HDC2010: Soldering issue

Howdy Henry,

To verify, both sides of your PCB board has the HDC device populated, is this correct? One was populated with peak temperature of 260C, while the other was populated at 150C. Each side is rested for 2 hours between population.

If this is the case, I wouldn't believe that these reflow temperatures will damage the device. The board should not be washed or exposed to solvents any time after the HDC devices are placed.

Best Regards,
Matt

Dear Matt,

Maybe I am not accurate to describe the situation.

Our Device's PCB is a FR4 2 layer board (Top Layer and Bottom Layer) . The HDC2010 will place on the Bottom.

Then, we will perform the soldering procedure as below:

Step 1, Place all the component on the Bottom Layer with HDC2010 sensor. Then, go thru the soldering oven according to JEDEC J-STD-020 with Peak Temperature 260 Deg C

Step 2, After completed, place the PCB into Room Temperature environment around 2 hours.

Step 3, Place all the component on the Top Layer. Then, go thru the soldering oven according to JEDEC J-STD-020 with Peak Temperature 260 Deg C

Step 4, After completed, place the PCB into Room Temperature environment around 2 hours.

Step 5, Place the Lead type component on the Top Layer. Then, go thru the soldering oven with Peak Temperature 150 Deg C 60sec duration.

After the above step, do it have any damage or side effect for the sensor?

Thanks!

Henry

Howdy Henry,

Thank you for the detailed explanation. My only concern is between step 1 and step 3. Here are some questions that you can help provide the answer to:

1) Are you washing the boards with any solvent or water after Step 1?
2) Is the HDC2010 device placed last in Step 1? -- We recommend that you place the HDC2010 last as soldering neighbor ICs may cross contaminate the device and inject particles of flux or vapor under the device.
3) Do you use No-Clean Solder Paste?
4) Can you verify if the HDC2010 device is placed last when soldering components on the Top Layer? The HDC2010 should be the last device populated on this layer, as any neighboring devices may cross contaminate the device when soldering, such as injecting flux or solder particles or vapor into the polymer of the device.

Best Regards,
Matt

Hi Matt,

Q1, No, we are no washing the board.

Q2, No, It is not the last soldering

Q3, Already used

Q4, We just swap the processing between step 1 and step 3

We are facing another problem. The HDC2010 will change the register setting by itself.

The device 1 symptom  is :

Temperature Reading = -40 Deg C

Humidity Reading = 0%RH

Register Reading          = 00 00 00 00 00 00 00 00 00 00 00 FF 00 FF 00 00

Normal Register Reading = C8 6D B7 5D 00 71 7B 00 00 00 00 FF 00 FF 55 00

If we re-program the register 0x0E and 0x0F by 55 01 hex, the temperature and humidity reading can be back to normal, but it only sustained a half of hour.

The device 2 symptom is:

Temperature Reading = +113 Deg C

Humidity Reading = 0.5%RH

After we re-program the register 0x0E and 0x0F by 55 01 hex, the temperature and humidity reading can be back to normal.

Would you help to explain why the register setting will change it by itself?

Regards,

Henry

Hi Henry,

It seems this is a duplicate thread to one that I've been receiving internally via Henry Fong @ serialsystem.

I've instructed the supporting engineer to obtain more data in the form of an oscilloscope frame of the faulty transaction. Additionally, Can you share a schematic of the platform during test? What is the percentage of prototypes with this behavior?

The information above would greatly help with debug.

Best Regards,
Matt

Dear Matt,

We already sent out the defective unit to Matthew Sauceda.

Best Regards,
Henry

Hi Henry,

Thanks for this information. I believe we've received this shipment recently though our shipping department. I'll align with logistics and verify we obtain the package. May I know, is it a device return, or is it the complete product? If it is a product, can you provide steps to evaluate? You can follow up with me offline by sending me a private e2e message in the case you wish to keep the information from being publicly posted.

Best regards,
Matt