Hardware Manual

https://www.phytec.de/cdocuments/?doc=DBeSCw


Component Placement

phyCORE-i.MX8M mini SOM

phyBOARD-Polis (phyCORE-i.MX8M mini Carrier Board)



Mechanical Files

phyCORE-i.MX8M mini SOM (PCB: )

File Type

Download

Published

3D Model



DXF



phyCORE-i.MX8M mini Single Board Computer (PCB: )

File Type

Download

Published

3D Model



DXF



Footprint

The following file includes the technical specifications required to mate phyCORE-i.MX8M mini SOM to your custom carrier board. 

TBD


Pin Muxing

Use the following resources to plan your carrier board design and select the pin multiplex setting for each processor pad. 

Description

Download

Published

PHYTEC spreadsheet


NXP Pins Tool Configuration File

2020-08-10 09:40 AM

Schematics

PHYTEC Schematics are controlled documents and made available upon request. Register for an account first and then Submit a Schematic Request.


Soldering Information

The phyCORE-i.MX8M mini has a direct solder connection (DSC) that allows it to be populated directly onto a carrier board with a pick and place machine. 

  • For the best soldering results, we recommend using the parameters in this guide as much as possible. Variations may cause issues when soldering the phyCORE-i.MX8M mini SOM
  • Due to the SOM's weight and to reduce the soldering cycles, we recommend populating the SOM on top of the assembly-side of the carrier board with the SOM's assembly-side facing upwards.
  • For technical support or additional information, please contact our technical support team.

The modules are shipped in reels. For more information, please contact sales@phytec.com.

Dimensional Drawings



All dimensions and tolerances as per EIA 481 standard.

Links for Dimensional Drawings

Moisture Sensitivity, Shelf Life, and Storage


The phyCORE-i.MX8M mini SOM is rated at Moisture Sensitivity Level (MSL) 3 and requires proper storage before soldering (see IPC / JEDEC J-STD-033C). PHYTEC recommends storing the modules shrink-wrapped in the original packaging. If the packaging is opened, store the SOMs in humidity reduced storage (rel. Humidity <10%, T <30 ° C / 86 ° F). The shelf life for sealed packaging is 12 months at <40 ° C and <90% rel. humidity.

Paste printing


Stencils

  • Stencil thickness: 100µm / 4mil
  • Stencil alignment: 25% off the smallest pad
  • For better durability in regards to mechanical vibrations and shock, the golden edges of the module can be soldered. PHYTEC conducts mechanical stress tests without soldered edges and this does not yield problems (shock test: 40g, sinusoidal vibrations: 8g at 10 - 150Hz; random noise vibrations: 4g at 10 - 500 Hz). PHYTEC also performs temperature shock tests without soldered edges and this does not yield problems (750 cycles from -40 ° C to 125 ° C).

Solder paste

The following solder paste type has been approved for mounting the module onto a carrier:

  • SAC305 (Lead-free: Alpha OM-340 Type 4 or equivalent)

Coplanarity

The coplanarity measured for the phyCORE-i.MX8M mini is <0.003" bow and twist (with a 98% confidence interval). It is important that the carrier board is also coplanar. If the carrier board is thinner than the phyCORE-i.MX8M mini, it is recommended that the carrier board be supported near the center during the reflow process, ie a reflow fixture should be used to minimize the potential bow of the carrier board.

SMT pick and place

  • Placement Nozzle: Largest nozzle that is available on the machine
  • Nozzle Pick Surface: Center of Shield on phyCORE-i.MX8M mini SOM
  • Placement Speed: Slowest speed for the machine
  • Placement alignment: 10% of pad diameter (compensating for module weight and supporting alignment). 
  • The module should be the last component placed on the carrier board to reduce the risk of unexpected shifting.

SMT Process Parameter Reference


ProcessSMT ProcessSpecification Recommendations



Screen Print


Solder PasteLeaded: Indium NC-SMQ92J
Lead-free: Alpha OM-340
Stencil Thickness0.15 mm / 5 mil
Stencil Diameter1.47 mm / 58 mil
Paster Alignment25% off the pad (offset <0.25 diameter)




PnP
Placement Nozzle0>15 mm vacuum 
Nozzle Pick SurfacePnP cap center
SpeedSlowest speed for the machine
Placement SequencePlace the SOM last
Placement Alignment50% off the pad (offset <.5 diameter)

ReflowBelt Speed0.6 -1.1 m/sec

Refer to SMT Profile below

Soldering


PHYTEC's soldering profiles for vapor phase soldering is based on J-STD-020E (see below). The liquidus time is between 60 - 90 seconds. PHYTEC recommends a maximum of three soldering processes. The peak body temperature of the populated components should not exceed 260°C.

Classification Profile (J-STD-020E1, Table 5-2, Page 8)

Profile FeaturePb-Free Assembly
Preheat/Soak:
Temperature Min (Tsmin)
Temperature Max (Tsmax)
Time (ts) from (Tsmin to Tsmax)

150°C 
200°C
60-120 seconds
Ramp-up Rate (TL to Tp)3°C  / second max.
Liquidus temperature (TL)
Time (tL) maintained above TL
217°C 
60-150 seconds
Peak Package Body TemperatureFor users: Tp must not exceed the classification temperature in Table 4-2. 
For suppliers: Tp must equal or exceed the classification temperature in Table 4-2.
Time (Tp)* within 5°C of the specified classification temperature (Tc), see Figure 5-1.30* seconds
Ramp-down Rate (Tp to TL)6°C  / second max.
Time 25°C  to peak temperature8 minutes max
*Tolerance for peak profile temperature (Tp) is defined as a supplier minimum and a user maximum.

Note 1:  All temperatures in the above table are measured at the center of the SOM, measured on the top surface that is facing up during assembly/reflow (e.g. live-bug). If the assembly is reflowed in a way 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 useage.

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 the above 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 MSL by using procedures/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.

Classification Profile (J-STD-020E1, Figure 5-1, Page 8)