Flux collection method and flux collection apparatus

Patent metadata

Field	Value
Publication number	US-11511364-B2
Application number	US-201916274126-A
Country	US
Kind code	B2
Filing date	Feb 12, 2019
Priority date	Jun 26, 2018
Publication date	Nov 29, 2022
Grant date	Nov 29, 2022

Abstract

A method and an apparatus for collecting flux are disclosed. A rosin particle contained in an atmosphere gas, and a vapor of a solvent or an atomized solvent particle are mixed in a mixing section upstream of a flux collection unit-side inlet, and a gas containing a mixed particle is cleaned by electrostatic precipitation. The solvent particle adheres to the rosin particle, and forms an aggregate of larger particle size.

First claim

What is claimed is:

1. A method for collecting a flux in an atmosphere gas introduced into a flux collection apparatus from inside of a reflow furnace, the method comprising:
mixing, in a mixing section of the flux collection apparatus, a rosin particle contained in the atmosphere gas with a vapor of a solvent or an atomized solvent particle so as to form a mixed particle before entry into an inlet of a flux collection unit of the flux collection apparatus; and
collecting, in the flux collection unit of the flux collection apparatus, the mixed particle by electrostatic precipitation from a gas containing the mixed particle,
wherein:
the flux collection apparatus is connected to the reflow furnace;
the flux collection apparatus includes a first pipe, and a second pipe;
the first pipe connects a first outlet of the reflow furnace to a portion of the second pipe which is upstream of the inlet of the flux collection unit;
the first outlet of the reflow furnace is an outlet through which the vapor of the solvent or the atomized solvent particle is sent out of a preheat zone of the reflow furnace;
the second pipe connects a second outlet of the reflow furnace to the inlet of the flux collection unit;
the second outlet of the reflow furnace is an outlet through which the atmosphere gas is sent out of the reflow furnace into the flux collection unit;
the mixing section is disposed at an intersection of the first pipe and the second pipe; and
the preheat zone of the reflow furnace is a zone to which a circuit board with an applied solder paste containing the solvent is transported.

2. The method according to claim 1 , wherein the rosin particle has a particle size distribution with a median that is smaller than a median of a particle size distribution of the mixed particle.

3. The method according to claim 1 , wherein the solvent is a solvent that dissolves a rosin component, a polar protic solvent, or a solvent having a flash point that is higher than a temperature of the atmosphere gas containing the rosin particle.

4. A method for collecting a flux in an atmosphere gas introduced into a flux collection apparatus from inside of a reflow furnace, the method comprising:
mixing, in a mixing section of the flux collection apparatus, a rosin particle contained in the atmosphere gas with a vapor of a solvent or an atomized solvent particle so as to form a mixed particle before entry into an inlet of a flux collection unit of the flux collection apparatus; and
collecting, in the flux collection unit of the flux collection apparatus, the mixed particle by electrostatic precipitation from a gas containing the mixed particle,
wherein:
the flux collection unit is disposed inside the reflow furnace;
the flux collection apparatus includes a first pipe, and a second pipe;
the first pipe connects a first outlet of the reflow furnace to a portion of the second pipe which is upstream of the inlet of the flux collection unit;
the first outlet of the reflow furnace is an outlet through which the vapor of the solvent or the atomized solvent particle is sent out of a preheat zone of the reflow furnace;
the second pipe connects a second outlet of the reflow furnace to the inlet of the flux collection unit;
the second outlet of the reflow furnace is an outlet through which the atmosphere gas is sent out of the reflow furnace into the flux collection unit;
the mixing section is disposed at an intersection of the first pipe and the second pipe; and
the preheat zone of the reflow furnace is a zone to which a circuit board impregnated with the solvent is transported.

5. A flux collection apparatus comprising:
an electrostatic-precipitation flux collection unit;
a first pipe;
a second pipe; and
a mixing section configured to mix a vapor of a solvent or an atomized solvent particle with a rosin particle of an atmosphere gas to form a mixed particle,
wherein:
the first pipe is configured to connect a first outlet of a reflow furnace to a portion of the second pipe which is upstream of an inlet of the electrostatic-precipitation flux collection unit;
the first pipe is configured to send the vapor of the solvent or the atomized solvent particle from a preheat zone of the reflow furnace to the mixing section;
the second pipe is configured to connect a second outlet of the reflow furnace to the inlet of the electrostatic-precipitation flux collection unit;
the second pipe is configured to send the atmosphere gas from the reflow furnace into the electrostatic-precipitation flux collection unit; and
the mixing section is disposed at an intersection of the first pipe and the second pipe.

6. The flux collection apparatus according to claim 5 , wherein the mixing section is configured to spray the solvent into the atmosphere.

7. The flux collection apparatus according to claim 5 , wherein the rosin particle has a particle size distribution with a median that is smaller than a median of a particle size distribution of the mixed particle.

8. A reflow furnace comprising the flux collection apparatus of claim 5 .

9. The method according to claim 4 , wherein the rosin particle has a particle size distribution with a median that is smaller than a median of a particle size distribution of the mixed particle.

10. The method according to claim 4 , wherein the solvent is a solvent that dissolves a rosin component, a polar protic solvent, or a solvent having a flash point that is higher than a temperature of the atmosphere gas containing the rosin particle.

Assignees

• Panasonic Ip Man Co Ltd
• Panasonic Intelletual Property Man Co Ltd

Inventors

• Yamaguchi Naoshi
• Nagai Koichi
• Takano Yasuyuki
• Kanda Toshiro

Classifications

• B23K3/085 Primary

  Cooling, heat sink or heat shielding means · CPC title

• B03C3/41

  Ionising-electrodes · CPC title

• B01D47/06

  Spray cleaning · CPC title

• B03C3/0175 Primary

  Amassing particles by electric fields, e.g. agglomeration · CPC title

• B03C3/01 Primary

  Pretreatment of the gases prior to electrostatic precipitation · CPC title