Vacuum eutectic reflow soldering furnace with pressure regulating system

Abstract

The invention discloses a vacuum eutectic reflow soldering furnace with a pressure regulating system, which comprises a furnace body with an air inlet and an air outlet; the air inlet is connected with an air inlet pipeline, and an air inlet cooling valve and an air inlet proportion adjusting valve are arranged on the air inlet pipeline to form a pressurization system; the air outlet is connected with an air outlet pipeline, a first baffle valve is arranged on the air outlet pipeline, and a vacuum pump is externally connected to the air outlet pipeline to form a vacuum system; and the pressurizing system and the vacuum system alternately carry out air intake and air exhaust on the furnace body and are used for realizing alternate pressurizing and vacuumizing operation of the furnace body. The pressurization system and the vacuum system are arranged on the furnace body, air intake and air exhaust are alternately carried out on the furnace body, alternate pressurization and vacuum pumping operation of the furnace body is achieved, bubbles in the central area of the chip can move out of the central area of the chip in the expansion and contraction movement process, and therefore the chip is prevented from being damaged. And finally, the voidage of the large-area bonding pad is reduced.

Description

Technical Field

[0001] This invention belongs to the technical field of vacuum eutectic reflow oven equipment, specifically, it relates to a vacuum eutectic reflow oven with a pressure regulating system. Background Technology

[0002] A vacuum eutectic reflow oven is a device that performs eutectic bonding of semiconductor chips in a vacuum environment. By creating a vacuum environment and using reducing process gases to protect the products and solder from oxidation, the equipment improves the bonding quality, enhances the heat transfer performance of the bonded devices, and ultimately improves the reliability of electronic devices.

[0003] Vacuum eutectic reflow ovens play a crucial role in the manufacturing and packaging of semiconductor chips. Their unique vacuum eutectic bonding technology ensures that semiconductor chips are not affected by oxidation during the bonding process.

[0004] Theoretically, absolute vacuum can effectively reduce void ratio. However, in actual production, when the chip is too large, it is difficult to remove air bubbles in the central area of ​​the chip by vacuuming.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] This invention provides a vacuum eutectic reflow oven with a voltage regulation system. By setting up a pressurization system and a vacuum system on the oven body, the oven body is alternately pressurized and evacuated to achieve alternating pressurization and vacuuming operations. This allows air bubbles in the central area of ​​the chip to escape from the central area of ​​the chip during the expansion and contraction process, ultimately reducing the void ratio of large-area solder pads.

[0007] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is: a vacuum eutectic reflow oven with a voltage regulating system, comprising, The furnace body has an air inlet and an air outlet; The air inlet is connected to an air inlet pipe, which is equipped with an air inlet cooling valve and an air inlet proportional regulating valve to form a pressurization system; The air outlet is connected to an air outlet pipeline, which is equipped with a first baffle valve and externally connected to a vacuum pump to form a vacuum system. The pressurization system and vacuum system alternately introduce and extract air into the furnace body to achieve alternating pressurization and vacuuming operations.

[0008] Furthermore, the furnace body is also equipped with a pressure relief system, which includes at least an exhaust pipe. The exhaust pipe is connected to the gas outlet pipe through a pressure relief branch, and a one-way check valve is installed at the connection between the pressure relief branch and the gas outlet pipe.

[0009] Furthermore, the pressure relief system also includes a high-flow-rate pressure relief air path and a low-flow-rate pressure relief air path, which are connected in parallel to the outlet pipe. A second baffle valve is installed at the parallel outlet pipe to switch between the high-flow-rate pressure relief air path and the low-flow-rate pressure relief air path.

[0010] Furthermore, the high-flow-rate pressure relief air path includes a high-flow-rate pressure relief valve, which achieves high-flow-rate exhaust through a one-way check valve and an exhaust pipe.

[0011] Furthermore, the low-flow pressure relief air path includes a low-flow pressure relief valve, which achieves low-volume exhaust through a one-way check valve and an exhaust pipe.

[0012] Furthermore, a pressure sensor is also installed on the gas outlet pipe to monitor the pressure inside the furnace body in real time.

[0013] Furthermore, a safety valve is also installed on the gas outlet pipe. The safety valve is set with a preset opening pressure and is used to automatically release pressure when the internal pressure of the furnace is too high.

[0014] Furthermore, a vacuum gauge is installed on the gas outlet pipeline to monitor the vacuum value in the furnace body and / or the gas outlet pipeline in real time.

[0015] Furthermore, it also includes a control system, which includes at least a PID regulator electrically connected to a vacuum gauge and / or a pressure sensor.

[0016] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art: 1. This invention sets up a pressurization system and a vacuum system on the furnace body, and alternately introduces and removes air from the furnace body to achieve alternating pressurization and vacuuming operations. This allows air bubbles in the central area of ​​the chip to escape from the central area of ​​the chip during the expansion and contraction process, ultimately reducing the void ratio of large-area solder pads.

[0017] 2. This invention incorporates a pressure relief system on the furnace body, with a one-way check valve installed between the gas outlet pipe and the first baffle valve. During pressure relief and cooling, the internal pressure of the furnace body and pipes exceeds the opening pressure of the one-way check valve, allowing the gas inside the furnace body to be discharged through the exhaust pipe. During vacuum conditions, the one-way check valve automatically seals due to the pressure difference between the internal vacuum and atmospheric pressure. The furnace body is then evacuated via the first baffle valve and an external vacuum pump, ensuring the safety of the furnace body and the pressure regulating system.

[0018] 3. This invention sets up a high-flow-rate pressure relief gas path and a low-flow-rate pressure relief gas path in the pressure relief system, and controls the gas path conduction through a low-flow-rate pressure relief valve, a high-flow-rate pressure relief valve, and a second baffle valve. It can automatically match and select the pressure relief speed according to the actual pressure relief pressure, and select the appropriate pressure relief gas path accordingly, thereby ensuring the reliability and safety of the pressure relief system.

[0019] 4. By setting up a pressure sensor and a vacuum gauge and electrically connecting them to the control system, the vacuum value or pressure value of the furnace body is uploaded to the control system in real time during the operation of the pressurization system or the vacuum system, and is judged by comparing it with the preset vacuum value range and pressure value range.

[0020] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0021] The accompanying drawings, as part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation of the invention. Obviously, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the voltage regulating system in an embodiment of the present invention; Figure 2 This is a schematic diagram of the gas flow in the pressurization system of an embodiment of the present invention; Figure 3 This is a schematic diagram of gas flow in the vacuum system according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the gas flow in the high-flow-rate pressure relief gas path of the pressure relief system in an embodiment of the present invention; Figure 5 This is a schematic diagram of the gas flow in the low-flow-rate pressure relief gas path of the pressure relief system in an embodiment of the present invention.

[0022] Description of main components in the diagram: 1. Furnace body; 101. Air inlet; 102. Air outlet; 2. Air inlet proportional control valve; 3. Air inlet cooling valve; 4. Air inlet pipeline; 5. Air outlet pipeline; 6. Second baffle valve; 7. Small flow pressure relief valve; 8. Large flow pressure relief valve; 9. One-way check valve; 10. Exhaust stack; 11. Vacuum gauge; 12. First baffle valve; 13. Safety valve; 14. Pressure sensor.

[0023] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0025] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] like Figures 1 to 5 As shown, the vacuum eutectic reflow oven with a voltage regulating system according to the present invention includes, Furnace body 1 has an air inlet 101 and an air outlet 102; The air inlet 101 is connected to the air inlet pipe 4, wherein the air inlet pipe 4 is equipped with an air inlet cooling valve 3 and an air inlet proportional regulating valve 2 to form a pressurization system. The air outlet 102 is connected to an air outlet pipe 5, wherein a first baffle valve 12 is installed on the air outlet pipe 5 and a vacuum pump is connected externally to form a vacuum system. The pressurization system and the vacuum system alternately introduce and extract air into the furnace body 1 to achieve alternating pressurization and vacuuming operations.

[0028] In this invention, the furnace body 1 of the vacuum eutectic reflow oven has an air inlet 101 on one side. Of course, for more complete and rapid air intake, air inlets 101 can be provided on both sides of the furnace body 1. One and / or both air inlets 101 of the furnace body 1 are connected to the air intake pipeline 4 via air intake branch pipes. (See attached diagram) Figure 1 The intake pipe 4 is provided with an intake cooling valve 3 and an intake proportional regulating valve 2 from left to right.

[0029] The bottom of the furnace body 1 is provided with an air outlet 102, which is connected through an air outlet pipe 5. The port of the air outlet pipe 5 is connected to a preset vacuum pump. A first baffle valve 12 is provided between the furnace body 1 and the vacuum pump to control the gas in the air outlet pipe 5 and to provide corresponding protection for the vacuum pump when it is not working.

[0030] Specific implementation process: In order to eliminate air bubbles in the central area of ​​the chip during the eutectic bonding process of semiconductor chips, the furnace body 1 is pressurized by a pressurization system; then, after closing the relevant valves of the pressurization system, the furnace body 1 is evacuated by a vacuum pump through the exhaust pipe 5. By repeating the above pressurization and evacuation operations, the air bubbles in the central area of ​​the chip can be moved out of the central area of ​​the chip during the expansion and contraction process, and finally the void ratio of large-area solder pads is reduced.

[0031] Among them, by setting an air intake cooling valve 3 on the air intake pipe 4, the semiconductor chip entering the furnace body 1 can be cooled, and the semiconductor chip can be quickly reduced from the process temperature required for eutectic welding to the room temperature, thereby ensuring the stability and uniformity of the temperature inside the furnace and thus optimizing the welding process. Meanwhile, an air intake proportional regulating valve 2 is also installed on the air intake pipe 4, which can control the pressure and flow rate of the air source according to the needs, and pressurize the inside of the vacuum eutectic reflow oven cavity through one and / or two air intake ports 101, so as to accurately control the air intake flow rate and air intake pressure of the oven body 1.

[0032] Furthermore, the furnace body 1 is also provided with a pressure relief system, which includes at least an exhaust pipe 10. The exhaust pipe 10 is connected to the gas outlet pipe 5 through a pressure relief branch, and a one-way check valve 9 is provided at the connection between the pressure relief branch and the gas outlet pipe 5.

[0033] In this invention, a vacuum system and a pressure relief system are connected to the port of the exhaust pipe 5 via a tee. The exhaust pipe 10 in the pressure relief system is connected to the exhaust pipe 5 via a pressure relief branch, and the one-way check valve 9 is provided between the pressure relief branch and the tee.

[0034] During depressurization and cooling, the internal pressure of the furnace body 1 and pipelines is greater than the opening pressure of the one-way check valve 9, and the gas inside the furnace body 1 is discharged through the exhaust pipe 10. During vacuuming, the one-way check valve 9 is automatically sealed due to the pressure difference formed by the vacuum inside the system and atmospheric pressure. The furnace body 1 is then evacuated through the first baffle valve 12 and the external vacuum pump. Thus, the safety of the furnace body 1 and the pressure regulating system is ensured by the setting of the one-way check valve 9.

[0035] Furthermore, the pressure relief system also includes a high-flow-rate pressure relief air path and a low-flow-rate pressure relief air path, which are connected in parallel to the outlet pipe 5. A second baffle valve 6 is provided at the parallel outlet pipe 5 to switch between the high-flow-rate pressure relief air path and the low-flow-rate pressure relief air path.

[0036] In this invention, the pressure relief system has two pressure relief air paths: a high-flow-rate pressure relief air path and a low-flow-rate pressure relief air path. The high-flow-rate and low-flow-rate pressure relief air paths can be selectively opened on the outlet pipe 5. Specifically, the high-flow-rate and low-flow-rate pressure relief air paths are connected in parallel on the outlet pipe 5, and a second baffle valve 6 for controlling the air path opening is installed on the corresponding parallel outlet pipe 5.

[0037] Specifically, the high-flow-rate pressure relief air path includes a high-flow-rate pressure relief valve 8, which achieves high-flow-rate exhaust through a one-way check valve 9 and an exhaust pipe 10. The low-flow pressure relief air path includes a low-flow pressure relief valve 7, which achieves low-flow exhaust through a one-way check valve 9 and an exhaust pipe 10.

[0038] In this invention, the high-flow-rate pressure relief gas path specifically comprises: gas outlet 102 - gas outlet branch pipe - high-flow-rate pressure relief valve 8 - gas outlet pipeline 5 - one-way check valve 9 - gas outlet cylinder. By opening the high-flow-rate pressure relief valve 8 and simultaneously closing the second baffle valve 6 and the low-flow-rate pressure relief valve 7, the gas is finally discharged at the exhaust cylinder 10 through the aforementioned high-flow-rate pressure relief gas path.

[0039] In addition, the low-flow pressure relief gas path is specifically as follows: gas outlet 102 - gas outlet branch pipe - low-flow pressure relief valve 7 - gas outlet branch pipe - gas outlet pipeline 5 - one-way check valve 9 - gas outlet cylinder. By opening the low-flow pressure relief valve 7 and simultaneously closing the second baffle valve 6 and the high-flow pressure relief valve 8, the gas is finally discharged at the exhaust cylinder 10 through the above-mentioned low-flow pressure relief gas path.

[0040] The aforementioned high-flow-rate and low-flow-rate pressure relief gas paths can be automatically matched and selected according to the actual pressure relief pressure, thereby selecting the appropriate pressure relief gas path and ensuring the reliability and safety of the pressure relief system.

[0041] Finally, to achieve rapid cooling within the furnace body 1, the high-flow pressure relief valve 8, the low-flow pressure relief valve 7, and the second baffle valve 6 can be opened, ensuring the entire exhaust pipe 5 and all its branches are open. The overall cooling process involves first sending cooling gas into the furnace body 1 through the intake cooling valve 3 and intake pipe 4, thereby providing sufficient and rapid cooling to the chips and internal components of the furnace body 1; then, the gas is discharged at maximum flow rate through the opened second baffle valve 6 and exhaust pipe 5-exhaust stack 10, achieving rapid cooling of the furnace body 1 while ensuring the reliability and safety of the pressure relief system.

[0042] Furthermore, a vacuum gauge 11 is installed on the outlet pipe 5 to monitor the vacuum value in the outlet pipe 5 in real time.

[0043] In this invention, a vacuum gauge 11 is provided near the first baffle valve 12 and the three-way valve. During the specific operation of the vacuum system, the vacuum value of the gas outlet pipe 5 and the furnace body 1 can be monitored in real time by the vacuum gauge 11. Technicians can judge the vacuum status in the furnace body 1 based on the real-time vacuum value obtained.

[0044] If the vacuum value of furnace body 1 does not meet the preset standard vacuum range, the technicians can be alerted. Specifically, a buzzer or warning light can be electrically connected to it to facilitate timely inspection and maintenance of furnace body 1 and related pipelines by technicians.

[0045] Furthermore, a pressure sensor 14 is also installed on the gas outlet pipe 5 to monitor the pressure inside the furnace body 1 in real time.

[0046] Specifically, it also includes a control system, which includes at least a PID regulator electrically connected to the vacuum gauge 11 and / or the pressure sensor 14.

[0047] In this invention, a pressure sensor 14 is installed at the air outlet 102 of the furnace body 1, thereby enabling real-time monitoring of the internal pressure of the furnace body 1. Simultaneously, through an external control system, when the aforementioned vacuum gauge 11 or pressure sensor 14 is operating in the pressurization or vacuuming system, the vacuum or pressure data of the furnace body 1 is uploaded to the control system in real time, and a judgment is made by comparing it with preset vacuum and pressure ranges.

[0048] The control system includes at least a PID pressure regulator, which controls the pressurized gas source pressure and works in conjunction with the aforementioned intake proportional control valve 2 to control the input gas flow rate and pressure. Based on the data from the pressure sensor 14, it determines whether the control system needs to issue a working command to perform gas pressure regulation on the intake pipeline 4 or the furnace body 1.

[0049] Furthermore, a safety valve 13 is also provided on the gas outlet pipe 5. The safety valve 13 is set with a preset opening pressure and is used to automatically release pressure when the internal pressure of the furnace body 1 is too high.

[0050] In this invention, a safety valve 13 is installed on the gas outlet pipe 5 of the furnace body 1. The actuating element of the safety valve 13 is set with a preset opening pressure and is sealed with lead. When the internal pressure of the furnace body 1 exceeds the preset pressure range, the safety valve 13 can automatically release pressure, effectively ensuring the safety of the furnace body 1.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. The implementation schemes in the above embodiments can be further combined or replaced. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A vacuum eutectic reflow soldering furnace having a pressure regulating system, characterized by: The utility model relates to a kind of furnace, including, Furnace body, with air inlet and air outlet; The air inlet is connected with air inlet pipeline, wherein air inlet pipeline is provided with air inlet cooling valve and air inlet proportional regulating valve, forming pressurization system; The air outlet is connected with air outlet pipeline, wherein air outlet pipeline is provided with first flapper valve, and vacuum pump is connected outside, forming vacuum system; The pressurization system and vacuum system alternately carry out air intake and air exhaust to furnace body, for realizing the alternate pressurization and vacuumizing operation of furnace body.

2. The vacuum eutectic reflow soldering furnace with pressure regulating system according to claim 1, characterized in that: The furnace body is also provided with pressure relief system, and the pressure relief system at least includes exhaust cylinder, the exhaust cylinder is communicated with air outlet pipeline by pressure relief branch, and one-way check valve is arranged at the connection of pressure relief branch and air outlet pipeline.

3. The vacuum eutectic reflow soldering furnace with pressure regulating system according to claim 2, characterized in that: The pressure relief system further includes large-flow pressure relief gas path and small-flow pressure relief gas path, and the large-flow pressure relief gas path and the small-flow pressure relief gas path are connected in parallel on the air outlet pipeline, and second flapper valve is arranged at the parallel air outlet pipeline, for switching the large-flow pressure relief gas path and the small-flow pressure relief gas path.

4. The vacuum eutectic reflow soldering furnace with pressure regulating system according to claim 3, characterized in that: The large-flow pressure relief gas path includes large-flow pressure relief valve arranged therein, and the large-flow pressure relief valve realizes large-flow exhaust through one-way check valve and exhaust cylinder.

5. The vacuum eutectic reflow soldering furnace with pressure regulating system according to claim 3 or 4, characterized in that: The small-flow pressure relief gas path includes small-flow pressure relief valve arranged therein, and the small-flow pressure relief valve realizes small-flow exhaust through one-way check valve and exhaust cylinder.

6. The vacuum eutectic reflow soldering furnace with pressure regulating system according to claim 5, characterized in that: Pressure sensor is further arranged on the air outlet pipeline, for monitoring the pressure inside furnace body in real time.

7. The vacuum eutectic reflow soldering furnace with pressure regulating system according to claim 6, characterized in that: Safety valve is further arranged on the air outlet pipeline, and the safety valve is provided with preset opening pressure, for automatically relieving pressure when the pressure inside furnace body is too high.

8. The vacuum eutectic reflow soldering furnace with pressure regulating system according to claim 7, characterized in that: Vacuum gauge is arranged on the air outlet pipeline, for monitoring the vacuum value in furnace body and / or air outlet pipeline in real time.

9. The vacuum eutectic reflow soldering furnace with pressure regulating system according to claim 8, characterized in that: Further including control system, and the control system at least includes PID pressure regulator, and is electrically connected with vacuum gauge and / or pressure sensor.

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