High-flatness sintering mold

Abstract

The high-flatness sintering mold is characterized in that the high-flatness sintering mold comprises an upper mold body and a lower mold body, the upper mold body is provided with a main body and a hot-pressing mechanism, and hot-pressing guide columns are fixedly arranged in the four corner areas of the bottom face of a pressing head floating base respectively; the lower die comprises a lower die base, guide sleeves and a lower die heating block, the lower die heating block and the guide sleeves are fixedly arranged at the end, facing the upper die, of the lower die base, and the guide sleeves are arranged around the outer side area of the lower die heating block at intervals and correspond to and are matched with the hot-pressing guide columns; the lower die base is provided with heat insulation blocks on the bottom face of the lower die heating block in a left-right-front-back mode. The upper die heating block and the lower die heating block are respectively provided with a water cooling channel, and the water cooling channels are communicated with a cooling water inlet and a cooling water outlet.

Description

Technical Field

[0001] This invention relates to the field of sintering equipment, and more specifically to a high-flatness sintering mold used in sintering equipment. Background Technology

[0002] In the field of semiconductor chip packaging, the connection between the chip and the substrate is generally achieved through sintering bonding. This involves fixing the chip using micro / nano silver paste or silver film, or micro / nano metals, or silver / copper solder paste. During the sintering process, pressure is applied to the semiconductor chip at 150–300°C using a pressure head to promote the densification and aggregation of the micro / nano metal particles, while simultaneously causing the organic solvents in the micro / nano metal solder paste to evaporate, thus achieving mechanical and electrical connections between the chip and the substrate. The control and uniformity of heating and pressure during the sintering process are critical indicators. Minimizing porosity in the silver paste, improving sintering quality, eliminating solder voids, increasing soldering efficiency, and reducing losses are core aspects that the sintering process must focus on. To prevent damage to the chip from the pressing device, a coating is placed between the pressing device and the chip; a new coating is needed for each hot pressing. In addition, during the sintering process, semiconductor products exposed to oxygen at elevated temperatures will oxidize, affecting the quality and reliability of semiconductor packaging. Nitrogen can effectively replace or dilute the oxygen in the sealed transfer chamber, which controls the oxygen content, thus requiring the oxygen content in the chamber to be maintained at a low level. Summary of the Invention

[0003] One objective of this invention is to provide a high-flatness sintering mold that provides high-precision guidance during mold closing and hot pressing, and achieves a flatness of ±0.01mm with the product during hot pressing and sintering, thus meeting the requirements for hot pressing and sintering of products with high flatness and dimensional accuracy.

[0004] One objective of this invention is to provide a high-flatness sintering mold. During hot pressing, the lower end of the pressure rod is connected to the arc surface of the floating block to achieve sufficient contact surface between the two and uniform pressure transmission. Furthermore, due to the precise guidance of the hot pressing guide post and the guide sleeve, the pressure head and the product can be kept in high-flatness contact during hot pressing, ensuring the flatness of the pressed surface and improving the sintering quality.

[0005] One objective of this invention is to provide a high-flatness sintering mold that can adjust the hot pressing temperature through the water-cooling channels of the upper and lower mold heating blocks, and can also rapidly cool the product after sintering through the water-cooling channels of the upper and lower mold heating blocks, thereby realizing the preheating, sintering and cooling processes, improving sintering efficiency, and significantly reducing the size of related equipment.

[0006] One objective of this invention is to provide a high-flatness sintering mold. Since the upper mold heating block and the lower mold heating block are provided with heat insulation blocks on the five sides other than the side facing the product, forming a heat insulation enclosure, the heat generated by the heating block can be blocked from being transferred in that direction, so that the heat is concentrated in the product direction, thereby reducing the energy consumption of hot pressing sintering, reducing the temperature fluctuation during sintering, and further improving the sintering quality.

[0007] According to one aspect of the present invention, a high-flatness sintering mold is provided, characterized in that it comprises an upper mold and a lower mold, wherein... The upper mold has a main body and a hot pressing mechanism. The hot pressing mechanism includes a hot pressing cylinder located in the main body, a hot pressing piston built into the hot pressing cylinder, a pressure rod, and a floating base for the pressure head. A protruding floating block is fixed to the upper end of the floating base for the pressure head. The upper end of the pressure rod is connected to the hot pressing piston, and the lower end is movably connected to the protruding floating block. The floating base for the pressure head is provided with an upper mold heating block, and heat insulation blocks are provided on the top, left, right, front, and rear of the upper mold heating block. Hot pressing guide pillars are fixed to the four corner areas of the bottom surface of the floating base for the pressure head. The lower mold includes a lower mold base, a guide sleeve, and a lower mold heating block. The lower mold base is fixedly provided with a lower mold heating block at one end facing the upper mold, and guide sleeves are provided at intervals around the outer area of ​​the lower mold heating block, corresponding to and matching the hot pressing guide post. The lower mold base is provided with heat insulation blocks on the bottom surface, left and right sides, front and back of the lower mold heating block. The upper mold heating block and the lower mold heating block are respectively provided with water cooling channels, and the water cooling channels are connected to a cooling water inlet and a cooling water outlet.

[0008] In a preferred embodiment, the main body of the upper mold has a connecting plate, a cylinder body, and a guide plate stacked from top to bottom. The connecting plate has a high-pressure air inlet, a cooling water inlet, and a cooling water outlet. The hot-pressing cylinder is located in the cylinder body of the main body. The hot-pressing piston divides the hot-pressing cylinder into an upper chamber and a lower chamber. The high-pressure air inlet communicates with the upper chamber. The upper end of the pressure rod first passes through the through hole of the guide plate to reach the hot-pressing piston, and the lower end passes through the through hole of the guide plate and is movably connected to the convex floating block.

[0009] In a preferred embodiment, a lifting guide column is further provided between the guide plate and the floating base of the pressure head.

[0010] In a preferred embodiment, when the high-flatness sintering mold is closed, the upper mold is inserted into the guide sleeve of the lower mold through the hot-pressing guide post on the bottom surface of the pressure head floating base; during hot pressing, the hot-pressing piston drives the pressure rod to press down, causing the pressure head floating base to move further down based on the guidance of the hot-pressing guide post for hot pressing.

[0011] In a preferred embodiment, after the product in the high flatness sintering mold is sintered, the product is cooled by the water cooling channels of the upper mold heating block and the lower mold heating block.

[0012] In a preferred embodiment, the lower end of the pressure rod is a concave end.

[0013] In a preferred embodiment, the upper mold heating block and the lower mold heating block are the same size horizontally.

[0014] In a preferred embodiment, at least one side of the upper mold heating block or the lower mold heating block is provided with a thermocouple.

[0015] In a preferred embodiment, the lower mold base is provided with a cooling water inlet and a cooling water outlet.

[0016] In a preferred embodiment, the upper mold is provided with an electrical docking plug.

[0017] During operation, the high-flatness sintering mold closes, and the upper mold is accurately aligned by inserting a hot-pressing guide post into the guide sleeve of the lower mold. High-pressure gas is introduced through the high-pressure air inlet of the upper mold, and the hot-pressing piston drives the pressure rod downward, causing the pressure head to float and the entire base to move, especially the pressure head, to move further downward for hot pressing. During the hot pressing process, the lower end of the pressure rod is connected to the arc surface of the convex floating block, ensuring sufficient contact surface for uniform pressure transmission. The precise guidance of the hot-pressing guide post and guide sleeve ensures high flatness contact between the pressure head and the product, guaranteeing the flatness of the pressed product and improving the sintering quality. It can meet the requirements for sintering products with high flatness and dimensional accuracy. The flatness of the product during hot pressing sintering can reach ±0.01mm. If the heating temperature is too high, rapid temperature adjustment can be achieved through the water-cooling channels of the upper and lower mold heating blocks. Similarly, after sintering, the product can be rapidly cooled through these same channels, enabling preheating, sintering, and cooling processes, improving sintering efficiency, and significantly reducing the size of the equipment. Since the upper and lower mold heating blocks have heat-insulating blocks on all five sides except the side facing the product, forming a heat-insulating enclosure, the heat generated by the heating blocks is prevented from transferring in that direction, concentrating heat towards the product. This reduces energy consumption during hot pressing sintering, minimizes temperature fluctuations during sintering, and further improves sintering quality. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural schematic diagram of a high-flatness sintering mold according to an embodiment.

[0019] Figure 2 for Figure 1 A side view diagram.

[0020] Figure 3 for Figure 1 A top view diagram.

[0021] Figure 4 for Figure 3 Sectional view at AA.

[0022] Figure 5 for Figure 1 Schematic diagram of the upper mold section at different angles.

[0023] Figure 6 for Figure 1 A schematic diagram of the lower mold section. Detailed Implementation

[0024] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0025] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "X-axis," "Y-axis," "Z-axis," 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, the above terms should not be construed as limiting this invention.

[0026] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0027] refer to Figures 1 to 6 A preferred embodiment of a high-flatness sintering mold is provided.

[0028] A high-flatness sintering mold, comprising: an upper mold 1 and a lower mold 2, wherein... The upper mold 1 has a main body 11 and a hot pressing mechanism, wherein the main body 11 has a connecting plate 13, a cylinder 14, and a guide plate 15. The connecting plate 13, the cylinder 14, and the guide plate 15 are stacked from top to bottom. The main body 11 is also provided with a high-pressure air inlet 131, a cooling water inlet 133, and a cooling water outlet 132. Preferably, the high-pressure air inlet 131, the cooling water inlet 133, and the cooling water outlet 132 are located on the connecting plate 13.

[0029] Hot pressing mechanism: It involves a hot-press cylinder 31, a hot-press piston 32, a pressure rod 33, and a floating base 12 for the pressure head, etc.

[0030] A thermostatic cylinder 31 is housed within the cylinder body 14 of the main body 11. A thermostatic piston 32 is built into the thermostatic cylinder 31 and is sealed to the inner wall of the thermostatic cylinder 31 via a sealing ring. The thermostatic piston 32 divides the thermostatic cylinder 31 into an upper chamber and a lower chamber. A high-pressure air inlet 131 communicates with the upper chamber of the thermostatic cylinder 31. The upper end of the pressure rod 33 is connected to the thermostatic piston 32, and the lower end is connected to the pressure head floating base 12. A protruding floating block 34 protruding from the upper surface of the pressure head floating base 12 is fixedly provided on the upper end of the pressure head floating base 12. The lower end of the pressure rod 33 is a concave end with an inwardly concave arc surface. Correspondingly, the protruding floating block 34 has an outwardly convex arc surface that matches the concave end. The lower end of the pressure rod 33 is connected to the protruding floating block 34 to achieve sufficient contact surface between the two, enabling uniform pressure transmission and micro-adjustment of position. In addition, when the upper end of the pressure rod 33 is connected to the hot-pressing piston 32, it first passes through the through hole of the guide plate 15 to reach the hot-pressing piston 32. A bushing 331 or the like can be provided between the pressure rod 33 and the through hole of the guide plate 15 to ensure the flexibility of the pressure rod 33 in vertical movement.

[0031] The floating base 12 of the pressure head is provided with an upper mold heating block 36 and a top surface of the upper mold heating block 36, and heat insulation blocks 37 are provided on the left, right, front and back respectively. That is, the top surface of the upper mold heating block 36, the left, right, front and back heat insulation blocks 37 respectively block the heat generated by the upper mold heating block 36 from being transferred in that direction, so that the heat is concentrated in the product direction, thereby reducing the energy consumption of hot pressing sintering.

[0032] Hot-pressing guide columns 41 are provided at the four corners of the bottom surface of the floating base 12.

[0033] Preferably, a lifting guide column 35 is also provided between the guide plate 15 of the main body 11 of the upper mold 1 and the floating base 12 of the pressure head. That is, the lifting guide column 35 is respectively located at the four corners of the upper part of the floating base 12 of the pressure head. The lifting guide column 35 moves upward and inserts into the corresponding hole or bushing 331 of the guide plate 15. When the floating base 12 of the pressure head is driven to rise and fall by the hot-pressing piston 32 through the pressure rod 33, the four lifting guide columns 35 can further improve the stability of the rise and fall. This is conducive to the uniform transmission of pressure to the pressure head, so as to perform high-temperature sintering of the product under pressure, while ensuring the flatness of the pressed surface.

[0034] Lower mold 2: The lower mold 2 includes a lower mold base 2a, a guide sleeve 42, and a lower mold heating block 21.

[0035] The lower mold base 2a has a lower mold heating block 21 fixedly mounted on its upper end, and a guide sleeve 42 matching the hot pressing guide post 41 is provided around the outer area of ​​the lower mold heating block 21 on the upper surface of the lower mold base 2a. Specifically, guide sleeves 42 are provided at the four corner areas of the upper surface of the lower mold base 2a corresponding to the positions of the hot pressing guide post 41 of the upper mold 1. The size and shape of the guide sleeves 42 match the hot pressing guide post 41.

[0036] In addition, the lower mold base 2a is provided with heat insulation blocks 22 on the bottom surface, left, right and front and back of the lower mold heating block 21 to block the heat generated by the upper mold heating block 36 from being transferred in that direction, so that the heat of the lower mold heating block 21 is concentrated in the product direction, thereby reducing the energy consumption of hot pressing sintering.

[0037] In addition, the setting of the upper mold heating block 36 or the lower mold heating block 21 can form a surrounding heating on the upper and lower parts of the product, which can reduce the temperature fluctuation during sintering and improve the sintering quality.

[0038] Preferably, at least one side of the upper mold heating block 36 or the lower mold heating block 21 is provided with a thermocouple for detecting and controlling the heating temperature. The upper mold heating block 36 and the lower mold heating block 21 are the same size and horizontal.

[0039] Water cooling mechanism: The upper mold heating block 36 is provided with a water cooling channel 5, which is connected to the cooling water inlet 133 and cooling water outlet 132 of the upper mold 1 to form a water cooling cycle.

[0040] Similarly, the lower mold heating block 21 is also equipped with a water-cooling channel 5, which is connected to the cooling water inlet 133 and cooling water outlet 132 of the lower mold 2 to form a water cooling circulation. Thus, both the upper mold heating block 36 and the lower mold heating block 21 are equipped with water-cooling systems, enabling temperature control and product cooling. This allows for preheating, sintering, and cooling processes within the sintering mold, improving sintering efficiency and significantly reducing the size of related equipment. Furthermore, preferably, the upper mold 1 is also equipped with an electrical connector to facilitate data / control command exchange between the mold and other structures or the sintering equipment host / control box, as well as rapid assembly and connection with the sintering equipment.

[0041] Working principle: The molds are closed, and the upper mold 1 is accurately aligned by inserting the hot-pressing guide post 41 into the guide sleeve 42 of the lower mold 2. High-pressure gas is input through the high-pressure air inlet 131 of the upper mold, and the hot-pressing piston 32 drives the pressure rod 33 to press down, causing the pressure head to float and the base 12 to move as a whole, especially the pressure head, to move further down for hot pressing. During the hot pressing process, the lower end of the pressure rod 33 is connected to the arc surface of the convex floating block 34, so that the two have sufficient contact surface to achieve uniform pressure transmission. Due to the precise guidance of the hot-pressing guide post 41 and the guide sleeve 42, the pressure head and the product can be kept in high flatness contact during hot pressing, ensuring the flatness of the pressed product and improving the sintering quality. It can meet the requirements of high flatness and dimensional accuracy for sintering products. The flatness of the product during hot pressing sintering can reach ±0.01mm. If the heating temperature is too high, it can be quickly adjusted through the water-cooling channels 5 of the upper mold heating block 36 and the lower mold heating block 21. After the product is sintered, it can also be quickly cooled through the water-cooling channels 5 of the upper mold heating block 36 and the lower mold heating block 21, realizing the preheating, sintering and cooling process, improving sintering efficiency and significantly reducing the size of related equipment. Since the upper mold heating block 36 and the lower mold heating block 21 have heat insulation blocks on the five sides other than the side facing the product, forming a heat insulation enclosure, it can block the heat generated by the heating block from being transferred in that direction, so that the heat is concentrated in the direction of the product, thereby reducing the energy consumption of hot pressing sintering, reducing the temperature fluctuation during sintering, and further improving the sintering quality.

[0042] It will be understood by those skilled in the art that the above embodiments are merely examples, and features of different embodiments can be combined with each other to obtain implementation methods that are readily conceivable according to the content disclosed in the present invention but are not explicitly shown in the accompanying drawings.

[0043] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments, and any variations or modifications may be made to the implementation of the present invention without departing from the stated principles.

Claims

1. A high-flatness sintering mold, characterized in that: Includes upper mold and lower mold, among which The upper mold has a main body and a hot pressing mechanism. The hot pressing mechanism includes a hot pressing cylinder located in the main body, a hot pressing piston built into the hot pressing cylinder, a pressure rod, and a floating base for the pressure head. A protruding floating block is fixed to the upper end of the floating base for the pressure head. The upper end of the pressure rod is connected to the hot pressing piston, and the lower end is movably connected to the protruding floating block. The floating base for the pressure head is provided with an upper mold heating block, and heat insulation blocks are provided on the top, left, right, front, and rear of the upper mold heating block. Hot pressing guide pillars are fixed to the four corner areas of the bottom surface of the floating base for the pressure head. The lower mold includes a lower mold base, a guide sleeve, and a lower mold heating block. The lower mold base is fixedly provided with a lower mold heating block at one end facing the upper mold, and guide sleeves are provided at intervals around the outer area of ​​the lower mold heating block, corresponding to and matching the hot pressing guide post. The lower mold base is provided with heat insulation blocks on the bottom surface, left and right sides, front and back of the lower mold heating block. The upper mold heating block and the lower mold heating block are respectively provided with water cooling channels, and the water cooling channels are connected to a cooling water inlet and a cooling water outlet.

2. The high flatness sintering mold according to claim 1, characterized in that: The main body of the upper mold has a connecting plate, a cylinder body, and a guide plate stacked from top to bottom. The connecting plate has a high-pressure air inlet, a cooling water inlet, and a cooling water outlet. The hot-pressing cylinder is located in the cylinder body of the main body. The hot-pressing piston divides the hot-pressing cylinder into an upper chamber and a lower chamber. The high-pressure air inlet is connected to the upper chamber. The upper end of the pressure rod first passes through the through hole of the guide plate to reach the hot-pressing piston. The lower end passes through the through hole of the guide plate and is movably connected to the convex floating block.

3. The high flatness sintering mold according to claim 2, characterized in that: A lifting guide column is also provided between the guide plate and the floating base of the pressure head.

4. The high flatness sintering mold according to claim 3, characterized in that: When the high-flatness sintering mold is closed, the upper mold is inserted into the guide sleeve of the lower mold through the hot-pressing guide post on the bottom surface of the pressure head floating base; during hot pressing, the hot-pressing piston drives the pressure rod to press down, causing the pressure head floating base to move further down based on the guidance of the hot-pressing guide post for hot pressing.

5. The high flatness sintering mold according to claim 3, characterized in that: After the product is sintered in the high flatness sintering mold, it is cooled down through the water cooling channels of the upper mold heating block and the lower mold heating block.

6. The high flatness sintering mold according to claim 3, characterized in that: The lower end of the pressure rod is a concave end.

7. The high flatness sintering mold according to claim 3, characterized in that: The upper mold heating block and the lower mold heating block are the same size horizontally.

8. The high flatness sintering mold according to claim 3, characterized in that: The upper mold heating block or the lower mold heating block is provided with a thermocouple on at least one side.

9. The high flatness sintering mold according to claim 3, characterized in that: The lower mold base is provided with a cooling water inlet and a cooling water outlet.

10. The high flatness sintering mold according to claim 3, characterized in that: The upper mold is equipped with an electrical connection plug.

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