Underfill Injection Molding in Flip-Chip Packaging with Different Bumps Array Arrangements

2008 ◽  
Vol 594 ◽  
pp. 163-168
Author(s):  
Chao Ming Lin ◽  
Chun Yi Chu ◽  
Wei Lin Chang
Keyword(s):  
Injection Molding ◽  
Thin Shell ◽  
Flip Chip ◽  
Shear Strain Rate ◽  
Flow Front ◽  
Injection Process ◽  
Packing Pressure ◽  
Ic Packaging ◽  
Flip Chip Packaging ◽  
Cavity Filling

The injection molding IC packaging process involves chip packaging and encapsulation techniques comprising mainly of cavity-filling and curing processes. In this paper, the complex 3D geometries and flow behaviors are simplified and modeled by a 2.5D thin-shell simulation. Important aspects of the cavity-filling process include the choosing of bumps array types, the cavity geometry, the injection process, the packing pressure, and the process temperature. The current investigation considers the filling and curing in the different bumps array types. It is shown that the applicable array arrangement provides improved filling results on the flow front, curing, shear strain-rate and velocity vector distributions. These results show the better choice using the geometry parameters in the bumps array arrangement is to consider the performances of the local and global penetrations together.

A Surface Energy Approach to Developing an Analytical Model for the Underfill Flow Process in Flip-Chip Packaging

2021 ◽  
Author(s):  
X.J. Yao ◽  
Weijie Jiang ◽  
Jiahui Yang ◽  
Junjie Fang ◽  
W.J. (Chris) Zhang
Keyword(s):  
Surface Energy ◽  
Analytical Model ◽  
Flip Chip ◽  
Cfd Simulation ◽  
Flow Front ◽  
New Approach ◽  
Solder Bumps ◽  
Regular Triangle ◽  
Filling Time ◽  
Flip Chip Packaging

Abstract This paper presents a new approach to formulating an analytical model for the underfill process in flip-chip packaging to predict the flow front and the filling time. The new approach is based on the concept of surface energy along with the energy conservation principle. This approach avoids the need of modeling the flow path to predict the flow front and the filling time and thus it is suitable to different configurations of solder bumps, including different shapes and arrangements of solder bumps in flip-chip packaging. An experiment along with the CFD simulation was performed based on a proprietarily developed testbed to verify the effectiveness of this approach. Both the experimental and simulation results show that the proposed approach along with its model is accurate for flip-chip packages with different configurations besides the configuration of a regular triangle arrangement of solder bumps and a spherical shape of the solder bump.

Optimization of Process Parameters for Injection Molding Based on Taguchi Technique

2012 ◽  
Vol 538-541 ◽  
pp. 1170-1174
Author(s):  
Shi Jun Fu
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Orthogonal Design ◽  
Mold Temperature ◽  
Optimum Process ◽  
Process Conditions ◽  
Injection Time ◽  
Melt Temperature ◽  
Injection Process ◽  
Packing Pressure

In this paper, Taguchi and CAE technique are combined to study the influence of process conditions on the warpage of injection molding parts through twice orthogonal design experiments, and the injection process parameters are optimized according to the warpage. For the parameters selected, melt temperature and packing pressure have effects on the warpage of injection molding parts are highly significant, injection time is significant, other parameters have little effects. Within the range of experiments, the warpage decreased with the rise of the melt temperature and packing pressure. At last, the optimum process parameters of injection are that the mold temperature is 60°C, packing time is 10s, melt temperature is240°C, packing pressure is 115MPa and injection time is 0.4s.

A High-Linearity 76–85-GHz 16-Element 8-Transmit/8-Receive Phased-Array Chip With High Isolation and Flip-Chip Packaging

2014 ◽  
Vol 62 (10) ◽  
pp. 2337-2356 ◽  
Author(s):  
Bon-Hyun Ku ◽  
Ozgur Inac ◽  
Michael Chang ◽  
Hyun-Ho Yang ◽  
Gabriel M. Rebeiz
Keyword(s):  
Flip Chip ◽  
Phased Array ◽  
High Isolation ◽  
High Linearity ◽  
Flip Chip Packaging

The Study of Underfill Epoxy Hardness in Reducing Curing Process Time for Flip Chip Packaging

2011 ◽  
Vol 462-463 ◽  
pp. 1194-1199
Author(s):  
Zainudin Kornain ◽  
Azman Jalar ◽  
Rozaidi Rashid ◽  
Shahrum Abdullah
Keyword(s):  
Thermal Expansion ◽  
Flip Chip ◽  
Ball Grid Array ◽  
Process Time ◽  
Curing Process ◽  
Curing Time ◽  
Hold Temperature ◽  
Flip Chip Packaging ◽  
Time Cycle ◽  
The Impact

Underfilling is the vital process to reduce the impact of the thermal stress that results from the mismatch in the co-efficient of thermal expansion (CTE) between the silicon chip and the substrate in Flip Chip Packaging. This paper reported the pattern of underfill’s hardness during curing process for large die Ceramic Flip Chip Ball Grid Array (FC-CBGA). A commercial amine based underfill epoxy was dispensed into HiCTE FC-CBGA and cured in curing oven under a new method of two-step curing profile. Nano-identation test was employed to investigate the hardness of underfill epoxy during curing steps. The result has shown the almost similar hardness of fillet area and centre of the package after cured which presented uniformity of curing states. The total curing time/cycle in production was potentially reduced due to no significant different of hardness after 60 min and 120 min during the period of second hold temperature.

Effect of gas counter pressure on shrinkage and residual stress for injection molding process

2017 ◽  
Vol 37 (5) ◽  
pp. 505-520 ◽  
Author(s):  
Wen-Ren Jong ◽  
Shyh-Shin Hwang ◽  
Ming-Chieh Tsai ◽  
Chien-Chou Wu ◽  
Chi-Hung Kao ◽  
...  
Keyword(s):  
Residual Stress ◽  
Injection Molding ◽  
Flow Direction ◽  
Injection Molding Process ◽  
Molding Process ◽  
Daily Lives ◽  
Counter Pressure ◽  
Packing Pressure ◽  
Sink Marks ◽  
Feedback Data

Abstract Plastic products are common in contemporary daily lives. In the plastics industry, the injection molding process is advantageous for features such as mass production and stable quality. The problem, however, is that the melt will be affected by the residual stress and shrinkage generated in the process of filling and cooling; hence, defects such as warping, deformation, and sink marks will occur. In order to reduce product deformation and shrinkage during the process of molding, the screw of the injection molding machine will start the packing stage when filling is completed, which continuously pushes the melt into the cavity, thus making up for product shrinkage and improving their appearance, quality, and strength. If the packing pressure is too high, however, the internal residual stress will increase accordingly. This study set out to apply gas counter pressure (GCP) in the injection molding process. By importing gas through the ends of the cavity, the melt was exposed to a melt front pressure, which, together with the packing pressure from the screw, is supposed to reduce product shrinkage. The aim was to investigate the impacts of GCP on the process parameters via the changes in machine feedback data, such as pressure and the remaining injection resin. This study also used a relatively thin plate-shaped product and measurements, such as the photoelastic effect and luminance meter, to probe into the impacts of GCP on product residual stress, while a relatively thick paper-clip-shaped product was used to see the impacts of GCP on shrinkage in thick parts. According to the experimental results, the addition of GCP resulted in increased filling volume, improvement of product weight and stability, and effective reduction of section shrinkage, which was most obvious at the point closest to the gas entrance. The shrinkage of the sections parallel and vertical to the flow direction was proved to be reduced by 32% and 16%, respectively. Moreover, observations made via the polarizing stress viewer and luminance meter showed that the internal residual stress of a product could be effectively reduced by a proper amount of GCP.

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