www.sensirion.com

Version 1 – March 2022

20/21

4.5 Soldering Instructions

For soldering, standard reflow soldering ovens may be used. The sensors are designed to withstand soldering profile based on

IPC/JEDEC J-STD-020 with a maximum peak temperature of 235°C during up to 30 sec for Pb-free assembly in IR/Convection

reflow ovens.

Note that due to the comparably large size of the SCD42 sensor significant temperature differences across the sensor element

can occur during reflow soldering. Specifically, the temperature within the sensor cap can be higher than the temperature

measured at the pad using usual temperature monitoring methods. Care must be taken that a temperature of 235° C is not

exceeded at any time in any part of the sensor.

Do not apply any board wash process step subsequently to the reflow soldering. Note that the dust cover on top of the cap must

not be removed or wetted with any liquid. Finally, the SCD42 is not compatible with vapor phase reflow soldering.

is restored after at most five days after the soldering process, independently on whether the sensor is operated or not.

Average ramp-up rate

< 3 °C / second

Liquid phase

▪

▪

< 220 °C

< 60 seconds

Peak temperature

▪

▪

≤ 235 °C

< 30 seconds

Ramp-down rate

< 4 °C / seconds for

Table 28 Soldering profile parameter

4.6 Traceability

All SCD42 sensors have a distinct electronic serial number for identification and traceability (see chapter 3.8.2). The serial

number can be decoded by Sensirion only and allows for tracking through production, calibration, and testing.

5 Ordering Information

the latest product information and local distributors, visit http://www.sensirion.com/.

Part Name

Description

Ordering quantity (pcs)

Product Number

SCD42-D-R2

SCD42 CO2 sensor SMD component as reel, I2C

600 sensors per reel

3.000.634

SEK-SCD41-Sensor

SEK-SCD41-Sensor set; SCD41 on development

board with cables

1

3.000.455

SEK-SensorBridge

Sensor Bridge to connect SEK-SCD41-Sensor to

computer

1

3.000.124

Table 29 SCD42 ordering options

6 Revision History

Date

Version

Page(s)

Changes

September 2021

0.9

all

Preliminary version

September 2021

0.91

1, 20

Minor revisions (page 1), addition of product number (page 20)

October 2021

0.92

4

Moisture sensitivity level (MSL) changed to 1

March 2022

1

3

20

Clarification on additional sensor accuracy drift (Table 1)

Addition of temporary accuracy deviation after reflow soldering process (4.5)