Analysis of Broken Wires during Gold Wire Bonding Process

2012 ◽  
Vol 503 ◽  
pp. 298-302
Author(s):  
Ming Qiang Pan ◽  
Tao Chen ◽  
Li Guo Chen ◽  
Li Ning Sun

Wire bonding is one of the critical technologies of devices production, assembly and packaging in the microelectronic and MEMS field. During bonding process, the gold wires break easily, because the wires are repeatedly operated with high-speed. Therefore, the experiments were performed to analyze bonding process and the reason causing wire break. The results show that it is critical to prevent the broken wire to control the pressure wire pressure, the speed and angle of the pulling wire structure, the clamp gap, the capillary tip gap, and discharging energy in bonding process. the broken wire doesn’t occurs when the pressure wire pressure, the speed of the pulling wire structure, the angle of the pulling wire structure, the clamp gap, the capillary tip gap, the time and the current are 3-5g, 5rad/s and 10rad, 0.1-0.3mm, 1mm, 35ms and 10mA , respectively.

2012 ◽  
Vol 160 ◽  
pp. 77-81
Author(s):  
Jing Jing Tian ◽  
Lei Han

Kick-up phenomenon during looping is an important factor in thermosonic wire bonding. In this study, the loping process during wire bonding was recorded by using high-speed camera, and wire profiles evolution was obtained from images sequence by image processing method. With a polynomial fitting, the wire loop profiling was described by the curvature changing, and kick-up phenomenon on gold wire was found between the instant of 290th frame(0.0537s) to 380th frame (0.0703s), the change of curvature is divided into three phases, a looping phase, a mutation phase and a kick-up phase. While in the kick-up phase, the kick up phenomenon is the most obvious. These experimental results were useful for in-depth study of kick-up phenomenon by simulation.


2010 ◽  
Vol 2010 (1) ◽  
pp. 000650-000655
Author(s):  
Bernd K. Appelt ◽  
William T. Chen ◽  
Andy Tseng ◽  
Yi-Shao Lai

Fine pitch wire bonding has traditionally been the domain of gold wires. The significant increase in gold commodity prices has driven a continuous reduction in wire diameters to minimize the impact of the raw materials cost of the wire. This has reached a point now where copper wires are beginning to displace gold wires despite the technical challenges associated with copper wires. The basic challenges like propensity for oxidation, hardness and propensity for corrosion can be managed with the appropriate investment in tooling and infrastructure. Doubts are persisting about yield and reliability. With a very methodical approach to developing the process controls, it can be demonstrated that yields are as good as those for gold despite the fact that copper bonds are not reworkable. Likewise, the typical JEDEC reliability tests can be full filled. Here, an extensive effort has been placed on extended JEDEC testing to demonstrate that with good process control and proper materials choices, test durations of more than 2x can be passed. This excellent performance demonstrates that copper wire bonding can be as good as or better than gold wire bonding.


2013 ◽  
Vol 804 ◽  
pp. 151-157 ◽  
Author(s):  
Hao Wen Hsueh ◽  
Fei Yi Hung ◽  
Truan Sheng Lui

Sliver wire was the novel material to replaced gold wire in wire bonding process, and rare earth element was often added to improve the properties of silver wires. The annealing effect (at 225°C~275°C for 30min) on the tensile mechanical properties of silver wires with φ=20μm was investigated. In addition, the microstructural characteristics and the mechanical properties before and after an electric flame-off (EFO) process were also studied. Free-air ball (FAB) of 85μm diameter from 20μm diameter pure silver wire was too huge for bonding process, otherwise the silver wire was added 0.05 wt.% lanthanum to form Ag-La alloy wire to reduce the diameter of FAB. FAB of Ag-La alloy wire with a 55μm diameter, and can avoid short-circuited. In addition, microstructures, tensile properties and the micro-hardness of Ag-La alloy wires indicated that the best annealing temperature was 425 °C.


2012 ◽  
Vol 2012 (1) ◽  
pp. 000638-000649 ◽  
Author(s):  
Bob Chylak ◽  
Horst Clauberg ◽  
John Foley ◽  
Ivy Qin

During the past two years copper wire bonding has entered high volume manufacturing at a number of leading edge OSATs and IDMs. Usage of copper wire has achieved 20% market share and is expected to exceed 50% within three years. Products spanning the range from low pin count devices with relatively large wire diameter to FPGA's with nearly one thousand wires at 20 μm or even 18 μm wire are now using copper wire. This paper will discuss the requirements for developing a robust copper wire bonding process and then moving it to high volume manufacturing. Process optimization begins with the selection of the appropriate wire diameter, ball diameter, bonding tool and bonding process type. These are functions not only of the bond pad opening, but also of the pad aluminum thickness and relative sensitivity of the pad to damage. Proper optimization depends on the availability of new and modified bond quality metrologies, such as extensive reliance on cross-sectioning and intermetallic coverage measurements. The bonding window of a copper wire bonding process is defined in substantially new terms compared to optimization in gold wire bonding. Once an optimized process has been developed in the lab on a single bonder, it needs to be verified. Copper wire bond processes are much less forgiving with respect to the acceptable variability on the manufacturing floor. To ensure that the process is stable, a low volume pre-manufacturing test is highly recommended. This not only makes sure that the process is stable across multiple bonders, but also ensures the adequacies of manufacturing controls, incoming materials quality and sufficient equipment calibration and maintenance procedures.


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