Precision Jetting of Solder Paste – A Versatile Tool for Small Volume Production

2014 ◽  
Vol 2014 (1) ◽  
pp. 000438-000443 ◽  
Author(s):  
K.-F. Becker ◽  
M. Koch ◽  
S. Voges ◽  
T. Thomas ◽  
M. Fliess ◽  
...  
Keyword(s):  
Process Development ◽  
Droplet Diameter ◽  
Rheological Behaviour ◽  
High Volume ◽  
Electronic System ◽  
High Viscosity ◽  
Solder Paste ◽  
Process Data ◽  
Current Standard ◽  
Conductive Adhesives

During the last years, jetting processes for higher viscosity materials have gained widespread interest in microelectronics manufacturing. Main reasons for this interest are high throughput/productivity of jetting, contactless material deposition, high volume precision and freely designable deposition patterns. In previous studies [i,ii] we have demonstrated the jetability of different resin-based materials, being exemplary for unfilled adhesive, for low viscous Underfill resin and for higher viscosity Glob Top materials. The focus of our previous work was on the dosing of various encapsulants - Underfill material with low viscosity and near Newtonian behaviour and Glob Top resins, being non-Newtonian fluids due to higher matrix viscosity and higher filler content (up to 70 wt %) with resulting increased filer/filler and filler/matrix interaction. During the last years jetting has become widely used and has been applied to the dosing of much more complex materials, combining high viscosity matrix materials with odd shaped and compressive particles. Examples for these materials are conductive adhesives and also solder pastes, where the jetting system developed by Swedish company Mydata set's the current standard for solder paste jetting. In a technological study solder paste jetting using different jetting systems has been investigated in comparison to solder paste dispensing and solder paste printing, especially material rheological behaviour and the correspondence to processability have been evaluated in detail. To illustrate the potential of solder paste jetting as a flexible and powerful tool for electronic system prototyping, a test vehicle has been designed, containing areas for SMD soldering and for process reproducibility. To determine process quality not only basic process data on droplet diameter, resulting material depot size and positioning accuracy have been evaluated, but also statistical means have been employed to determine process homogeneity and stability depending on the respective parameter set. Summarized this paper gives an insight into solder jet process development and describes material rheology demands and limitations and thus allows the optimized use of advanced solder jetting technology for electronics assemblies.

Precision Jetting of Glob Top Materials – a methodology for process optimization

2012 ◽  
Vol 2012 (1) ◽  
pp. 000351-000358 ◽  
Author(s):  
K.-F. Becker ◽  
M. Koch ◽  
J. Bauer ◽  
T. Braun ◽  
R. Aschenbrenner ◽  
...  
Keyword(s):  
High Speed ◽  
Process Development ◽  
Droplet Diameter ◽  
High Volume ◽  
High Viscosity ◽  
Process Data ◽  
Camera System ◽  
Ceramic Substrates ◽  
Whole Process ◽  
Material Deposition

During the last years, jetting processes for higher viscosity materials have gained widespread interest in microelectronics manufacturing. Main reasons for this interest are high throughput/productivity of jetting, contactless material deposition, high volume precision and freely designable deposition patterns. In previous studies we have demonstrated the jetability of different resin-based materials, being exemplary for unfilled adhesive, for low viscous Underfill resin and for higher viscosity Glob Top materials. The focus of our previous work was on the dosing of Underfill material, where this study is dealing with more complex materials – Glob Top resins. These materials are non-Newtonian fluids - the flow curves of the filled materials can be described by models of Cross or Herschel/Bulkey. Furthermore, highly filled and paste-like mixtures show a significant time dependency of formation of structural equilibrium after deformation, so process development needs to take this into account, so detailed material analysis is described within this study. To illustrate the potential of jetting as a flexible and powerful tool for Chip on Board encapsulation, both, simple test-structures (dots, lines, dams) but also more complex demonstrators have been assembled using wire bonded ICs on ceramic substrates and encapsulants showing viscosities ranging from 10 Pas to > 100 Pas. Not only basic process data on droplet diameter, resulting material depot size and positioning accuracy have been evaluated, but also statistical means have been employed to determine process homogeneity and stability depending on the respective parameter set. Additionally, the whole process was followed by a high-speed camera system, providing detailed information on actual jetting behaviour during droplet release, flight and impact. Summarized this paper gives a detailed insight into jet process development for high viscosity Glob Top materials and describes process design rules and limitations and thus allows the optimized use of advanced jetting technology for Chip on Board assemblies.

Understanding the Effects of Process Parameters to Compensate for Substrate Warpage in Chip on Flex (CoF) Assembly Using Conventional Reflow

2019 ◽  
Vol 2019 (1) ◽  
pp. 000428-000433
Author(s):  
Varun Soman ◽  
Vikram Venkatadri ◽  
Mark D. Poliks
Keyword(s):  
Substrate Surface ◽  
Cost Effective ◽  
High Volume ◽  
High Yield ◽  
Solder Paste ◽  
Conductive Adhesives ◽  
Process Yield ◽  
Aperture Diameter ◽  
Solder Balls ◽  
Aperture Opening

Abstract Mounting rigid silicon (Si) die on a flex substrate presents a unique set of challenges. Substrate surface flatness and warpage of the flex substrate before and during thermal processing being two of the biggest issues. Various processes such as thermocompression bonding using anisotropic conductive films and thermosonic bonding using non-conductive adhesives have been shown to be effective for chip on flex (CoF) applications. However, these processes sacrifice process throughput and are less cost effective. Hence these methods may not be suitable for high volume manufacturing (HVM). For this reason, a process that is suitable for HVM and uses standard reflow processes and equipment is highly desirable. This works presents preliminary results for such a CoF process that uses a simple fixture and standard processes, materials and equipment. CoF process for Si die using two types of interconnects, solder balls or Cu pillars, was developed. Solder paste was stencil printed before pick and place of the Si die to offset the lack of flex substrate flatness and substrate warpage. The effect of stencil aperture diameter and placement force on process yield and stand-off height was studied. It was demonstrated that high yield can be obtained with a process that uses wider stencil aperture opening for both type of interconnects investigated. It was also observed that the placement force did not have any effect on process yield or stand-off height. The process can also be easily scaled up for HVM.

scholarly journals Research and Development of a 3D Jet Printer for High-Viscosity Molten Liquids

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 554
Author(s):  
Yang Yang ◽  
Shoudong Gu ◽  
Jianfang Liu ◽  
Hongyu Tian ◽  
Qingqing Lv
Keyword(s):  
Liquid Velocity ◽  
New Technology ◽  
Droplet Diameter ◽  
Average Diameter ◽  
High Viscosity ◽  
Taper Angle ◽  
Voltage Difference ◽  
Low Viscosity ◽  
Cooling Mechanism ◽  
Molten Liquid

Micro-droplet jetting manufacture is a new 3D printing technology developed in recent years. Presently, this new technology mainly aims at ejecting a low-viscosity medium. Therefore, a device for ejecting high-viscosity molten liquid is designed by analyzing the injection principle of high-viscosity molten liquid. Initially, the cooling mechanism is designed to overcome the defect that the piezoelectric stacks cannot operate in high-temperature conditions. Thereafter, the mathematical model of the liquid velocity in the nozzle is derived, and the factors influencing injection are verified by Fluent. Subsequently, a prototype of the jet printer is fabricated, and the needle velocity is tested by the laser micrometer; the relationship between voltage difference and the needle velocity is also obtained. The experimental results matched the theoretical model well, showing that the voltage difference, needle radius, nozzle diameter, and taper angle are closely related to the injection performance of the 3D jet printer. By using a needle with a radius of 0.4 mm, a nozzle with a diameter of 50 μm, a taper angle of 90°, a supply pressure of 0.05 Mpa, and a voltage difference of 98 V, a molten liquid with a viscosity of 8000 cps can be ejected with a minimum average diameter of 275 μm, and the variation of the droplet diameter is within ±3.8%.

scholarly journals Design of a Tri-Axial Surface Micromachined MEMS Vibrating Gyroscope

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2822
Author(s):  
Rocco Crescenzi ◽  
Giuseppe Vincenzo Castellito ◽  
Simone Quaranta ◽  
Marco Balucani
Keyword(s):  
Integrated Circuit ◽  
Large Scale ◽  
Manufacturing Industry ◽  
Low Cost ◽  
High Volume ◽  
Electronic System ◽  
Sensors And Actuators ◽  
Micro Electro Mechanical Systems ◽  
Final Assembly ◽  
Comb Drives

Gyroscopes are one of the next killer applications for the MEMS (Micro-Electro-Mechanical-Systems) sensors industry. Many mature applications have already been developed and produced in limited volumes for the automotive, consumer, industrial, medical, and military markets. Plenty of high-volume applications, over 100 million per year, have been calling for low-cost gyroscopes. Bulk silicon is a promising candidate for low-cost gyroscopes due to its large scale availability and maturity of its manufacturing industry. Nevertheless, it is not suitable for a real monolithic IC integration and requires a dedicated packaging. New designs are supposed to eliminate the need for magnets and metal case package, and allow for a real monolithic MEMS-IC (Integrated Circuit) electronic system. In addition, a drastic cost reduction could be achieved by utilizing off-the-shelf plastic packaging with lead frames for the final assembly. The present paper puts forward the design of a novel tri-axial gyroscope based on rotating comb-drives acting as both capacitive sensors and actuators. The comb-drives are comprised of a single monolithic moving component (rotor) and fixed parts (stators). The former is made out of different concentrated masses connected by curved silicon beams in order to decouple the motion signals. The sensor was devised to be fabricated through the PolyMUMPs® process and it is intended for working in air in order to semplify the MEMS-IC monolithic integration.

Challenges of Data Acquisition and Analysis for Characteristics-Driven and Metrology-Based Optimization of Milling Process Development

2014 ◽  
Vol 704 ◽  
pp. 233-238
Author(s):  
Laura Niendorf ◽  
Markus Grosse Boeckmann ◽  
Robert Schmitt
Keyword(s):  
Data Mining ◽  
Process Development ◽  
Early Stage ◽  
Milling Process ◽  
Production Environment ◽  
Process Data ◽  
Related Data ◽  
Research Activities ◽  
Future Production ◽  
Set Up

The research and practical use of data and data-mining in production environment is still at an early stage. Although almost every manufacturing company collects a lot of process and product related data they often do neither use nor deploy this data in order to optimize or even analyze their production processes. The acquisition of process data brings several advantages. On the one hand the implicit knowledge is permanently stored and on the other hand it is possible to learn from previous process failures. The acquired knowledge could then be applied to all future production tasks. Although many research activities can be observed since the late 90s, none of them managed the transfer to practical usage. In order to encourage the practical transfer of data-mining in production environment this paper presents a metrology-based test set-up and therewith arising challenges when consistently acquiring and processing inhomogeneous process, product and machine data. For the experimental set-up, on-machine metrology systems were developed and integrated into a 5-axis milling machine to gain much significant data.

scholarly journals Pattern of care and effectiveness of treatment for glioblastoma patients in the real world: Results from a prospective population-based registry. Could survival differ in a high-volume center?

2014 ◽  
Vol 1 (4) ◽  
pp. 166-171 ◽  
Author(s):  
Alba A. Brandes ◽  
Enrico Franceschi ◽  
Mario Ermani ◽  
Alicia Tosoni ◽  
Fiorenzo Albani ◽  
...  
Keyword(s):  
Methylation Status ◽  
High Volume ◽  
Population Based ◽  
Phase Iii ◽  
Treatment Center ◽  
Current Standard ◽  
Pattern Of Care ◽  
Phase Iii Trials ◽  
Emilia Romagna Region ◽  
High Volume Center

Abstract Background As yet, no population-based prospective studies have been conducted to investigate the incidence and clinical outcome of glioblastoma (GBM) or the diffusion and impact of the current standard therapeutic approach in newly diagnosed patients younger than aged 70 years. Methods Data on all new cases of primary brain tumors observed from January 1, 2009, to December 31, 2010, in adults residing within the Emilia-Romagna region were recorded in a prospective registry in the Project of Emilia Romagna on Neuro-Oncology (PERNO). Based on the data from this registry, a prospective evaluation was made of the treatment efficacy and outcome in GBM patients. Results Two hundred sixty-seven GBM patients (median age, 64 y; range, 29–84 y) were enrolled. The median overall survival (OS) was 10.7 months (95% CI, 9.2–12.4). The 139 patients ≤aged 70 years who were given standard temozolomide treatment concomitant with and adjuvant to radiotherapy had a median OS of 16.4 months (95% CI, 14.0–18.5). With multivariate analysis, OS correlated significantly with KPS (HR = 0.458; 95% CI, 0.248–0.847; P = .0127), MGMT methylation status (HR = 0.612; 95% CI, 0.388–0.966; P = .0350), and treatment received in a high versus low-volume center (HR = 0.56; 95% CI, 0.328–0.986; P = .0446). Conclusions The median OS following standard temozolomide treatment concurrent with and adjuvant to radiotherapy given to (72.8% of) patients aged ≤70 years is consistent with findings reported from randomized phase III trials. The volume and expertise of the treatment center should be further investigated as a prognostic factor.

An automated electronic system for managing radiation treatment plan peer review reduces missed reviews at a large, high-volume academic center

2016 ◽  
Vol 6 (6) ◽  
pp. e307-e314 ◽  
Author(s):  
Peter E. Gabriel ◽  
Kristina D. Woodhouse ◽  
Alexander Lin ◽  
Jarod C. Finlay ◽  
Richard B. Young ◽  
...  
Keyword(s):  
Peer Review ◽  
Radiation Treatment ◽  
Treatment Plan ◽  
High Volume ◽  
Electronic System ◽  
Academic Center

Rheological characterization of non-Brownian suspensions based on structure kinetics

2018 ◽  
Vol 30 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Kurian J. Vachaparambil ◽  
Gustaf Mårtensson ◽  
Lars Essén
Keyword(s):  
Rheological Behaviour ◽  
Functional Materials ◽  
Kinetics Model ◽  
Test Fluid ◽  
Solder Paste ◽  
Content Type ◽  
Proposed Model ◽  
Breakdown Rates ◽  
Structural Breakdown ◽  
Parameter Values

Purpose The purpose of the paper is to develop a methodology to characterize the rheological behaviour of macroscopic non-Brownian suspensions, like solder paste, based on microstructural evolution. Design/methodology/approach A structure-based kinetics model, whose parameters are derived analytically based on assumptions valid for any macroscopic suspension, is developed to describe the rheological behaviour of a given fluid. The values of the parameters are then determined based on experiments conducted at a constant shear rate. The parameter values, obtained from the model, are then adjusted using an optimization algorithm using the mean deviation from experiments as the cost function to replicate the measured rheology. A commercially available solder paste is used as the test fluid for the proposed method. Findings The initial parameter values obtained through the analytical model indicates a structural breakdown that is much slower than observations. But optimizing the parameter values, especially the ones associated with the structural breakdown, replicates the thixotropic behaviour of the solder paste reasonably well, but it fails to capture the structure build-up during the three interval thixotropy test. Research limitations/implications The structural kinetics model tends to under-predict the structure build-up rate. Practical implications This study details a more realistic prediction of the rheological behaviour of macroscopic suspensions like solder paste, thermal interface materials and other functional materials. The proposed model can be used to characterize different solder pastes and other functional fluids based on the structure build-up and breakdown rates. The model can also be used as the viscosity definitions in numerical simulations instead of simpler models like Carreau–Yasuda and cross-viscosity models. Originality/value The rheological description of the solder paste is critical in determining its validity for a given application. The methodology described in the paper provides a better description of thixotropy without relying on the existing rheological measurements or the behaviour predicted by a standard power-law model. The proposed model can also provide transient viscosity predictions when shear rates vary in time.

scholarly journals Use of a superspreader adjuvant to reduce spray application volumes on avocados

2004 ◽  
Vol 57 ◽  
pp. 266-270 ◽  
Author(s):  
R.E. Gaskin ◽  
D.W. Manktelow ◽  
S.J. Skinner ◽  
G.S. Elliott
Keyword(s):  
High Volume ◽  
Spray Application ◽  
Application Technology ◽  
Current Standard ◽  
Standard Practice ◽  
Reduced Volume ◽  
Spray Volume ◽  
Copper Fungicide ◽  
Current Standard Practice

This study was undertaken to determine whether pesticide spray volumes on avocados could be substantially lowered with the use of a superspreader adjuvant and to identify an optimum spray volume and adjuvant rate to maximise spray retention Groundbased airblast applications of copper fungicide were made to 45 year old fruitbearing trees Spray retention was quantified on foliage and fruit at a range of canopy heights and positions Spray deposits on foliage were maintained or improved using reduced volume sprays (500700 litres/ha) incorporating the superspreader DuWett compared to the standard high volume treatment (2500 litres/ ha) The adjuvant maintained total spray deposits on fruit using 35 times less spray volume than is current standard practice There was no evidence of phytotoxicity on any fruit or foliage due to adjuvant sprays The study highlighted deficiencies in current spray application technology used on avocados

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