• 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.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.79-83
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• 2007

We have developed a compact and cost-effective camera module on the basis of wafer-scale replication technology. A multiple-layered structure of several aspheric lenses in a mobile camera module is first assembled by bonding multiple glass-wafers on which 2-dimensional replica arrays of identical aspheric lenses are UV-embossed, followed by dicing the stacked wafers and packaging them with image sensor chips. We have demonstrated a VGA camera module fabricated by the wafer-scale replication processing with various UV-curable polymers having refractive indices between 1.4 and 1.6, and with three different glass-wafers of which both surfaces are embossed as aspheric lenses having 200 um sag-height and aspheric-coefficients of lens polynomials up to tenth-order. We have found that precise compensation in material shrinkage of the polymer materials is one of the most technical challenges, in order to achieve a higher resolution in wafer-scaled lenses for mobile camera modules.

• 접착 및 계면
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• 제5권4호
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• pp.1-8
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• 2004

다이싱 테이프에 사용되는 UV경화형 점착제를 아크릴 공중합체를 butyl acrylate, acrylic acid, methyl methacrylate를 용액 중합을 통해 중합한 뒤, trimethylolpropane triacrylate를 블렌딩하여 제조하였다. 제조된 점착제는 UV 조사량에 따라 접착력, 유리전이온도 ($T_g$)를 측정하였는데 UV 조사량이 증가할수록 접착력은 급격하게 감소하였고 $T_g$도 증가하였다. 웨이퍼 표면에 점착 샘플을 부착하여 UV 조사 후 박리하여 표면을 관찰한 결과 점착잔류물을 남기지 않았다.

• Journal of the Optical Society of Korea
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• 제10권3호
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• pp.124-129
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• 2006

We have developed a compact and cost-effective camera module on the basis of wafer-scale-replica processing. A multiple-layered structure of several aspheric lenses in a mobile-phone camera module is first assembled by bonding multiple glass-wafers on which 2-dimensional replica arrays of identical aspheric lenses are UV-embossed, followed by dicing the stacked wafers and packaging them with image sensor chips. This wafer-scale processing leads to at least 95% yield in mass-production, and potentially to a very slim phone with camera-module less than 2 mm in thickness. We have demonstrated a VGA camera module fabricated by the wafer-scale-replica processing with various UV-curable polymers having refractive indices between 1.4 and 1.6, and with three different glass-wafers of which both surfaces are embossed as aspheric lenses having $230{\mu}m$ sag-height and aspheric-coefficients of lens polynomials up to tenth-order. We have found that precise compensation in material shrinkage of the polymer materials is one of the most technical challenges, in orderto achieve a higher resolution in wafer-scaled lenses for mobile-phone camera modules.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2008년도 춘계학술발표논문집
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• pp.46-48
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• 2008

나노복합 블레이드가 반도체 웨이퍼 가공을 위한 마이크로급 나노장치나 그 이상의 나노급 구조체를 위해 사용되었다. 금속 블레이드는 실리콘 웨이퍼 가공을 위해 사용되어 왔다. 그러나, 최근 레진 복합 블레이드는 반도체나 핸드폰의 쿼츠 웨이퍼 가공에 사용된다. 유기 또는 비유기 재료 선정은 기계가공성, 전기 전도성, 강도, 연성 및 웨이퍼 저항을 가진 블레이드를 만드는데 중요하다. 고성능 응용의 증대 요구에 따라 개발된 고기술 비유기성 재료의 혼합은 낮은 가격에 고기능의 신뢰도를 필요로 한다. 나노 입자의 크기를 가진 레진 복합물의 마이크로 설계는 입자간 상호작용의 제어가 필요하다. 형상 제작 동안 마이크로 차원에 두께를 유지하기 위해서는 마이크로/나노급 제작을 위한 가공기술이 중요한 것 중의 하나이다. 본 연구에서는 핫 프레스 구조물이 원래 설계 기준과 두께 차이의 실험 접근법을 사용해 만들어졌다. 다른 습식 공정 기술은 차원의 허용치를 개선하기 위해 만들었다. 실험들과 해석들은 신뢰성 결과가 사용가능함을 보여주었다. 반도체 시장에 사용될 레진 복합 블레이드의 개선 효과가 논의되었다.

• 반도체디스플레이기술학회지
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• 제22권3호
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• pp.1-7
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• 2023

Recently, in the semiconductor industry, memory device market is focusing on producing ultra-thin wafers for high integration. In the wafer manufacturing process, wafers after backgrinding and CMP process must be picked up as individual dies and subjected to be peeled off from the dicing tape. However, ultra-thin dies are vulnerable to the possibility of breakage and failure in their thickness and size. This research studies the mechanism of peeling a die with a high-aspect ratio using a thermopneumatic method instead of a die ejector with physical pins. Setting compressed air and the temperature as main factors, we determine the success of the digester using thermopneumatic system and analyze the good die to find the possibility of making mass-production equipment.

• 공업화학
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• 제34권5호
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• pp.522-528
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• 2023

반도체 제조공정인 다이싱 공정용 점착 테이프를 제조하기 위해 다양한 개수의 광 반응기를 갖는 화합물을 합성하였고 아크릴 공중합체에 도입하여 UV 경화형 아크릴 점착제를 제조하였다. 합성된 광반응성 화합물(f = 2 또는 3)의 구조는 NMR을 이용하여 확인하였다. 광반응성 화합물(f = 1~3)은 우레탄 반응을 통해 아크릴 점착제의 곁가지로 도입되었고, FT-IR 측정을 통해 UV 경화형 아크릴 점착제가 성공적으로 합성되었음을 확인하였다. UV 조사 전 후의 박리강도 변화는 실리콘 웨이퍼를 기재로 하여 평가되었으며, UV 조사 전 점착제의 높은 박리강도(~2000 gf/25 mm)가 UV조사 후 크게 감소(~5 gf/25 mm)하였다. 다 관능성 광 반응기가 도입된 점착제의 점착력 감소 효과가 가장 컸으며 FE-SEM을 통한 표면 잔류물 측정 결과, UV 조사 후의 표면 잔류물도 매우 낮은 수준(~0.2%)으로 관찰되었다.

• Journal of Welding and Joining
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• 제31권3호
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• pp.84-88
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• 2013

These days embedded technology may be the most significant development in the electronics industry. The study focused on the development of active device embedding using flexible printed circuit in view of process and materials. The authors fabricated 30um thickness Si chip without any crack, chipping defects with a dicing before grinding process. In order to embed chips into flexible PCB, the chip pads on a chip are connected to bonding pad on flexible PCB using an ACF film. After packaging, all sample were tested by the O/S test and carried out the reliability test. All samples passed environmental reliability test. In the future, this technology will be applied to the wearable electronics and flexible display in the variety of electronics product.

• 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.

• 한국재료학회지
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• 제20권11호
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• pp.617-622
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• 2010

We have studied methods to save Si source during the fabrication process of crystalline Si solar cells. One way is to use a thin silicon wafer substrate. As the thickness of the wafers is reduced, mechanical fractures of the substrate increase with the mechanical handling of the thin wafers. It is expected that the mechanical fractures lead to a dropping of yield in the solar cell process. In this study, the mechanical properties of 220-micrometer-solar grade Cz p-type monocrystalline Si wafers were investigated by varying saw-damage etching conditions in order to improve the flexural strength of ultra-thin monocrystalline Si solar cells. Potassium hydroxide (KOH) solution and tetramethyl ammonium hydroxide (TMAH) solution were used as etching solutions. Etching processes were operated with a varying of the ratio of KOH and TMAH solutions in different temperature conditions. After saw-damage etching, wafers were cleaned with a modified RCA cleaning method for ten minutes. Each sample was divided into 42 pieces using an automatic dicing saw machine. The surface morphologies were investigated by scanning electron microscopy and 3D optical microscopy. The thickness distribution was measured by micrometer. The strength distribution was measured with a 4-point-bending tester. As a result, TMAH solution at $90^{\circ}C$ showed the best performance for flexural strength.