Preparation method of functionally gradient diamond/aluminum composite material packaging shell

Abstract

The invention discloses a preparation method of a functionally gradient diamond / aluminum composite material packaging shell, and relates to a diamond / aluminum composite material and a near-net forming preparation method of the diamond / aluminum composite material. The preparation method of the functionally gradient diamond / aluminum composite material packaging shell comprises the specific steps that 1, diamond particles and aluminum powder are mechanically mixed according to a certain proportion and then pressed into a cold-pressed blank; 2, the cold-pressed blank is heated in a liquid-solid separation mold system to be in a liquid-solid mixed melting state; 3, the mold filling process is completed by liquid-solid mixed melting slurry under the action of pressure, and directional separation treatment is completed by part of the metal liquid phase through a liquid-solid separation channel so as to adjust the volume ratio of diamond on the top of a cavity; and 4, the remaining slurry is solidified layer by layer under the action of a bottom end cooling system, pressure maintaining is continuously conducted in the process, and finally a diamond / aluminum composite material gradient packaging shell is prepared. The chip bearing part at the bottom of a shell is high in diamond content, and has high thermal conductivity while the thermal expansion coefficient is matched with that of a chip; the diamond content at the top of a wall body is low, so that the welding compatibility with a cover plate material is ensured.

Description

technical field

[0001] The invention designs a method for preparing a functionally graded diamond / aluminum composite packaging casing. Background technique

[0002] Different from the heat dissipation substrate, different functional areas of the package housing have different requirements for performance. In order to ensure the matching of the chip at the bottom of the housing, low thermal expansion coefficient and high thermal conductivity are required; the top of the housing wall requires low reinforcement phase content to ensure solderability with the package cover. At present, the packaging shells are all machined from uniform block samples, which not only causes a great waste of raw materials, but also cannot solve the problem of performance difference requirements.

[0003] The functionally graded composite material with high diamond content at the bottom of the shell and low diamond content at the top of the wall perfectly solves the above problems and maximizes the ...

Examples

specific Embodiment approach 1

[0044] use figure 1 The liquid-solid separation system shown prepares a functionally graded diamond / aluminum composite package shell.

[0045] The diamond particles and aluminum powder are weighed according to the ratio (1:9-1:1), placed in a 3D mixer for mechanical mixing, and the mixing time is 1-48 hours.

[0046]Put the mixed powder into a cold-press mold, hold the pressure for 0.5-5 minutes under a pressure of 20-400 MPa, and make a block-shaped cold-press billet.

[0047] Put the cold-pressed billet into the liquid-solid separation mold system and keep it warm at 630-730°C for 10-60 minutes to make a liquid-solid mixed molten slurry in which diamond particles and liquid metal aluminum coexist.

[0048] Under the action of the special-shaped indenter, the fluidity of the molten metal is ahead of that of the diamond particles, and it is reversely extruded from the bottom. The diamond content at the bottom of the shell is high, and the diamond content at the top of the wal...

specific Embodiment approach 2

[0052] This embodiment is different from the specific embodiment one in that:

[0053] Diamond particles and aluminum powder are mechanically mixed in a planetary ball mill.

[0054] The cold-pressed billet is heated under an inert gas protection atmosphere to prepare a liquid-solid mixed molten slurry.

[0055] The liquid-solid separation channel is a circular hole with a diameter of 0.5-5 mm.

[0056] The layer-by-layer solidification of the composite material is realized by forced cooling with an external cold iron.

specific Embodiment approach 3

[0058] This embodiment is different from the specific embodiment one in that:

[0059] The cold-pressed billet is placed in the pass with H 2 After being heated to a liquid-solid mixed molten state in an atmosphere-protected heating furnace, it is transferred to a special mold system with a liquid-solid separation channel.

[0060] The layer-by-layer solidification of the composite material is achieved by forced air cooling.

technical field

[0001] The invention designs a method for preparing a functionally graded diamond / aluminum composite packaging casing. Background technique

[0002] Different from the heat dissipation substrate, different functional areas of the package housing have different requirements for performance. In order to ensure the matching of the chip at the bottom of the housing, low thermal expansion coefficient and high thermal conductivity are required; the top of the housing wall requires low reinforcement phase content to ensure solderability with the package cover. At present, the packaging shells are all machined from uniform block samples, which not only causes a great waste of raw materials, but also cannot solve the problem of performance difference requirements.

[0003] The functionally graded composite material with high diamond content at the bottom of the shell and low diamond content at the top of the wall perfectly solves the above problems and maximizes the ...

Examples

specific Embodiment approach 1

[0044] use figure 1 The liquid-solid separation system shown prepares a functionally graded diamond / aluminum composite package shell.

[0045] The diamond particles and aluminum powder are weighed according to the ratio (1:9-1:1), placed in a 3D mixer for mechanical mixing, and the mixing time is 1-48 hours.

[0046]Put the mixed powder into a cold-press mold, hold the pressure for 0.5-5 minutes under a pressure of 20-400 MPa, and make a block-shaped cold-press billet.

[0047] Put the cold-pressed billet into the liquid-solid separation mold system and keep it warm at 630-730°C for 10-60 minutes to make a liquid-solid mixed molten slurry in which diamond particles and liquid metal aluminum coexist.

[0048] Under the action of the special-shaped indenter, the fluidity of the molten metal is ahead of that of the diamond particles, and it is reversely extruded from the bottom. The diamond content at the bottom of the shell is high, and the diamond content at the top of the wal...

specific Embodiment approach 2

[0052] This embodiment is different from the specific embodiment one in that:

[0053] Diamond particles and aluminum powder are mechanically mixed in a planetary ball mill.

[0054] The cold-pressed billet is heated under an inert gas protection atmosphere to prepare a liquid-solid mixed molten slurry.

[0055] The liquid-solid separation channel is a circular hole with a diameter of 0.5-5 mm.

[0056] The layer-by-layer solidification of the composite material is realized by forced cooling with an external cold iron.

specific Embodiment approach 3

[0058] This embodiment is different from the specific embodiment one in that:

[0059] The cold-pressed billet is placed in the pass with H 2 After being heated to a liquid-solid mixed molten state in an atmosphere-protected heating furnace, it is transferred to a special mold system with a liquid-solid separation channel.

[0060] The layer-by-layer solidification of the composite material is achieved by forced air cooling.

Images