Hot air vacuum acid flux reflow soldering furnace for semiconductor packaging

Abstract

The utility model discloses a hot air vacuum formic acid reflow soldering furnace for semiconductor package welding, including hearth, be equipped with conveying mechanism in the hearth, the conveying direction of conveying mechanism is divided into preheating area, formic acid vacuum area, high temperature area and vacuum area in proper order along the hearth. Preheating area includes upper chamber one, intermediate chamber one and lower chamber one, and the intermediate chamber one is passed through from the conveying mechanism, and the intermediate chamber one and lower chamber one are conducted through the through -hole on both sides of the width direction of conveying mechanism, and the centrifugal fan no. The heating assembly no. 1 is arranged in the upper chamber one or lower chamber one. The reflow soldering furnace layout is reasonable, improves product quality, and the double -sided heat dissipation module is heated evenly.

Description

Technical Field

[0001] This utility model relates to the field of reflow oven technology, and in particular to a hot air vacuum formic acid reflow oven for semiconductor packaging soldering. Background Technology

[0002] Semiconductor packaging includes double-sided heat sink modules. One side of the module has heat sink fins that rest against a carrier. Reflow ovens typically use a single hot air heating method, resulting in low heat transfer efficiency. The heat sink fins of the double-sided heat sink module cannot receive hot air, causing uneven temperature distribution and affecting subsequent processing. Furthermore, the reflow oven layout is often inefficient, typically consisting of only one vacuum zone where gas is injected for reaction. However, a single vacuum zone cannot effectively reduce metal oxides and remove air bubbles, impacting product quality. Utility Model Content

[0003] To overcome the above-mentioned shortcomings, the purpose of this utility model is to provide a hot air vacuum formic acid reflow oven for semiconductor packaging welding, which has a reasonable layout, improves product quality, and provides uniform heating from the double-sided heat dissipation module.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is: a hot air vacuum formic acid reflow oven for semiconductor packaging soldering, comprising a furnace chamber, wherein a conveying mechanism is installed inside the furnace chamber, and the furnace chamber is sequentially divided into the following sections along the conveying direction of the conveying mechanism: The preheating zone includes an upper cavity, an intermediate cavity, and a lower cavity. The conveying mechanism passes through the intermediate cavity and the intermediate cavity and the lower cavity are connected by through holes on both sides of the width direction of the conveying mechanism. Centrifugal fans blowing air toward the conveying mechanism are provided in both the upper cavity and the lower cavity. A heating component is provided in either the upper cavity or the lower cavity. Formic acid vacuum zone includes a lower chamber and an upper chamber that can cover the lower chamber and form a vacuum cavity. An acid supply assembly is fixed on the lower chamber. A high-temperature zone, wherein the temperature of the high-temperature zone is higher than the temperature of the preheating zone; The vacuum zone includes a lower housing and an upper housing that can cover the lower housing and form a vacuum cavity. The beneficial effects of this utility model are as follows: By using a reasonable regional layout, the double-sided heat dissipation module is subjected to preheating, formic acid reduction, heating, and vacuum defoaming in sequence, which improves the welding effect of the double-sided heat dissipation module and reduces bubbles.

[0005] The preheating zone uses an up-and-down airflow pattern, blowing air from both the top and bottom of the double-sided heat dissipation module to improve the preheating effect of the double-sided heat dissipation module.

[0006] Furthermore, an air box is provided within the upper cavity, dividing it into chamber one and chamber two. The heating assembly is fixed within chamber one. Multiple air outlets facing the conveying mechanism are evenly distributed on the bottom plate of the air box. The centrifugal fan within the upper cavity draws gas from chamber one and blows it towards chamber two. The air box ensures that the hot air blown by the centrifugal fan is evenly distributed within chamber two, significantly increasing the uniformity of the hot air blowing onto the double-sided heat dissipation module.

[0007] Furthermore, the heating component one consists of multiple electric heating tubes fixed inside the chamber one.

[0008] Furthermore, the acid supply assembly includes a vaporization tank, which is connected to a gas storage tank and to the vacuum chamber via a pipeline, on which a switching valve is installed. Furthermore, the high-temperature zone includes an upper cavity, an intermediate cavity, and a lower cavity. The conveying mechanism passes through the intermediate cavity. Centrifugal fans are installed in both the upper cavity and the lower cavity to blow air toward the conveying mechanism. Heating components are installed in both the upper cavity and the lower cavity.

[0009] Furthermore, both the upper cavity and the lower cavity are provided with a wind box, the heating component is located outside the wind box, the centrifugal fan draws the heated gas from outside the wind box and blows it into the wind box, and the wind box is provided with an air outlet on the surface facing the conveying mechanism.

[0010] Furthermore, the furnace chamber also includes a cooling zone located on the side of the vacuum zone away from the high-temperature zone, and the cooling zone is used for cooling the double-sided heat dissipation module.

[0011] Furthermore, the cooling zone includes an upper cavity three, an intermediate cavity three, and a lower cavity three. The conveying mechanism passes through the intermediate cavity three. Centrifugal fans three that blow air toward the conveying mechanism are provided in both the upper cavity three and the lower cavity three. Heat exchangers are provided in both the upper cavity three and the lower cavity three.

[0012] Furthermore, both the upper cavity three and the lower cavity three are provided with air boxes three, the heat exchanger is located outside the air box three, the centrifugal fan three draws the cooled gas outside the air box three and blows it into the air box three, and the air box three has an air outlet three on its surface facing the conveying mechanism. Attached Figure Description Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model; Figure 2 This is a three-dimensional structural diagram of the preheating zone in an embodiment of the present invention; Figure 3 This is a cross-sectional view of the preheating zone in an embodiment of this utility model; Figure 4 This is a schematic diagram of the formic acid vacuum region in an embodiment of the present invention; Figure 5 This is a three-dimensional structural diagram of the high-temperature zone in an embodiment of the present invention; Figure 6 This is a cross-sectional view of the high-temperature zone in an embodiment of this utility model; Figure 7 This is a cross-sectional view of the cooling zone in an embodiment of this utility model.

[0013] In the picture: 1. Preheating zone; 11. Upper chamber 1; 111. Air box 1; 11a. Chamber 1; 11b. Chamber 2; 12. Intermediate chamber 1; 13. Lower chamber 1; 14. Through hole; 15. Centrifugal fan 1; 16. Heating assembly 1; 2. Conveying mechanism; 3. Formic acid vacuum zone; 31. Lower chamber 1; 32. Upper chamber 1; 33. Acid supply assembly; 331. Vaporization tank; 332. Piping; 4. High-temperature zone; 41. Upper cavity II; 42. Middle cavity II; 43. Lower cavity II; 44. Air box II; 45. Centrifugal fan II; 46. Heating assembly II; 5. Vacuum region; 6. Cooling zone; 61. Upper cavity three; 62. Middle cavity three; 63. Lower cavity three; 64. Air box three; 65. Centrifugal fan three; 66. Heat exchanger. Detailed Implementation The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the scope of protection of the present invention.

[0014] This utility model relates to a hot air vacuum formic acid reflow oven for semiconductor packaging soldering; see appendix. Figure 1 As shown, the reflow oven includes a furnace chamber, and a conveying mechanism 2 is installed inside the furnace chamber. The reflow oven includes a base and a top cover hinged to the base, with the top cover closing onto the base to form the furnace chamber. The conveying mechanism 2 can be a conveyor line, which will not be described in detail here.

[0015] The furnace chamber is divided into a preheating zone 1, a formic acid vacuum zone 3, a high-temperature zone 4, and a vacuum zone 5 along the conveying direction of the conveying mechanism 2. The preheating zone 1 preheats the double-sided heat dissipation module to approximately 160°C. The formic acid vacuum zone 3 uses a vacuum-filling formic acid method to reduce the metal oxides on the double-sided heat dissipation module. The high-temperature zone 4 melts the alloy welding sheets. The vacuum zone 5 uses a vacuum method to expel air bubbles trapped within the molten alloy, thus achieving void-free welding.

[0016] In this embodiment, the furnace chamber is divided into the aforementioned areas in sequence. Through a reasonable area layout, the double-sided heat dissipation module is subjected to preheating, formic acid reduction, heating, and vacuum defoaming in sequence, thereby improving the welding effect of the double-sided heat dissipation module and reducing bubbles.

[0017] See appendix Figure 2 and attached Figure 3 As shown, the preheating zone 1 includes an upper cavity 11, an intermediate cavity 12, and a lower cavity 13 separated by a partition. The upper cavity 11 is located on the upper cover, the intermediate cavity 12 is formed between the upper cover and the base, and the lower cavity 13 is located on the base. The conveying mechanism 2 passes through the intermediate cavity 12, and the intermediate cavity 12 and the lower cavity 13 are connected by through holes 14 on both sides of the width direction of the conveying mechanism 2. Centrifugal fans 15 that blow air toward the conveying mechanism 2 are provided in both the upper cavity 11 and the lower cavity 13, and heating components 16 are provided in either the upper cavity 11 or the lower cavity 13.

[0018] In the prior art, since the preheating zone 1 is only for preheating, it is usually done by blowing hot air from above. However, in this application, the bottom of the double-sided heat dissipation module has heat dissipation fins, and the contact area with the conveying mechanism 2 is small. Therefore, blowing hot air from above alone cannot effectively preheat the double-sided heat dissipation module. Therefore, in this embodiment, the preheating zone 1 adopts an up-and-down blowing method, blowing air from both the top and bottom directions of the double-sided heat dissipation module to improve the preheating effect. At the same time, the lower cavity 13 and the middle cavity 12 are connected through the through hole 14, and the gas in the middle cavity can be drawn into the lower cavity 13, realizing the connection between the upper cavity 11 and the lower cavity 13. At this time, a heating component 16 heats all preheating zones 1.

[0019] In one embodiment, see Appendix Figure 3As shown, an air box 111 is provided inside the upper cavity 11, which divides the upper cavity 11 into a first chamber 11a and a second chamber 11b, with the first chamber 11a surrounding the second chamber 11b. The heating assembly 16 is fixed inside the first chamber 11a. Multiple air outlets 1 facing the conveying mechanism 2 are evenly distributed on the bottom plate of the air box. The centrifugal fan 15 inside the upper cavity 11 draws gas from the first chamber 11a and blows it towards the second chamber 11b. An air inlet is also provided on the air box 111 to connect the first chamber 11a and the second chamber 11b. The centrifugal fan is fixed at the air inlet, drawing the heated gas from the first chamber 11a into the second chamber 11b through the air inlet. After filling the second chamber 11b, the gas is evenly blown onto the conveying mechanism 2 from the air outlets 1. This structure greatly increases the uniformity of the hot air blown onto the double-sided heat dissipation module.

[0020] A centrifugal fan in the lower chamber 13 draws gas from the middle chamber 12 through the through holes 14 on both sides into the lower chamber 2 43, and then blows it onto the conveying mechanism 2. Because the conveying structure includes a fixed plate with an array of air holes, the gas blown out of the lower chamber 13 can pass through the air holes and be evenly blown onto the double-sided heat dissipation module. The gas flow direction in the preheating zone 1 is shown in the appendix. Figure 3 As shown by the arrow in the image.

[0021] The heating component 16 consists of multiple electric heating tubes fixed in the chamber 11a. For example, there are two electric heating tubes fixed in the chamber 11a of the upper cavity 11. The two electric heating tubes are symmetrically arranged on both sides of the centrifugal fan 15 in the width direction of the conveying mechanism 2.

[0022] See appendix Figure 4 As shown, the formic acid vacuum zone 3 includes a lower housing 31 and an upper housing 32 that covers the lower housing 31 and forms a vacuum cavity. An acid supply assembly 33 is fixed on the lower housing. The formic acid vacuum zone 3 is located after the preheating zone 1. Formic acid is injected while the vacuum is being created to reduce the metal oxides on the double-sided heat dissipation module and improve the welding effect of the double-sided heat dissipation module.

[0023] The acid supply assembly 33 includes a vaporization tank 331, which is connected to a gas storage tank and to the vacuum chamber 11a via a pipeline 332. A switching valve is installed on the pipeline 332. Formic acid in the gas storage tank is pumped into the vaporization tank 331, vaporized in the vaporization tank 331, and then transported to the vacuum chamber 1 via the pipeline 332.

[0024] The lower chamber is also equipped with a gas pipe that is connected to the vacuum chamber. The gas pipe is connected to an external vacuum generator. When the vacuum generator is working, it extracts the air from the vacuum chamber, creating a vacuum, and then formic acid is injected.

[0025] The temperature of the high-temperature zone 4 is higher than that of the preheating zone 1. The high-temperature zone 4 is heated by hot air from the top and bottom to melt the alloy welding sheet.

[0026] See appendix Figure 5 and attached Figure 6 As shown, the high-temperature zone 4 includes an upper cavity 41, an intermediate cavity 42, and a lower cavity 43. The conveying mechanism 2 passes through the intermediate cavity 42. Centrifugal fans 45 are installed in both the upper cavity 41 and the lower cavity 43 to blow air towards the conveying mechanism 2. Heating components 46 are installed in both the upper cavity 41 and the lower cavity 43. In this embodiment, the heating components 46 are installed in both the upper cavity 41 and the lower cavity 43, enabling high temperatures. The hot air blowing onto and below the double-sided heat dissipation module is at approximately the same temperature. Therefore, the lower cavity 43 does not need to extract gas from the intermediate cavity 42; instead, the gas is heated directly in the lower cavity 43 and then blown onto the double-sided heat dissipation module.

[0027] Both the upper cavity 41 and the lower cavity 43 are equipped with air boxes 44. The heating assembly 46 is located outside the air boxes 44. The centrifugal fan 45 draws in the heated gas from outside the air boxes 44 and blows it into the air boxes 44. Air outlets are provided on the surface of the air boxes 44 facing the conveying mechanism 2. The structures inside the upper cavity 41 and the lower cavity 43 are the same as those inside the upper cavity 11, improving the uniformity of hot air blowing and ensuring even heating of the double-sided heat dissipation module. For gas flow in the high-temperature zone 4, please refer to the appendix. Figure 6 As shown by the arrow in the image.

[0028] Vacuum zone 5 includes a lower housing and an upper housing that covers the lower housing and forms a vacuum cavity. Vacuum zone 5 and formic acid vacuum zone 3 have basically the same structure, except that vacuum zone 5 does not have an acid supply component 33, and only requires vacuum treatment.

[0029] The furnace chamber also includes a cooling zone 6, which is located on the side of the vacuum zone 5 away from the high-temperature zone 4. The cooling zone 6 is used to cool the double-sided heat dissipation module. The cooling zone 6 is cooled by upper and lower cold air to cool the double-sided heat dissipation module to below 60°C.

[0030] See appendix Figure 7 As shown, the cooling zone 6 includes an upper cavity 61, an intermediate cavity 62, and a lower cavity 63. The conveying mechanism 2 passes through the intermediate cavity 62. Centrifugal fans 65 that blow air toward the conveying mechanism 2 are provided in both the upper cavity 61 and the lower cavity 63. Heat exchangers 66 are provided in both the upper cavity 61 and the lower cavity 63.

[0031] Both the upper cavity 3 61 and the lower cavity 3 63 are provided with air boxes 3 64. The heat exchanger 66 is located outside the air box 3 64. The centrifugal fan 3 65 draws the cooled gas outside the air box 3 64 and blows it into the air box 3 64. The air box 2 44 has an air outlet 3 on its surface facing the conveying mechanism 2.

[0032] The upper cavity 3 61 and lower cavity 3 63 have the same structure as the upper cavity 2 41 and lower cavity 2 43. The difference is that the heating component 2 is replaced with a heat exchanger 66 that can cool air. The heat exchanger 66 includes a heat exchange plate, and the heat exchange plate has a heat exchange channel in which a cooling medium flows.

[0033] The above embodiments are only for illustrating the technical concept and features of this utility model. Their purpose is to enable those skilled in the art to understand the content of this utility model and implement it. They cannot be used to limit the protection scope of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be covered within the protection scope of this utility model.

Claims

1. A hot air vacuum formic acid reflow oven for semiconductor packaging soldering, comprising a furnace chamber, wherein a conveying mechanism is provided inside the furnace chamber, characterized in that: The furnace chamber is divided sequentially along the conveying direction of the conveying mechanism into: The preheating zone includes an upper cavity, an intermediate cavity, and a lower cavity. The conveying mechanism passes through the intermediate cavity and the intermediate cavity and the lower cavity are connected by through holes on both sides of the width direction of the conveying mechanism. Centrifugal fans blowing air toward the conveying mechanism are provided in both the upper cavity and the lower cavity. A heating component is provided in either the upper cavity or the lower cavity. Formic acid vacuum zone includes a lower chamber and an upper chamber that can cover the lower chamber and form a vacuum cavity. An acid supply assembly is fixed on the lower chamber. A high-temperature zone, wherein the temperature of the high-temperature zone is higher than the temperature of the preheating zone; The vacuum zone includes a lower housing and an upper housing that can cover the lower housing and form a vacuum cavity.

2. The hot air vacuum formic acid reflow oven for semiconductor packaging soldering according to claim 1, characterized in that: An air box is provided inside the upper cavity, which divides the upper cavity into a chamber 1 and a chamber 2. The heating component is fixed inside the chamber 1. Multiple air outlet holes 1 facing the conveying mechanism are evenly distributed on the bottom plate of the air box 1. The centrifugal fan 1 inside the upper cavity draws the gas from the chamber 1 and blows it out towards the chamber 2.

3. The hot air vacuum formic acid reflow oven for semiconductor packaging soldering according to claim 2, characterized in that: The heating component consists of multiple electric heating tubes fixed inside the chamber.

4. The hot air vacuum formic acid reflow oven for semiconductor packaging soldering according to claim 1, characterized in that: The acid supply assembly includes a vaporization tank, which is connected to a gas storage tank and to the formic acid vacuum zone via a pipeline, which is equipped with a switch valve.

5. The hot air vacuum formic acid reflow oven for semiconductor packaging soldering according to claim 1, characterized in that: The high-temperature zone includes an upper cavity, an intermediate cavity, and a lower cavity. The conveying mechanism passes through the intermediate cavity. Centrifugal fans are installed in both the upper cavity and the lower cavity to blow air toward the conveying mechanism. Heating components are installed in both the upper cavity and the lower cavity.

6. The hot air vacuum formic acid reflow oven for semiconductor packaging soldering according to claim 5, characterized in that: Both the upper cavity and the lower cavity are provided with air boxes. The heating component is located outside the air box. The centrifugal fan draws the heated gas from outside the air box and blows it into the air box. The air box has an air outlet on its surface facing the conveying mechanism.

7. The hot air vacuum formic acid reflow oven for semiconductor packaging soldering according to any one of claims 1-6, characterized in that: The furnace chamber also includes a cooling zone located on the side of the vacuum zone away from the high-temperature zone, and the cooling zone is used for cooling the double-sided heat dissipation module.

8. The hot air vacuum formic acid reflow oven for semiconductor packaging soldering according to claim 7, characterized in that: The cooling zone includes an upper cavity three, an intermediate cavity three, and a lower cavity three. The conveying mechanism passes through the intermediate cavity three. Centrifugal fans three that blow air toward the conveying mechanism are provided in both the upper cavity three and the lower cavity three. Heat exchangers are provided in both the upper cavity three and the lower cavity three.

9. The hot air vacuum formic acid reflow oven for semiconductor packaging soldering according to claim 8, characterized in that: Both the upper cavity 3 and the lower cavity 3 are provided with air boxes 3. The heat exchanger is located outside the air boxes 3. The centrifugal fan 3 draws out the cooled gas outside the air boxes 3 and blows it into the air boxes 3. The air boxes 3 have air outlet holes 3 on the surface facing the conveying mechanism.

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