Optoelectronic Packaging Research Articles

Optimization of laser-based glass frit bonding for optoelectronic packaging using response surface methodology

Optimization of laser-based glass frit bonding for optoelectronic packaging using response surface methodology

Forward Kinematics Analysis of High-Precision Optoelectronic Packaging Platform

Abstract To meet the requirements of high-precision motion control for optoelectronic packaging platforms, we propose an improved particle swarm optimization (PSO) and backpropagation (IPSO-BP) neural network for solving the forward kinematics problem (FKP) of platforms. The focus of this paper is the 6-pss flexible parallel platform commonly used in optoelectronic packaging. First, a platform inverse kinematics problem (IKP) based on a flexibility matrix is solved using geometric and vector analysis. The conventional PSO-BP network is then optimized utilizing uniform design (UD), a random learning strategy, and space reduction techniques in FKP. Finally, simulations and experiments demonstrate that the proposed IPSO-BP network for solving the FKP on high-precision optoelectronic packaging platforms is feasible. Compared to BP and PSO-BP, this network has a higher resolution, faster convergence speed, and error control at the submicron level, which satisfies the motion control requirements of the platform at the micron level. This study lays a solid foundation for the production of high-quality devices in optoelectronic packaging.

Theoretical study and physical tests on the influence of process parameters of needle on dispensing quality

Theoretical study and physical tests on the influence of process parameters of needle on dispensing quality

Cost-effective screen printing approach for Ce/Nd-doped ZnAl2O4 films: tuning crystallinity induced by the substrate.

Near-infrared (NIR) emitting phosphors are currently receiving considerable attention owing to their high demand in various applications, such as light detection and ranging (LiDAR), short-range communications, security, biosensing and night vision lighting applications. The miniaturization of photonic components demands the integration of thin films into exploitable devices. In this context, NIR emitting ZnAl2O4:Ce/Nd films of hundreds of nanometer thickness are synthesized using a scalable and cost-efficient approach to screen printing. Cerium co-doping is responsible for the Nd emission in the NIR through energy transfer by exciting the films under UV excitation at around 360 nm. Through the proper design of ink, dense Nd/Ce doped ZnAl2O4 ceramic films were produced using polycrystalline alumina. The use of polycrystalline alumina substrates opens up new opportunities because this ceramic is a cheap and well-known substrate for optoelectronic packaging. During manufacturing, as a direct effect of predominant crystal growth over the polycrystalline alumina substrate, an increase in emission intensity is achieved. The results obtained by X-ray photoelectron (XPS) and X-ray absorption near edge spectroscopy (XANES) serve to determine the oxidation state of Ce. The findings of this study indicate that a higher concentration of Ce4+ promotes NIR emission. This study may contribute to a better understanding of film production processes of films based on the ZnAl2O4 matrix and guide future studies on films for NIR emitters.

Experimental and numerical investigation of residual stress and post-weld-shift of coaxial laser diodes during the optoelectronic packaging process

Experimental and numerical investigation of residual stress and post-weld-shift of coaxial laser diodes during the optoelectronic packaging process

An Efficient Method to Determine the Thermal Behavior of Composite Material with Loading High Thermal Conductivity Fillers

Improvement of the thermal conductivity of encapsulant material using doping filler is an important requirement for electronic device packaging. We proposed a simple method for determining the thermal characteristics of composite material that can help save time, increase research performance, and reduce the cost of buying testing equipment. Based on the theory of Fourier law, a general 3D model is simplified into a 2D model, which can then be applied to calculate the thermal conductivity of the tested sample. The temperature distribution inside the sample is simulated by the finite element method using MATLAB software; this is a simple and useful option for researchers who conduct studies on thermal conduction. In addition, an experimental setup is proposed to help determine the extent of thermal conductivity improvement in a sample with doping filler compared to a bare sample. This method is helpful for research on optoelectronics packaging, which relates to the enhancement of thermal conductivity composite material.

Phase Change Material Behavior in Finite Thickness Slabs Under a Step Response Heat

Abstract Phase change materials (PCMs) can provide thermal buffering to systems that experience transient heat loads, including electronics and optoelectronics packaging. Placing the PCM in the primary path of heat rejection decreases the thermal resistance between the heat source and the PCM volume, but increases the total thermal resistance between the heat source and heat sink. In systems that operate in both steady-state and transient regimes, this introduces tradeoffs between cooling performance in these distinct regimes. Employing a conductive finite volume model, Parapower, we investigate those tradeoffs considering the impact of adding a layer of gallium (Ga), a low melting point metal, and a layer of copper (Cu) between a planar heat source and a convective boundary condition heatsink. We demonstrate: (1) side-by-side comparisons of latent (Ga) and sensible (Cu) heat storage layers must consider different layer thicknesses to account for the different thermal storage mechanisms, (2) for short periods of time, conditions exist in which a PCM outperforms a traditional heat sink for transient thermal buffering at an equivalent steady-state temperature rise, and (3) under these conditions, the Ga layer is approximately an order of magnitude thinner than the equivalent Cu, leading to significant mass and volume savings.

One-pot synthesis of multifunctional silicone elastomer: Ring-opening copolymerization of D4 and Dual-D4Vi

Herein, a Dual-D4Vi monomer is designed for one-pot synthesis of multifunctional silicone elastomer. Dual-D4Vi plays dual roles in silicone elastomer. It functions both as monomer and as cross-linker, and thus can copolymerize with octamethyl cyclotetrasiloxane (D4) for one-pot synthesis of multifunctional silicone elastomer. This is different from the conventional multi-step preparation process which needs polymerization and vulcanization. Dual-D4Vi is synthesized by a simple hydrosilylation reaction with high yield and characterized by FTIR, NMR and LC/MS spectrometry. And this method can be used for both laboratory research and large-scale preparation. Notably, the mixture of the prepolymer before heat-curing was water-like with the viscosity as low as 10 mPa·s, endowing this type of material system with wide applicability in gap filling, 3D printing, optoelectronic device packaging and roll-to-plate hot embossing. Moreover, the very low initial viscosity and good flow behavior also allows substantially adjustable filler type and content. Additionally, the polymerization rate is fast. The viscosity can reach 100 Pa·s within 20 s. And the polymerization is controllable by adjusting the reaction temperature and catalyst dosage.

Synthesis and investigation of structural, thermal, magnetic, and dielectric properties of multifunctional epoxy/Li0.5Al0.35Fe2.15O4/Al2O3 nanocomposites

Until recently, multifunctional epoxy nanocomposites (MENCs) have attracted the attention of many researchers due to their properties which can be tuned for the desired application. For high-frequency microelectronic and optoelectronic device packaging, materials with low dielectric permittivity, low dielectric losses, high dielectric strength, and high thermal conductivity have been required. Toward this goal, epoxy/Li 0.5 Al 0.35 Fe 2.15 O 4 /Al 2 O 3 (wt.%: (95:5-y:y): y ranges from 1 to 5 wt.% by steps of 1 wt.%) nanocomposites were prepared and investigated. The nanocomposite samples were characterized by X-ray diffraction, FT-IR spectroscopy, transmission electron microscope, scanning electron microscope, and thermogravimetric analyzer. In the present study, the thermal conductivity of the samples is enhanced in the direction of increasing the Al 2 O 3 nanofillers, contrary to the thermal stability. The sigmoid M−H curves of the samples reveal their soft ferrimagnetic nature. As the nonmagnetic Al 2 O 3 nanofillers content increases, the magnetic parameters M s , M r , and L s decrease, while H c and S q increase with the magnetic anisotropy increase. The interesting results of decreasing σʹ ac , ε′ , and tanδ for the composite samples of y = 1 to 4 wt.% to values below the unfilled epoxy sample are explained depending on the dual interface nanolayer model (DINM). Also, based on the DINM, the increase of T g and dielectric strength for the same samples is interpreted.

The adhesion of epoxy treated by microwave oxygen plasma

• Shear strength of un-aged and aged epoxy for up to two months as a function of plasma power was investigated. • Shear strength of aged (up to two months) oxygen plasma treated epoxy with silicone increased significantly. • Hydrophobic recovery was observed after ageing but contributed minimal effect on the shear strength. • 300-W plasma-treated epoxy produced the highest shear strength with the lowest adhesive failure percentage. • Increment of LMWOM that formed cross-links with underlying polar groups in epoxy contributed to enhancement of the strength. Strong adhesion between epoxy and silicone is essential for optoelectronic packaging. The adhesion of epoxy can be enhanced by microwave plasma treatment in oxygen flow. However, the plasma effect is time dependent. The shear strength of un-aged and aged epoxy for up to two months was systematically investigated as a function of plasma power (200–600 W) with different surface analysis tools. The shear strength between epoxy and silicone assembly was correlated with surface wettability, chemical, and structural properties. 300-W plasma-treated epoxy revealed the highest shear strength and the factors contributing to the improved strength were identified. The phenomenon of hydrophobic recovery was recorded after ageing, which had minimal effect on the reduction of shear strength. By keeping the plasma-treated surface for up to two months, a significant increment of shear strength was demonstrated below one week of ageing. Beyond that, a slight deterioration of the strength was observed but the reduction was still higher than the un-aged surface. The reasons behind of these observations have been elucidated and justified.

A Six-Degree-of-Freedom Compliant Parallel Platform for Optoelectronic Packaging

Optoelectronic packaging is an important component of optical communication systems. However, it is a challenge for the packaging equipment to simultaneously have multiple degrees of freedom (DOF), wide range, and high precision. In this article, a six-degree-of-freedom (6-DOF) compliant parallel platform with all these features is presented. This platform has a parallel basic structure with large-stroke flexible joints. Based on elastokinematic analysis, the inverse kinematics solution of the platform is derived, and the effectiveness of the platform is proved by analyzing the 6-DOF motion via finite element analysis. The reachable workspace of the platform is analyzed, and its solution process is simplified using the inverse distance weighted method. Furthermore, a prototype of the proposed platform is presented and its accuracy is evaluated through experiments. Error compensation is used to significantly improve the motion accuracy of the platform. A closed-loop control that uses optical power meters instead of a multi-DOF detection device is proposed for optoelectronic packaging. The performance of the prototype applied to the packaging of coaxial optoelectronic devices is also demonstrated by experiments. The results demonstrate that the 6-DOF compliant parallel platform can successfully carry out the optical alignment of optoelectronic devices.

Computational Designing of Low Energy Band Gap of New Donor-Acceptor (D-A) Copolymer Monomers for Organic Solar Cells: DFT and TD-DFT Study

Via this look at efforts have been made to increase a chain of latest donor-acceptor (D-A) systems through the usage of 4-methoxy-2,7,nine-trimethyl-9H-carbazole (2,7-MMCB) as a electron donor and benzo[c][1,2,5] oxadiazole (BCO); benzo[c] [1,2,5] thiadiazole (BCT); benzo[c][1,2,5]selenadiazole (BCS); [1,2,5]oxadiazolo[3,4-c]pyridine (OCP); [1,2,5] thiadiazolo [3,4-c]pyridine (TCP); [1,2,5] selenadiazolo [3,4-c]pyridine (SCP); [1,2,5] oxadiazolo[3,4-d]pyridazine (ODP); [1,2,5] thiadiazolo[3,4-d]pyridazine (TDP) as electron acceptors. In this work, we executed calculations of DFT and TD-DFT/B3LYPmethod with /6-31G basis. Calculated and explored theoretical expertise of the HOMO, LUMO oenergies, the band gap (Eg), and the open-circuit voltage (Voc) of the studied compounds. To take a look at the relationship between molecularstructure and optoelectronic properties, the consequences of the extraordinary acceptor effect on the geometries and optoelectronic residences of those substances were discussed. The outcomes acquired show how the digital residences can be modified with many lessons of acceptors through the substituent and suggest that 2,7MMCB-ODP, 2,7MM CB-TDP, and 2,7MM CB-SDP are these compounds as suitable candidates for optoelectronic packages in solar cells inclusive of BHJ.

Impact of Ultraconfinement on Composite Barriers

Flexible optoelectronic packaging is required to provide an ultrahigh barrier to oxygen under ambient conditions, meaning at a relative humidity above 50%. Many polymeric packaging materials, howev...

Systematic approach to realizing optimal moving order selection for multi-axis precise motion system

Abstract This paper presents a systematic approach for selecting the optimal moving order (MO) in a multi-axis precise motion system (MPMS). According to the proposed procedure, an optimal high-efficiency MO selection approach for high-efficiency and high-accuracy requirement is introduced. First, the characteristics of the giving MPMS are analysed, and the error model is established. The orthogonal test method is used to evaluate the influence on the MO caused by different MPMS configurations. Second, the number of possible MOs can be narrowed to limited and satisfied MO types. By calculating the deviations after each step, all directional movements can be arranged. Third, considering that both the accuracy and efficiency are important indexes, a series of systematic formulations are developed to select the optimal MO to balance accuracy and efficiency. A case for which a six-axis precise platform is adopted in an optoelectronic packaging system is implemented, and the methods of high-quality MO selection are verified by performing a series of experiments, and the methods are shown to be useful and effective. To balance the proportion of efficiency and accuracy, the formula and corresponding model are proposed to select the MO. The approach is not only beneficial to the accuracy improvement and trajectory planning of MPMS, but also helpful in terms of reducing the computational processing for the following algorithm. For the engineers using in precise industry area, the proposed approach can significantly improve the operative precision of MPMS with an optimal MO. This methodology of MO can also be the basis of references to error-related analyses on MPMS.

Biodegradable blends of graphene quantum dots and thermoplastic starch with solid-state photoluminescent and conductive properties

Polymer composites based on blends of graphene quantum dots (GQDs) with thermoplastic starch (TPS) were prepared by melt-extrusion combined with hot pressing. The GQDs/TPS films were characterized as potential novel, high-performance, and ecofriendly composites replacing traditional non-biodegradable plastic packaging materials. GQDs stock solutions of different concentrations were incorporated into TPS matrices in order to analyze the solid-state fluorescent properties and conductive properties of GQDs/TPS films. The fluorescent, conductive, morphological, mechanical, and optical properties of the GQDs/TPS films were characterized by ultraviolet-visible spectroscopy, surface resistance measurement, scanning electron microscopy, Fourier-transform infrared (FT-IR) spectroscopy, tensile testing, and X-ray diffraction (XRD). FT-IR studies indicated hydrogen bonding between the oxygen-containing groups on GQDs surfaces and the -OH groups in the TPS. The mechanical testing results showed the optimum GQDs loading of 10.9 wt% in the blend. XRD and TEM studies indicated uniform graphene dispersions in the TPS matrix for ≤10.9 wt% GQDs loading; further increases in loading caused agglomeration. The maximum photoluminescence intensity and conductivity of the materials were obtained at 10.9 wt% GQDs loading. These materials have potential applicability in flexible optoelectronic packaging materials.

A novel geometric error modeling optimization approach based on error sensitivity analysis for multi-axis precise motion system

In this paper, a novel error modeling approach for multi-DOF precise motion platform (MPMP) based on the error sensitivity analysis (ESA) is introduced. Sensitivity analysis (SA) is widely adopted for finding the essential parameters in system in mathematical way. This paper leads an error sensitivity analysis based on Monte Carlo thought into geometric error model. Through comparing the variance between the set of evaluated error and corresponding orientation deviations, a sensitive order with several sensitive levels can be developed. Conventional error modeling method only concentrates the systematic accuracy, while calculation efficiency is also important. Thus, this error modeling optimization approach based on sensitivity analysis is beneficial for the high-accuracy and high-quantity manufacture environments, which is more precise and effective. It also can save the computational volume for the calculation in error model. A case study of the new error modeling optimization procedure for six-axis stage in the alignment in optoelectronic packaging system (OPS) is carried out. The time-consumed results indicate that the optimized error model can not only keep high-accuracy requirement, but also improve the computational efficiency, which is informative and effective for MPMP motion control. For large number working situation, the optimized error model is available as well.

Inverse Kinematic Modeling of a 6-PSS Compliant Parallel Platform for Optoelectronic Packaging

This paper presents an inverse kinematic analysis of a 6-Prismatic-Spherical-Spherical (6-PSS) compliant parallel platform for optoelectronic packaging. The platform is driven by the piezoelectric motors, which combines the advantages of parallel platforms and wide-range flexure hinges. Since the rotation center of the wide-range flexible hinges constantly varies with the motion of the platform, it causes much error for positioning accuracy of the platform in applications. In this paper, an inverse kinematic solution based on elastokinematic analysis is proposed, in which the deformation of the wide-range flexure hinges is considered. And finally, several different cases based on the elastokinematic model are given, the results prove this method effective.

Investigation of stamping and heat treatment processes on the microstructure and blanking characteristics of Au80Sn20 eutectic alloy

Au80Sn20 eutectic alloy solder is extensively used in high-end microelectronics and optoelectronics packaging because of its good liquidity, high thermal conductivity, excellent resistance to fatigue, corrosion and creep. However, the brittleness and hardness of the δ-AuSn phase and ζ’-Au5Sn phase and massive primary phase make the processing and molding of Au80Sn20 eutectic alloy very difficult leading to inevitably limitations of its application. To improve the blanking ability of Au80Sn20 eutectic alloy, effects of stamping temperature, heat treatment on blanking of Au80Sn20 eutectic alloy were studied in this paper. Results showed that Au80Sn20 eutectic alloy had poor blanking performance at room temperature. However, the hot blanking process can reduce the hardness of the alloy which could improve the blanking performance significantly. With the extension of annealing time, the high temperature hardness of the alloy decreased first and then increased, reflecting that, suitable annealing process can reduce the residual stress in the alloy and reduce the adverse effects of the annealing process in the anisotropy of the initial lamellar eutectic structure. At the same time, ultrathin Au80Sn20 solder ring with smooth edge, can be made from an equiaxed eutectic structure in which the grains are uniformly fine if annealed for 120 min at 260 °C.

An inverse kinematic analysis modeling on a 6-PSS compliant parallel platform for optoelectronic packaging

Multiple degree of freedom motion platform is always one of the important components in optoelectronic packaging systems, its characteristics have a vital impact on the performances of optoelectronic packaging. This paper presents a 6-Prismatic-Spherical-Spherical compliant parallel platform for optoelectronic packaging. This platform is a kind of parallel layout structure, which uses the piezoelectric motors as active joints and the large-stroke flexure hinges are employed as passive joints. An inverse kinematic modeling based on elastokinematic analysis is analyzed and deduced. The elastokinematic analysis considers the elastic deformation of the large-stroke flexure hinges in movement process, and improves the positioning accuracy of the compliant parallel platform in applications. The finite element analysis model and the prototype of the compliant parallel platform are developed, and the validity of the proposed method is finally verified. This paper provides a theoretical reference and experimental data for the inverse kinematic analysis of six degrees of freedom motion compliant parallel platforms with large-stroke flexure hinges.

A precision temperature control approach for piezoelectric jet dispenser

Abstract Jet dispenser is widely used in LED (light emitting diode), microelectronic and optoelectronic packaging field. Temperature fluctuation of adhesives is a significant factor which affects the consistency of jet dispenser. As the working condition of jet dispenser is variable, the traditional PID temperature control method cannot meet requirements of high precision dispensing. A new temperature control system is designed for a proposed jet dispenser. Fuzzy PID temperature control approach is applied in the system. Temperature fluctuation is decreased from ±3.2 to ±1.1 °C with the new system. The jetting performance will be improved with the temperature control approach.