Precise solder dispensing in high-throughput micro-device packaging applications

2014 ◽  
Vol 2014 (DPC) ◽  
pp. 001284-001294
Author(s):  
Hanzhuang Liang ◽  
Linh Rolland ◽  
Floriana Suriawidjaja ◽  
Mani Ahmadi ◽  
Heakyoung Park
Keyword(s):  
High Throughput ◽  
Smart Phone ◽  
Mesh Size ◽  
Solder Paste ◽  
Mems Devices ◽  
Production Lines ◽  
Stencil Printing ◽  
Content Type ◽  
Packaging Design ◽  
Wide Range

Advanced micro-device packaging sets high and dynamic standard for its supplier industries for speed, precision and flexibility. A high-precision and high-throughput solder paste dispensing process has been developed to fill the gap between novel packaging design and traditional processes of stencil printing and slow dispensing. This process is being used in 25 PCBA production lines to package smart phones, MEMS devices and automobile control panels. These production lines are in full service 24/6 with each dispense system running at 2500unit per hour for simple MEMS patterns, 144uph for complex smart phone patterns and 6uph of full automobile control panels. A well-controlled valve design is applied to achieve high dispensing accuracy at fast speeds. This has removed process design barriers related to dispensing and has matched the high-end platform capability. This process also provides packaging designers with a flexibility superior to the existing solder printing process. The dispense pattern and route can be modified at cost, in minutes and during any step in the design or the assembly stage. Dispensed shapes include dots, lines, rectangle frames and annular rings, with fine edge definition 40um or less. This process can cover a wide range of pattern dimensions between 0.18mm and 100mm. Solder pastes that can be dispensed during this process have 80~90% metal content, type 4 to 6 mesh size. New processes are under development to further push limitations on throughput, dimension, flexibility and material dispensability.

Optimising pin-in-paste technology using gradient boosted decision trees

2018 ◽  
Vol 30 (3) ◽  
pp. 164-170 ◽  
Author(s):  
Péter Martinek ◽  
Oliver Krammer
Keyword(s):  
Decision Tree ◽  
Prediction Method ◽  
Percentage Error ◽  
Solder Paste ◽  
Hole Filling ◽  
Decision Tree Learning ◽  
Stencil Printing ◽  
Content Type ◽  
Learning Techniques ◽  
Through Hole

Purpose This paper aims to present a robust prediction method for estimating the quality of electronic products assembled with pin-in-paste soldering technology. A specific board quality factor was also defined which describes the expected yield of the board assembly. Design/methodology/approach Experiments were performed to obtain the required input data for developing a prediction method based on decision tree learning techniques. A Type 4 lead-free solder paste (particle size 20–38 µm) was deposited by stencil printing with different printing speeds (from 20 mm/s to 70 mm/s) into the through-holes (0.8 mm, 1 mm, 1.1 mm, 1.4 mm) of an FR4 board. Hole-filling was investigated with X-ray analyses. Three test cases were evaluated. Findings The optimal parameters of the algorithm were determined as: subsample is 0.5, learning rate is 0.001, maximum tree depth is 6 and boosting iteration is 10,000. The mean absolute error, root mean square error and mean absolute percentage error resulted in 0.024, 0.03 and 3.5, respectively, on average for the prediction of the hole-filling value, based on the printing speed and hole-diameter after optimisation. Our method is able to predict the hole-filling in pin-in-paste technology for different through-hole diameters. Originality/value No research works are available in current literature regarding machine learning techniques for pin-in-paste technology. Therefore, we decided to develop a method using decision tree learning techniques for supporting the design of the stencil printing process for through-hole components and pin-in-paste technology. The first pass yield of the assembly can be enhanced, and the reflow soldering failures of pin-in-paste technology can be significantly reduced.

The behaviour of solder pastes in stencil printing with electropolishing process

2013 ◽  
Vol 25 (3) ◽  
pp. 164-174 ◽  
Author(s):  
Yong‐Won Lee ◽  
Keun‐Soo Kim ◽  
Katsuaki Suganuma
Keyword(s):  
Circuit Board ◽  
Surface Finishing ◽  
Design Parameters ◽  
Solder Paste ◽  
Stencil Printing ◽  
Printing Process ◽  
Content Type ◽  
Solder Paste Printing ◽  
Solder Mask

PurposeThe purpose of this paper is to study the effect of the electropolishing time of stencil manufacturing parameters and solder‐mask definition methods of PCB pad design parameters on the performance of solder paste stencil printing process for the assembly of 01005 chip components.Design/methodology/approachDuring the study, two types of stencils were manufactured for the evaluations: electroformed stencils and electropolished laser‐cut stencils. The electroformed stencils were manufactured using the standard electroforming process and their use in the paste printing process was compared against the use of an electropolished laser‐cut stencil. The electropolishing performance of the laser‐cut stencil was evaluated twice at the following intervals: 100 s and 200 s. The performance of the laser‐cut stencil was also evaluated without electropolishing. An optimized process was established after the polished stencil apertures of the laser‐cut stencil were inspected. The performance evaluations were made by visually inspecting the quality of the post‐surface finishing for the aperture wall and the quality of that post‐surface finishing was further checked using a scanning electron microscope. A test board was used in a series of designed experiments to evaluate the solder paste printing process.FindingsThe results demonstrated that the length of the electropolishing time had a significant effect on the small stencil's aperture quality and the solder paste's stencil printing performance. In this study, the most effective electropolishing time was 100 s for a stencil thickness of 0.08 mm. The deposited solder paste thickness was significantly better for the enhanced laser‐cut stencil with electropolishing compared to the conventional electroformed stencils. In this printing‐focused work, print paste thickness measurements were also found to vary across different solder‐mask definition methods of printed circuit board pad designs with no change in the size of the stencil aperture. The highest paste value transfer consistently occurred with solder‐mask‐defined pads, when an electropolished laser‐cut stencil was used.Originality/valueDue to important improvements in the quality of the electropolished laser‐cut stencil, and based on the results of this experiment, the electropolished laser‐cut stencil is strongly recommended for the solder paste printing of fine‐pitch and miniature components, especially in comparison to the typical laser‐cut stencil. The advantages of implementing a 01005 chip component mass production assembly process include excellent solder paste release, increased solder volume, good manufacture‐ability, fast turnaround time, and greater cost saving opportunities.

Precise, high throughput dispensing of thermal interface material in BGA packaging applications

2016 ◽  
Vol 2016 (DPC) ◽  
pp. 001391-001412
Author(s):  
Hanzhuang Liang ◽  
Linh Rolland
Keyword(s):  
High Throughput ◽  
Flip Chip ◽  
Consumer Electronics ◽  
Thermal Interface Material ◽  
Production Lines ◽  
Heat Spreader ◽  
Heavy Load ◽  
Thermal Interface ◽  
Wide Range ◽  
Complicated Geometries

In a flip chip BGA package, thermal interface materials (TIMs) are applied for thermal management between the die and the heat spreader or between the heat spreader and the heat sink to conduct the heat generated in the die during component operation. Without a thermal interface, the die will overheat and the components will not function properly. Advanced microelectronics packaging demands high and dynamic standards of its supplier industries in relation to speed, precision and flexibility. For example, the demands on functionality, power density and performance of the components within a die are largely enhanced along with TIM requirements for higher heat resistance. Manufacturers are being asked to apply TIMs on more dies in more complicated geometries and to dispense them during any packaging process. This brings increased challenges for TIM dispensing equipment, such as the ability to handle abrasive and dry TIMs at a high throughput while maintaining precision and repeatability. A high-precision, high-throughput TIM dispensing process has been developed to fill the gap between the traditional slower dispensing of simple patterns and the challenges from emerging package designs. This process is being used in flip chip BGA production lines in package applications from consumer electronics to automotive products. These production lines are in full 24/7 operation with each dispensing system running at 240 units per hour (uph) for audio-video consumer electronics, 360 uph for CPUs/GPUs on smart phones and 750 uph for automobile control panels and computation servers. In this new dispensing system, the valve can be tightly controlled to achieve high dispensing accuracy at fast speeds. The dispense pattern and route can be modified at no cost, in minutes, and during any step in the design or the assembly stage. Shapes that can be dispensed include dots, lines, boxes and circles with fine height and edge definitions of 25micron and 45micron. The process can cover a wide range of pattern dimensions between 0.5mm and 100mm at flow rates of 30–370 mg/sec at a repeatability of 3–15% three sigma. Even TIM that has viscosity as high as 1500kcPs with a heavy load of large and coarse particles such as metals, ceramic and glass beads can be dispensed using this equipment and process. New equipment and processes are under development to further push the limit on higher throughput and precision, increased flexibility and material dispensability.

Cleaning control of stencil printing subject to performance deterioration

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rui Xi ◽  
Jiangyou Yu ◽  
Le Cao ◽  
Xiaojiang Zheng ◽  
Jun Guo
Keyword(s):  
Failure Rate ◽  
System Reliability ◽  
Control Method ◽  
Solder Paste ◽  
Rate Model ◽  
Stencil Printing ◽  
Printing Process ◽  
Content Type ◽  
Printing Quality ◽  
Printing System

Purpose Most solder paste printers are configured to periodically clean the stencil to maintain printing quality. However, a periodical cleaning control may result in excessive cleaning operations. The purpose of this paper is to develop a control method to schedule stencil cleaning operations appropriately. Design/methodology/approach A hybrid failure rate model of the stencil printing process with age reduction factor and failure rate increase factor is presented. A stencil cleaning policy based on system reliability is introduced. An optimization model used to derive the optimal stencil cleaning schedule is provided. Findings An aperiodic stencil cleaning control with good adaptability is achieved. A comparative analysis indicates that aperiodic control has better printing system reliability than traditional periodical control under the same cleaning resource consumption. Originality/value Periodical cleaning control commonly used in industrial printing process often results in excessive cleaning operations. By incorporating the printing system reliability, this paper develops an aperiodic stencil cleaning control method based on hybrid failure rate model of the stencil printing process. It helps to reduce unnecessary cleaning operations while keeping printing quality stable.

Non-Newtonian numerical modelling of solder paste viscosity measurement

2019 ◽  
Vol 31 (3) ◽  
pp. 176-180 ◽  
Author(s):  
Tareq I. Al-Ma’aiteh ◽  
Oliver Krammer
Keyword(s):  
Apparent Viscosity ◽  
Material Model ◽  
Viscosity Measurement ◽  
Solder Paste ◽  
Material Models ◽  
Stencil Printing ◽  
Content Type ◽  
Shear Rates ◽  
Paste Viscosity ◽  
Measured Viscosity

PurposeThe purpose of this paper is to present the establishment of a computational fluid dynamics model for investigating different non-Newtonian rheological models of solder pastes by simulating solder paste viscosity measurement. A combined material model was established which can follow the measured, apparent viscosity values with lower error.Design/methodology/approachThe model included a parallel plate arrangement of rheometers. The diameter of the plate was 50 mm, whereas the gap between the plates was 0.5 mm. Only one quarter of the plate was modelled to enable using fine enough mesh, while keeping the calculation time low. Non-Newtonian properties were set using user defined function in Ansys, based on the Cross and Carreau–Yasuda material models. The viscosity values predicted by the mathematical models were compared to measured viscosity values of different types of solder pastes.FindingsIt was found that the Cross model predicts the apparent viscosity with a relatively high error (even approximately 50 per cent) at lower shear rates, whereas the Carerau–Yasuda model has higher errors at higher shear rates. The application of the proposed, combined model can result in a much lower error in the apparent viscosity between the calculated and measured viscosity values.Originality/valueThe error of Cross and Carreau–Yasuda material models has not been investigated yet in details. The proposed, combined material model can be applied for subsequent simulations via the described UDF, e.g. in the numerical modelling of the stencil printing. This can result in a more accurate modelling of the stencil printing process, which is inevitable considering the printing of solder paste for today fine-pitch, small size components.

scholarly journals Novel Yeast Bioassay for High-Throughput Screening of Matrix Metalloproteinase Inhibitors

2011 ◽  
Vol 77 (24) ◽  
pp. 8573-8577 ◽  
Author(s):  
Bjoern Diehl ◽  
Thorsten M. Hoffmann ◽  
Nina C. Mueller ◽  
Jens L. Burkhart ◽  
Uli Kazmaier ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Biologically Active ◽  
Yeast Cells ◽  
Mmp Inhibitors ◽  
Content Type ◽  
Yeast Cell Surface ◽  
Mmp Inhibitor ◽  
Wide Range ◽  
Anticancer Treatment

ABSTRACTDiverse malfunctions in the expression and regulation of matrix metalloproteinases (MMPs) are often the cause of severe human diseases, bringing the identification of specific MMP inhibitors into major focus, particularly in anticancer treatment. Here, we describe a novel bioassay based on recombinant yeast cells (Pichia pastoris) that express, deliver, and incorporate biologically active human MMP-2 and MMP-9 at the yeast cell surface. Using Sed1p for cell wall targeting and covalent anchorage, a highly efficient bioassay was established that allows high-throughput screening and subsequent validation of novel MMP inhibitors as potential anticancer drugs. In addition, we developed a straightforward synthesis of a new aspartate-derived MMP inhibitor active in the nM range and bearing an amino functionality that should allow the introduction of a wide range of side chains to modify the properties of these compounds.

scholarly journals Numerical investigation on the effect of solder paste rheological behaviour and printing speed on stencil printing

2020 ◽  
Vol 32 (4) ◽  
pp. 219-223
Author(s):  
Oliver Krammer ◽  
Tareq I. Al-Ma’aiteh ◽  
Balazs Illes ◽  
David Bušek ◽  
Karel Dušek
Keyword(s):  
Viscosity Model ◽  
Calculation Error ◽  
Solder Paste ◽  
Stencil Printing ◽  
Cross Model ◽  
Content Type ◽  
Viscosity Models ◽  
The Cross ◽  
The Difference ◽  
Printing Speed

Purpose The purpose of this paper is to investigate the effect of different viscosity models (Cross and Al-Ma’aiteh) and different printing speeds on the numerical results (e.g. pressure over stencil) of a numerical model regarding stencil printing. Design/methodology/approach A finite volume model was established for describing the printing process. Two types of viscosity models for non-Newtonian fluid properties were compared. The Cross model was fitted to the measurement results in the initial state of a lead-free solder paste, and the parameters of a Al-Ma’aiteh material model were fitted in the stabilised state of the same paste. Four different printing speeds were also investigated from 20 to 200 mm/s. Findings Noteworthy differences were found in the pressure between utilising the Cross model and the Al-Ma’aiteh viscosity model. The difference in pressure reached 33-34% for both printing speeds of 20 and 70 mm/s and reached 31% and 27% for the printing speed of 120 and 200 mm/s. The variation in the difference was explained by the increase in the rates of shear by increasing printing speeds. Originality/value Parameters of viscosity model should be determined for the stabilised state of the solder paste. Neglecting the thixotropic paste nature in the modelling of printing can cause a calculation error of even approximately 30%. By using the Al-Ma’aiteh viscosity model over the stabilised state of solder pastes can provide more accurate results in the modelling of printing, which is necessary for the effective optimisation of this process, and for eliminating soldering failures in highly integrated electronic devices.

scholarly journals High-Throughput Analysis of Gene Function in the Bacterial PredatorBdellovibrio bacteriovorus

mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Miles C. Duncan ◽  
Rebecca K. Gillette ◽  
Micah A. Maglasang ◽  
Elizabeth A. Corn ◽  
Albert K. Tai ◽  
...  
Keyword(s):  
High Throughput ◽  
Gram Negative Bacteria ◽  
Human Pathogens ◽  
High Throughput Analysis ◽  
Bdellovibrio Bacteriovorus ◽  
Gram Negative ◽  
Content Type ◽  
Genetically Engineer ◽  
Wide Range ◽  
Specific Species

ABSTRACTBdellovibrio bacteriovorusis a bacterial predator capable of killing and replicating inside most Gram-negative bacteria, including antibiotic-resistant pathogens. Despite growing interest in this organism as a potential therapeutic, many of its genes remain uncharacterized. Here, we perform a high-throughput genetic screen withB. bacteriovorususing transposon sequencing (Tn-seq) to explore the genetic requirements of predation. Two hundred one genes were deemed essential for growth in the absence of prey, whereas over 100 genes were found to be specifically required for predative growth on the human pathogensVibrio choleraeandEscherichia coliin both planktonic and biofilm states. To further this work, we created an ordered-knockout library inB. bacteriovorusand developed new high-throughput techniques to characterize the mutants by their stage of deficiency in the predator life cycle. Using microscopy and flow cytometry, we confirmed 10 mutants defective in prey attachment and eight mutants defective in prey rounding. The majority of these genes are hypothetical and previously uncharacterized. Finally, we propose new nomenclature to groupB. bacteriovorusmutants into classes based on their stage of predation defect. These results contribute to our basic understanding of bacterial predation and may be useful for harnessingB. bacteriovorusto kill harmful pathogens in the clinical setting.IMPORTANCEBdellovibrio bacteriovorusis a predatory bacterium that can kill a wide range of Gram-negative bacteria, including many human pathogens. Given the global rise of antibiotic resistance and dearth of new antibiotics discovered in the past 30 years, this predator has potential as an alternative to traditional antibiotics. For many years,B. bacteriovorusresearch was hampered by a lack of genetic tools, and the genetic mechanisms of predation have only recently begun to be established. Here, we comprehensively identify and characterize predator genes required for killing bacterial prey, as well as genes that interfere in this process, which may allow us to design better therapeutic predators. Based on our study, we and other researchers may ultimately be able to genetically engineer strains that have improved killing rates, target specific species of prey, or preferentially target prey in the planktonic or biofilm state.

A method for optimizing stencil cleaning time in solder paste printing process

2019 ◽  
Vol 31 (4) ◽  
pp. 233-239 ◽  
Author(s):  
JiangYou Yu ◽  
Le Cao ◽  
Hao Fu ◽  
Jun Guo
Keyword(s):  
Decision Model ◽  
Idle Time ◽  
Homogeneous Markov Chain ◽  
Solder Paste ◽  
Quality Loss ◽  
Stencil Printing ◽  
Discrete State ◽  
Printing Process ◽  
Content Type ◽  
Solder Paste Printing

PurposeStencil cleaning is an important operation in solder paste printing process. Frequent cleaning may interrupt printing process and increase idle time, as well as loss for performing cleaning. This paper aims to propose a method to optimize the stencil cleaning time and reduce unnecessary cleaning operations and losses.Design/methodology/approachThis paper uses a discrete-time, discrete-state homogeneous Markov chain to model the stencil printing performance degradation process, and the quality loss during the stencil printing process is estimated based on this degradation model. A stencil cleaning decision model based on renewal reward theorem is established, and the optimal cleaning time is obtained through a balance between quality loss and the loss on idle time.FindingsA stencil cleaning decision model for solder paste printing is established, and numerical simulation results show that there exists an optimal stencil cleaning time which minimizes the long-term loss.Originality/valueStencil cleaning control is very important for solder paste printing. However, there are very few studies focusing on stencil cleaning control. This research contributes to developing a model to optimize the stencil cleaning time in solder paste printing process.

scholarly journals Endogenous Gibbon Ape Leukemia Virus Identified in a Rodent (Melomys burtoni subsp.) from Wallacea (Indonesia)

2016 ◽  
Vol 90 (18) ◽  
pp. 8169-8180 ◽  
Author(s):  
Niccolò Alfano ◽  
Johan Michaux ◽  
Serge Morand ◽  
Ken Aplin ◽  
Kyriakos Tsangaras ◽  
...  
Keyword(s):  
Southeast Asia ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Leukemia Virus ◽  
Southeast Asian ◽  
Content Type ◽  
Hybridization Capture ◽  
Wide Range ◽  
Gibbon Ape Leukemia Virus ◽  
Koala Retrovirus

ABSTRACTGibbon ape leukemia virus (GALV) and koala retrovirus (KoRV) most likely originated from a cross-species transmission of an ancestral retrovirus into koalas and gibbons via one or more intermediate as-yet-unknown hosts. A virus highly similar to GALV has been identified in an Australian native rodent (Melomys burtoni) after extensive screening of Australian wildlife. GALV-like viruses have also been discovered in several Southeast Asian species, although screening has not been extensive and viruses discovered to date are only distantly related to GALV. We therefore screened 26 Southeast Asian rodent species for KoRV- and GALV-like sequences, using hybridization capture and high-throughput sequencing, in the attempt to identify potential GALV and KoRV hosts. Only the individuals belonging to a newly discovered subspecies ofMelomysburtonifrom Indonesia were positive, yielding an endogenous provirus very closely related to a strain of GALV. The sequence of the critical receptor domain for GALV infection in the IndonesianM. burtonisubsp. was consistent with the susceptibility of the species to GALV infection. The second record of a GALV inM. burtoniprovides further evidence thatM. burtoni, and potentially other lineages within the widespread subfamilyMurinae, may play a role in the spread of GALV-like viruses. The discovery of a GALV in the most western part of the Australo-Papuan distribution ofM. burtoni, specifically in a transitional zone between Asia and Australia (Wallacea), may be relevant to the cross-species transmission to gibbons in Southeast Asia and broadens the known distribution of GALVs in wild rodents.IMPORTANCEGibbon ape leukemia virus (GALV) and the koala retrovirus (KoRV) are very closely related, yet their hosts neither are closely related nor overlap geographically. Direct cross-species infection between koalas and gibbons is unlikely. Therefore, GALV and KoRV may have arisen via a cross-species transfer from an intermediate host whose range overlaps those of both gibbons and koalas. Using hybridization capture and high-throughput sequencing, we have screened a wide range of rodent candidate hosts from Southeast Asia for KoRV- and GALV-like sequences. Only aMelomysburtonisubspecies from Wallacea (Indonesia) was positive for GALV. We report the genome sequence of this newly identified GALV, the critical domain for infection of its potential cellular receptor, and its phylogenetic relationships with the other previously characterized GALVs. We hypothesize thatMelomysburtoni, and potentially related lineages with an Australo-Papuan distribution, may have played a key role in cross-species transmission to other taxa.

Sign in / Sign up

Export Citation Format

Share Document