Vacuum Soldering Apparatus and Control Method Therefor

Patent metadata

Field	Value
Publication number	US-2016339531-A1
Application number	US-201315108039-A
Country	US
Kind code	A1
Filing date	Dec 25, 2013
Priority date	Dec 25, 2013
Publication date	Nov 24, 2016
Grant date	—

Abstract

In a vacuum soldering apparatus and a control method thereof, in order to prevent flux scattering or solder scattering when voids are defoamed and/or deaerated from molten solder by evacuating a chamber to a target degree of vacuum as well as in order to be able to perform brief evacuation, an evaluation control of a pump is performed. The evaluation control of the pump is performed in which the plural evacuation control properties (# 1 through # 4 ) with the gradients θ plotting the degrees of vacuum (pressure P) in relation to evacuation time (time t) when a chamber is evacuated by a predetermined pump output, are previously prepared; and the control are changed from evacuation control property of small pump output to evacuation control property of large pump output based on the initially set gradient θ in the evacuation control property.

First claim

1 ) A vacuum soldering apparatus comprising:
a chamber that is capable of soldering a work under vacuum environment; an operation part that sets a condition of evacuating the chamber; a pump that evacuates the chamber based on the condition of evacuating the chamber; and a control portion that performs an evacuation control of the pump wherein a plurality of evacuation control properties with gradients θ are previously prepared, each gradient θ plotting degree of vacuum in relation to evacuation time when the chamber is evacuated by a predetermined pump output, and the control portion changes from the evacuation control property of small pump output to the evacuation control property of large pump output based on an initially set gradient θ in the evacuation control property.

2 ) The vacuum soldering apparatus according to claim 1 wherein the control portion observes the gradient θ of the evacuation control property to be changed, and
the control portion always compares the initially set gradient θ in the evacuation control property with the gradient θ of the evacuation control property to be changed and changes the control from the evacuation control property of small pump output to the evacuation control property of large pump output when both of the gradients θ of the evacuation control properties are agreed with each other in evacuation.

3 ) The vacuum soldering apparatus according to claim 1 further comprising a detection portion that detects vacuum pressure of the chamber and outputs pressure detection information; and
a storage portion that stores data in which the evacuation control properties are tabled,
wherein the control portion refers to the evacuation control properties based on the pressure detection information, and
the control portion changes the pump output from the evacuation control property with the large gradient θ to the evacuation control property with the small gradient θ when the vacuum pressure in the chamber reaches a change point of the degree of vacuum in the evacuation control property.

4 ) The vacuum soldering apparatus according to claim 1 wherein the control portion always compares the initially set gradient θ in the evacuation control property with a threshold gradient θth which is a change evaluation criterion, in evacuation; and
the control portion changes the control from the evacuation control property of small pump output to the evacuation control property of large pump output when the initially set gradient θ of the evacuation control property exceeds the threshold gradient θth.

5 ) A control method of a vacuum soldering apparatus wherein a control portion of the vacuum soldering apparatus that solders a work under vacuum environment performs the method comprising:
a step of obtaining and storing a plurality of evacuation control properties with gradients θ, each gradient θ plotting degree of vacuum in relation to evacuation time when a chamber for soldering is evacuated by a predetermined pump output; a step of setting the evacuation control properties with the gradient θ; and a step of controlling the pump output to change from the evacuation control property of small pump output to the evacuation control property of large pump output based on the gradient θ in the set evacuation control properties.

6 ) The control method of the vacuum soldering apparatus according to claim 5 wherein the control portion performs:
a step of obtaining the evacuation control properties at preliminary evacuation to prepare a table;
a step of observing the gradient θ of the evacuation control property to be changed at main evacuation;
a step of always comparing the initially set gradient θ in the evacuation control property with the gradient θ of the evacuation control property to be changed; and
a step of changing the control from the evacuation control property of small pump output to the evacuation control property of large pump output when both of the gradients θ of the evacuation control properties are agreed with each other in evacuation.

7 ) The control method of the vacuum soldering apparatus according to claim 5 wherein at preliminary evacuation, the control portion performs:
a step of obtaining the evacuation control properties to prepare a table; and
a step of finding out a change point of the evacuation control properties with the initially set gradient θ, and
wherein at main evacuation, the control portion performs:
a step of detecting the vacuum pressure of the chamber and referring to the tabled evacuation control properties based on the pressure detection information, and
a step of changing the pump output from the evacuation control property of the large gradient θ to the evacuation control property of the small gradient θ when the vacuum pressure in the chamber reaches the change point of the evacuation control properties.

8 ) The control method of the vacuum soldering apparatus according to claim 5 wherein the control portion always compares the initially set gradient θ in the evacuation control property with a threshold gradient θth which is a change evaluation criterion during evacuation; and
the control portion changes the control from the evacuation control property of small pump output to the evacuation control property of large pump output when the initially set gradient θ of the evacuation control property exceeds the threshold gradient θth.

Assignees

• Senju Metal Industry Co

Inventors

• Hiyama Tsutomu
• Inoue Hiroyuki
• Kimoto Shunsuke
• Kagaya Tomotake

Classifications

• H05K3/3494

  Heating processes for reflow soldering · CPC title

• H05K2203/085

  Using vacuum or low pressure · CPC title

• B23K2101/42

  Printed circuits · CPC title

• H05K2203/043

  Reflowing of solder coated conductors, not during connection of components, e.g. reflowing solder paste · CPC title

• B23K1/008

  Soldering within a furnace (B23K1/012 takes precedence) · CPC title