Method and device for reflow soldering with volume flow control

Abstract

According to one aspect of the invention it is possible to rapidly heat a soldering item by reducing an initially larger volume flow at a constant or increasing temperature, effectively preventing small components from overheating. By using the volume flow of a convection heater to control effective heat transmission occurring on said soldering item, it is also possible to adapt the soldering process in an extremely flexible manner to special process requirements by virtue of the fact that adjustment of a modified volume flow can be controlled in a very quick and precise manner.

Description

technical field

[0001] The present invention relates to a method and apparatus for reflow soldering, in which the objects to be brazed, assembled with parts, are subjected to a specific brazing in which a solder paste in contact with the parts at specific points is preheated It is then liquefied in the brazing zone to establish the desired brazing contact. Background technique

[0002] During the industrial mass production of modules with electronic components, it is often necessary to solder a large number of temperature-sensitive components to corresponding contact pads on the circuit board. For this purpose, the electronic part includes a suitable solder surface, which for a usual part is a wire connection or a contact pin, or in the case of a surface mounted part (SMD part) at an appropriate point. form of metal surface. As modules become increasingly miniaturized, individual parts continue to get smaller. The form of the part and its use partly imply a certain minimu...

Examples

Embodiment Construction

[0032] Figure 1a An example of a reflow soldering apparatus in the form of a transfer furnace 100 is schematically shown. In the example shown, the apparatus comprises at least a preheating zone 110, a brazing zone 120 and a cooling zone 130. In addition, a conveying device 150 is provided which conveys objects to be soldered (not shown), for example in the form of electronic circuit boards with various parts mountable with solder paste, through the respective zones 110 , 120 and 130 . In the example shown, the brazed region 120 is subdivided into two parts 120a and 120b. In section 120a, a volumetric flow of hot gas at a specific temperature T is directed via a first convective heater 121a onto a conveying device 150, or onto an object to be brazed thereon. Similarly, the brazing section 120b includes a convection heater unit 121b which directs a predetermined volume flow of hot gas at a specific temperature T onto the delivery device 150 or optionally onto the objects to b...

technical field

[0001] The present invention relates to a method and apparatus for reflow soldering, in which the objects to be brazed, assembled with parts, are subjected to a specific brazing in which a solder paste in contact with the parts at specific points is preheated It is then liquefied in the brazing zone to establish the desired brazing contact. Background technique

[0002] During the industrial mass production of modules with electronic components, it is often necessary to solder a large number of temperature-sensitive components to corresponding contact pads on the circuit board. For this purpose, the electronic part includes a suitable solder surface, which for a usual part is a wire connection or a contact pin, or in the case of a surface mounted part (SMD part) at an appropriate point. form of metal surface. As modules become increasingly miniaturized, individual parts continue to get smaller. The form of the part and its use partly imply a certain minimu...

Examples

Embodiment Construction

[0032] Figure 1a An example of a reflow soldering apparatus in the form of a transfer furnace 100 is schematically shown. In the example shown, the apparatus comprises at least a preheating zone 110, a brazing zone 120 and a cooling zone 130. In addition, a conveying device 150 is provided which conveys objects to be soldered (not shown), for example in the form of electronic circuit boards with various parts mountable with solder paste, through the respective zones 110 , 120 and 130 . In the example shown, the brazed region 120 is subdivided into two parts 120a and 120b. In section 120a, a volumetric flow of hot gas at a specific temperature T is directed via a first convective heater 121a onto a conveying device 150, or onto an object to be brazed thereon. Similarly, the brazing section 120b includes a convection heater unit 121b which directs a predetermined volume flow of hot gas at a specific temperature T onto the delivery device 150 or optionally onto the objects to b...

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