National Taiwan University

Robert Boschgmbh

Yee-Wen Yen

Jinn P Chu

Eckart Schellkes

Chia-Yu Liu

Wallace Chuang

Wen-Zhi Chang

Pin-Ju Huang

Chien-Chung Jao

I Made Wahyu Diyatmika

Meng-Yu Tsou

A solder paste includes a first solder alloy powder in an amount ranging from 30% to 95% by weight. The first solder alloy powder includes a first solder alloy with a solidus temperature of 200° C. to 260° C. The first solder alloy includes an Sn—Cu alloy or an Sn—Cu—Ag alloy. The solder paste further includes a second solder alloy powder in an amount ranging from 5% to 70% by weight, and a solder flux. The second solder alloy powder includes a second solder alloy with a solidus temperature below 250° C. The solder paste has a variable melting point. In multiple reflow soldering, a remelting of the solder paste is inhibited under different temperature conditions so that no functional failure occurs during assembly and/or packaging of PCBs or electronic devices due to melting of solder.

Sn—Cu mixed alloy solder paste, method of making the same and soldering method

The present invention relates to a tin whisker mitigation material using thin film metallic glass underlayer, which is a thin film metallic glass (TFMG) formed between a metal substrate and a tin layer. Particularly, the TFMG can be a ZrTiNiunderlayer or a ZrCuAlNi underlayer, capable of blocking off the interaction occurring in the interface of a copper layer (the metal substrate) and the tin layer, so as to carry out the inhibition of tin whisker growth. Moreover, a variety of experiment data are proposed for proving that the TFMG of the ZrTiNior the ZrCuAlNi can indeed be used to replace the conventionally used thick tin layer for being the underlayer between the copper layer (the metal substrate) and the tin layer, and then effectively inhibit the interaction occurring in the Cu/Sn interface and the growth of tin whisker by low manufacturing cost way.

Tin whisker mitigation material using thin film metallic glass underlayer

The present invention relates to a method for manufacturing Ni/In/Sn/Cu multilayer structure, in which a Ni/In/Sn/Cu multilayer structure is formed between a first substrate (copper substrate) and a second substrate (such as silicon wafer), and further, a plurality of intermetallic layers are formed in the Ni/In/Sn/Cu multilayer structure through a reflow bonding process and an aging heat treatment, wherein the intermetallic layers comprises a first intermetallic layer of (Cu,Ni)(Sn,In), a second intermetallic layer of (Cu,Ni)(Sn,In)and a third intermetallic layer of (Cu,Ni)(Sn,In). Therefore, the formed intermetallic layers makes the Ni/In/Sn/Cu multilayer structure performs good wettability, ductility, creep resistance, and fatigue resistance. Moreover, this Ni/In/Sn/Cu multilayer structure can be made by low-temperature bonding process, so that Ni/In/Sn/Cu multilayer structure can be an alternative solder for replacing the traditional high-temperature Pb solder and being applied in the package process of 3D IC.

Method for manufacturing Ni/In/Sn/Cu multilayer structure

A method for inhibiting growth of tin whiskers is provided. The method includes providing a metal substrate, forming a tin layer to cover the surface of the metal substrate, and treating the metal substrate covered the tin layer by an annealing process, wherein the annealing process is performed at 400&#xb0; C.-600&#xb0; C. and the surface of the tin layer is subsequently inhibited from growing tin whiskers.

Method for inhibiting growth of tin whiskers

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Taipei, Taiwan

Yee-Wen Yen