Copper and copper bonding method

Abstract

The invention relates to a copper and copper bonding method. The copper and copper bonding method comprises the following technological steps that first, surface preprocessing is carried out on a substrate and a chip, so that the surface roughness of the substrate is smaller than 0.3nm, no particles with the diameter larger than 1 micron exist on the surface of the substrate, the protruding height of copper solder joints on the substrate ranges from 100 nm to 500 nm, and the surface evenness of the substrate is smaller than 5%; second, the substrate is covered with a layer of covering material in a spin coating mode or a vacuum lamination mode, wherein the covering material is epoxy resin or photodecomposition adhesive film or back-side adhesive film or thermoplastic resin or a light resistance material; third, copper solder spots of the chip are aligned with the copper solder spots of the substrate; fourth, the chip is fixed to the substrate through a soft pressing head in a closed space filled with inert gas, the temperature ranges from 150 DEG C to 250 DEG C, the pressure of the soft pressing head ranges from 50 kN to 100 kN, and the time ranges from 30 minutes to 3 hours; fifth, after curing is carried out, a plurality of chips are stacked on the chip according to the steps. According to the copper and copper bonding method, high-density integration of copper wires super-dense pitches can be achieved, and fixation carried out after bonding is completed at the temperature lower than 200 DEG C.

Description

technical field [0001] The invention relates to a copper-copper bonding method, which belongs to the technical field of semiconductor packaging. Background technique [0002] With the vigorous development of the microelectronics industry, the integrated circuit electronic packaging industry is rapidly advancing towards the direction of small size, high performance, high density, and multi-chip. Therefore, the ultra-fine pitch of copper leads (such as 3 μm, 6 μm ) makes more sense. [0003] In the prior art, the patent WO 2012089105A1 discloses a spark plasma sintering process (SPS), the process temperature is between 200°C and 300°C, and the pressure is between 16 and 80MPa; but the bonding plasticity is poor, and the pitch cannot be achieved. Dense integration. Patent US 20080315421A1 discloses a surface-active bonding (SAB), which is carried out at room temperature and uses ultra-high vacuum pressure to bond the surface, but has higher requirements for surface cleanlines...

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Problems solved by technology

[0003] In the prior art, the patent WO 2012089105A1 discloses a spark plasma sintering process (SPS), the process temperature is between 200°C and 300°C, and the pressure is between 16 and 80MPa; but the bonding plasticity is poor, and the pitch cannot be achieved. intensive integration

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