Initial investigations into low-cost ultra-fine pitch solder printing process based on innovative laser printing technology

1999 ◽  
Vol 22 (4) ◽  
pp. 303-307
Author(s):  
A. Walker ◽  
D.F. Baldwin
2014 ◽  
Vol 2 (48) ◽  
pp. 20916-20922 ◽  
Author(s):  
Haibo Hu ◽  
Kun Zhang ◽  
Shuxin Li ◽  
Shulin Ji ◽  
Changhui Ye

The combination of laser printing technology and anin situelectropolymerization approach enables the fabrication of flexible, in-plane, and all-solid-state micro-supercapacitors with low-cost.


Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 474 ◽  
Author(s):  
Bei Wang ◽  
Manuel Baeuscher ◽  
Xiaodong Hu ◽  
Markus Woehrmann ◽  
Katharina Becker ◽  
...  

A novel capacitive sensor for measuring the water-level and monitoring the water quality has been developed in this work by using an enhanced screen printing technology. A commonly used environment-friendly conductive polymer poly(3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) for conductive sensors has a limited conductivity due to its high sheet resistance. A physical treatment performed during the printing process has reduced the sheet resistance of printed PEDOT:PSS on polyethylenterephthalat (PET) substrate from 264.39 Ω/sq to 23.44 Ω/sq. The adhesion bonding force between printed PEDOT:PSS and the substrate PET is increased by using chemical treatment and tested using a newly designed adhesive peeling force test. Using the economical conductive ink PEDOT:PSS with this new physical treatment, our capacitive sensors are cost-efficient and have a sensitivity of up to 1.25 pF/mm.


1999 ◽  
Author(s):  
Jianbiao Pan ◽  
Gregory L. Tonkay

Abstract Stencil printing has been the dominant method of solder deposition in surface mount assembly. With the development of advanced packaging technologies such as ball grid array (BGA) and flip chip on board (FCOB), stencil printing will continue to play an important role. However, the stencil printing process is not completely understood because 52–71 percent of fine and ultra-fine pitch surface mount assembly defects are printing process related (Clouthier, 1999). This paper proposes an analytical model of the solder paste deposition process during stencil printing. The model derives the relationship between the transfer ratio and the area ratio. The area ratio is recommended as a main indicator for determining the maximum stencil thickness. This model explains two experimental phenomena. One is that increasing stencil thickness does not necessarily lead to thicker deposits. The other is that perpendicular apertures print thicker than parallel apertures.


Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Timothy Campbell ◽  
Jonathan Stone ◽  
Arun Parmar ◽  
Edward Vates ◽  
Amrendra Miranpuri

Introduction: While stroke remains a leading cause of death and disability, recent advances in endovascular technology an important opportunity to make a significant impact in clinical outcomes. However, training opportunities are rare, preventing dissemination of these techniques. Hands-on training is further complicated by the critical time to therapy associated with stroke treatment. This physical simulator was built for neurosurgical residents and fellows to practice mechanical thrombectomy. Methods: A simplified virtual model of the anterior cerebral circulation was created based on patient imaging. This luminal model was 3D printed using flexible filament and attached to a guide catheter at the proximal carotid to provide endovascular access and an IV tube at the distal M2 branches to permit outflow. A 7Fr sheath was also connected at the anterior cerebral artery to permit placement of a simulated clot model and simulate a proximal M1 occlusion. This entire construct was placed into a container of polyvinyl alcohol (PVA) and after crosslinking the flexible print was removed. Results: Using 3D printing technology and polymer hydrogels, a low-cost, high fidelity stroke model was achieved. Despite its simplified anatomy, the model permitted realistic wire and catheter navigation through the different segments of the internal carotid and middle cerebral arteries. The ACOM sheath provided a convenient method to reliably place an embolism and created a life-like proximal M1 occlusion. Recanalization was performed using the solumbra technique, which is used in live-patient cases. Conclusions: This model demonstrated proof of concept for a mechanical thrombectomy simulation. The angiographic profile and response to endovascular tools created a training experience similar to live endovascular procedures. As the model is perfected visually and mechanically, next steps are to perform validation studies and create a training curriculum.


1992 ◽  
Vol 266 ◽  
Author(s):  
Mahendra R. Doshi ◽  
John H. Klungness

AbstractAdvances in printing technology have posted serious problems for the deinking industry. When ink is fused, as in laser printing and the photocopy process, when water resistant binders are included in coatings or ink formulations, and when varnishes are applied to printed papers, conventional methods fail to disperse inks and specks. The objective of this article is to review different approaches available for removing these inks and specks. Copying processes, coatings, and varnishing processes are discussed prior to discussing deinking and speck removal processes.Deinking ideally involves intense mechanical, chemical, and thermal action needed to detach non-dispersible inks from fibers. The detached ink is then removed by screens, cleaners, washing, and the flotation process. If higher brightness and cleanliness are desired, high-consistency dispersion, together with bleaching or the use of agglomerating chemicals (for photocopy-laser toners), may have to be considered. For coating specks, increasing the pH. increased pulping time, and removal by cleaners are typically used to reduce the number and size of specks. Varnish specks can be more difficult to remove than coating specks, as they are resistant to chemical treatment and are not easily removed by centrifugal cleaners. Flotation removal holds promise for removing varnish specks if particle size is controlled.


2018 ◽  
Vol 2018 (1) ◽  
pp. 000665-000671
Author(s):  
Jianbiao Pan ◽  
Malcolm Keif ◽  
Joshua Ledgerwood ◽  
Xiaoying Rong ◽  
Xuan Wang

Abstract The lightweight and bendable features of printed flexible electronics are increasingly attractive. Currently stretchable silver inks are formulated for wide traces, typically larger than 2 mm. To attach ultra-thin silicon chips that have fine pitch onto printed organic substrate, it is necessary to print fine trace width/space that matches the pitch of the chips, which may be less than 200 microns. This paper presents the development and optimization of the screen printing process for printing stretchable silver ink onto stretchable thermoplastic polyurethane (TPU) substrate. A test vehicle was designed including 50 μm/5 mm (line width/line length) to 350 μm/35 mm lines (at 4 biases). The stretchable ink selected was DuPont PE 873 and Dupont's PE 5025 ink (non-stretchable conductive flake silver) was used as a “control” to baseline the printing process. The substrate used was Bemis TPU ST604. The experiment was done on a DEK Horizon 03i printer. A DEK squeegee 200 (Blue) and a DEK 265 flood bar (200 mm) were used. A 2-level factorial design with three replicates was selected to investigate the effect of process parameters on the quality of prints. The quality of the prints is characterized by 1) resistance of traces, 2) sheet resistance, 3) z-axis height, and 4) trace width/spacing. We observed significant noise in the z-axis printed silver ink height measured by profilometry and concluded z-axis height is not a good response variable for characterizing screen printing stretchable silver ink onto TPU substrate, mainly due to high roughness of the TPU substrate. We proposed calculated sheet resistance based on the measured resistance value, trace width, and trace length, which can replace trace height measurements on rough profile substrates. We found that squeegee pressure and emulsion thickness have statistically significant effects on calculated sheet resistance of print traces while print speed does not have statistically significant effects. In our experiment setting levels, the lower the squeegee pressure, the lower the calculated sheet resistance that is achieved. The emulsion with higher emulsion over mesh (EOM) is better than the emulsion with lower EOM since it can achieve lower sheet resistance. After optimizing the screen printing process, we were able to print 100 μm (4 mils) trace width and spacing with high consistency.


2015 ◽  
Vol 2015 (1) ◽  
pp. 000379-000385 ◽  
Author(s):  
Brett Sawyer ◽  
Yuya Suzuki ◽  
Zihan Wu ◽  
Hao Lu ◽  
Venky Sundaram ◽  
...  

This paper describes the design, fabrication, and characterization of a two-metal layer RDL structure at 40 um pitch on thin glass interposers. Such an RDL structure is targeted at 2.5D glass interposer packages to achieve up to 1 TB/s die-to-die bandwidth and off-interposer data rates greater than 400 Gb/s, driven by consumer demand of online services for mobile devices. Advanced packaging architectures including 2.5D and 3D interposers require fine line lithography beyond the capabilities of current organic package substrates. Although silicon interposers fabricated using back-end-of-line processes can achieve these RDL wiring densities, they suffer from high electrical loss and high cost. Organic interposers with high wiring densities have also been demonstrated recently using a single sided thin film process. This paper goes beyond silicon and organic interposers in demonstrating fine pitch RDL on glass interposers fabricated by low cost, double sided, and panel-scalable processes. The high modulus and smooth surface of glass helps to achieve lithographic pitch close to that of silicon. Furthermore, the low loss tangent of glass helps in reducing dielectric losses, thus improving high-speed signal propagation. A semi-additive process flow and projection excimer laser ablation was used to fabricate two-metal layer RDL structures and bare glass RDL layers. A minimum of 3 um lithography and 20 um mico-via pitch was achieved. High-frequency characterization of these RDL structures demonstrated single-ended insertion losses of −0.097 dB/mm at f = 1 GHz and differential insertion losses of −0.05 dB/mm at f = 14 GHz.


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