Drop Reliability of Corner Bonded CSP in Portable Products

2003 ◽  
Author(s):  
Guoyun Tian ◽  
Yueli Liu ◽  
Pradeep Lall ◽  
R. Wayne Johnson ◽  
Sanan Abderrahman ◽  
...  
Keyword(s):  
Capillary Flow ◽  
Drop Test ◽  
Mechanical Shock ◽  
Solder Paste ◽  
Test Results ◽  
Mechanical Coupling ◽  
Small Areas ◽  
Common Solution ◽  
Four Corners ◽  
Capillary Underfill

The use of CSPs has expanded rapidly, particularly in portable electronic products. Many CSP designs will meet the thermal cycle or thermal shock requirements for these applications. However, mechanical shock (drop) and bending requirements often necessitate the use of underfills to increase the mechanical strength of the CSP-to-board connection. Capillary flow underfills processed after reflow, provide the most common solution to improving mechanical reliability. However, capillary underfill adds board dehydration, underfill dispense, flow and cure steps and the associated equipment to the assembly process. Corner bonding provides an alternate approach. Dots of underfill are dispensed at the four corners of the CSP site after solder paste print, but before CSP placement. During reflow the underfill cures, providing mechanical coupling between the CSP and the board at the corners of the CSP. Since only small areas of underfill are used, board dehydration is not required. This paper examines the manufacturing process for corner bonding including dispense volume, CSP placement and reflow. Drop test results are then presented. A conventional, capillary process was used for comparison of drop test results. Test results with corner bonding were intermediate between complete capillary underfill and non-underfilled CSPs. Finite element modeling results for the drop test are also included.

Drop-Impact Reliability of Chip-Scale Packages in Handheld Products

2003 ◽  
Author(s):  
Guoyun Tian ◽  
Yueli Liu ◽  
Pradeep Lall ◽  
R. Wayne Johnson ◽  
Sanan Abderrahman ◽  
...  
Keyword(s):  
Capillary Flow ◽  
Drop Test ◽  
Mechanical Shock ◽  
Solder Paste ◽  
Test Results ◽  
Mechanical Coupling ◽  
Small Areas ◽  
Common Solution ◽  
Impact Reliability ◽  
Capillary Underfill

The use of CSPs has expanded rapidly, particularly in portable electronic products. Many CSP designs will meet the thermal cycle or thermal shock requirements for these applications. However, mechanical shock (drop) and bending requirements often necessitate the use of underfills to increase the mechanical strength of the CSP-to-board connection. Capillary flow underfills processed after reflow, provide the most common solution to improving mechanical reliability. However, capillary underfill adds board dehydration, underfill dispense, flow and cure steps and the associated equipment to the assembly process. Corner bonding provides an alternate approach. Dots of underfill are dispensed at the four corners of the CSP site after solder paste print, but before CSP placement. During reflow the underfill cures, providing mechanical coupling between the CSP and the board at the corners of the CSP. Since only small areas of underfill are used, board dehydration is not required. This paper examines the manufacturing process for corner bonding including dispense volume, CSP placement and reflow. Drop test results are then presented. A conventional, capillary process was used for comparison of drop test results. Test results with corner bonding were intermediate between complete capillary underfill and non-underfilled CSPs. Finite element modeling results for the drop test are also included.

Solder Joint Encapsulant Adhesive – LGA High Reliability And Low Cost Assembly Solution

2013 ◽  
Vol 2013 (1) ◽  
pp. 000291-000297 ◽  
Author(s):  
Mary Liu ◽  
Wusheng Yin
Keyword(s):  
Solder Joint ◽  
Thermal Cycling ◽  
Capillary Flow ◽  
High Reliability ◽  
Low Cost ◽  
Cycling Performance ◽  
Solder Paste ◽  
Assembly Process ◽  
Soldering Process ◽  
Capillary Underfill

More and more Land Grid Array (LGA) components are being used in electronic devices such as smartphones, tablets and computers. In order to enhance LGA mechanical strength and reliability, capillary flow underfill is used to improve reliability. However, due to the small gap, it is difficult for capillary underfill to flow into the LGA at SMT level. Due to cost considerations, there are usually no pre-heating underfill or cleaning flux residue processes at the SMT assembly line. YINCAE solder joint encapsulant SMT 256 has been successfully used with solder paste for LGA assembly. Solder joint encapsulant is used in in-line LGA soldering process with enhanced reliability. It eliminates the underfilling process and provides excellent reworkability. The shear strength of solder joint is stronger than that of underfilled components. The thermal cycling performance using solder joint encapsulant is much better than that using underfill. Bottom IC of POP has been studied for further understanding of LGA assembly process parameters. All details such as assembly process, drop test and thermal cycling test will be discussed in the full paper.

Effect of Design Parameters on Drop Test Performance of Wafer Level Chip Scale Packages (WLCSP)

2011 ◽  
Author(s):  
Pushkraj Tumne ◽  
Vikram Venkatadri ◽  
Santosh Kudtarkar ◽  
Michael Delaus ◽  
Daryl Santos ◽  
...  
Keyword(s):  
Flip Chip ◽  
Bulk Solder ◽  
Consumer Electronics ◽  
Drop Test ◽  
Design Parameters ◽  
Mechanical Shock ◽  
Wafer Level ◽  
Cross Sectional ◽  
Right Censored Data ◽  
Solder Balls

Today’s consumer market demands electronics that are smaller, faster and cheaper. To cater to these demands, novel materials, new designs, and new packaging technologies are introduced frequently. Wafer Level Chip Scale Package (WLCSP) is one of the emerging package technologies that have the key advantages of reduced cost and smaller footprint. The portable consumer electronics are frequently dropped; hence the emphasis of reliability is shifting towards study of effects of mechanical shock loading increasingly. Mechanical loading typically induces brittle fractures (also known as intermetallic failures) between the solder bumps and bond pads at the silicon die side. This type of failure mechanism is typically characterized by the board level drop test. WLCSP is a variant of the flip-chip interconnection technique. In WLCSPs, the active side of the die is inverted and connected to the PCB by solder balls. The size of these solder balls is typically large enough (300μm pre-reflow for 0.5mm pitch and 250μm pre-reflow for 0.4mm pitch) to avoid use of underfill that is required for the flip-chip interconnects. Several variations are incorporated in the package design parameters to meet the performance, reliability, and footprint requirements of the package assembly. The design parameters investigated in this effort are solder ball compositions with different Silver (Ag) content, backside lamination with different thickness, WLCSP type –Direct and Re-Distribution Layer (RDL), bond pad thickness, and sputtered versus electroplated Under Bump Metallurgy (UBM) deposition methods for 8×8, 9×9, and 10×10 array sizes. The test vehicles built using these design parameters were drop tested using JEDEC recommended test boards and conditions as per JESD22-B11. Cross sectional analysis was used to identify, confirm, and classify the intermetallic, and bulk solder failures. The objective of this research was to quantify the effects and interactions of WLCSP design parameters through drop test. The drop test data was collected and treated as a right censored data. Further, it was analyzed by fitting empirical distributions using the grouped and un-grouped data approach. Data analysis showed that design parameters had a significant effect on the drop performance and played a vital role in influencing the package reliability.

scholarly journals Manufacture and Strength Analysis of Ergonomic Bicycle Helmet Made from Polymeric Foam Composite Strengthened by Oil Palm Empty Fruit Bunch Fiber with Free Fall Drop Test Method

2020 ◽  
Vol 64 (1) ◽  
pp. 33-38
Author(s):  
Mahadi Mahadi ◽  
Keyword(s):  
Oil Palm ◽  
Free Fall ◽  
Product Safety ◽  
Drop Test ◽  
Empty Fruit Bunch ◽  
Test Results ◽  
Shell Layer ◽  
Bicycle Helmet ◽  
Polymeric Foam ◽  
Foam Composite

This article contains a study report on the manufacturing of bicycle helmet models that use polymeric foam composite materials strengthened by oil palm empty fruit bunch (OPEFB). The test results of mechanical polymeric foam obtain tensile stress (σt) 1.17 MPa, compressive stress (σc) 0.51 MPa, bending stress (σb) 3.94 MPa, modulus of elasticity (E) 37.97 MPa, density ( ρ) 193 (kg / m3). The testing results of thermal conductivity (k) with ASTM C177-04 standard obtain 0.096 W/mK. Aerodynamic simulation is carried out on 5 bicycle helmet models with different variations of air ventilation formations and obtained the M4A model that best met the ergonomic criteria. The simulation results of the M4A helmet model are max 65.668 Pa of air pressure (Pu), 26,8 0C of inner wall temperature (Ti), 11.0724 m/s of air velocity (vi) and 0.89 of drag coefficient (CD). Bicycle helmet manufacturing is carried out by hand lay up method for shell layer and casting mold for liner by using GFRP polymer composite molds. Both layers are made by sandwich method with the composition of the shell layer is 100 grams resin, 15 grams glass fiber and 5 grams catalyst. The composition of the liner layer is 275 grams (50%) of unsaturated Polyester 157 BQTN-EX resin, 27.5 grams (5%) of OPEFB fiber, 247 grams (45%) of Blowing Agent Polyurethane and 27.5 grams (5%) of Methyl Ketone Perokside catalyst (MEKPO). The toughness of the helmet is tested by using a free fall drop test with the standard of Consumer Product Safety Commission (CPSC) with the height of impact 1.5 meters. The free fall drop test results are max 2.02 MPa of the impact stress of the M4A bicycle helmet model (σi) and max 283.77 joules of energy impact (Ei) which is close to the Consumer Product Safety Commission’s (CPSC) standard value of 110 joules.

High Pressure Test Results of a Catalytically Assisted Ceramic Combustor for a Gas Turbine

1999 ◽  
Vol 121 (3) ◽  
pp. 422-428 ◽  
Author(s):  
Y. Ozawa ◽  
Y. Tochihara ◽  
N. Mori ◽  
I. Yuri ◽  
T. Kanazawa ◽  
...  
Keyword(s):  
High Pressure ◽  
Gas Turbine ◽  
Catalytic Combustion ◽  
Ceramic Fiber ◽  
Outlet Temperature ◽  
Mechanical Shock ◽  
Test Results ◽  
Ceramic Tiles ◽  
Combustion Gas ◽  
Ceramic Liner

A catalytically assisted ceramic combustor for a gas turbine was designed to achieve low NOx emission under 5 ppm at a combustor outlet temperature over 1300°C. This combustor is composed of a burner system and a ceramic liner behind the burner system. The burner system consists of 6 catalytic combustor segments and 6 premixing nozzles, which are arranged in parallel and alternately. The ceramic liner is made up of the layer of outer metal wall, ceramic fiber, and inner ceramic tiles. Fuel flow rates for the catalysts and the premixing nozzles are controlled independently. Catalytic combustion temperature is controlled under 1000°C, premixed gas is injected from the premixing nozzles to the catalytic combustion gas and lean premixed combustion over 1300°C is carried out in the ceramic liner. This system was designed to avoid catalytic deactivation at high temperature and thermal and mechanical shock fracture of the honeycomb monolith of the catalyst. A combustor for a 10 MW class, multican type gas turbine was tested under high pressure conditions using LNG fuel. Measurements of emission, temperature, etc. were made to evaluate combustor performance under various combustion temperatures and pressures. This paper presents the design features and the test results of this combustor.

scholarly journals Strain Gage Test Results of Band-Type Locking Rings for a Typical Drum Type Radioactive Material Package

2002 ◽  
Author(s):  
Charles A. McKeel ◽  
Allen C. Smith
Keyword(s):  
Uniform Distribution ◽  
Strain Gage ◽  
Strain Distribution ◽  
Drop Test ◽  
Uniform Strain ◽  
Radioactive Material ◽  
Test Results ◽  
Lower Weight ◽  
Band Type

Band type closure rings are commonly used for securing the drum lid on radioactive material packages of lower weight classifications. Lid installation is achieved by placing the band around the perimeter of the lidded drum and tightening the single bolt in stages until a designated torque value is obtained. The band is subjected to heavy rapping with a soft hammer during installation to equilibrate the band strains around the drum perimeter. The study described here investigated the strain distributions in the band throughout the installation process. The results show that a uniform strain distribution is achieved during installation and that the hammering of the band aids in achieving the uniform distribution. The results of the strain levels after the drop test indicate that the locking rings maintain some pre-tension, even after severe targeted drops that crush a portion of the drum top.

LMS and Power Point Physics Lectures

2014 ◽  
Vol 519-520 ◽  
pp. 1605-1608
Author(s):  
Tatyana N. Gnitetskaya ◽  
Elena B. Ivanova ◽  
Cherednychenko Alexander
Keyword(s):  
Management System ◽  
Learning Management System ◽  
Heat Engine ◽  
Drop Test ◽  
Test Results ◽  
Advantages And Disadvantages ◽  
Learning Management ◽  
Power Point

There is a big gap between level of multimedia possibilities and level of using multimedia in training physics at the universities. In this paper the advantages and disadvantages of Power Point physics lectures are described. It is noted that one from important advantages is coordination of Power Point with Learning Management System. The examples of writing formulas, drawing graphics in time are presented in this paper. It is described the animated image illustrating the operation of a heat engine with the help of aniline drop. Test results allow us to give in this paper some guidelines on slide design to make information perceiving from the screen easier for students.

scholarly journals Load of gondola with floor decking at handling operations

2015 ◽  
Vol 2015 (4) ◽  
pp. 45-49
Author(s):  
Владимир Кобищанов ◽  
Vladimir Kobishchanov ◽  
Кирилл Герасимов ◽  
Kirill Gerasimov ◽  
Дмитрий Расин ◽  
...  
Keyword(s):  
Maximum Stress ◽  
The Body ◽  
Dynamic Loads ◽  
Normal Stresses ◽  
Test Results ◽  
Load Drop ◽  
Small Areas ◽  
Car Body ◽  
Deflected Mode ◽  
Solid Type

A gondola with a body of solid type – an eco-nomically effective unit of a rollingstock. Most of the damages of gondola bodies is caused at handling operations with the failure of requirements observance established. In the paper the assessment of deflected mode body in the body at the lump load drop with the mass of 500 kg is carried out. Normal stresses and travels arising at the blow of load in the sections of joints of frame beams between each other, side and end walls are analyzed. The values of stresses three times higher than the foreseen ones with “Standards…” are adopted as reference valuations. It is substantiated by test results and the comparison of material characteristics at deadweight and dynamic loads. As a result of car body multichoice computations on basis of the detailed MCE there was established the following: the closer the place of a lump blow to a supporting longitudinal to the car body end is, the stresses are higher in it. Stresses arising in the supporting longitudinal situated between an end girder and a body bolster beam reach 998 H/mm, at the same time in the middle of the car body of a gondola they do not exceed 450 H⁄mm². If a load lump falls down on the joint of cross-beams and longitudinal ones, then stresses in their sections 10-15 times less, than if the fall were to a strengthening beam. In the main the maximum stress distribution is limited by small areas located between two neighboring crossbeams. The research results have shown, it is necessary that additional bearing elements absorbing a blow should be introduced in a frame.

scholarly journals TEST RESULTS FOR CLONES OF GARLIC

2018 ◽  
pp. 11-12
Author(s):  
B. S. Salomov ◽  
M. H. Aramov
Keyword(s):  
Selection Process ◽  
Test Results ◽  
Tropical Regions ◽  
Small Areas ◽  
State Register ◽  
New Varieties ◽  
Selection For ◽  
The Republic ◽  
High Yielding Varieties ◽  
Almost All

A large number of forms and varieties of garlic created in the selection process allowed this culture to spread almost all over the world: in temperate regions, in subtropics and even in tropical regions. Currently, the world's acreage of garlic is 1.438 million hectares, the average yield is 16.9 tons per hectare, the gross yield is 24.255 million tons. The largest producers of garlic are China, India, South Korea and Egypt. The highest yield was recorded in Uzbekistan, Egypt, China, Tadjikistan. In Uzbekistan, it is grown everywhere, mainly on household plots and small areas in farms. In the republic, varieties of garlic are South-violet (1972) and May VIR (1978). Since 2004, the Surkhandarya Scientific Experimental Station of the VegetableMelon Crops and Potato Research Institute has been conducting selection work to create new varieties of garlic. As a result of the research, the Chidamli variety was introduced and, since 2016, introduced into the State Register. All zoned varieties belong to the group of autumn-sprouting varieties. In 2011- 2015, about 100 promising clones of garlic were evaluated in the south of Uzbekistan. The effectiveness of selection for the size of bulbs and teeth is revealed. Clones with a mass of bulbs and teeth are isolated. Clones with a bulb weight of more than 80 g and a tooth mass of more than 6 g are distinguished. They are a valuable source for the creation of high-yielding varieties of garlic in Uzbekistan.

Superior Drop Test Performance of BGA Assembly Using SAC105Ti Solder Sphere

2012 ◽  
Vol 2012 (1) ◽  
pp. 000829-000843
Author(s):  
Weiping Liu ◽  
Ning-Cheng Lee ◽  
Simin Bagheri ◽  
Polina Snugovesky ◽  
Jason Bragg ◽  
...  
Keyword(s):  
Test Performance ◽  
Electrical Response ◽  
Threshold Value ◽  
Drop Test ◽  
Data Sets ◽  
Solder Paste ◽  
Partial Fracture ◽  
Pasty Range ◽  
Reflow Temperature ◽  
Complete Fracture

Board-level drop test performance was evaluated and compared for the following four different solder combinations in BGA/CSP assembly: 1) SnPb paste with SnPb balls, 2) SnPb paste with SAC105Ti balls, 3) SAC305 paste with SAC105Ti balls, and 4) SAC305 paste with SAC105 balls. Presence of Ti improved the drop test performance significantly, despite the voiding side effect caused by its oxidation tendency. It is anticipated that the voiding can be prevented with the development of a more oxidation resistant flux. The consistently poor drop test performance of 105Ti/SnPb is caused by the wide pasty range resulted from mixing SAC105 with Sn63 solder paste. The effect of Ti in this system is overshadowed by the high voiding outcome due to this wide pasty range material. In view of this, use of SAC105 BGA with SnPb solder paste is not recommended, with or without Ti addition. High reflow temperature drove fracture shift to interface at package side, presumably through building up IMC thickness beyond the threshold value. A lower reflow temperature is recommended. Electrical response is consistent with complete fracture data. But, complete fracture trend is inconsistent with that of partial fracture trend, and neither data can provide a full understanding about the failure mode. By integrating complete fracture and partial fracture into “Virtual Fracture”, the failure mechanism becomes obvious and data sets become consistent with each other.

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