scholarly journals Multi-Hole Process Plate Modification for Chip on Lead Device at Die Attach Process

2020 ◽  
pp. 7-10
Author(s):  
E. Graycochea Jr. ◽  
R. Rodriguez ◽  
F. R. Gomez ◽  
B. C. Bacquian
Keyword(s):  
Die Attach ◽  
Hole Configuration ◽  
Die Bonding ◽  
Bouncing Effect ◽  
Lead Device

The paper focused on the improvement done in chip on lead (COL) leadframe package assembly manufacturing to address the leadframe bouncing effect during die attach process. A new and enhanced process plate is designed with multi-hole configuration to provide a strong vacuum underneath the leadframe and to maintain the planarity during dispensing and die bonding of silicon dies onto the leadframe. With the new multi-hole process plate, leadframe bouncing was successfully eliminated during die attach process. For future works, the multi-hole process plate could be used on devices with similar configuration.

Analysis of Two Electrical Failures Caused by Die Attach of Exposed Pad Package

2014 ◽  
Author(s):  
Jinglong Li ◽  
Motohiko Masuda ◽  
Yi Che ◽  
Miao Wu
Keyword(s):  
Bonding Process ◽  
Die Attach ◽  
Die Bonding ◽  
Generic Analysis

Abstract Die attach is well known in die bonding process. Its electrical character is simple. But some failures caused by die attach are not so simple. And it is not proper to analyze by a generic analysis flow. The analysis of two failures caused by die attach are presented in this paper.

scholarly journals Die-Attach Structure of Silicon-on-Glass MEMS Devices Considering Asymmetric Packaging Stress and Thermal Stress

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3979
Author(s):  
Jun Eon An ◽  
Usung Park ◽  
Dong Geon Jung ◽  
Chihyun Park ◽  
Seong Ho Kong
Keyword(s):  
Thermal Stress ◽  
Silicon Wafers ◽  
Experimental Results ◽  
Mems Devices ◽  
Microelectromechanical System ◽  
Die Attach ◽  
Lack Of Control ◽  
Die Bonding ◽  
Glass Process ◽  
Typical Process

Die attach is a typical process that induces thermal stress in the fabrication of microelectromechanical system (MEMS) devices. One solution to this problem is attaching a portion of the die to the package. In such partial die bonding, the lack of control over the spreading of the adhesive can cause non-uniform attachment. In this case, asymmetric packaging stress could be generated and transferred to the die. The performance of MEMS devices, which employ the differential outputs of the sensing elements, is directly affected by the asymmetric packaging stress. In this paper, we proposed a die-attach structure with a pillar to reduce the asymmetric packaging stress and the changes in packaging stress due to changes in the device temperature. To verify the proposed structure, we fabricated four types of differential resonant accelerometers (DRA) with the silicon-on-glass process. We confirmed experimentally that the pillar can control the spreading of the adhesive and that the asymmetric packaging stress is considerably reduced. The simulation and experimental results indicated that the DRAs manufactured using glass-on-silicon wafers as handle substrates instead of conventional glass wafers have a structure that compensates for the thermal stress.

Effect of Material Properties and Thickness of Die Attach on Delamination of Die Attach/Die Paddle Interface in Electronic Package

2010 ◽  
Author(s):  
Chia-Lung Chang ◽  
Po-Hsien Li
Keyword(s):  
Material Properties ◽  
Coefficient Of Thermal Expansion ◽  
Damage Parameter ◽  
Stress And Strain ◽  
Thermal Expansion Mismatch ◽  
The Finite Element Method ◽  
Electronic Package ◽  
Die Attach ◽  
Encapsulation Process ◽  
Die Bonding

The electronic package is a multi-layered structure that is consisted of several materials. Under the temperature loadings, the interfacial stresses between layered components are generated due to the CTE (coefficient of thermal expansion) mismatch between different materials. In die bonding process, the void or defect might exist at the die attach/die paddle interface. The void cause further delamination on the interface during the encapsulation process. In this study, the finite element method is used to construct the model of electronic package with a void on the die attach/die paddle interface. The energy release rate based on J integration, which is calculated by the stress and strain around the tip of crack, is used as a damage parameter to predict the tendency of further delamination during encapsulation. Effect of material properties (Young’s modulus and CTE) and die attach thickness on delamination of die attach/die paddle interface in package during encapsulation is studied.

Epoxy Die Attach Combined With Face-Up Die Bonding for Improved XYZ Placement Accuracy

2021 ◽  
Author(s):  
Tadeh Avanessian ◽  
Jim Clatterbaugh ◽  
Robin L. Zinsmaster ◽  
Leyla Hashemi
Keyword(s):  
Flip Chip ◽  
Coefficient Of Thermal Expansion ◽  
Test Results ◽  
Microelectronics Packaging ◽  
Bond Failure ◽  
Die Attach ◽  
Before And After ◽  
Placement Accuracy ◽  
Die Bonding ◽  
Heated Stage

Abstract Epoxy die attach is widely used in microcircuit assembly and enjoys advantages such as ease of deposition, fast curing, reworkability, and non-toxicity. These qualities also make it suitable for automated mass production. However, this method falls short when high placement accuracy is desired as the die can shift on uncured epoxy leading to die displacement from its original location. Gold to gold face-up bonding is another method utilized in microelectronics packaging given its proven bonding reliability and high placement accuracy for small devices. Nevertheless, it is difficult to achieve a reliable bond using this method for relatively larger devices. The nonplanarity of the bonding collet or the variation in the height of the gold bumps results in a tilted die attach and/or a weak bond between the die and the substrate. Moreover, CTE (Coefficient of Thermal Expansion) mismatch between the die, the gold bumps, and/or the substrate leads to bond failure due to temperature fatigue. This paper discusses a hybrid method to take advantage of the strengths of both methods mentioned above, culminating in a reliable process with high XYZ placement accuracy. To apply this method, epoxy is first dispensed on a gold-plated substrate. Using a flip chip machine, samples with plated gold bumps on their ground side are then placed on the substrate. The gold bumps are mainly used as targets and stand-offs to improve the placement accuracy and to control epoxy glue-line thickness. The force applied on the die, the time the force is applied, and the substrate temperature are controlled for optimum die attach. Moreover, along with the force applied by the vacuum tip, epoxy is partially cured on the flip chip machine heated stage before it is moved to an oven to complete the cure process. Die shear test results before and after temperature conditioning are compared with standard epoxy die attach and gold to gold face-up bonding for identical samples and the advantages are discussed.

scholarly journals Remarks on Wire and Die Bonding for Hybrid Circuits

1977 ◽  
Vol 4 (3-4) ◽  
pp. 157-161 ◽  
Author(s):  
A. Soffa
Keyword(s):  
Wire Bonding ◽  
Die Attach ◽  
Automatic Alignment ◽  
Die Bonding ◽  
Ball Detection ◽  
Automatic Wire ◽  
Programming Aids

Advances in hybrid automatic wire bonding include refined joy stick techniques, automatic alignment, a digitally operated head for higher speeds and flexibility, missing ball detection and programming aids. Advanced hybrid die attach equipment will have to accept a large variety of chip presentation techniques but will use CCTV and automatic alignment with microprocessor controls to aid programming and speed output.

In depth study of lead frame tape residuein quad flat non-leaded package

2019 ◽  
Vol 36 (4) ◽  
pp. 129-136
Author(s):  
Shri Kumaran Nadaraja ◽  
Boon Kar Yap
Keyword(s):  
Lead Frame ◽  
Correct Process ◽  
Adhesive Properties ◽  
Content Type ◽  
Die Attach ◽  
Viable Solution ◽  
Low Pass ◽  
Depth Study ◽  
Overall Performance ◽  
Die Bonding

Purpose Lead frame tape is a crucial support for lead frames in the IC assembly process. The tape residue on the quad flat non-leaded (QFN) could result in low reliability and failure in electrical conductivity tests. The tape residue would affect overall performance of the chips and contribute to low pass yield. The purpose of this paper is to present an in-depth study of tape residue and factors that may affect it. Design/methodology/approach An experiment using lead frame and tapes from three manufacturers with two types of die bond adhesives, namely, die attach film (DAF) and wafer back coating (WBC), was conducted. Copper (Cu) wire bonding and die bonding performances were measured in terms of process capability, stitch bond strength and die attach strength. Findings Results showed that no tape residue was observed on the thermoplastic adhesive-based lead frames manufactured by Hitachi after the de-taping process because of the tape’s thermoplastic adhesive properties. Originality/value This paper studies the occurrence of tape residue and a viable solution for it through the correct process optimization and combination of semiconductor manufacturing materials. Factors that may affect tape residue have also been studied and further research can be done to explore other options in the future as an alternate solution.

Optimizing the performance of the Au-Si system for high temperature die attach applications

2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000068-000076 ◽  
Author(s):  
M.F. Sousa ◽  
S. Riches ◽  
C. Johnston ◽  
P.S. Grant
Keyword(s):  
High Temperature ◽  
Thermal Stresses ◽  
Microstructural Analysis ◽  
Thin Foil ◽  
Bonding Process ◽  
Acoustic Microscopy ◽  
Harsh Environments ◽  
Potential Candidate ◽  
Die Attach ◽  
Die Bonding

The operation of electronic packages under exceptionally harsh environments presents a significant challenge for the microelectronics industry, for example, in down-hole, well-logging and turbo-machinery applications. High temperature Au based solders are one potential candidate for die attachment for harsh environments and is already used in limited cases. For Au-Si die bonding, some of the Si is provided by diffusion from the Si die itself. Therefore, the interfacial reaction between the Si and Au-Si thin foil solder preform is a key factor in the control of the die bonding process. Unfortunately, during the die bonding process, defects such as voids, delaminations, and impurities are not unusual. These defects are caused by the assembly process, chemical impurities, soldering reactions, and thermal stresses. Understanding these defects is critical for the reliable performance of the devices after bonding. In this paper, optimization of the Au-Si eutectic die bonding has been performed and near 100% bonded area confirmed by scanning acoustic microscopy achieved consistently. Die attach reliability was investigated by thermal shock and thermal cycling treatments, after which the bonded area showed some signs of degradation. Shear strength testing and microstructural analysis were also carried out. Die bond optimisation gave a significant improvement in both bonded area and reliability.

Optical Role of Die Bonding for Chip-on-Board White Light Emitting Diode Emitters

2016 ◽  
Vol 2016 (1) ◽  
pp. 000196-000201
Author(s):  
Gunwoo Kim ◽  
Yu-Chou Shih ◽  
Frank Shi
Keyword(s):  
Light Emitting Diode ◽  
Light Output ◽  
Packaging Materials ◽  
White Led ◽  
Optical Efficiency ◽  
Light Emitting ◽  
Die Attach ◽  
Die Bonding ◽  
First Time

Abstract The role of die attach adhesive in influencing light output of the white chip-on-board (COB) light emitting diode (LED) emitters is investigated using Monte-Carlo simulations. It is demonstrated for the first time that the use of an optically clear adhesive for replacing conventional adhesive for multiple COB white LED emitters leads to a significant enhancement in light output of up to 22 %. An optimization of packaging materials and process for multiple COB LED emitter to enhance optical efficiency is also studied.

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