Fine Grinding of Silicon Wafers: Grinding Marks

2002 ◽  
Author(s):  
Z. J. Pei ◽  
Alan Strasbaugh
Keyword(s):  
Silicon Wafer ◽  
Low Cost ◽  
Base Material ◽  
Silicon Wafers ◽  
High Yield ◽  
Manufacturing Processes ◽  
High Quality ◽  
Fine Grinding ◽  
Etched Silicon

In order to ensure high quality chips with high yield, the base material, semiconductor wafers (over 90% are silicon), must have superior quality. It is critically important to develop new manufacturing processes that allow silicon wafer manufacturers to produce high quality wafers at a reasonably low cost. A newly patented technology—fine grinding of etched silicon wafers—has great potential to manufacture very flat silicon wafers more cost-effectively. This paper presents an investigation of grinding marks in fine grinding. The investigation covers (1) nature of grinding marks, (2) factors that have effects on grinding marks, and (3) approaches to reduce grinding marks. Varying chuck speed during grinding operation is shown to be a very effective approach to reduce grinding marks. Conclusions from this study have direct impacts to the silicon wafer industry.

scholarly journals A Comparative Review Study on the Manufacturing Processes of Composite Grid Structures

10.30544/98 ◽  
2015 ◽  
Vol 21 (2) ◽  
pp. 79-88
Author(s):  
A. Fadavian ◽  
A. Davar ◽  
J. E. Jam ◽  
S. H. Taghavian
Keyword(s):  
Low Cost ◽  
Aerospace Industry ◽  
Filament Winding ◽  
Manufacturing Processes ◽  
High Quality ◽  
Fiber Placement ◽  
Comparative Review ◽  
Review Study ◽  
Composite Grid ◽  
Curing Method

Filament winding and fiber placement are low-cost, fast, and suitable processes for manufacturing composite grid structures. Resulted structures are high quality products. They have the advantage of carrying heavy structural loads as well as light structural weight. Composite Grid Structures (CGS) are manufactured with varying geometries such as circular (cylindrical and conic) and flat. They are applied in hightech industries including aerospace industry. In this paper, the manufacturing processes of these structures and their various aspects (including winding method, mandrel material and curing method) are reviewed and compared in detail.

The Role of Just‐In‐Time in Supply Chain Management

2000 ◽  
Vol 11 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Robert J. Vokurka ◽  
Rhonda R. Lummus
Keyword(s):  
Low Cost ◽  
New Product ◽  
Competitive Environment ◽  
Just In Time ◽  
Manufacturing Processes ◽  
High Quality ◽  
Chain Management ◽  
Product Innovations ◽  
Technological Developments

In today's competitive environment, markets are becoming more international, dynamic, and customer‐driven. Customers are demanding more variety, better quality and service, including both reliability and faster delivery. Technological developments are occurring at a faster pace, resulting in new product innovations and improvements in manufacturing processes. The resulting competitive environment requires low cost, high quality products in increasing varieties. These changes have instigated changes in business and manufacturing strategies.

Experimental Investigations of Silicon Wafer Grinding

2007 ◽  
Vol 329 ◽  
pp. 361-366
Author(s):  
J.H. Liu ◽  
Zhi Jian Pei ◽  
Graham R. Fisher
Keyword(s):  
Integrated Circuits ◽  
Silicon Wafer ◽  
Silicon Wafers ◽  
Experimental Investigations ◽  
High Quality ◽  
The Third ◽  
Grinding Processes ◽  
Grinding Parameters ◽  
The Wire ◽  
Sawing Process

The majority of integrated circuits are built on silicon wafers. To manufacture high-quality silicon wafers, a series of processes are needed. After a wire sawing process slices silicon ingots into wafers, grinding processes can be used to flatten the sliced wafers. This paper reports three experimental investigations on wafer grinding. The first investigation was to study the effectiveness of soft-pad grinding in removing the wire-sawing induced waviness. The second was to explore the capability of grinding in achieving super flatness. The third was to study the effects of grinding parameters on wafer flatness.

Drilling of Microholes on Silicon Wafer With Ultrasonic Workpiece Holder

2008 ◽  
Author(s):  
Chuan-Yu Tsui ◽  
Chia-Che Wu ◽  
Ming-Chyuan Lu ◽  
Chi-Feng Huang
Keyword(s):  
Silicon Wafer ◽  
Ultrasonic Vibration ◽  
High Efficiency ◽  
Silicon Wafers ◽  
High Quality ◽  
Edge Chipping ◽  
Machining Quality ◽  
Hard And Brittle Materials ◽  
Series Of Experiments ◽  
Micro Tools

This paper presents a study to improve machining quality concerning the method of drilling ceramics and other hard and brittle materials such as silicon wafers. Instead of making the drill vibrate by the ultrasonic actuator, a new design of PZT-driving ultrasonic workpiece wafer holder is proposed to ensure the high quality, high efficiency and longer life for micro tools in drilling the silicon wafer. In this paper, ultrasonic workpiece holders are first designed by FEA and fabricated experimentally. Then, the ultrasonic holders is used for a series of experiments under different vibration conditions to examine the behavior of drilled hole accuracy, and edge chipping on the drilled hold surface. Also, the behavior of tool during ultrasonic vibration of holder is examined experimentally. The result demonstrates the ultrasonic workpiece holder could enhance the quality and efficiency for drilling silicon wafers.

scholarly journals Graphene Quantum Dots with High Yield and High Quality Synthesized from Low Cost Precursor of Aphanitic Graphite

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 375 ◽  
Author(s):  
Shuling Shen ◽  
Junjie Wang ◽  
Zhujun Wu ◽  
Zheng Du ◽  
Zhihong Tang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Low Cost ◽  
Graphene Quantum Dots ◽  
High Strength ◽  
High Yield ◽  
Average Thickness ◽  
High Quality ◽  
Graphene Oxide Quantum Dots ◽  
2D Nanosheets ◽  
First Time

It is difficult to keep the balance of high quality and high yield for graphene quantum dots (GQDs). Because the quality is uncontrollable during cutting large 2D nanosheets to small 0D nanodots by top-down methods and the yield is low for GQDs with high quality obtained from bottom-up strategy. Here, aphanitic graphite (AG), a low-cost graphite contains a large amount of small graphite nanocrystals with size of about 10 nm is used as the precursor of graphene oxide quantum dots (GO-QDs) for the first time. GO-QDs with high yield and high quality were successfully obtained directly by liquid phase exfoliating AG without high strength cutting. The yield of these GO-QDs can reach up to 40 wt. %, much higher than that obtained from flake graphite (FG) precursor (less than 10 wt. %). The size of GO-QDs can be controlled in 2–10 nm. The average thickness of GO-QDs is about 3 nm, less than 3 layer of graphene sheet. Graphene quantum dots (GQDs) with different surface properties can be easily obtained by simple hydrothermal treatment of GO-QDs, which can be used as highly efficient fluorescent probe. Developing AG as precursor for GQDs offers a way to produce GQDs in a low-cost, highly effective and scalable manner.

scholarly journals An optimized method to obtain high-quality RNA from different tissues in Lilium davidii var. unicolor

2021 ◽  
Author(s):  
Chunlei Wang ◽  
Xuemei Hou ◽  
Nana Qi ◽  
Changxia Li ◽  
Yanyan Luo ◽  
...  
Keyword(s):  
Low Cost ◽  
Rna Extraction ◽  
Rna Isolation ◽  
Extraction Methods ◽  
High Yield ◽  
Rna Seq ◽  
High Quality ◽  
Ctab Method ◽  
Different Tissues ◽  
Lilium Davidii

Abstract Background: The high quality, high yield and purity RNA samples are essential for subsequent molecular experiments such as RT-PCR, qPCR and RNA-seq. However, harvest high quality RNA samples from different tissues in Lilium davidii var. unicolor is a great challenge due to its polysaccharides, polyphenols and other secondary metabolites. In this study, three RNA extraction methods, namely modified TRIzol method, Kit and CTAB methods were reported to obtain the total RNA from Lilium davidii var. unicolor, and the efficient RNA extraction protocol (modified TRIzol method) was described. Results: A Nano drop spectrophotometer and 1% gel electrophoresis were used to detect the RNA quality and integrity. Compared with Kit and CTAB methods, the higher RNA concentrations from different tissues were obtained and the A260/280 ratios of RNA samples were ranged from1.97 to 2.27 when using the modified TRIzol method. None of intact RNA bands were gained from the modified CTAB method, indicating that the RNA samples isolation were degraded. As a result of the modified TRIzol method, the RNA samples in the different tissues from Lilium presented clear 28S and 18S bands.Conclusions: Here, modified TRIzol method is an easy, efficient, and low-cost method for RNA isolation from Lilium davidii var. unicolor. Thus, modified TRIzol method is sufficient to gain eligible RNA to support further molecular experiments in Lilium davidii var. unicolor.

A Low-Cost, High Quality MRI Breast Scanner Using Prepolarization

1999 ◽  
Author(s):  
Albert Macovski
Keyword(s):  
Low Cost ◽  
High Quality

Visible Light Assisted Hantzsch Reaction: Synthesis of Polycyclic Dihydropyridines

2019 ◽  
Vol 16 (8) ◽  
pp. 676-682
Author(s):  
Ankusab Noorahmadsab Nadaf ◽  
Kalegowda Shivashankar
Keyword(s):  
Reaction Time ◽  
Light Intensity ◽  
Ammonium Acetate ◽  
Low Cost ◽  
Aromatic Aldehydes ◽  
Light Irradiation ◽  
High Yield ◽  
Short Reaction Time ◽  
Green Protocol ◽  
Dihydropyridine Derivatives

The polycyclic dihydropyridine nucleus represents the heterocyclic system of invaluable core motifs with wide applications in chemical, biological and physical properties. Although this kind of compounds have been extensively synthesized by other groups, the synthesis of these compounds under CFL light intensity were not explored. The synthesis of polycyclic dihydropyridine derivatives were achieved through the reaction of 4-hydroxycoumarin, aromatic aldehydes and ammonium acetate under CFL light irradiation conditions. A series of polycyclic dihydropyridine derivatives were prepared under CFL light irradiation conditions with high yield, short reaction time, ambient condition and without the use of catalyst. The results displayed an efficient method for the synthesis of polycyclic dihydropyridine derivatives. Clean profile, short reaction time, low cost and use of CFL light intensity instead of catalyst making it a genuinely green protocol.

Using Low Temperature, Cost-effective and Green Methods to Carbon Nanohorn Synthesis

2019 ◽  
Vol 9 (2) ◽  
pp. 157-160
Author(s):  
Ali Hasani
Keyword(s):  
Laser Ablation ◽  
Melting Point ◽  
Palm Olein ◽  
Arc Discharge ◽  
Low Cost ◽  
The Other ◽  
High Yield ◽  
Reaction Field ◽  
Carbon Nanohorns ◽  
Graphite Rod

Background: Laser ablation method has high-yield and pure SWCNHs. On the other hand, arc discharge methods have low-cost production of SWCNHs. However, these techniques have more desirable features, they need special expertness to use high power laser or high current discharge that either of them produces very high temperature. As for the researches, the temperatures of these techniques are higher than 4727°C to vaporize the graphite. So, to become aware of the advantages of SWCNHs, it is necessary to find a new way to synthesize SWCNHs at a lower temperature. In other words, reaction field can be expandable at a moderate temperature. This paper reports a new way to synthesize SWCNHs at an extremely reduced temperature. Methods: According to this study, the role of N2 is the protection of the copper holder supporting the graphite rod by increasing heat transfer from the holder. After the current of 70 A was supplied to the system, the temperature of graphite rod was raised to 1600°C. It is obvious that this temperature is somehow higher than the melting point of palladium, 1555°C, and much lower than graphite melting point, 3497°C. Results: Based on the results, there are transitional precursors simultaneous with the SWCNHs. This composition can be created by distortion of the primary SWCNTs at the higher temperature. Subsequently, each SWCNTs have a tendency to be broken into individual horns. With increasing the concentration of the free horns, bud-like SWCNHs can be produced. Moreover, there are individual horns almost separated from the mass of single wall carbon nanohorns. This structure is not common in SWCNHs synthesized by the usual method such as arc discharge or laser ablation. Through these regular techniques, SWCNHs are synthesized as cumulative particles with diameters about 30-150 nm. Conclusion: A simple heating is needed for SWCNTs transformation to SWCNHs with the presence of palladium as catalyst. The well-thought-out mechanism for this transformation is that SWCNTs were initially changed to highly curled shape, and after that were formed into small independent horns. The other rout to synthesize SWCNHs is the pyrolysis of palm olein at 950°C with the assistance of zinc nitrate and ferrocene. Palm olein was used as a promising, bio-renewable and inexpensive carbon source for the production of carbon nanohorns.

Sign in / Sign up

Export Citation Format

Share Document