness and aperture
size to get good results.
7.4
Bake Information
The ATSAMA5D27-WLSOM1 module is rated MSL 3, indicating that storage and assembly processes must be
compliant with IPC/JEDEC J-STD-033C.
The ATSAMA5D27-WLSOM1 module has a total thickness of 3.287 mm (PCB and SMD mounted) and is comparable
to a die package. Thus baking instructions must comply with Table 4-1 of J-STD-033-C as a package body comprised
between 2.0 mm and 4.5 mm.
Refer to the highlighted information in the table below.
SAMA5D27 Wireless SOM1
Assembly and Storage Information
©
2021 Microchip Technology Inc.
and its subsidiaries
Complete Datasheet
DS60001590D-page 56
