A no-remelting high-temperature and high-pressure injection mold for power semiconductor device packaging

Abstract

The present invention relates to a non-remelting high-temperature and high-pressure injection mold for power semiconductor device packaging, which includes a moving mold component and a fixed mold component. The moving mold component includes an upper template, a hot runner plate, and a temperature regulating plate arranged in sequence. The moving mold component is provided with a main runner penetrating through the upper template and the hot runner plate, and a first temperature sensor is arranged in the hot runner plate; the fixed mold assembly includes a lower mold and a cavity template arranged in the lower mold. A cavity is arranged in the cavity template, a cavity cooler is arranged in the cavity, and a pressure sensor and a second temperature sensor are arranged in the side wall of the cavity; the first temperature sensor, the pressure sensor, and the second temperature sensor are all connected to a mold control system. Compared with the prior art, the present invention synergistically uses the temperature and pressure sensing control technology with sub-millisecond response speed to realize a temperature, pressure, recrystallization speed, and anti-remelting system with three-dimensional target control characteristics, and realizes reliable packaging of the heterogeneous structure embedding components of the third-generation semiconductor chip.

Description

Technical Field

[0001] The invention relates to a semiconductor device thermoplastic material packaging mold, in particular to a non-remelting high-temperature and high-pressure injection mold for power semiconductor device packaging. Background Art

[0002] At present, due to the upgrade of semiconductor chip materials from the first generation to the third generation wide bandgap materials, the existing devices manufactured by thermosetting plastic encapsulation materials (mainly EMC) and injection molding (transfer molding) packaging processes can no longer give full play to the excellent characteristics of the third generation wide bandgap material chips with an operating junction temperature above 175°C due to the limitations of the inherent characteristics of materials and processes, thereby limiting the expansion of the cost-effectiveness advantage of the third generation semiconductor devices. However, the excellent comprehensive characteristics of thermoplastic plastic encapsulation materials (LCP, PI, modified PA) can fully meet the electrothermal characteristics of the high operating junction temperature of the third generation semiconductor chips, but it is impossible to realize the packaging process through injection molding (transfer molding) technology and equipment, that is, it is impossible to complete the transformation from chips to devices with practical engineering significance.

[0003] The key process parameters of thermoplastic molding materials, such as temperature, pressure, fluidity, etc., are very different from those of thermosetting molding materials. The melt temperature of injection molding alone is much higher than the melt temperature of the chip bonding layer material currently used, while the melt temperature of the chip bonding layer material is much lower than the melt temperature of injection molding. In a high-temperature and high-pressure packaging environment, the chip bonding layer material will inevitably remelt. The remelting of the bonding layer material will cause the following problems:

[0004] 1. The metallographic structure of the solid crystal layer material will change, seriously affecting its inherent electrothermal properties;

[0005] 2. In the remelting state, the solid crystal layer material will react with the volatile gas produced by the molten plastic sealing material to form micropores that destroy the thermal conductivity of the solid crystal layer;

[0006] 3. Under high-pressure injection molding conditions, the chip position will drift, causing the electrode bonding lead to open circuit and causing the device to fail.

[0007] It can be seen that avoiding remelting of the die-bonding layer material is the key to successfully implementing the thermoplastic material packaging process and ensuring the effective reliability of the final device product.

[0008] Since the current injection molds of thermoplastic materials are all used for the packaging of homogeneous structure embedded parts, the range of process parameters required for the molding temperature and pressure of the injection melt is relatively broad, while there is no requirement for targeted control of process parameters such as the local molding temperature and pressure in the cavity. Therefore, it is impossible to achieve the packaging of multi-heterogeneous structure embedded parts such as semiconductor chip devices with high reliability requirements. Summary of the invention

[0009] The object of the present invention is to provide a non - remelting high - temperature and high - pressure injection mold for power semiconductor device packaging to overcome the defects of the above - mentioned existing technologies.

[0010] The object of the present invention can be achieved by the following technical solutions:

[0011] A non - remelting high - temperature and high - pressure injection mold for power semiconductor device packaging, comprising a moving mold component and a fixed mold component. The moving mold component includes a top template, a hot runner plate, and a temperature regulating plate arranged in sequence. The moving mold component is provided with a main runner penetrating through the top template and the hot runner plate, and a first temperature sensor is arranged in the hot runner plate;

[0012] The fixed mold assembly includes a lower mold and a cavity template arranged in the lower mold. A cavity is arranged in the cavity template, a cavity cooler is arranged in the cavity, and a pressure sensor and a second temperature sensor are arranged on the side wall of the cavity;

[0013] The first temperature sensor, the pressure sensor, and the second temperature sensor are all connected to a mold control system.

[0014] Preferably, a cavity heat shielding layer is arranged at the bottom of the cavity.

[0015] Preferably, an instantaneous cooler connected to the cavity is arranged in the cavity template.

[0016] Preferably, a high - sensitivity temperature sensor is arranged at the location of the instantaneous cooler.

[0017] Preferably, the instantaneous cooler is connected to the bottom of the cavity.

[0018] Preferably, a runner heat shielding layer is arranged between the temperature regulating plate and the hot runner plate.

[0019] Preferably, the pressure sensor and the second temperature sensor are arranged on one side wall of the cavity, and the cavity cooler is arranged on the other side wall opposite to this side wall.

[0020] Preferably, the mold control system adopts a mold control system MCU with a sub - millisecond response speed.

[0021] Preferably, the cavity has two parts, and the cavity cooler is arranged between the two parts of the cavity.

[0022] Preferably, the cavity cooler is tubular.

[0023] Compared with the existing technology, the present invention has the following advantages:

[0024] 1. This device solves the technical problem of the thermoplastic material packaging of the heterogeneous structure embedding components of the third-generation semiconductor chips, constructs an equipment system for the packaging of the third-generation semiconductor chip devices with high reliability and engineeringization, enables the third-generation semiconductor chips to maximize their specific energy under the specified use technical conditions, and enables their devices to obtain better reliability indicators and higher cost performance.

[0025] 2. The cavity is provided with a cavity cooler, a cavity heat shield, a pressure sensor and a temperature sensor. A high-response-speed anti-remelting temperature adjustment component integrating a high-sensitivity sensor and an instantaneous cooler is placed in the cavity heat shield, which can realize the synchronous automatic adjustment of the temperature, pressure and flow rate of the molten body at multiple points inside the cavity.

[0026] 3. The moving die component is provided with sensors, a temperature adjustment plate and a runner heat shield, which can realize the coordinated automatic adjustment of the temperature, pressure and flow rate of the injection-molded molten body and the relevant parameters inside the cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of the present invention;

[0028] Figure 2 is a schematic diagram of the coordinated control of the mold of the present invention.

[0029] Reference numerals in the figures: 1. Injection nozzle of the injection molding machine, 2. Upper template, 3. Hot runner plate, 4. First temperature sensor, 5. Runner heat shield, 6. Temperature adjustment plate, 7. High-sensitivity temperature sensor, 8. Instantaneous cooler, 9. Cavity heat shield, 10. Cavity cooler, 11. Cavity template, 12. Lower die, 13. Cavity sensor, 14. Cavity, 15. Main runner, 16. Mold control system MCU, 17. Injection molding machine MCU, 18. Peripheral cooling system. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and gives the detailed implementation manners and specific operation processes, but the protection scope of the present invention is not limited to the following embodiments.

[0031] Embodiment

[0032] As Figure 1 shown, the present application proposes a non-remelting high-temperature and high-pressure injection mold for the packaging of power semiconductor devices, including a moving die component and a fixed die component.

[0033] The moving die component includes an upper template 2, a hot runner plate 3, and a temperature regulating plate 6 arranged in sequence. The moving die component is provided with a main runner 15 penetrating through the upper template 2 and the hot runner plate 3, and the main runner 15 is connected to the nozzle 11 of the thermoplastic material injection molding machine. A first temperature sensor 4 is arranged in the hot runner plate 3, and the first temperature sensor 4 is connected to a mold control system with sub-millisecond response speed for external temperature and pressure sensing control to perform signal interaction processing. A runner thermal shielding layer 5 made of a press-in type highly heat-insulating material is arranged between the temperature regulating plate 6 and the hot runner plate 3.

[0034] The fixed die assembly includes a lower die 12 and a cavity template 11 arranged in the lower die 12. A cavity 14 is arranged in the cavity template 11. A tubular cavity cooler 10 is arranged in the cavity 14. A cavity sensor 13, including a pressure sensor and a second temperature sensor, is arranged on the side wall of the cavity 14. Both the pressure sensor and the second temperature sensor are connected to the mold control system. A cavity thermal shielding layer 9 made of a press-in type highly heat-insulating material is arranged at the bottom of the cavity 14 to form a local heat-insulating layer structure. An instantaneous cooler 8 connected to the bottom of the cavity 14 is arranged in the cavity template 11. A highly sensitive temperature sensor 7 is arranged at the instantaneous cooler 8, and the highly sensitive temperature sensor 7 is connected to the mold control system. The highly sensitive temperature sensor 7 and the instantaneous cooler 8 are integrated to form a high-response speed anti-re-melting temperature regulating component. The cavity 14 can realize synchronous automatic regulation of the temperature, pressure, and flow rate of the molten body at multiple internal points.

[0035] The instantaneous cooler 8 and the cavity cooler 10 are connected to an external cooling system 18, and the external cooling system 18 is controlled by the mold control system. The mold control system uses a mold control system MCU16 with sub-millisecond response speed.

[0036] Specifically, a pressure sensor and a second temperature sensor are placed on one side wall of the cavity 14, and the cavity cooler 10 is arranged on the other side wall opposite to this side wall. In this embodiment, as Figure 1 shown, the cavity 114 has two parts, and the cavity cooler 10 is arranged between the two parts of the cavity 14.

[0037] This device collaborates with the sub-millisecond response speed temperature and pressure sensing control technology to realize a temperature, pressure, recrystallization speed, and anti-re-melting system with three-dimensional target control characteristics, and realizes reliable encapsulation of the heterogeneous structure embedding component of the third-generation semiconductor chip.

[0038] The usage method of this device:

[0039] Place the heterogeneous structure embedding component of the third-generation semiconductor chip in position in the cavity 14 of the fixed die component, turn on the thermoplastic material injection molding machine, and move the moving die component downward to complete the mold closing of the moving die component and the fixed die component; make the molten body of the thermoplastic material be injected into the cavity 14 under high pressure through the nozzle 1 of the injection molding machine and the hot runner plate 3; as Figure 2As shown, under the coordinated action of the cavity sensor 13, the first temperature sensor 4, the high-sensitivity temperature sensor 7, the instantaneous cooler 8, and the cavity cooler 10 controlled by the mold control system, the melt completes the non-remelting high-temperature and high-pressure injection molding process.

[0040] The third-generation semiconductor high-power discrete devices encapsulated by the device of the present application have been tested by a third-party national component reliability testing agency. The operating ambient temperature Ta > 155 °C and the operating junction temperature Tj > 225 °C both meet the standards of AEC-Q100, AEC-Q101, and Grade 0 (space-grade).

Claims

1. A no-remelting high-temperature and high-pressure injection mold for power semiconductor device packaging, comprising a moving mold part and a fixed mold part, characterized in that The moving die component includes an upper template (2), a hot runner plate (3), and a temperature regulating plate (6) arranged in sequence. The moving die component is provided with a main runner (15) passing through the upper template (2) and the hot runner plate (3), and a first temperature sensor (4) is arranged in the hot runner plate (3); The fixed die component includes a lower die (12) and a cavity template (11) arranged in the lower die (12). A cavity (14) is arranged in the cavity template (11), a cavity cooler (10) is arranged in the cavity (14), and a pressure sensor and a second temperature sensor are arranged on the side wall of the cavity (14); The first temperature sensor (4), the pressure sensor, and the second temperature sensor are all connected to the die control system; A cavity heat shield layer (9) is arranged at the bottom of the cavity (14); An instantaneous cooler (8) connected to the cavity (14) is arranged in the cavity template (11); A high-sensitivity temperature sensor (7) is arranged at the location of the instantaneous cooler (8), and the high-sensitivity temperature sensor (7) is connected to the die control system; The instantaneous cooler (8), the cavity cooler (10) are connected to an external cooling system (18), and the external cooling system (18) is controlled by the die control system.

2. The high-temperature and high-pressure injection mold without remelting for power semiconductor device packaging according to claim 1, characterized in that The instantaneous cooler (8) is connected to the bottom of the cavity (14).

3. A non-remelting high-temperature and high-pressure injection mold for power semiconductor device packaging according to claim 1, characterized in that, A runner heat shield layer (5) is arranged between the temperature regulating plate (6) and the hot runner plate (3).

4. A non-remelting high-temperature and high-pressure injection mold for power semiconductor device packaging according to claim 1, characterized in that, The pressure sensor and the second temperature sensor are arranged on one side wall of the cavity (14), and the cavity cooler (10) is arranged on the other side wall opposite to this side wall.

5. A non-reflow high-temperature and high-pressure injection mold for power semiconductor device packaging according to claim 1, characterized in that, The die control system adopts a die control system MCU (16) with a sub-millisecond response speed.

6. A non-remelting high-temperature and high-pressure injection mold for power semiconductor device packaging according to claim 1, characterized in that, The cavity (14) is divided into two parts, and the cavity cooler (10) is arranged between the two parts of the cavity (14).

7. A non-remelting high-temperature and high-pressure injection mold for power semiconductor device packaging according to claim 1, characterized in that, The cavity cooler (10) is tubular.

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