Influence of heating direction on BGA solder balls structure

2017 ◽  
Author(s):  
Alexandr Otahal ◽  
Jakub Somer ◽  
Ivan Szendiuch
Keyword(s):  
Solder Balls ◽  
Heating Direction

Time Domain Reflectometry Technique for Failure Analysis

2004 ◽  
Author(s):  
Teoh King Long ◽  
Ko Yin Fern
Keyword(s):  
Failure Analysis ◽  
Time Domain ◽  
Time Domain Reflectometry ◽  
Fault Isolation ◽  
Reference Plane ◽  
First Case ◽  
Main Emphasis ◽  
Plastic Ball ◽  
Solder Balls ◽  
Non Destructive

Abstract In time domain reflectometry (TDR), the main emphasis lies on the reflected waveform. Poor probing contact is one of the common problems in getting an accurate waveform. TDR probe normalization is essential before measuring any TDR waveforms. The advantages of normalization include removal of test setup errors in the original test pulse and the establishment of a measurement reference plane. This article presents two case histories. The first case is about a Plastic Ball Grid Array package consisting of 352 solder balls where the open failure mode was encountered at various terminals after reliability assessment. In the second, a three-digit display LED suspected of an electrical short failure was analyzed using TDR as a fault isolation tool. TDR has been successfully used to perform non-destructive fault isolation in assisting the routine failure analysis of open and short failure. It is shown to be accurate and reduces the time needed to identify fault locations.

Based on the technology of electromagnetic force driving and differential pressure control for producing solder balls

2021 ◽  
Vol 286 ◽  
pp. 129236
Author(s):  
Tongju Wang ◽  
Yongping Lei ◽  
Peng Zhao ◽  
Jian Lin ◽  
Hanguang Fu
Keyword(s):  
Electromagnetic Force ◽  
Pressure Control ◽  
Differential Pressure ◽  
Solder Balls

Zn diffusion and reflow behaviour of Sn-9Zn and Sn-8.5Zn-0.5Ag-0.01Al-0.1Ga solders on a Ni/Cu substrate under IR reflow

2014 ◽  
Vol 26 (2) ◽  
pp. 87-95 ◽  
Author(s):  
J. Mittal ◽  
K.L. Lin
Keyword(s):  
Theoretical Calculations ◽  
Research Work ◽  
Content Type ◽  
Diffusion Behavior ◽  
Zn Diffusion ◽  
Cu Substrate ◽  
Practical Applications ◽  
Substrate Interface ◽  
Solder Balls ◽  
Practical Implications

Purpose – This paper aims to compare the reflow and Zn diffusion behaviors in Sn-Zn and Sn-8.5Zn-0.5Ag-0.01Al-0.1Ga (5E) solders during soldering on a Ni/Cu substrate under infrared (IR) reflow. The study proposes a model on the effect of various elements particularly Zn diffusion behavior in the solders on the formation of intermetallic compounds (IMCs). Design/methodology/approach – The melting activities of two solders near their melting points on copper substrates are visualized in an IR reflow furnace. Reflowed solder joints were analyzed using scanning electron microscope and energy dispersive X-ray spectroscopy. Findings – Reflow behaviors of the solders are similar. During melting, solder balls are first merged into each other and then reflow on the substrate from top to bottom. Both solders show a reduced amount of Zn in the solder. Theoretical calculations demonstrate a higher Zn diffusion in the 5E solder; however, the amount of Zn actually observed at the solder/substrate interface is lower than Sn-9Zn solder due to the formation of ZnAg3 in the solder. A thinner IMC layer is formed at the interface in the 5E solder than the Sn-Zn solder. Research limitations/implications – The present work compares the 5E solder only with Sn-Zn solder. Additional research work may be required to compare 5E solder with other solders like Sn-Ag, SnAgCu, etc. to further establish its practical applications. Practical implications – The study ascertains the advantages of 5E solder over Sn-Zn solder for all practical applications. Originality/value – The significance of this paper is the understanding of the relation between reflow behavior of solders and reactivity of different elements in the solder alloys and substrate to form various IMCs and their influence on the formation of IMC layer at solder/substrate interface. Emphasis is provided for the diffusion behavior of Zn during reflow and respective reaction mechanisms.

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.

Effects of inductor patterns on temperature and deformation behavior of ship hull plate by induction heating

2018 ◽  
Vol 232 (23) ◽  
pp. 4371-4389
Author(s):  
Shuiming Zhang ◽  
Cungen Liu ◽  
Xuefeng Wang ◽  
Zhi Yang
Keyword(s):  
Induction Heating ◽  
Opposite Direction ◽  
Thermal Deformation ◽  
Transient Analysis ◽  
Ship Hull ◽  
Temperature Dependent ◽  
Thermal Forming ◽  
Ship Hull Plate ◽  
Heating Direction ◽  
Transverse Shrinkage

This paper mainly investigated the effects of different inductor patterns on thermal forming behavior of ship hull plate by moving induction heating. Alternately-coupled electromagnetic-thermal analysis procedure considering temperature-dependent material properties was firstly implemented at each moving step of inductor, followed with uncoupled thermal-mechanical transient analysis to obtain corresponding thermal deformation. Then temperature distribution, dimensions (breadth b and depth h) of heat-affected zone, and deformation obtained from codirectional current-carrying inductor with no gap and opposite-direction current-carrying inductor with gap were compared, respectively. And effects of heating directions and distance T2 of ODIG were also analyzed. It turns out that codirectional current-carrying inductor with no gap can generate much larger transverse shrinkage at 1.8–2.5 mm/s than opposite-direction current-carrying inductor with gap, otherwise smaller at 3.2–4.0 mm/s, likewise larger temperature gradient at 1.8–4.0 mm/s and thus larger bending angular deformation. Besides, heating direction “Out” can generate larger deformation than “In” and deformation for opposite-direction current-carrying inductor with gap can be effectively improved through adjusting distance T2 until 13 mm. These indicate that adopting appropriate inductor patterns, heating direction and distance T2 of opposite-direction current-carrying inductor with gap can significantly improve thermal forming behavior.

Effect of Thickness of Pd Plating Layer on Shear Strength of Lead-Free Solder Ball Joint With Electroless Ni/Pd/Au Plated Electrode

2011 ◽  
Author(s):  
Takahiro Kano ◽  
Ikuo Shohji ◽  
Tetsuyuki Tsuchida ◽  
Toshikazu Ookubo
Keyword(s):  
Reaction Layer ◽  
Shear Force ◽  
Solder Ball ◽  
Lead Free ◽  
Joint Interface ◽  
Lead Free Solder ◽  
Solder Balls ◽  
Free Solder ◽  
Ball Joints ◽  
Electroless Ni

An electroless Ni/Pd/Au plated electrode is expected to be used as an electrode material for lead-free solder to improve joint reliability. The aim of this study is to investigate the effect of the thickness of the Pd layer on joint properties of the lead-free solder joint with the electroless Ni/Pd/Au plated electrode. Solder ball joints were fabricated with Sn-3Ag-0.5Cu (mass%) lead-free solder balls and electroless Ni/Pd/Au and Ni/Au plated electrodes. Ball shear force and microstructure of the joint were investigated. The (Cu,Ni)6Sn5 reaction layer formed in the joint interface in all specimens. The thickness of the reaction layer decreased with increasing the thickness of the Pd layer. In the joint with a Pd layer 0.36 μm thick, the remained Pd layer was observed in the joint interface. In the joint, impact shear force decreased compared with that of the joint without the remained Pd layer. On the contrary, when the thickness of the Pd layer was less than 0.36 μm, the Pd layer was not remained in the joint interface and impact shear force improved. Impact shear force of the joint with the electroless Ni/Pd/Au plated electrode was higher than that with the electroless Ni/Au one.

scholarly journals Growth Kinetics of Reaction Layers in Flip Chip Joints with Cu-cored Lead-free Solder Balls

2004 ◽  
Vol 45 (3) ◽  
pp. 754-758 ◽  
Author(s):  
Ikuo Shohji ◽  
Yuji Shiratori ◽  
Hiroshi Yoshida ◽  
Masahiko Mizukami ◽  
Akira Ichida
Keyword(s):  
Growth Kinetics ◽  
Flip Chip ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Balls ◽  
Free Solder ◽  
Kinetics Of Reaction ◽  
Kinetics Of
Sign in / Sign up

Export Citation Format

Share Document