Showing papers in "Electronics & Packaging in 2014"
Journal Article•
TL;DR: The whole control system through simulation and online logic analyzer demonstrate that SDRAM controller can read and write control accurately, stable and reliable, and it can be applied to different speeding cache systems.
Abstract: According to the problem controling the SDRAM(Synchronous Dynamic Random Access Memory) timing in the cache the image data are complicated, presents a SDRAM controller design based on a core of FPGA(Field Programmable Gate Array). Use the thought divided module,which put the SDRAM controller divide into different functional blocks are connected through the signal state of line, and the associated modules control the whole process through state machine. In addition, in order to improve the speed of the SDRAM buffer, select work mode under the SDRAM page burst.As a result, the speed of SDRAM read and write improved dramatically. The whole control system through simulation and online logic analyzer demonstrate that: SDRAM controller can read and write control accurately, stable and reliable, and it can be applied to different speeding cache systems.
5 citations
Journal Article•
TL;DR: Based on the traditional PFD, the structure is designed with internal signal to control circuit logic, and its transfer characteristic is nonlinear as discussed by the authors, which can realize a quick lock acquisition of a phase locked loop.
Abstract: Because of the effect on the lock speed of phase locked loop by the blind zone of phase frequency detector(PFD),the paper proposes a PFD circuit structure which can realise a quick lock acquisition of a phase locked loop.Based on the traditional PFD,the structure is designed with internal signal to control circuit logic,and its transfer characteristic is nonlinear.When the input phase error is lager than π,the reset pulse signal is suppressed,and the input clock edge is avoided missing.The blind zone is eliminated effectively to speed up the lock acquisition of a phase locked loop.Based on SMIC 0.18 μm standard CMOS process,the PFD circuit structure is designed,simulated,analysed and verified in full custom design method.The simulation results indicate that the PLL with the proposed PFD circuit structure can accelerate lock acquisition by 34.27%,and its locking time is 2.95 μs working in the frequency of 400 MHz.
4 citations
Journal Article•
TL;DR: In this article, the authors presented several key technologies of 3D-TSV package, such as, via fabrication, film deposition on via sidewall,via filling,copper CMP,ultra-thin wafer grinding, chip/wafer stacking bonding.
Abstract: 3D-TSV package technology is the best impactful technique approach to achieve three dimension system package with multifunction,high-performance,high-reliability,more light weight,thinner,smaller.The paper presented several key technologies of 3D-TSV package,such as,via fabrication,film deposition on via sidewall,via filling,copper CMP,ultra-thin wafer grinding,chip/wafer stacking bonding.And discussed techno-theory,techno-characteristic,application area,development status of key technologies,the key equipments,the key materials,and application of 3D-TSV package technology.
3 citations
Journal Article•
TL;DR: In this article, the reason of stress concentration in the potting is analyzed and the method of avoiding stress concentration is discussed from encapsulation material, encapsulation technology and product designing.
Abstract: When offline storage test device work in high shock, severe vibration, temperature impact and other harsh environments, the reliability of the circuit system running is extremely important. In order to ensure the circuit system work normally in the harsh environment, the circuit module is reinforced by potting. The circuit encapsulation body which circuit module are potted with epoxy resin often failure operation in test. The analysis result show that stress concentration is the main factor which lead to that. The reason of stress concentration in the potting is analyzed. Furthermore, the method of avoiding stress concentration is discussed from encapsulation material, encapsulation technology and product designing.
2 citations
Journal Article•
TL;DR: In this paper, the authors studied the effect of Sb content on the properties of lead-free filler metals and found that Sb can improve the performance of the filler metal with halogenless soldering aid.
Abstract: Influence of content of Sb on the property of SnAg3.5Cu0.7Ga1 filler metals were studied.The results showed that with increasing of the Sb content,the solidus and liquidus temperature of the SnAg3.5Cu0.7Ga1 filler metals increased,but was lower than 230 ℃.With the content of Sb added 0.5%,the wettability of the SnAg3.5Cu0.7Ga1 filler metals with halogenless soldering aid at 240 ℃ did not changed.With the increasing of the content of Sb up to 1.0%,the wettability of the SnAg3.5Cu0.7Ga1 filler metals improved.A small amount of Sb can improve SnAg3.5Cu0.7Ga1 lead-free filler metals' resistance to oxidation; The amount of cycles to crack in turn increased.It can also to improve the copper alloy brazed joint's thermal fatigue strength using SnAg3.5Cu0.7Ga1 lead-free filler metals.
1 citations
Journal Article•
TL;DR: In this article, the bottle-neck factors in the application were studied in order to improve the solder ability, Ti-Cu-Ni-Au compound-plating on Diamond/Cu was produced by PVD and ECD, the compoundplating has good adhesion strength and solder ability.
Abstract: As a new generation of electronic packaging material, Diamond/Cu composites have excellent performances such as high thermal conductivity and adjustable CTEThe bottle-neck factors in the application were studied in this paper In order to improve the solder ability, Ti-Cu-Ni-Au compound-plating on Diamond/Cu was produced by PVD and ECD, the compound-plating has good adhesion strength and solder ability Furthermore, compound-plating has good wettability with Au80Sn20 The result show that, Diamond/Cu has more excellent effectiveness of heat-emission on the same condition, which the temperature fall reach 20 ℃ compare to MoCu
1 citations
Journal Article•
TL;DR: In this article, the authors have verified the efficiency of Mindlin plate theory on analysis of high frequency vibration of quartz crystal plate and obtained clear cloud pictures of displacement of the thickness shear vibrations of quartz plate and displacement pictures on the length and width direction.
Abstract: Based on the three-dimensional theory of piezoelectricity,the quartz crystal resonator with consideration of package structures have been investigated by the finite element software ANSYS.With adding conductive adhesive support,sealing base and cover,the paper obtained clear cloud pictures of displacement of the thicknessshear vibrations of quartz crystal plate and displacement pictures on the length and width direction.Numerical results showed that compared with free vibration,the effect of sealing base and cover on the thickness-shear vibration of quartz crystal plate is little.In the paper,the obtained results have verified efficiency of Mindlin plate theory on analysis of high frequency vibration of quartz crystal plate.
1 citations