Curing device for reducing holes in surface of element in powder encapsulation based on positive pressure

Abstract

The utility model discloses a curing device for reducing holes in the surface of an element in powder encapsulation based on positive pressure, which comprises a drying oven provided with a stirring fan, a compressed air inlet valve and a pressure gauge are respectively arranged on the drying oven, and an air compression pump is arranged on the outer side of the drying oven; compressed air is introduced into the drying oven through a compressed air inlet valve by an air compression pump, and a flow meter is arranged between the air compression pump and the compressed air inlet valve. Compressed air is introduced into the drying oven by the air compression pump through the compressed air inlet valve, and the pressure above 0.15 MPa is kept in the drying oven by adjusting the flow of the compressed air, so that even if certain gas leakage is caused when the stirring fan works, the positive pressure on the interior of the drying oven after the air gap of the element is heated and expanded can be eliminated, and the drying efficiency is improved. The hole problem in the curing process is greatly reduced, and the qualified rate of powder packaging is improved.

Description

Technical Field

[0001] This utility model belongs to the field of component encapsulation technology, and relates to a curing device based on positive pressure to reduce surface pores of components in powder encapsulation. Background Technology

[0002] Epoxy powder and phenolic powder are thermosetting materials widely used in the encapsulation of electronic components. A typical process is: component preheating – powder coating – surface leveling – heat curing. The purpose of preheating the component is to bring its surface to the melting temperature of the thermosetting material, allowing the encapsulating powder to adhere to the component surface and form an encapsulation layer when the component is immersed in the powder bath. The curing process ensures that the material molecules fully cross-link to form a dense, network-like encapsulation layer.

[0003] However, during powder encapsulation, some corners or gaps in the component are encapsulated within the powder. After the powder melts and flows across the component surface, some air gaps are sealed inside. During the curing process, the gas in these air gaps expands due to heating and curing, breaking through the molten layer on the surface and forming holes. These holes can allow moisture or other contaminants to penetrate the component, causing premature component failure. Utility Model Content

[0004] The technical problem solved by this utility model is to provide a curing device based on positive pressure to reduce the porosity of the component surface in powder encapsulation, which can effectively reduce the porosity that appears on the component surface during the powder encapsulation process and improve the pass rate of powder encapsulation.

[0005] This utility model is achieved through the following technical solution:

[0006] A curing apparatus for reducing surface porosity of components in powder encapsulation based on positive pressure includes an oven equipped with a stirring fan, a compressed air inlet valve and a pressure gauge on the oven, and an air compressor pump installed outside the oven; compressed air is introduced into the oven by the air compressor pump through the compressed air inlet valve, and a flow meter is installed between the air compressor pump and the compressed air inlet valve.

[0007] Furthermore, the oven is also equipped with a control box, and the air compressor pump is electrically connected to the control box.

[0008] Furthermore, the oven is also equipped with a pressure relief valve, which is electrically connected to the control box.

[0009] Furthermore, the heating belt of the oven is located at the upper part of the oven body, and a conveyor belt is also located below the heating belt 8.

[0010] Furthermore, the stirring fan is located at the top of the oven.

[0011] Furthermore, the flow rate of compressed air is adjusted to maintain a pressure of over 0.15 MPa inside the oven.

[0012] Compared with the prior art, the present invention has the following beneficial technical effects:

[0013] This invention provides a curing device for reducing surface porosity of components in powder encapsulation based on positive pressure. An air compressor pump supplies compressed air to the oven through a compressed air inlet valve, with a flow meter installed between the pump and the oven. A pressure gauge is also installed on the oven to monitor the real-time pressure. By adjusting the compressed air flow rate, the pressure inside the oven is maintained above 0.15 MPa. Even if some gas leakage occurs during the operation of the stirring fan, the positive pressure on the oven caused by the thermal expansion of the component's air gap is eliminated, significantly reducing porosity during the curing process. This effectively reduces porosity on the surface of components during powder encapsulation production and improves the yield rate of powder encapsulation.

[0014] Furthermore, in order to control the pressure inside the oven more precisely, when the air pressure inside the oven exceeds 0.18MPa, the pressure relief valve can be opened through the control box to release some of the gas.

[0015] The curing device provided by this invention, which reduces surface porosity of components in powder encapsulation based on positive pressure, can be widely used in the encapsulation production of thermosetting materials such as power epoxy powder and phenolic powder, and can improve the pass rate of powder encapsulation. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the curing device of this utility model;

[0017] Figure 2 This is a schematic diagram of the internal layout of the drying oven of this utility model;

[0018] Among them, 1 is the compressed air inlet valve, 2 is the agitator fan, 3 is the pressure gauge, 4 is the control box, 5 is the drying oven, 6 is the drying oven door handle, 7 is the conveyor belt, and 8 is the heating belt. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings. These descriptions are intended to explain the present invention and not to limit it.

[0020] During the heating and curing process, the air gap of the component will expand in volume. When the component is placed in the curing device for heating and curing, the temperature will rise from 25℃ to 150℃. At this time, according to the ideal gas law, if the volume remains unchanged, the pressure will become approximately (150+273) / (25+273)≈1.38 times the original pressure, which is about 1.38 atmospheres, or about 0.138 MPa.

[0021] Because conventional curing ovens often have poor gas mixing and door sealing, the air volume inside the oven expands during the curing heating process and then leaks out through the gaps, preventing the expansion of the volume inside the oven from creating positive pressure. However, the air gaps inside the components expand without leaking out, thus creating positive pressure relative to the oven. When the pressure reaches the strength of the outer layer, it will break the wall and create holes.

[0022] See Figure 1 The present invention proposes the following curing device:

[0023] A curing apparatus for reducing surface porosity of components in powder encapsulation based on positive pressure includes an oven equipped with a stirring fan, a compressed air inlet valve and a pressure gauge on the oven, and an air compressor pump installed outside the oven; compressed air is introduced into the oven by the air compressor pump through the compressed air inlet valve, and a flow meter is installed between the air compressor pump and the compressed air inlet valve.

[0024] This invention features an air compressor pump installed outside the oven 5. Compressed air is introduced into the oven 5 through the compressed air inlet valve 1, and a flow meter is installed between the two. A pressure gauge 3 is also installed on the oven 5 to detect the real-time pressure inside the oven. By adjusting the flow rate of the compressed air, the pressure inside the oven is maintained above 0.15 MPa. In this way, even if the stirring fan 2 causes some gas leakage when it is working, the positive pressure inside the oven after the component air gap is heated and expanded can be eliminated, which greatly reduces the porosity problem during the curing process.

[0025] In order to control the pressure inside the oven more precisely, a pressure relief valve is also installed on the oven. When the air pressure inside the oven exceeds 0.18MPa, the pressure relief valve can be opened through the control box 4 to release some of the gas.

[0026] The mixing fan is generally located at the top, while the air inlet for internal circulation is located inside the inner walls on both sides.

[0027] Since compressed air is introduced into the curing oven to provide positive pressure, the sealing requirements for the oven can be appropriately relaxed; therefore, to facilitate the removal and placement of components from the oven, such as... Figure 2 As shown, the present invention places the heating belt 8 of the oven at the upper end of the oven body, and the conveyor belt 7 is placed below the heating belt 8. The components are placed on the conveyor belt 7 for easy handling.

[0028] The curing device provided by this invention, which reduces surface porosity of components in powder encapsulation based on positive pressure, can be widely used in the encapsulation production of thermosetting materials such as power epoxy powder and phenolic powder, and can improve the pass rate of powder encapsulation.

[0029] The embodiments given above are preferred examples of implementing this utility model, and this utility model is not limited to the above embodiments. Any non-essential additions or substitutions made by those skilled in the art based on the technical features of the technical solution of this utility model shall fall within the protection scope of this utility model.

Claims

1. A curing apparatus for reducing surface porosity of components in powder encapsulation based on positive pressure, comprising an oven equipped with a stirring fan, characterized in that, The oven is also equipped with a compressed air inlet valve and a pressure gauge, and an air compressor pump is installed on the outside of the oven. Compressed air is introduced into the oven by the air compressor pump through the compressed air inlet valve, and a flow meter is installed between the air compressor pump and the compressed air inlet valve.

2. The curing apparatus for reducing surface porosity of components in powder encapsulation based on positive pressure as described in claim 1, characterized in that, The oven is also equipped with a control box, and the air compressor pump is electrically connected to the control box.

3. The curing apparatus for reducing surface porosity of components in powder encapsulation based on positive pressure as described in claim 2, characterized in that, The oven is also equipped with a pressure relief valve, which is electrically connected to the control box.

4. The curing apparatus for reducing surface porosity of components in powder encapsulation based on positive pressure as described in claim 2, characterized in that, The heating belt of the oven is located at the upper part of the oven body, and a conveyor belt is also located below the heating belt.

5. The curing apparatus for reducing surface porosity of components in powder encapsulation based on positive pressure as described in claim 1, characterized in that, The stirring fan is located at the top of the oven.

6. The curing apparatus for reducing surface porosity of components in powder encapsulation based on positive pressure as described in claim 1, characterized in that, Adjust the flow rate of compressed air to maintain a pressure of over 0.15 MPa inside the oven.

Images