Overview and development trends in the field of MEMS packaging

Reichl, H.; Grosser, V.

doi:10.1109/memsys.2001.906464

Cited by 52 publications

(24 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1 Adhesive failure dominated in bonds formed by thinner films and transitioned into mostly cohesive failures in thicker films. However, a variation in the degree of plasticity was observed, not only between specimens, but within the same specimen.…”

Section: B Bond Toughness Resultsmentioning

confidence: 99%

“…This improves the accuracy of the calculation. The critical energy release rate for this specimen is given by (1) where is the Young's modulus, is the Poisson's ratio, is the critical load at which crack propagation occurs, is the distance between the upper and lower rollers, is the width of the specimen, and and are the thickness of the unnotched wafer and notched wafer, respectively. Equation (1) shows as functions of the specimen geometry and applied load, both of which can be measured quite accurately.…”

Section: B Mechanical Testingmentioning

confidence: 99%

“…It is often application specific. With a majority of the devices being produced in low volume, packaging cost can reach more than 70% of the total cost [1]. Since packaging is frequently a die-level process, the cost may be reduced by packaging at the wafer-level.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Fabrication of wafer-level thermocompression bonds

Tsau

Spearing

Schmidt

2002

J. Microelectromech. Syst.

View full text Add to dashboard Cite

Abstract-Thermocompression bonding of gold is a promising technique for achieving low temperature, wafer-level bonding. The fabrication process for wafer bonding at 300 C via compressing gold under 7 MPa of pressure is described in detail. One of the issues encountered in the process development was e-beam source spitting, which resulted in micrometer diameter sized Au on the surfaces, and made bonding difficult. The problem was solved by inserting a tungsten liner to the graphite crucible. Surface segregation of Si on the Au surface at the bonding temperature was observed. Using Auger spectroscopy, a 1500 Å SiO 2 barrier layer was shown to be sufficient in preventing Si from reaching the surface. Lastly, a four-point bend delamination technique was used to quantify the bond toughness. The associated process steps that were required to prepare the test specimens are described. The critical strain energy release rate for the bonds ranged between 22 to 67 J/m 2 and was not shown to be strongly associated with the gold bond layer thickness in the thickness range studied (0.23 to 1.4 m).[828]Index Terms-Thermocompression bonding, wafer bonding.

show abstract

Section: B Bond Toughness Resultsmentioning

confidence: 99%

Section: B Mechanical Testingmentioning

confidence: 99%

See 1 more Smart Citation

Fabrication of wafer-level thermocompression bonds

Tsau

Spearing

Schmidt

2002

J. Microelectromech. Syst.

View full text Add to dashboard Cite

show abstract

“…On the other hand, being a single metal system, sintered Nano-silver will not have the intermetallic formation that leads to potential failure mechanism for multiple metal systems. Nevertheless, the occurrence of electrical migration and dry migration which cause Ag to build up at cathode in dendrites form that will reach the anode that will later cause failure of the device [5].…”

Section: Introductionmentioning

confidence: 99%

Investigation on Thermocompression Bonding Using Lead Free Sinterable Paste and High Lead Solder Paste for Power QFN Application

Chandrakasan

Ovinis

2016

MATEC Web of Conferences

View full text Add to dashboard Cite

Abstract. Persistently growing Power QFN packages are used in various fields especially micro-electronics, aerospace, oil and gas as well. However, the particular industries is pushing forward to reduce the use of hazardous materials in the process of manufacturing and assemblies. Thermo-compression die-attach layer is perceived to be the most critical element in power QFN packages as the increase in operating temperature requires new materials with suitable thermo-chemical properties also with suitable melting points of next generation lead free die attachment material. In this situation, Hi-lead solder (RM218: Pb92.5Sn5Ag2.5) which known as high temperature material is widely being used in most semiconductor assembly for die attach, yet it deduce few reliability challenges like solder voids, the clip tilt performance and also solder splash which has been considered as major quality issue in assembly of Power QFN packages (FET die, IC die and clip attach). As a solution, sintering epoxy paste (SPC073-3: Sn96.5/Ag3/Cu0.5) is being considered as a replacement. In this case, sintering epoxy paste demonstrating excellent electrical and thermal performance for Power QFN packages which is known to be demanded in market. Thus, this study investigates the differential pastes sintering paste and also solder paste, in order to identify best die attachment material to be used in thermo-compression bonding method. Therefore, the shear strength was resulting good indication where the sintering paste was recorded 2.4 Kg/mm meanwhile the solder paste was recorded 0Kg/mm at peak temperature of 260°C. Besides of that, the pot life seems promising as the sintering paste seems to have constant viscosity of 100Pa*s throughout the 48 hours tested while, high lead solder paste records viscosity from 100Pa*s marginally increase as the time increase which effects the inconsistency of pot life. Last but not least, the voids mechanisms proves sintering epoxy paste has the same pinhole voids as its individual, but the solder paste's pinhole voids are not same as individuals which easily can fail when the particular shear force was applied. Hence, sintering epoxy paste could resolve the quality issue by using thermo-compression bonding method and produce the better reliability than the solder paste.

show abstract

“…However, packaging of the individual devices can account for more than 70% of the device cost [1]. Wafer-level bonding lowers these costs substantially.…”

Section: Introductionmentioning

confidence: 99%

Wafer-level Au–Au bonding in the 350–450 °C temperature range

Tofteberg

Schjølberg-Henriksen

Fasting

et al. 2014

J. Micromech. Microeng.

View full text Add to dashboard Cite

Abstract:Metal thermocompression bonding is a hermetic wafer-level packaging technology that facilitates vertical integration and shrinks the area used for device sealing. In this paper, Au-Au bonding at 350, 400 and 450 °C has been investigated, bonding wafers with 1 µm Au on top of 200 nm TiW. Test Si laminates with device sealing frames of width 100, 200, and 400 µm were realized. Bond strengths measured by pull tests ranged from 8-102 MPa and showed that the bond strength increased with higher bonding temperatures and decreased with increasing frame width. Effects of eutectic reactions, grain growth in the Au film and stress relaxation causing buckles in the TiW film were most pronounced at 450 °C and negligible at 350 °C. Bond temperature below the Au-Si eutectic temperature 363 °C is recommended. CONFIDENTIAL -FOR REVIEW ONLY JMM-100282.R2Wafer-level Au-Au bonding in the 350-450 °C temperature range Abstract. Metal thermocompression bonding is a hermetic wafer-level packaging technology that facilitates vertical integration and shrinks the area used for device sealing. In this paper, Au-Au bonding at 350, 400 and 450 °C has been investigated, bonding wafers with 1 µm Au on top of 200 nm TiW. Test Si laminates with device sealing frames of width 100, 200, and 400 µm were realized. Bond strengths measured by pull tests ranged from 8-102 MPa and showed that the bond strength increased with higher bonding temperatures and decreased with increasing frame width. Effects of eutectic reactions, grain growth in the Au film and stress relaxation causing buckles in the TiW film were most pronounced at 450 °C and negligible at 350 °C. Bond temperature below the Au-Si eutectic temperature 363 °C is recommended. Submitted to: Journal of Micromechanics and Microengineering IntroductionMicroelectromechanical system (MEMS) technology enables sensitive and reliable devices to be produced at low cost due to the advantages of batch processing. However, packaging of the individual devices can account for more than 70% of the device cost [1]. Wafer-level bonding lowers these costs substantially. Several bonding technologies are used in packaging of commercial MEMS devices. Glass-frit bonding [2-4], anodic bonding [5,6] and fusion bonding [7,8] are well known and widely used techniques for wafer-level packaging and sealing of MEMS devices.Recently, metal thermocompression bonding has found its application as a hermetic waferlevel packaging technology that facilitates vertical integration. Thermocompression bonding, also referred to as diffusion bonding, is a form of solid-state welding. Pressure and heat are applied simultaneously to bring two metal surfaces into close contact. The atoms can then migrate from lattice site to lattice site joining the interface together [9,10]. To enable metal-to-metal contact, the bonding mechanism must deform the two surfaces in contact in order to disrupt any intervening surface films [11].Cu, Al, and Au are the three most commonly applied metals for thermocompression bonding. The lowest proces...

show abstract

Overview and development trends in the field of MEMS packaging

Cited by 52 publications

References 5 publications

Fabrication of wafer-level thermocompression bonds

Fabrication of wafer-level thermocompression bonds

Investigation on Thermocompression Bonding Using Lead Free Sinterable Paste and High Lead Solder Paste for Power QFN Application

Wafer-level Au–Au bonding in the 350–450 °C temperature range

Contact Info

Product

Resources

About