MK Electron supplies solder paste for large US client

Semiconductor package boding wire company MK Electron is expanding its supply of solder paste, tape and film, TheElec has confirmed.

The company is seeing “meaningful” sales from solder paste and electro magnetic interference (EMI) shielding disposable films, a MK Electron official said.

The materials are supplied to an outsourced semiconductor assembly and test (OSAT) company that processes them. The OSAT company then supply the finished chip package to a smartphone assembly factory that manufacturers the phones for a US-based company, they said.

Solder paste is a mix of solder powder and flux. It is used to attach the die to the chip package. 

Germany’s Heraeus, US’ MacDermid Alpha Electronics Solutions and Japan’s Koki are some of the global powerhouses in solder paste.

The US customer previously mostly used paste from Alpha.

MK Electron’s solder paste is a Type 6. The type number refers to the size of the metal particles in the paste __ higher the number, smaller the particle size. Type 6 paste’s solder powder particle is between 5 to 15 micrometers in size. 

The OSAT company currently uses mostly Type 4 to 5 pastes. Type 4’s particle size is between 20 to 38 micrometers.

MK Electron was the only South Korean company that can develop and commercially supply Type 6 solder paste, the official said. The company operates a heat resistant titanium alloy melting furnace and can make alloy fast and in the precise ratio that the customer wants it. The company also has price competitiveness, the official said.

EMI shielding polyimide carrier film, which has been contributing sales to MK Electron since last year, was also being used by the same client as the solder paste. EMI shielding is use to block the interference between chips __ this allows components to be designed more densely, leading to the finished product being smaller or having a bigger battery. EMI shielding has been applied to smartphones chips for the past couple of years.

Polyimide carrier film is a disposable material. A packaged chip is placed on the film. Then the shielding material is sputtered on to the chip. The chip is removed from the film after the process. The film is then disposed of. The film must be adhesive and easily removable at the same time. MK Electron is hoping that its solder paste and new tape and film businesses contribute over hundreds of billion wons in sales within a couple of years going forward, the official said.

Currently, most of the company’s sales come from bonding wires. MK Electron posted sales of 350 billion won in 2019, with around 90% coming from bonding wire. South Korean analysts believe MK Electron benefited from the global supply chain freeze caused by the COVID-19 pandemic. They expect MK Electron to post sales of 450 billion won this year, a growth of 30% from 2019.