# Soldering a CubeNode onto a PCB

To solder a CubeNode onto a PCB, you can do the following:

1. Prepare "no clean" soldering paste to remove the need for post-soldering PCB cleaning. 
2. Prepare a convention-type soldering oven. This allows for more precise temperature control compared to an infrared-type radiation oven. 
3. Configure the oven settings.  

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*  Take into account the following for the final soldering temperature:
  * Soldering paste type
  * Baseboard size, thickness, and material properties
* Do not exceed the peak temperature of the recommended soldering profile. 
* Do not use a damp heat process during the soldering. 
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4. Bake the PCB.
5. Preheat the PCB to remove all the residual humidity using the following parameters:
   * Temperature rise rate: Max 3 °C/s
   * Time: 60 \~ 120 s
   * End temperature: 150 \~ 200 °C

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* Insufficient preheating causes large solder balls to be formed.
* Excessive preheating can lead to both fine and large solder balls clustering.
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6. Perform the heating-flow to the PCB with the following parameters:

* Time limit above 217 °C liquidus temperature: 40 \~ 100s
* Peak reflow temperature: 245 °C

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Avoid sudden temperature increases to prevent solder paste slump.
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7. Perform a controlled cooling process to cool the PCB with the following parameters:
   * Temperature fall rate: Max 4 °C/s

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A controlled cooling process prevents the solder from becoming brittle.
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8. It is recommended to conduct an optical inspection after the soldering.
9. PCB cleaning is recommended if a soldering paste other than "no-clean" was used.

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Do not clean the PCB with the following:

* Water (may cause short-circuits)
* Alcohol or organic solvent (may leave inaccessible residues)
* Ultrasonic cleaner (may cause permanent damage)
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