scholarly journals Effects of Frequency and Surface Cleanliness of Al–Si Electrode on Ultrasonic Bonding Characteristics of Thick Al Wire Bonding

1996 ◽  
Vol 37 (9) ◽  
pp. 1492-1496 ◽  
Author(s):  
Jin Onuki ◽  
Masahiro Koizumi ◽  
Isao Ishikawa
Keyword(s):  
Wire Bonding ◽  
Ultrasonic Bonding ◽  
Bonding Characteristics

Mechanism and Model of Bond Formation in Ultrasonic Wire Bonding

2015 ◽  
Author(s):  
T. Calvin Tszeng
Keyword(s):  
Flip Chip ◽  
Critical Phenomenon ◽  
Bond Formation ◽  
Interfacial Shear Stress ◽  
Wire Bonding ◽  
Micromechanics Model ◽  
Ultrasonic Bonding ◽  
Microelectronic Devices ◽  
Ultrasonic Wire Bonding ◽  
Technological Significance

Despite being a critical phenomenon of tremendous technological significance in ultrasonic flip-chip and wire bonding processes of today’s microelectronic devices, interfacial bond formation still calls for better understanding at a fundamental level. The goal of the research is to improve these processes through better understanding and modeling of bond formation. This paper presents a micromechanics model that addresses increasing contact area during ultrasonic cyclic loading cycle. The micromechanics model provides interfacial shear stress as boundary condition to FEM simulations of ultrasonic bonding processes. Comparison between preliminary results and experimental data is conducted.

Wire bonding characteristics of gold conductors for low temperature co-fired ceramic applications

2004 ◽  
Vol 44 (2) ◽  
pp. 287-294 ◽  
Author(s):  
Cristina Lopez ◽  
Liang Chai ◽  
Aziz Shaikh ◽  
Vern Stygar
Keyword(s):  
Low Temperature ◽  
Wire Bonding ◽  
Bonding Characteristics

Ultrasonic Bonding on Unstable Pin

2016 ◽  
Vol 2016 (1) ◽  
pp. 000398-000401
Author(s):  
Henri Seppänen
Keyword(s):  
Visual Inspection ◽  
Laser Doppler Vibrometer ◽  
Wire Bonding ◽  
Ultrasonic Frequency ◽  
Ultrasonic Power ◽  
Ultrasonic Bonding ◽  
The Press ◽  
Plastic Frame ◽  
Ultrasonic Wire Bonding ◽  
Stable Surfaces

Abstract In power electronics modules, ultrasonic wire bonding is a common method to make electronic connections between the connector pins and the IGBTs. In these modules the connector pins are often residing on top of the plastic frame. Due to the pins being in positions which are hard to reach, clamping of these pins is either suboptimal or not used. This poor or absent clamping combined with the plastic frame's elasticity (softness) means that the pin has more freedom to move compared to the bonding on a metal substrate or IC. In our experiments we measured the pin and the plastic frame displacement with a laser Doppler vibrometer during the ultrasonic heavy wire (400 um in diameter Al wire) bonding process. We measured that the press fitted pin can move laterally along the ultrasonic excitation axis (2.0 ± 0.2) um whereas the frame under the pin moved (0.3 ± 0.1) um. This indicates that the pin slips over the frame while bonding. The slipping of the pin is also visible on the ultrasonic frequency waveforms of the transducer. While molded pins in general are thought to be more stable compared to the press fitted pins, similar behavior is seen in heavy wire bonding where high ultrasonic power is needed. We measured molded frame displacement (0.6 ± 0.2) um while bonding on the pin. In this paper we show how to use process traces and visual inspection to detect unstable pins and how to improve bondability on unstable pins by selecting process parameters that are optimized for the unstable pins rather than stable surfaces.

Cu Heavy Wirebonding for High Power Device Interconnection

2013 ◽  
Vol 2013 (1) ◽  
pp. 000318-000323
Author(s):  
Baik-Woo Lee ◽  
Chang-Sik Kim ◽  
Changmo Jeong ◽  
Younghun Byun ◽  
Jeong-Won Yoon ◽  
...  
Keyword(s):  
Wire Bonding ◽  
Thermal Shock Test ◽  
Mechanical And Thermal Properties ◽  
Power Devices ◽  
Shock Test ◽  
Bonding Parameters ◽  
Transmission Electron ◽  
Simple Protocol ◽  
Bonding Characteristics ◽  
Insight Into

To replace conventional Al heavy wire bonding in interconnecting power devices, we have explored the use of Cu heavy wire bonding, which offers superior electrical, mechanical, and thermal properties compared to Al wires that leads to better interconnection reliability. Chip pad metallizations that are strong enough to support Cu wires firmly against chip pads and endure high bonding parameters were first evaluated by 3D finite element modeling (FEM) of the Cu heavy wire bonding process. The FEM results indicated that an electroless plated Ni layer may be used as the primary candidate for the pad metallization of Cu heavy wire bonding because it enables the reinforcement of standard Al pads in power devices and allows for metallurgical interaction with Cu wires. Further, the deposition of the Ni layer entailed a simple protocol. The three major bonding parameters including force, ultrasonic energy, and time were optimized to achieve successful wire bonding of 300-μm-thick Cu wires to pads strengthened with Ni layers in power devices. Microstructures and compositions of the bonded interface were analyzed by transmission electron microscopy, which provided insight into the bonding characteristics between the Cu wires and the Ni pads. Reliability tests of the bonding were also carried out by the thermal shock test and pressure cooker test.

Wire Bonding: The Ultrasonic Bonding Mechanism

2020 ◽  
Vol 2020 (1) ◽  
pp. 000230-000234
Author(s):  
Lee Levine
Keyword(s):  
Phase Diagram ◽  
Equilibrium Phase ◽  
Welding Process ◽  
Initial Mixture ◽  
Equilibrium Phase Diagram ◽  
Wire Bonding ◽  
Bonding Wire ◽  
Time Deformation ◽  
Ultrasonic Bonding ◽  
Wedge Bonding

Abstract Wire bonding is a welding process. During both ball and wedge bonding, wire and bond pad are massively deformed between the bond tool and the anvil of the bond pad or substrate. The dominant variables affecting deformation are ultrasonic energy, temperature, bond force and bond time. Deformation exposes new surface material that is clean and has not been exposed to atmospheric contamination and oxidation. As the new wire and bond pad surfaces mix, they form diffusion couples that grow and transform into the intermetallic weld nugget. The initial mixing is not at equilibrium in that it does not initially form the compounds described by the equilibrium phase diagram, but temperature and time very quickly allows diffusion to relax the initial mixture into the equilibrium phase diagram compounds. This paper will discuss the mechanisms behind the formation of ball and wedge bonds.

Failure Analysis on Power Trench MOSFET Devices with Copper Wire Bonds

2011 ◽  
Author(s):  
Huixian Wu ◽  
Arthur Chiang ◽  
David Le ◽  
Win Pratchayakun
Keyword(s):  
Failure Analysis ◽  
Copper Wire ◽  
New Technology ◽  
Analytical Techniques ◽  
Wire Bonding ◽  
Bonding Process ◽  
Wire Bonds ◽  
Copper Wire Bonding ◽  
Wet Chemical ◽  
Microelectronic Components

Abstract With gold prices steadily going up in recent years, copper wire has gained popularity as a means to reduce cost of manufacturing microelectronic components. Performance tradeoff aside, there is an urgent need to thoroughly study the new technology to allay any fear of reliability compromise. Evaluation and optimization of copper wire bonding process is critical. In this paper, novel failure analysis and analytical techniques are applied to the evaluation of copper wire bonding process. Several FA/analytical techniques and FA procedures will be discussed in detail, including novel laser/chemical/plasma decapsulation, FIB, wet chemical etching, reactive ion etching (RIE), cross-section, CSAM, SEM, EDS, and a combination of these techniques. Two case studies will be given to demonstrate the use of these techniques in copper wire bonded devices.

Decapsulation Techniques for Cu Wire Bonding Package

2009 ◽  
Author(s):  
Dongmei Meng ◽  
Joe Rupley ◽  
Chris McMahon
Keyword(s):  
Laser Ablation ◽  
Thin Layer ◽  
Chemical Etching ◽  
Wire Bonding ◽  
Methods And Techniques ◽  
Wet Chemical ◽  
Wet Chemical Etching ◽  
Reliability Issue ◽  
Etch Time ◽  
Device Technology

Abstract This paper presents decapsulation solutions for devices bonded with Cu wire. By removing mold compound to a thin layer using a laser ablation tool, Cu wire bonded packages are decapsulated using wet chemical etching by controlling the etch time and temperature. Further, the paper investigates the possibilities of decapsulating Cu wire bonded devices using full wet chemical etches without the facilitation of laser ablation removing much of mold compound. Additional discussion on reliability concerns when evaluating Cu wirebond devices is addressed here. The lack of understanding of the reliability of Cu wire bonded packages creates a challenge to the FA engineer as they must develop techniques to help understanding the reliability issue associated with Cu wire bonding devices. More research and analysis are ongoing to develop appropriate analysis methods and techniques to support the Cu wire bonding device technology in the lab.

BGA and Advanced Package Wire to Wire Bonding for Backside Emission Microscopy

1999 ◽  
Author(s):  
Jim B. Colvin
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Wire Bonding ◽  
Preparation Technique ◽  
Low Profile ◽  
Normal Test ◽  
Silicon Thickness ◽  
Working Distance ◽  
Polished Side ◽  
Analytical Tools

Abstract A new method of preparation will be shown which allows traditional fixturing such as test heads and probe stations to be utilized in a normal test mode. No inverted boards cabled to a tester are needed since the die remains in its original package and is polished and rebonded to a new package carrier with the polished side facing upward. A simple pin reassignment is all that is needed to correct the reverse wire sequence after wire to wire bonding or wire to frame bonding in the new package frame. The resulting orientation eliminates many of the problems of backside microscopy since the resulting package orientation is now frontside. The low profile as a result of this technique allows short working distance objectives such as immersion lenses to be used across the die surface. Test equipment can be used in conjunction with analytical tools such as the emission microscope or focused ion beam due to the upright orientation of the polished backside silicon. The relationship between silicon thickness and transmission for various wavelengths of light will be shown. This preparation technique is applicable to advanced packaging methods and has the potential to become part of future assembly processes.

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