LIS2MDL (LGA-12L) Leakage current

[Mallik18]

Hi Team,

We have designed and manufactured several thousand PCBs that include the LIS2MDL (LGA‑12L) sensor. All boards are functioning correctly from an operational standpoint. However, because our devices run on battery power, load current is critical.

We have observed a leakage current at the LIS2MDL power supply input, ranging from approximately 10 µA to 1500 µA. We are currently unable to determine whether the cause is related to the assembly process or the component itself.

Notably, when we clean under IC to remove flux residues, the leakage current decreases significantly. While this confirms that contamination is influencing the issue, manually cleaning every board is not a feasible solution for our production scale.

Could you please advise on possible root causes or provide recommendations to prevent this leakage issue without requiring manual cleaning for each unit?

Your support would be greatly appreciated.

 

[Peter BENSCH]

Welcome @Mallik18, to the community!

Well, you have already confirmed through cleaning that the leakage current was caused by flux residues and not by the device. For a battery-powered device, where every nanoampere of leakage current must be avoided, it is absolutely essential to prevent or remove flux residues.

Your only options are therefore to either wash the boards after soldering or to use a no-clean solder paste.

Does it answer your question?

Regards
/Peter

[Mallik18]

We are using no clean flux only.

And we are following below cleaning procedure.

Remove IC --> clean the flux residue --> Mount the IC again --> Test again --> Low leakage

Any precautions or recommendation for PCB Footprint and Assembly process to avoid flux residue. Everyone knows that mounting IC on PCB with solder paste having zero flux is difficult.

[Federica Bossi]

Hi @Mallik18 ,

Unfortunately the response is not so easy because it is mandatory to know the material composition of used flux. Many customers, after the soldering, wash the PCB (if it is possible). The high current in presence of flux means that this flux is conductive and creates a resistive path between VDD and GND. It is also possible to verify if it is possible to change the solder paste avoiding FLUX

[young]

Hi Mallik18,

Have you tested the current consumption of the LIS2MDL in high-resolution or low-power mode? How is the performance?

I tested several pieces of the chip, the current consumption were all different. Could it also be caused by leakage current? 

What is the decreased current consumption after clean under IC to remove flux residues？

Is the chip working normally after cleaning?

I am looking forward to your reply.

Thanks

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Mallik18]

Hi Team,

Have you tested the current consumption of the LIS2MDL in high-resolution or low-power mode? How is the performance?

>> We have tested and performance is good.

I tested several pieces of the chip, the current consumption were all different. Could it also be caused by leakage current? 

>> Yes, we are also facing same.

What is the decreased current consumption after clean under IC to remove flux residues？

>> Load current dropping from 1.5A to 100uA approx.

Is the chip working normally after cleaning?

>> Yes chip is working after cleaning

[young]

Hi Mallik18，

I still observed a leakage current (80uA) at the LIS2MDL power supply input in Power-Down or High-Resolution mode when testing this chip individually. For example, the power consumption of a normal chip is 4uA, while an abnormal one is 83uA in Power-Down mode. Then I found the difference in diode characteristics between the normal and abnormal chips.

Have you tested this parameter ？

I am looking forward to your reply.

Thanks

[nikosandreadakis]

Hello,

I am experiencing the same issue with the IIS2MDC.

I performed several measurements using a Joulescope with the IC in different configurations:

• Stand-alone device

• Custom board

• Evaluation board

In addition, we produced a batch of 60 boards, and all of them exhibit the same behavior. More details about the issue can be found in the link provided in the original post.

For the production process we used Indium8.9HF solder paste with an 80 µm stencil. The reflow profile followed the recommendations in the datasheet, and the maximum peak temperature did not exceed 250 °C.

Currently, I am coordinating with the factory to perform X-ray inspection of the IC and all solder joints to rule out assembly issues. I will update this thread once I receive the results.

At this stage, I suspect there may be an issue with the IC itself, as small changes in the environment appear to significantly affect its current consumption.

Best regards