74lx1g04 STMicroelectronics, 74lx1g04 Datasheet - Page 6

• Manufacturer Part Number: 74lx1g04
• Description: Low Voltage Cmos Single Inverter With 5v Tolerant Input
• Manufacturer: STMicroelectronics

74LX1G04
Figure 1 : RECOMMENDED SOLDERING REFLOW PROFILE FOR LEADFREE FLIP-CHIP
MOUNTING ON PCB
For Flip-Chip mounting on the PCB, STMicroelectronics recommends the use of a solder stencil aperture
of 330 x 330 µm² maximum and a typical stencil thickness of 125µm. Flip-Chips are fully compatible with
the use of near eutectic 95.5Sn 4Ag 0.5Cu solder paste with no clean flux. ST's recommendations for
Flip-Chip board mounting are illustrated on the soldering reflow profile shown in figure 1 below.
Dwell time in the soldering zone (with temperature higher than 220°C) has to be kept as short as possible
to prevent component and substrate damages. Peak temperature must not exceed 260°C. Controlled
atmosphere (N2 or N2H2) is recommended during the whole reflow, specially above 150°C.
Flip-Chips are able to withstand three times the previous recommended reflow profile in order to be
compatible with a double reflow when SMDs are mounted on both sides of the PCB plus one additional
repair. A maximum of three soldering reflows are allowed for these leadfree packages (with repair step
included). The use of a no clean flux is highly recommended to avoid any cleaning operation. In order to
prevent any bump cracks, ultrasonic cleaning methods are not recommended.
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Temperature (˚C)
Temperature (˚C)
260˚C max
260˚C max
255˚C
255˚C
125 ˚C
125 ˚C
220˚C
220˚C
180˚C
180˚C
0
0
0
0
3˚C/s max
3˚C/s max
1
1
90 to 150 sec
2
2
3
3
4
4
90 sec max
90 sec max
10-30 sec
10-30 sec
5
5
2˚C/s recommended
6
6
6˚C/s max
2˚C/s recommended
6˚C/s max
Time (min)
Time (min)
7
7