Soldering flux collecting system

Abstract

The invention relates to a soldering flux collecting system which is used for collecting soldering flux in a reflow soldering furnace and comprises an air draft unit (1) and a purification unit (2) which are sequentially connected in the flowing direction of soldering flux gas. The purifying unit (2) comprises a shell (3), a filtering module (4), a purifying electric field module (5) and a collecting module (6), wherein the filtering module (4), the purifying electric field module (5) and the collecting module (6) are installed in the shell (3). The filtering module (4) comprises a first filtering assembly (41) and a second filtering assembly (42), and the first filtering assembly (41), the purifying electric field module (5) and the second filtering assembly (42) are sequentially arranged in the flowing direction of scaling powder gas. Compared with the prior art, by means of the electrostatic ionization and adsorption functions of the purification electric field module (5), efficient adsorption and purification of scaling powder gas in the SMT reflow soldering furnace are achieved, and the device has the advantages of being high in purification efficiency, convenient to install, suitable for application scenes where a large amount of soldering paste is used and the like.

Description

Technical Field

[0001] The invention relates to the technical field of SMT reflow soldering, and in particular to a soldering flux collection system. Background Art

[0002] In the surface mount technology (SMT) production line, the reflow oven is a special device for soldering circuit boards with electronic components. It provides a stable heating environment and controls the temperature of different temperature zones through software, so that the solder paste is gradually heated and melted, infiltrates between the surface mounted components and the circuit board, and solidifies after cooling, so that they can be reliably soldered together. Its working state is divided into two parts: heating and cooling.

[0003] The hot air reflow oven transfers heat energy to the parts to be soldered through the laminar flow of hot air. During the heating process, when the solder paste melts, the flux will gradually vaporize and volatilize into the furnace as the temperature rises, and its vapor will spread to all parts of the furnace with the hot air, including the furnace cooling section. After cooling, the flux vapor will condense into liquid and adhere to the inner wall of the cooling module, the reflow orifice plate, etc. When the liquid flux continues to accumulate to a certain extent, it will form droplets and eventually drip down. Since the circuit board is an assembly line operation, there is a high probability of dripping onto the circuit board, which can easily cause the quality of the circuit board to be unqualified or even scrapped, resulting in actual losses. Based on this, removing the flux must be considered in the design of the reflow oven.

[0004] At present, there are two ways to remove the flux: one is to directly extract the flux vapor and discharge it through the flue gas duct; the other is to use the flux collection system of the reflow soldering furnace itself to collect it and then do harmless treatment. The first method has been less used due to environmental and safety requirements. The second method is more common. Usually, an exhaust port is set in the heating part of the equipment. Before the flux vapor enters the cooling section, it is connected to the flux collection device through a pipeline. Using the heat exchange principle, the device through which the flux vapor passes is cooled and reduced by a refrigerant (mostly water), so that the flux becomes liquid and precipitates and is collected and processed, and then the "purified" gas is refilled into the furnace, thereby achieving the effect of saving nitrogen consumption, and only a small amount of flux will escape to the cooling part of the equipment, reducing the risk of "droplets" contaminating the product. Existing flux collection devices often use cold and heat exchange to cool and purify the flux gas. Gas cooling and reheating bring about large heat loss and high energy consumption. Most customers work continuously. After a certain period of accumulation, a small amount of escaped flux will gradually accumulate in the cooling area, and the maintenance frequency will increase. Therefore, it is urgent to develop an efficient flux collection system. Summary of the invention

[0005] The purpose of the present invention is to provide a soldering flux collection system in order to overcome the defects in the prior art.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A soldering flux collection system is used for collecting soldering flux in a reflow oven, and comprises an exhaust unit and a purification unit which are sequentially connected along the flow direction of the soldering flux gas.

[0008] Furthermore, the purification unit includes a shell and a filter module installed in the shell, a purification electric field module and a collection module for collecting soldering flux.

[0009] Furthermore, the filter module includes a first filter component and a second filter component, and the first filter component, the purification electric field module and the second filter component are arranged in sequence along the flow direction of the flux gas.

[0010] Furthermore, the exhaust unit is arranged at the exhaust port of the heating area of ​​the reflow oven, and the purification unit is connected to the reflow oven through a pipeline.

[0011] Furthermore, the exhaust unit is a motor exhaust box, which is used to send the extracted hot air containing flux vapor into the purification unit.

[0012] Furthermore, the shell includes an air inlet and an air outlet.

[0013] Furthermore, the air inlet is connected to the exhaust unit through a hot exhaust duct, and the air outlet is connected to the reflow oven through a clean air return duct.

[0014] Furthermore, the shell is made of carbon steel with baking varnish.

[0015] Furthermore, the filter module and the purification electric field module are installed in the housing in a detachable manner, which is convenient for cleaning and maintenance.

[0016] Furthermore, the mesh number of the first filter component is smaller than the mesh number of the second filter component.

[0017] Furthermore, the first filter assembly uses a stainless steel wire mesh to effectively filter large particle waste in the flux gas.

[0018] Furthermore, the second filter component is made of iron-nickel alloy to finely filter the purified gas.

[0019] Furthermore, the purification electric field module includes an ionization component and an adsorption component which are sequentially arranged along the flow direction of the flux gas.

[0020] Furthermore, the ionization component is electrically connected to an external power source.

[0021] Furthermore, the voltage of the ionization component is higher than the voltage of the adsorption component.

[0022] Furthermore, the adsorption component includes an adsorption plate for adsorbing charged particles.

[0023] Furthermore, the collection module is arranged below the filtering module and the purification electric field module.

[0024] The invention also provides a method for using the soldering flux collecting system.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The present invention utilizes the principles of electrostatic ionization and adsorption to efficiently adsorb and purify the flux gas in the SMT reflow oven. Compared with the existing flux collection system, the flux collection efficiency is above 95%, and it is suitable for application scenarios that require the use of a large amount of solder paste.

[0027] (2) The present invention is compact, occupies a small area, and has flexible installation positions. It can be placed outside the equipment as an independent unit and connected to the equipment body through a pipeline. It has a simple structure, is easy to maintain, has few wearing parts, and is easy and quick to maintain.

[0028] (3) The present invention improves the collection efficiency of flux gas in the reflow soldering furnace, greatly reduces the risk of product contamination, and maximizes the extension of the product maintenance cycle, reduces the interruption of maintenance time to production, and thus improves economic benefits.

[0029] (4) The present invention utilizes the principle of electrostatic ionization and adsorption to remove the soldering flux from the hot gas in the furnace. The heat loss of the gas mainly occurs in the transmission pipeline, and the temperature drop is very small. The purified gas is reheated to the original temperature with a small amount of heat and a short time, so the energy consumption is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the present invention.

[0031] Figure 2 It is a schematic diagram of the structure of the purification unit in the present invention.

[0032] Description of the markings in the figure:

[0033] 1-exhaust unit, 2-purification unit, 3-housing, 4-filter module, 41-first filter component, 42-second filter component, 5-purification electric field module, 51-ionization component, 52-adsorption component, 6-collection module. DETAILED DESCRIPTION

[0034] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0035] In the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention; the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0037] Embodiment 1:

[0038] The present embodiment provides a flux collection system for collecting flux in an SMT reflow oven. The flux collection system of the present embodiment includes an exhaust unit 1 and a purification unit 2 connected in sequence along the flow direction of the flux gas. The purification unit 2 includes a shell 3 and a filter module 4 installed in the shell 3, a purification electric field module 5, and a collection module 6 for collecting flux. The filter module 4 includes a first filter component 41 and a second filter component 42, and the first filter component 41, the purification electric field module 5, and the second filter component 42 are arranged in sequence along the flow direction of the flux gas.

[0039] Embodiment 2:

[0040] The present embodiment provides a flux collection system for collecting flux in an SMT reflow oven. The present embodiment comprises an exhaust unit 1 and a purification unit 2 connected in sequence along the flow direction of the flux gas. The exhaust unit 1 in the present embodiment is a motor exhaust box, which is arranged at the exhaust port of the heating area of ​​the reflow oven.

[0041] The purification unit 2 includes a carbon steel painted shell 3 and a filter module 4, a purification electric field module 5 and a collection module 6 for collecting flux installed in the shell 3. The shell 3 includes an air inlet and an air outlet. The air inlet is connected to the exhaust unit 1 through a hot exhaust duct; the air outlet is connected to the reflow oven through a clean air return duct to discharge the purified gas back to the reflow oven.

[0042] The filter module 4 includes a first filter assembly 41 in front and a second filter assembly 42 in rear. The first filter assembly 41, the purification electric field module 5 and the second filter assembly 42 are sequentially arranged along the flow direction of the flux gas. The mesh number of the first filter assembly 41 is smaller than the mesh number of the second filter assembly 42. The first filter assembly 41 uses a stainless steel wire mesh to effectively filter large particle waste in the flux gas; the second filter assembly 42 uses an iron-nickel alloy to finely filter the purified gas.

[0043] The purification electric field module 5 includes an ionization component 51 and an adsorption component 52 which are sequentially arranged along the flow direction of the flux gas. The ionization component 51 in this embodiment is a high-voltage electrostatic ionization device, which is electrically connected to an external power supply. The adsorption component 52 is a low-voltage electric field area, including an adsorption plate for adsorbing charged particles. The collection module 6 in this embodiment is arranged at the bottom of the purification unit 2 for recovering the flux. In this embodiment, the filter module 4, the purification electric field module 5 and the collection module 6 are all detachably installed in the housing 3 for easy cleaning and maintenance.

[0044] Embodiment 3:

[0045] The present embodiment provides a flux collection system and a method for using the same.

[0046] The flux vapor generated when the SMT reflow oven is working contains rosin film-forming agent, activator, thixotropic agent, solvent and other ingredients. The motor exhaust box (exhaust unit 1, selected from Shanghai Langshi Electronic Equipment Co., Ltd.) is located at the exhaust port of the heating area of ​​the reflow oven, and the gas containing the flux is sucked away by the motor exhaust box through the exhaust port. The gas is transmitted to the inlet of the electrostatic fume purifier (purification unit 2, selected from Jiumu Environmental Protection OSP-80) through a hot exhaust pipe with a diameter of 3 inches. The shell 3 of the electrostatic fume purifier is made of carbon steel paint, which includes a pre-filter (first filter component 41), a purification electric field (purification electric field module 5) and a post-filter (second filter component 42). The pre-filter uses a stainless steel wire mesh to effectively filter large particles of waste in the flux gas. The purification electric field is divided into a high-voltage part and a low-voltage part. After the flux particles are charged in the high-voltage discharge area of ​​the electric field, when passing through the adsorption plate in the low-voltage area, they are adsorbed and separated by the Coulomb force and are effectively adsorbed and purified. The post-filter is made of iron-nickel alloy and performs fine filtration on the purified gas. The purifier can handle a gas flow rate of 11.5m / s, and no smoke is discharged outside the outlet, indicating that the purification unit 2 has a good purification effect. The gas carrying flux is retained in the collection tray (collection module 6) of the fume purifier through a series of filtration, ionization and adsorption in the electrostatic fume purifier. The cleaned gas passes through a 3-inch diameter purified gas return air duct and returns to the reflow soldering furnace through the heating module. Before the adsorption plate in the low-pressure area is saturated with adsorption, part of the smoke will fall into the collection tray at the bottom of the equipment. After adsorption is saturated, the fume will not be able to be processed. At this time, it is necessary to take out the cleaning equipment and clean the electric field. In the present embodiment, the pre-filter, the purification electric field and the post-filter all adopt a pull-out structure for easy cleaning and maintenance.

[0047] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A soldering flux collection system for collecting soldering flux in an SMT reflow oven, characterized in that: It comprises an exhaust unit (1) and a purification unit (2) which are connected in sequence along the flow direction of the soldering flux gas; The purification unit (2) comprises a housing (3), a filtering module (4) installed in the housing (3), a purification electric field module (5), and a collecting module (6) for collecting soldering flux; The filter module (4) comprises a first filter component (41) and a second filter component (42), and the first filter component (41), the purification electric field module (5) and the second filter component (42) are arranged in sequence along the flow direction of the soldering flux gas.

2. A soldering flux collection system according to claim 1, characterized in that: The exhaust unit (1) is arranged at the exhaust port of the heating area of ​​the reflow soldering furnace, and the purification unit (2) is connected to the reflow soldering furnace via a pipeline.

3. A soldering flux collection system according to claim 1, characterized in that: The housing (3) comprises an air inlet and an air outlet; The air inlet is connected to the exhaust unit (1) via a hot exhaust duct, and the air outlet is connected to the reflow oven via a clean air return duct.

4. A soldering flux collection system according to claim 1, characterized in that: The filter module (4) and the purification electric field module (5) are installed in the housing (3) in a detachable manner.

5. A soldering flux collection system according to claim 1, characterized in that: The mesh number of the first filter component (41) is smaller than the mesh number of the second filter component (42).

6. A soldering flux collection system according to claim 1, characterized in that: The purification electric field module (5) comprises an ionization component (51) and an adsorption component (52) which are sequentially arranged along the flow direction of the soldering flux gas.

7. A soldering flux collection system according to claim 6, characterized in that: The ionization component (51) is electrically connected to an external power source, and the voltage of the ionization component (51) is higher than the voltage of the adsorption component (52).

8. A soldering flux collection system according to claim 6, characterized in that: The adsorption component (52) comprises an adsorption plate for adsorbing charged particles.

9. A soldering flux collection system according to claim 1, characterized in that: The collection module (6) is arranged below the filtering module (4) and the purification electric field module (5).

10. A method of using the soldering flux collection system according to any one of claims 1 to 9.

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