ES9027SPRO datasheet(86/89 Pages) ESS

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ES9027PRO Datasheet

VERSION 0.4.1

ESS TECHNOLOGY, INC. 109 Bonaventura Drive, San Jose, CA 95134, USA Tel (408) 643-8800 • WWW.ESSTECH.COM

Reflow Process Considerations

Temperature Controlled

For lead-free soldering, the characterization and optimization of the reflow process is the most important factor to consider.

The lead-free alloy solder has a melting point of 217°C. This alloy requires a minimum reflow temperature of 235°C to ensure good wetting. The

maximum reflow temperature is in the 245°C to 260°C range, depending on the package size (RPC-2 Pb-Free Process – Classification

Temperatures (Tc)). This narrows the process window for lead-free soldering to 10°C to 20°C.

The increase in peak reflow temperature in combination with the narrow process window makes the development of an optimal reflow profile a

critical factor for ensuring a successful lead-free assembly process. The major factors contributing to the development of an optimal thermal profile

are the size and weight of the assembly, the density of the components, the mix of large and small components, and the paste chemistry being used.

Reflow profiling needs to be performed by attaching calibrated thermocouples well adhered to the device as well as other critical locations on the

board to ensure that all components are heated to temperatures above the minimum reflow temperatures and that smaller components do not

exceed the maximum temperature limits (Table RPC-2).

To ensure that all packages can be successfully and reliably assembled, the reflow profiles studied and recommended by ESS are based on the

JEDEC/IPC standard J-STD-020 revision D.1.

Figure 22 – IR/Convection Reflow Profile (IPC/JEDEC J-STD-020D.1)

Reflow is allowed 3 times. Caution must be taken to ensure time between re-flow runs does not exceed the allowed time by the moisture sensitivity

label. If the time elapsed between the re-flows exceeds the moisture sensitivity time bake the board according to the moisture sensitivity label

instructions.

Manual

Allowed up to 2 times with maximum temperature of 350°C no longer than 3 seconds.

ES9027SPRO Datasheet(PDF) 86 Page - ESS Technology,Inc