PCF8574_PCF8574A

All information provided in this document is subject to legal disclaimers.

© NXP B.V. 2013. All rights reserved.

Product data sheet

Rev. 5 — 27 May 2013

23 of 33

NXP Semiconductors

PCF8574; PCF8574A

transport, the solder wave parameters, and the time during which components are

exposed to the wave

17.4 Reflow soldering

Key characteristics in reflow soldering are:

higher minimum peak temperatures (see Figure 21) than a SnPb process, thus

reducing the process window

window for a mix of large and small components on one board

heated to the peak temperature) and cooling down. It is imperative that the peak

temperature is high enough for the solder to make reliable solder joints (a solder paste

characteristic). In addition, the peak temperature must be low enough that the

packages and/or boards are not damaged. The peak temperature of the package

depends on package thickness and volume and is classified in accordance with

Table 11 and 12

Moisture sensitivity precautions, as indicated on the packing, must be respected at all

times.

Studies have shown that small packages reach higher temperatures during reflow

soldering, see Figure 21.

Table 11.

SnPb eutectic process (from J-STD-020D)

Package thickness (mm)

Package reflow temperature (

C)

< 350

 350

< 2.5

235

220

 2.5

220

220

Table 12.

Lead-free process (from J-STD-020D)

Package thickness (mm)

Package reflow temperature (

C)

< 350

350 to 2000

> 2000

< 1.6

260

260

260

1.6 to 2.5

260

250

245

> 2.5

250

245

245