Purpose

This paper aims to investigate the sintering and solid liquid interdiffusion bonding (SLID) techniques to attach AlGaN/GaN-on-Si chips to direct bond copper (DBC) substrate. The influence of metal layers deposited on the backside of AlGaN/GaN-on-Si dies on the assembly process is also investigated.

Design/methodology/approach

The authors assumed the value of the shear strength to be a basic parameter for evaluation of mechanical properties. Additionally, the surface condition after shearing was assessed by SEM photographs and the shear surface was studied by X-ray diffraction method. The SLID requires Sn-plated DBC substrate and can be carried out at temperature slightly higher than 250°C and pressure reduced to 4 MPa, while the sintering requires process temperature of 350°C and the pressure at least 7.5 MPa.

Findings

Ag-, Au-backside covered high electron mobility transistor (HEMT) chips can be assembled on Sn-plated DBC substrates by SLID technology. In case of sintering technology, Cu- or Ag-backside covered HEMT chips can be assembled on Ag- or Ni/Au-plated DBC substrates. The SLID process can be realized at lower temperature and decreased pressure than sintering process.

Research limitations/implications

For SLID technology, the adhesion between Cu-backside covered HEMT die and DBC with Sn layer loses its operational properties after short-term ageing in air at temperature of 300°C.

Originality/value

In the SLID process, Sn-Cu and Sn-Ag intermetallic compounds and alloys are responsible for creation of the joint between Sn-plated DBC and micropowder Ag layer, while the sintered joint between the chip and Ag-based micropowder is formed in diffusion process.

中文翻译：

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开发将 AlGaN/GaN/Si 芯片连接到 DBC 衬底的组装技术

目的

本文旨在研究将 AlGaN/GaN-on-Si 芯片连接到直接键合铜 (DBC) 衬底的烧结和固液互扩散键合 (SLID) 技术。还研究了沉积在 AlGaN/GaN-on-Si 芯片背面的金属层对组装过程的影响。

设计/方法/方法

作者假定剪切强度值是评价机械性能的基本参数。此外，剪切后的表面状态通过SEM照片评估，剪切表面通过X射线衍射方法研究。SLID 需要镀锡的 DBC 基板，可以在略高于 250°C 的温度和降低到 4 MPa 的压力下进行，而烧结需要 350°C 的工艺温度和至少 7.5 MPa 的压力。

发现

Ag、Au 背面覆盖的高电子迁移率晶体管 (HEMT) 芯片可以通过 SLID 技术组装在镀锡的 DBC 基板上。在烧结技术的情况下，Cu 或 Ag 背面覆盖的 HEMT 芯片可以组装在 Ag 或 Ni/Au 镀 DBC 基板上。SLID 工艺可以在比烧结工艺更低的温度和更低的压力下实现。

研究限制/影响

对于 SLID 技术，在 300°C 温度下在空气中短期老化后，Cu 背面覆盖的 HEMT 芯片和 DBC 之间的附着力会失去其操作性能。

原创性/价值

在 SLID 工艺中，Sn-Cu 和 Sn-Ag 金属间化合物和合金负责在镀锡 DBC 和微粉 Ag 层之间形成接头，而在扩散过程中形成芯片和 Ag 基微粉之间的烧结接头.