Reflow Soldering - Philips TDA8950 Product Data Sheet

NXP Semiconductors
15.4 Reflow soldering
TDA8950_2
Product data sheet
Key characteristics in reflow soldering are:
•
Lead-free versus SnPb soldering; note that a lead-free reflow process usually leads to
higher minimum peak temperatures (see
reducing the process window
•
Solder paste printing issues including smearing, release, and adjusting the process
window for a mix of large and small components on one board
•
Reflow temperature profile; this profile includes preheat, reflow (in which the board is
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 12 and 13
Table 12. SnPb eutectic process (from J-STD-020C)
Package thickness (mm)
< 2.5
2.5
Table 13. Lead-free process (from J-STD-020C)
Package thickness (mm)
< 1.6
1.6 to 2.5
> 2.5
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
Package reflow temperature ( C)
3
Volume (mm )
< 350
235
220
Package reflow temperature ( C)
3
Volume (mm )
< 350
260
260
250
30.
Rev. 02 — 11 June 2009
2 150 W class-D power amplifier
Figure 30) than a SnPb process, thus
350
220
220
350 to 2000
260
250
245
TDA8950
> 2000
260
245
245
© NXP B.V. 2009. All rights reserved.
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