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1 Overview of Soldering Technology
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Semiconductor Package Mount Manual
VPS (Vapor Phase Soldering Method)
In this method, a special inert liquid is heated by a heater and the product to be soldered is immersed in the saturated
vapor atmosphere acquired by the boiling of that liquid, and the vapor that contacts the product releases its latent heat of
vaporation as it condenses. This results in highly efficient and even soldering of the product.
Figure 1.9 shows the structure of the equipment used in this method. This equipment consists of the first vapor phase
used for the batch reflow soldering, a preheater, cooling, and a second vapor phase to prevent splashing of the liquid from
the first vapor phase.
Vapor phase soldering has the following characteristics.
1. Advantages
 The efficiency with which heat is transmitted to the work is extremely high and the whole work is heated evenly
regardless of the shapes of the components.
 Since the latent heat of vaporation is used, the temperature can be controlled precisely.
 Since soldering is performed in an inert atmosphere, there is minimal oxidation or contamination of the soldered
sections.
 As a result of the above features, the heating conditions can be kept low and the processing times can be short.
As a result, the thermal stress applied to the packages is minimal.
2. Disadvantages
 High running costs.
Conveyor
Second cooling coil
Second vapor
phase
First cooling coil
First vapor
phase
Heater
Inert liquid (boiling)
Figure 1.9 Vapor Phase Soldering Method (Example)
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R50ZZ0003EJ0500 Rev. 5.00
Feb 03, 2015