IHLP Solder Profile and Cleaning Guide

IHLP Solder Profile and Cleaning Guide
www.vishay.com
Vishay Dale
Instructions
ASSEMBLY INSTRUCTIONS
General
This document provides instructions on mounting for the
different types of packages, specifically on the different
methods of soldering.
If the device is to be mounted near heat-generating
components, consideration must be given to the resultant
increase in ambient temperature.
Soldering Instructions
Protection against overheating is essential when a device is
being soldered. Therefore, the PCB traces should be left as
long as possible. The maximum permissible soldering
temperature is governed by the maximum permissible heat
that may be applied to the package.
The temperature of parts in an IR furnace, with a mixture
of radiation and convection, cannot be determined in
advance. Temperature measurement may be performed
by measuring the temperature of a certain component
while it is being transported through the furnace.
The temperatures of small components, soldered
together with larger ones, may rise up to 280 °C.
Influencing parameters on the internal temperature of the
component are as follows:
• Time and power
• Mass of the component
• Size of the component
• Size of the printed circuit board
The maximum soldering iron (or solder bath) temperatures
are given in the individual Datasheets. During soldering, no
forces must be transmitted from the pins to the case (e.g.,
by spreading the pins).
• Absorption coefficient of the surfaces
Soldering Methods
• Ratio of radiated and convected energy
There are several methods for soldering devices onto the
substrate. The following list is not complete.
As a general rule of thumb, maximum temperature
should be reached within 360 s and time above solder
liquids temperature should be reached in less than 180 s.
a. Soldering in the Vapor Phase
Soldering in saturated vapor is also known as
condensation soldering. This soldering process is used
as a batch system (dual vapor system) or as a continuous
single vapor system. Both systems may also include a
pre-heating of the assemblies to prevent high
temperature shock and other undesired effects.
b. Infrared Soldering
By using infrared (IR) reflow soldering, the heating is
contact-free and the energy for heating the assembly is
derived from direct infrared radiation and from
convection.
The heating rate in an IR furnace depends on the
absorption coefficients of the material surfaces and on
the ratio of component's mass to an As-irradiated
surface.
• Packing density
• Wavelength spectrum of the radiation source
Temperature/time profiles of the entire process and the
influencing parameters are given. The IR reflow profile is
shown in Figure 1.
c. Wave Soldering
In wave soldering one or more continuously replenished
waves of molten solder are generated, while the
substrates to be soldered are moved in one direction
across the crest of the wave. Maximum soldering
temperature should not exceed 260 °C for 20 s.
d. Iron Soldering
This process cannot be carried out in a controlled
situation. It should therefore not be used in applications
where reliability is important. There is no SMD
classification for this process.
CLEANING INSTRUCTIONS
A no clean solder system is recommended for IHLP’s.
If cleaning must be performed, an Isopropyl alcohol is recommended. If de-ionized Water Wash is used insure it is followed by
a thorough warm air dry cycle to avoid oxidation.
Some cleaning solutions, especially those containing non-linear alcohol will attack the IHLP and should be avoided. It is
recommended that any chemical cleaning solution be thoroughly rinsed with clean water. The IHLP should be tested for
compatibility with any cleaning solution before production assembly.
Revision: 22-Jun-12
Document Number: 34339
1
For technical questions, contact: [email protected]
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
IHLP Solder Profile and Cleaning Guide
www.vishay.com
Vishay Dale
TYPICAL REFLOW SOLDERING PROFILE
Peak Reflow Temperature
Duration within 5 °C
of Peak Temp
Temperature
Liquidus Temperature of Solder
Pre-Heat Temp Range
Cool Down Rate
Time Above Liquidus
Ramp Rate
Pre-Heat Dwell Time
Time
Fig. 1 - Infrared reflow soldering (SMD package)
LEAD (Pb)-FREE SOLDER (SnAgCu) REFLOW PROFILE ATTRIBUTES
PROFILE ATTRIBUTE
Peak Reflow Temperature
PROFILE ATTRIBUTE
255 (± 5) °C
Time within 5 °C of Peak Temperature
30 s max.
Liquidus Temperature of Solder
~ 217 °C
Cool Down Rate
6 °C/s max.
Time above Liquidus
60 s to 150 s
Pre-heat Temperature Range
150 °C to 200 °C
Pre-heat Dwell Time
60 s to 120 s
Maximum Ramp Rate
3 °C/s max.
Revision: 22-Jun-12
Document Number: 34339
2
For technical questions, contact: [email protected]
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000