Product Info

LTE Standard Module Series
EC21 Mini PCIe Hardware Design
EC21_Mini_PCIe_Hardware_Design 61 / 64
 Do not apply solder mask on the PCB area where the module is mounted, so as to ensure better heat
dissipation performance.
 The reference ground of the area where the module is mounted should be complete, and add ground
vias as many as possible for better heat dissipation.
 Add a heatsink on the top of the module and the heatsink should be designed with as many fins as
possible to increase heat dissipation area. Meanwhile, a thermal pad with high thermal conductivity
should be used between the heatsink and module.
 Add a thermal pad with appropriate thickness at the bottom of the module to conduct the heat to
PCB.
The following figure shows the referenced heatsink design.
Figure 17: Referenced Heatsink Design
1. The module offers the best performance when the internal BB chip stays below 105°C. When the
maximum temperature of the BB chip reaches or exceeds 105°C, the module works normal but
provides reduced performance (such as RF output power, data rate, etc.). When the maximum BB
chip temperature reaches or exceeds 115°C, the module will disconnect from the network, and it will
recover to network connected state after the maximum temperature falls below 115°C. Therefore, the
thermal design should be maximally optimized to make sure the maximum BB chip temperature
always maintains below 105°C. Customers can execute AT+QTEMP command and get the
maximum BB chip temperature from the first returned value.
2. For more detailed guidelines on thermal design, please refer to document [4].
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