Introduction

This Application Note provides a guide on how to solder the phyCORE-i.MX 6UL/ULL module.

Delivery Format

The modules are shipped in 56 mm tapes with a feed of 48 mm (outer reel diameter: 33 cm). 175 pieces are on one reel and 10 slots are empty to enable mounting on a tape feeder.

All other dimensions and tolerances are as per EIA 481 standard.

A0 = 35.50 E 0.20
B0 = 35.50 E 0.20
K0 =  3.30 E 0.20
P1 = 48.00 E 0.10
W  = 56.00 E 0.30
t  =  0.30 E 0.05

Production Settings

Moisture Sensitivity, Shelf Life, and Storage

The modules are rated MSL 3, which means storing them requires adequately before soldering (see IPC/JEDEC J-STD-033C). Store the modules shrink-wrapped in the original packing or, if the packing is opened, store them in a humidity-reduced storage area (rel. humidity < 10%, T < 30°C / 86°F). The shelf life in sealed packaging is 12 months at < 40°C and < 90 % rel. humidity.

Paste Printing

For paste printing, PHYTEC recommends at least a 100 µm stencil without pad reduction. We use type 4 paste. If you want to have more solder paste, it is possible to overprint the pad away from the SOM by a maximum of 0,5mm.

A0 = 35.50 E 0.20
B0 = 35.50 E 0.20
K0 =  3.30 E 0.20
P1 = 48.00 E 0.10
W  = 56.00 E 0.30
t  =  0.30 E 0.05

Placement

For accuracy, the modules have to be placed with a placement machine. Pin 1 is in the corner of the NAND Flash (green marker). With the fix camera of the placement machine, check the fiducial points on the bottom of the SOM. Pin 1 is marked with only 3 fiducial points instead of 4, as can be seen in phyCORE-i.MX 6UL / ULL Top, Bottom, and Side View.

The nozzle has to be able to pick up at least 6 grams. We pick the SOM with a Samsung CP45 TN110 nozzle in the middle of the module and place the module last on the PCB.

The link phyCORE-i.MX 6UL/ULL within the category Dimensioned Drawing on the phyCORE‑i.MX 6UL/ULL download page (https://www.phytec.de/p/som/phycore-imx-6-ul-ull/#downloads/) leads to the layout data. It is available in different file formats. The use of this data helps with integrating the phyCORE-i.MX 6UL/ULL SOM as a single component in your design.

Soldering

Our soldering profiles for the vapor phase soldering are based on J-STD-020E (see below). The liquidus time amounts between 60 s and 90 s, and we recommend a maximum of three soldering processes. The peak body temperature of the populated parts is 260°C.

Note 1:  All temperatures refer to the center of the package, measured on the package body surface that is facing up during assembly reflow (e.g. live-bug). If parts are reflowed in other than the normal live bug assembly reflow orientation (i.e., dead-bug), Tp must be within±2°C of the livebug Tp and still meet the Tc requirements, otherwise, the profile must be adjusted to achieve the latter. To accurately measure actual peak package body temperatures, refer to JEP140 for recommended thermocouple use.

Note2:  Reflow profiles in this document are for classification /preconditioning and are not meant to specify board assembly profiles. Actual board assembly profiles should be developed based on specific process needs and board designs and should not exceed the parameters in this table. For example, if Tc is 260 °C and time Tp is 30 seconds, this means the following for the supplier and the user:

• For a supplier:   The peak temperature must be at least 260 °C. The time above 255 °C must be at least 30 seconds.
• For a user:   The peak temperature must not exceed 260 °C. The time above 255 °C must not exceed 30 seconds.

Note 3:  All components in the test load must meet the classification profile requirements. 

Note 4:  SMD packages classified to a given moisture sensitivity level by using Procedures or Criteria defined within any previous version of J-STD-020, JESD22-A112 (rescinded), IPC-SM-786 (rescinded) do not need to be reclassified to the current revision unless a change in classification level or a higher peak classification temperature is desired.

Revision History