• 반도체디스플레이기술학회지
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• 제5권3호
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• pp.5-10
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• 2006

This paper investigates cutting qualities after laser dicing and predicts the problems that can be generated by laser dicing. And through 3 point bending test, die strength is measured and the die strength after laser dicing is compared with the die strength after mechanical sawing. Laser dicing is chiefly considered as an alternative to overcome the defects of mechanical sawing such as chipping on the surface and crack on the back side. Laser micromachining is based on the thermal ablation and evaporation mechanism. As a result of laser dicing experiments, debris on the surface of wafer is observed. To eliminate the debris and protect the surface, an experiment is done using a water soluble coating material and ultrasonic. The consequence is that most of debris is removed. But there are some residues around the cutting line. Unlike mechanical sawing, chipping on the surface and crack on the back side is not observed. The cross section of cutting line by laser dicing is rough as compared with that by mechanical sawing. But micro crack can not be seen. Micro crack reduces die strength. To measure this, 3 point bending test is done. The die strength after laser dicing decreases to a half of the die strength after mechanical sawing. This means that die cracking during package assembly can occur.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.327-329
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• 2006

In this paper, the cutting qualities by laser dicing and fracture strength of a silicon die is investigated. Laser micromachining is the non-contact process using thermal ablation and evaporation mechanisms. By these mechanisms, debris is generated and stick on the surface of wafer, which is the problem to apply laser dicing to semiconductor manufacture process. Unlike mechanical sawing using diamond blade, chipping on the surface and crack on the back side of wafer isn't made by laser dicing. Die strength by laser dicing is measured via the three-point bend test and is compared with the die strength by mechanical sawing. As a results, die strength by laser dicing shows a decrease of 50% in compared with die strength by mechanical sawing.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2006년도 춘계학술대회
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• pp.251-254
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• 2006

In this paper, cutting qualifies and fracture strength of silicon dies by laser dicing are investigated. Laser micromachining is the non-contact process using thermal ablation and evaporation mechanisms. By these mechanisms, debris is generated and stick on the surface of wafer, which is the problem to apply laser dicing to semiconductor manufacture process. Unlike mechanical sawing using diamond blade, chipping on the surface and crack on the back side of wafer isn't made by laser dicing. Die strength by laser dicing is measured via the three-point bending test and is compared with the die strength by mechanical sawing. As a results, die strength by the laser dicing shows a decrease of 50% in compared with die strength by the mechanical sawing.

• 마이크로전자및패키징학회지
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• 제21권4호
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• pp.63-68
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• 2014

For a nanoscale Cu/low-k wafer, inter-layer dielectric (ILD) and metal layers peelings, cracks, chipping, and delamination are the most common dicing defects by traditional diamond blade saw process. Sidewall void in sawing street is one of the key factors to bring about cracks and chipping. The aim of this research is to evaluate laser grooving & mechanical sawing parameters to eliminate sidewall void and avoid top-side chipping as well as peeling. An ultra-fast pico-second (ps) laser is applied to groove/singulate the 28-nanometer node wafer with Cu/low-k dielectric. A series of comprehensive parametric study on the recipes of input laser power, repetition rate, grooving speed, defocus amount and street index has been conducted to improve the quality of dicing process. The effects of the laser kerf geometry, grooving edge quality and defects are evaluated by using scanning electron microscopy (SEM) and focused ion beam (FIB). Experimental results have shown that the laser grooving technique is capable to improve the quality and yield issues on Cu/low-k wafer dicing process.

• 한국기계가공학회지
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• 제16권6호
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• pp.1-6
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• 2017

Recently, the brittle materials such as ceramics, glass, sapphire and textile material have been widely used in semiconductors, aerospace and automobile owing to high functional characteristics. On the other hand, it has the characteristics of difficult-to-cut material relative to all materials. In this study, diamond electro-deposited band-saw machine was developed to operate stably using water-coolant type through relative motion between band-saw tool and $Al_2O_3$ material. High densified $Al_2O_3$ material was manufactured by spark plasma sintering method. The bulk density was observed by the Archimedes law and the theoretical density was estimated to be $3.88g/cm^3$ and its hardness 14.7 MPa. From the dicing sawing test of $Al_2O_3$ specimen, behavior of surface roughness and band-saw wear are dominantly affected by the increase of the band-saw linear velocity. Additionally, an continuous pattern type of diamond band-saw was a very effective due to entry impact as a one-off for brittle material.

• 한국정밀공학회지
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• 제17권3호
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• pp.47-57
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• 2000

In this study, PC-based dicing machine and driving software were constructed for the purpose of automation of wafer cutting process. To automate the machine, hard automation including vision, loading, and software were considered in the development. Auto loading device and vision system were adopted for the increase of productivity, GUI software programmed for the expedient operation. The dicing machine is operated by the control algorithm and some parameters. It is verified that this kind of PC based automation has a great potential compared with the conventional dicing machine when applied to manufacturing some kinds of wafers as a test purpose.

• 마이크로전자및패키징학회지
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• 제10권4호
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• pp.53-60
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• 2003

CCD(Charge-Coupled Device) wafer와 같이 표면이 polymer 성분의 micro lens로 구성되어있는 경우 passivation 막을 도포하지 않는 것이 보통인데, 이때 particle이 lens 표면에 쉽게 달라붙는 현상이 나타나게 된다. 특히 sawing 하면서 발생하는 particle은 치명적인 불량을 유발한다. 본 연구에서는 sawing에서 발생한 particle을 효과적으로 flushing하기위한 방안으로 측면노즐과 중심노즐의 분사위치, 분사각도, 퍼짐각도를 최적화 하고, 아울러 flushing 노즐을 추가한 새로운 형태의 wafer saw를 도입하였다. 개선된 saw를 적용하여 실험한 결과 particle로 인한 CCD chip의 불량률이 9.l%로부터 0.63%로 현격하게 개선되었음을 확인할 수 있었다.

• 한국재료학회지
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• 제19권5호
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• pp.288-292
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• 2009

This article shows various factors that influence the thermal-cycling reliability of semiconductor devices utilizing the lead-on-chip (LOC) die attach technique. This work details how the modification of LOC package design as well as the back-grinding and dicing process of semiconductor wafers affect passivation reliability. This work shows that the design of an adhesion tape rather than a plastic package body can play a more important role in determining the passivation reliability. This is due to the fact that the thermal-expansion coefficient of the tape is larger than that of the plastic package body. Present tests also indicate that the ceramic fillers embedded in the plastic package body for mechanical strengthening are not helpful for the improvement of the passivation reliability. Even though the fillers can reduce the thermal-expansion of the plastic package body, microscopic examinations show that they can cause direct damage to the passivation layer. Furthermore, experimental results also illustrate that sawing-induced chipping resulting from the separation of a semiconductor wafer into individual devices might develop into passivation cracks during thermal-cycling. Thus, the proper design of the adhesion tape and the prevention of the sawing-induced chipping should be considered to enhance the passivation reliability in the semiconductor devices using the LOC die attach technique.

• 한국레이저가공학회지
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• 제11권1호
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• pp.19-24
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• 2008

It has been recognized that laser dicing of wafers results in low mechanical strength compared to the conventional sawing techniques. Thermal shock generated by rapid thermal loading is responsible for this problem. This work presents a two-dimensional ultra-short thermo elastic model for numerical simulation of femtosecond laser ablation of metals in the high-fluence regime where the phase explosion is dominant. Laser-induced thermoelastic stress is analyzed for Ni. The results show that the laser-induced thermal shock is large enough to induce mechanical damages.