HUAWEI MU509-65 HSDPA LGA Module
Hardware Guide
Mechanical Specifications
Issue 01 (2016-04-08)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
66
6.9.4 Welding Area Treatment
Step 1
Remove the old solder by using a soldering iron and solder braid that can wet the
solder.
Step 2
Clean the pad and remove the flux residuals.
Step 3
Solder pre-filling: Before the module is installed on a board, apply some solder paste
to the pad of the module by using the rework fixture and stencil or apply some solder
paste to the pad on the PCB by using a rework stencil.
It is recommended that a fixture and a mini-stencil be made to apply the solder paste in the
rework.
6.9.5 Module Installation
Install the module precisely on the module and ensure the right installation direction of
the module and the reliability of the electrical connection with the PCB. It is
recommended that the module be preheated in order to ensure that the temperature
of all parts to be soldered is uniform during the reflow process. The solder quickly
reflows upon heating so the parts are soldered reliably. The solder joints undergo
proper reflow duration at a preset temperature to form a favorable Intermetallic
Compound (IMC).
It is recommended that a special clamp be used to pick the module when the module is
installed on the pad after applied with some solder.
A special rework device must be used for the rework.
6.9.6 Specifications of Rework
Temperature parameter of rework: for either the removing or welding of the module,
the heating rate during the rework must be equal to or smaller than 3°C/s, and the
peak temperature between 240°C
–250°C. The following parameters are
recommended during the rework.
Figure 6-11
Temperature graph of rework