Dicing challenges in microelectronics and micro electro-mechanical systems (MEMS)

 Both in semiconductor and micro electro-mechanical systems (MEMS) technology, a back end machining process is detaching the individual components by dicing the wafer into chips. To maximize the wafer surface available for integrated circuits or MEMS devices, the street width between the component structures has to be kept at a minimum. Therefore, there is a continuous thrust to minimize edge chipping as well as reduce the dicing wheel width. Furthermore, the dicing process may induce subsurface damages and microcracks particularly detrimental for packaging technology like flip chip technology, putting strain on the chip. Reducing the feed rate will result in a cutting mechanism which not only minimizes edge chip formation but also microcrack. By using gang wheels, the productivity may be maintained despite a lower feed rate.     

A general purpose task queueing mechanism for small machines

A general purpose mechanism for the queueing of tasks is an important component in an ‘intelligent satellite’ system interfacing a community of users to a range of computing facilities. The queueing mechanism should provide spooling, warm and cold restarts, the ability to pool common resources (e.g. a number of line printers), a means of servicing the queues on a priority basis, and a flexible control mechanism for the system operators. The implementation of such a system for a small (i.e. 16-bit) computer system is described.     

The complexity of small universal Turing machines: A survey

We survey some work concerned with small universal Turing machines, cellular automata, tag systems, and other simple models of computation. For example, it has been an open question for some time as to whether the smallest known universal Turing machines of Minsky, Rogozhin, Baiocchi and Kudlek are efficient (polynomial time) simulators of Turing machines. These are some of the most intuitively simple computational devices and previously the best known simulations were exponentially slow. We discuss recent work that shows that these machines are indeed efficient simulators. As a related result, we also find that Rule 110, a well-known elementary cellular automaton, is also efficiently universal. We also review a large number of old and new universal program size results, including new small universal Turing machines and new weakly, and semi-weakly, universal Turing machines. We then discuss some ideas for future work arising out of these, and other, results.     

Large parallel machines can be extremely slow for small problems

We consider concurrent-write PRAMs with a large number of processors of unlimited computational power and an infinite shared memory. Our adversary chooses a small number of our processors and gives them a 0–1 input sequence (each chosen processor gets a bit, and each bit is given to one processor). The chosen processors are required to compute thePARITY of their input, while the others do not take part in the computation. Ifat most q processors are chosen andq 1/2 log logn, then we show that computing PARITY needsq steps in the worst case. On the other hand, there exists an algorithm which computes PARITY inq steps (for anyq <n) in this model, thus our result is sharp. Surprisingly, if our adversary choosesexactly q of our processors, then they can compute PARITY in [q/2] + 2 steps, and in this case we show that it needs at least [q2] steps. Our result implies that large parallel machines which are efficient when only a small number of their processors are active cannot be constructed. On the other hand, a result of Ajtai and Ben-Or [1] shows that if we haven input bits which contain at most polylogn 1's and polynomially many processors which are all allowed to work, then thePARITY can be solved inconstant time.     

Large parallel machines can be extremely slow for small problems

We consider concurrent-write PRAMs with a large number of processors of unlimited computational power and an infinite shared memory. Our adversary chooses a small number of our processors and gives them a 0–1 input sequence (each chosen processor gets a bit, and each bit is given to one processor). The chosen processors are required to compute thePARITY of their input, while the others do not take part in the computation. Ifat most q processors are chosen andq ≤1/2 log logn, then we show that computing PARITY needsq steps in the worst case. On the other hand, there exists an algorithm which computes PARITY inq steps (for anyq <n) in this model, thus our result is sharp. Surprisingly, if our adversary choosesexactly q of our processors, then they can compute PARITY in [q/2] + 2 steps, and in this case we show that it needs at least [q2] steps. Our result implies that large parallel machines which are efficient when only a small number of their processors are active cannot be constructed. On the other hand, a result of Ajtai and Ben-Or [1] shows that if we haven input bits which contain at most polylogn 1's and polynomially many processors which are all allowed to work, then thePARITY can be solved inconstant time.     

Squeeze-film effects in MEMS devices with perforated plates for small amplitude vibration

Squeeze-film effects of perforated plates for small amplitude vibration are analyzed through modified Reynolds equation (MRE). The analytical analysis reckons in most important influential factors: compressibility of the air, border effects, and the resistance caused by vertical air flow passing through perforated holes. It is found that consideration of air compressibility is necessary for high operating frequency and small ratio of the plate width to the attenuation length. The analytical results presented in this paper agree with ANSYS simulation results better than that under the air incompressibility assumption. The analytical analysis can be used to estimate the squeeze-film effects causing damping and stiffness added to the system. Since the value of Reynolds number involved in this paper is low (< 1), inertial effects are neglected.     

Some observations concerning alternating turing machines using small space

We make some observations concerning alternating Turing machines operating in small space. For example, we show that alternating Turing machines using o(log n) space are more powerful than nondeterministic Turing machines using the same space-bound. In fact, we show that there is a language over a unary alphabet that can be accepted by an on-line alternating Turing machine in log n space, but not by any off-line nondeterministic Turing machine in o(log n) space. We also investigate the weak vs. strong space bounds and on-line vs. off-line machines at these low tape bounds.     

Semi-online scheduling problems on a small number of machines

We consider the semi-online parallel machine scheduling problem of minimizing the makespan given a priori information: the total processing time, the largest processing time, the combination of the previous two or the optimal makespan. We propose a new algorithm that can be applied to the problem with the known total or largest processing time and prove that it has improved competitive ratios for the cases with a small number of machines. Improved lower bounds of the competitive ratio are also provided by presenting adversary lower bound examples.     

Lower bounds for online makespan minimization on a small number of related machines

In online makespan minimization, the jobs characterized by their processing time arrive one-by-one and each has to be assigned to one of the m uniformly related machines. The goal is to minimize the length of the schedule. We prove new combinatorial lower bounds for m=4 and m=5, and computer-assisted lower bounds for m≤11.     

Polyimide/tetraethoxysilane-based hybrid polyfilms for microelectronics application

Polyimide (PI) has been extensively investigated as matrix for blends in the search of novel materials for microelectronics and engineering. Tetraethoxysilane (TEOS) is used as precursor for inorganic/organic hybrid material. The processing of PI with TEOS in thin film form offers considerable advantages to the state-of-the art for developing low dielectric constant materials with improved mechanical and hygroscopic properties for microelectronics devices. Taking this into account, the TEOS was incorporated in polyamic acid—a precursor to the PI and a number of properties were evaluated for PI?+?TEOS films with different concentrations of TEOS. The films prepared with 10^?3–10?wt% concentration of TEOS exhibit good overall balance of processing behaviour. The 350°C cured PI?+?TEOS films have shown lower dielectric constant with respect to PI. The lower dielectric constant of PI?+?TEOS films, as determined by Dielectric Impedance Analyzer was attributed to the in situ generation of air containing silica domains derived from TEOS dispersed within the PI matrix in nano meter regime. FTIR analysis has confirmed the generation of silica while AFM analysis showed the distinct appearance of silica domains dispersed into the PI matrix. The mechanical properties were evaluated by Universal Testing Machine on PI and PI/TEOS films. The films with 10^?3–1?wt% composition of TEOS showed enhancement in overall mechanical properties while higher concentration i.e. 5 and 10 wt% of TEOS containing PI showed deterioration with respect to pure PI. The water absorption isotherms were measured and their absorption behaviour was correlated with dielectric constant and associated morphology.     

Displays for business machines: operation liquid crystal displays of photocopier machines

It is important to remember that liquid crystal display (LCD) technology was common in business machines long before it was adopted by the cellular telephone industry.This chapter details the role of LCD technology in business machines, using the multi-function photo copier as an illustrative example. Additionally, the function sharing capability of hard keys in conjunction with LCD technology is introduced.     

A parameterized complexity view on non-preemptively scheduling interval-constrained jobs: few machines,small looseness,and small slack

We study the problem of non-preemptively scheduling n jobs, each job j with a release time \(t_j\), a deadline \(d_j\), and a processing time \(p_j\), on m parallel identical machines. Cieliebak et al. (2004) considered the two constraints \(|d_j-t_j|\le \lambda {}p_j\) and \(|d_j-t_j|\le p_j +\sigma \) and showed the problem to be NP-hard for any \(\lambda >1\) and for any \(\sigma \ge 2\). We complement their results by parameterized complexity studies: we show that, for any \(\lambda >1\), the problem remains weakly NP-hard even for \(m=2\) and strongly W[1]-hard parameterized by m. We present a pseudo-polynomial-time algorithm for constant m and \(\lambda \) and a fixed-parameter tractability result for the parameter m combined with \(\sigma \).     

Piezocomposite ultrasonic transducer for high-frequency wire-bonding of microelectronics devices

Piezocomposite ultasonic transducers for high-frequency microelectronics wire bonding have been developed to alleviate the intrinsic mode coupling and high mechanical quality factor (Q_m) in piezoceramic transducers. In this paper, a 136 kHz transducer fabricated using lead zirconate titanate (PZT)/epoxy 1–3 piezocomposite rings with 77 μm epoxy width and 0.89 PZT volume fraction is presented, together with a PZT piezoceramic transducer of similar structure. With the guide of a finite-element modal analysis, the nature of most experimental resonance modes in the transducers is identified. The low lateral coupling of the composite rings effectively suppresses the non-axial and many other spurious resonances in the composite transducer, retaining only the axial-mode resonances. Due to the effect of epoxy damping, the composite transducer exhibits a 2.4-times reduction in Q_m to a desired low value of 296. This transducer has good potential to be used in commercial wire bonders for enabling high-frequency wire-bonding technology.     

MEMS: the systems function revolution

Information systems are no longer confined to desktops but are rapidly becoming part of cars, personal digital assistants, and palmtop systems. In this context, systems must be able not only to compute but also to sense their physical environment and respond to it. These requirements move beyond even complex microelectronics, calling for a functionality that combines electrical and mechanical components. This new functionality is realized in microelectro-mechanical systems (MEMS). MEMS devices are fast becoming part of everything from automobiles and fighter aircraft to printers and telecommunications switching equipment. According to the authors, despite some obvious advantages, MEMS are not well understood by the systems design and applications community, ironically, the ones to whom MEMS offer the greatest opportunities for enhancing system functionality. One area of confusion is how MEMS are produced and how that process differs from microelectronics manufacturing. The authors explain similarities and differences and identify some trends and motivations leading to a new systems functionality     

Measurement of dynamic properties of small volumes of fluid using MEMS

A model based on the response of a micro-rheometer which permits the measurement of the linear viscoelastic properties of small volumes of a fluid is described. The configuration involves a liquid being contained within a capillary bridge between two flat smooth parallel platens that are actuated sinusoidally using a compliant MEMS device. Approximate closed-form equations are derived to analyse the data taking account of both the capillary forces and those arising from viscoelastic flow. The approximate theory is compared to a full numerical simulation of the response of the MEMS rheometer and the validity is discussed.