PCF8563_6

© NXP B.V. 2008. All rights reserved.

Product data sheet

Rev. 06 — 21 February 2008

28 of 32

NXP Semiconductors

PCF8563

Real-time clock/calendar

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

exposed to the wave

15.4 Reflow soldering

Key characteristics in reflow soldering are:

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

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

Table 29.

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

Package thickness (mm)

Package reflow temperature (

°C)

< 350

≥ 350

< 2.5

235

220

≥ 2.5

220

220

Table 30.

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

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