Improvement of ELK Reliability in Flip Chip Packages using Bond-on-Lead (BOL) Interconnect Structure

2010 ◽  
Vol 2010 (1) ◽  
pp. 000197-000203 ◽  
Author(s):  
Eric Ouyang ◽  
MyoungSu Chae ◽  
Seng Guan Chow ◽  
Roger Emigh ◽  
Mukul Joshi ◽  
...  
Keyword(s):  
Finite Element ◽  
Flip Chip ◽  
Low Cost ◽  
Reliability Testing ◽  
Element Simulation ◽  
Testing Data ◽  
Flip Chip Packaging ◽  
Solder Mask ◽  
The Cost ◽  
Low K

In this paper, a novel flip chip interconnect structure called Bond-On-Lead (BOL) and its ability to reduce stress in the sensitive sub-surface ELK (Extra Low K) layers of the die is presented. BOL is a new low cost flip chip packaging solution which was developed by STATSChipPAC to dramatically reduce the cost of flip chip packaging. The BOL solution allows for efficient substrate routing by virtue of the use of narrow BOL pads and the removal of solder mask in the area of the BOL pads, which eliminates the limitations associated with solder mask opening sizes and positional tolerances. In addition to the compelling cost benefits, modeling results are confirmed with empirical reliability testing data to show that BOL is superior to the traditional Bond-on-Capture Pad (BOC) configuration from a mechanical stress and reliability perspective. The focus of this paper is on the theoretical analysis of the stress, strain, and warpage associated with the BOL configuration compared with the traditional BOC structure. For the package deformation, the global finite element method is used to simulate the package warpage. For the local bumping reliability, the focus is on the ELK layers which are the critical locations affecting the package's reliability. The local finite element simulation is conducted to compare the critical ELK layers stresses with BOL structure vs. with traditional BOC structure.

Cost Comparison of Fan-out Wafer Level Packaging and Flip Chip Packaging

2017 ◽  
Vol 2017 (DPC) ◽  
pp. 1-37 ◽  
Author(s):  
Amy Lujan
Keyword(s):  
Flip Chip ◽  
Cost Effective ◽  
Cost Comparison ◽  
Cost Modeling ◽  
Wafer Level ◽  
Design Features ◽  
Wafer Level Packaging ◽  
Flip Chip Packaging ◽  
The Right ◽  
The Cost

In recent years, there has been increased focus on fan-out wafer level packaging with the growing inclusion of a variety of fan-out wafer level packages in mobile products. While fan-out wafer level packaging may be the right solution for many designs, it is not always the lowest cost solution. The right packaging choice is the packaging technology that meets design requirements at the lowest cost. Flip chip packaging, a more mature technology, continues to be an alternative to fan-out wafer level packaging. It is important for many in the electronic packaging industry to be able to determine whether flip chip or fan-out wafer level packaging is the most cost-effective option. This paper will compare the cost of flip chip and fan-out wafer level packaging across a variety of designs. Additionally, the process flows for each technology will be introduced and the cost drivers highlighted. A variety of package sizes, die sizes, and design features will be covered by the cost comparison. Yield is a key component of cost and will also be considered in the analysis. Activity based cost modeling will be used for this analysis. With this type of cost modeling, a process flow is divided into a series of activities, and the total cost of each activity is accumulated. The cost of each activity is determined by analyzing the following attributes: time required, labor required, material required (consumable and permanent), capital required, and yield loss. The goal of this cost comparison is to determine which design features drive a design to be packaged more cost-effectively as a flip chip package, and which design features result in a lower cost fan-out wafer level package.

A novel polymer technology for underfill

2012 ◽  
Vol 1428 ◽  
Author(s):  
Osamu Suzuki ◽  
Toshiyuki Sato ◽  
Paul Czubarow ◽  
David Son
Keyword(s):  
Flip Chip ◽  
Mechanical Analysis ◽  
Reliability Testing ◽  
Hybrid Polymer ◽  
Scanning Calorimetry ◽  
Inorganic Hybrid ◽  
Fine Pitch ◽  
Capillary Type ◽  
Tin Silver Copper ◽  
Low K

AbstractCapillary type underfill is still the mainstream underfill for mass production flip chip applications. Flip chip packages are migrating to ultra low-k, Pb-free, 3D and fine pitch packages. Underfill selection is becoming more critical. This paper discusses the performance and potential of underfills using a novel organic-inorganic hybrid polymer technology.Compared to eutectic and high lead solder, tin-silver-copper solder has lower C.T.E., higher elasticity and greater brittleness. In light of these properties, it is generally better to select high Tg and lower CTE underfill in order to prevent bump fatigue during reliability testing. Given the brittleness of low-k dielectric layers of flip chips, the destruction of low-k layers by stress inside the flip chip packages has become a major issue. Underfills for low-k packages should have low stress, and the warpage should be small. It is expected that as the low-k trend expands, the underfill is required to provide less stress. Low Tg underfill shows lower warpage. New chemical technologies have been developed to address the needs of underfills for low-k/Pb-free flip chip packages, specifically organic-inorganic hybrid polymer compounds. The organic-inorganic hybrid polymer provides excellent cure properties which enable a balanced combination of low stress and good bump protection. The material properties of the underfill were characterized using Differential Scanning Calorimetry (DSC), Thermo-Mechanical Analysis (TMA), and Dynamic Mechanical Analysis (DMA). A daisy-chained test vehicle was used for reliability testing. A detailed study is presented on the underfill properties, reliability data, as well as finite element modeling results.

Underfill Assessments and Validations for Low-k FCBGA

2006 ◽  
Author(s):  
Nicholas Kao ◽  
Jeng Yuan Lai ◽  
Jase Jiang ◽  
Yu Po Wang ◽  
C. S. Hsiao
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Flip Chip ◽  
Failure Modes ◽  
Solder Bump ◽  
Material Selection ◽  
Coefficient Of Thermal Expansion ◽  
Electrical Performance ◽  
Low K ◽  
Underfill Material

With the trend of electronic consumer product toward more functionality, high performance and miniaturization, IC chip is required to deliver more I/Os signals and better electrical characteristics under same package form factor. Thus, Flip Chip BGA (FCBGA) package was developed to meet those requirements offering better electrical performance, more I/O pins accommodation and high transmission speed. For high-speed application, the low dielectric constant (low-k) material that can effectively reduce the signal delays is extensively used in IC chips. However, the low-k material possesses fragile mechanical property and high coefficient of thermal expansion (CTE) compared with silicon chip, which raises the reliability concerns of low-k material integrated into IC chip. The typical reliability failure modes are low-k layer delamination and bump crack under temperature loading during assembly and reliability test. Delamination is occurred in the interface between low-k dielectric layers and underfill material at chip corner. Bump crack is at Under Bump Metallization (UBM) corner. Thus, the adequate underfill material selection becomes very important for both solder bump and low-k chips [1]. This paper mainly characterized FCBGA underfill materials to guide the adequate candidates to prevent failures on low-k chip and solder bump. Firstly, test vehicle was a FCBGA package with heat spreader and was investigated the thermal stress by finite element models. In order to analyze localized low-k structures, sub-modeling technique is used for underfill characterizations. Then, the proper underfill candidates picked from modeling results were experimentally validated by reliability tests. Finally, various low-k FCBGA package structures were also studied with same finite element technique.

The Mathematical Model of Simulative Calculation for the Process of Airbag Landing

2014 ◽  
Vol 635-637 ◽  
pp. 228-232
Author(s):  
Jian He ◽  
Ji Sheng Ma ◽  
Da Lin Wu
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Calculation Method ◽  
Low Cost ◽  
Analytical Analysis ◽  
Heavy Equipment ◽  
Element Simulation ◽  
The Mathematical Model

Airbag is widely used in heavy equipment dropped field with its efficient cushion performance and low cost. The calculation method used now for the process of airbag landing mainly is simulative calculation: analytical analysis and finite element simulation, but there are less systematic introduction for the mathematical model behind these methods in past papers. This paper mainly does the summary for the mathematical model of vented airbag which is usually used.

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