废弃电路板的化学处理方法

随着电子产业的迅速发展,印刷电路板的废弃量也在逐年增加。大量的废弃印刷电路板可能对环境造成严重的污染。废弃印刷电路板具有极高回收价值,如果采用适当的方法对其进行回收,不但可以节省我国日益紧缺的矿产资源,而且对环境保护有着极大的意义。本文阐述了废弃电路板资源回收的经济意义和环境意义,并详细介绍了湿法处理、热解法处理和超临...     

Printed solid-state electrolytes for form factor-free Li-metal batteries

With the ever-growing interest in ubiquitous smart electronics and the Internet of Things, the demand for high-energy-density power sources with aesthetic versatility has increased tremendously. High energy density Li-metal batteries have attracted considerable attention for fulfilling the high energy density requirement of smart electronics. To obtain form factor-free Li-metal batteries with both design diversity and electrochemical reliability, printed solid-state electrolytes are required as a key component because of their viability for the printing/solidification-based fabrication process and electrode-customized chemical/physical properties. This review presents an overview of printed solid-state electrolytes for form factor-free Li-metal batteries with a focus on materials chemistry and fabrication requirements. In addition, their structural/physical/electrochemical properties were discussed in terms of compatibility with Li-metal batteries.     

印制线路板铜表面粗化液的新型添加剂

利用红外光谱、核磁共振谱等分析仪器结合分离技术对在印制线路板制作过程中应用性能较好的国外铜表面粗化液的添加剂进行了剖析,然后根据剖析结果和应用实验确定了新型铜表面粗化液的添加剂配方。应用化学分析方法测定了新型铜表面粗化液添加剂对双氧水的稳定性。该添加剂的应用性能达到了国外产品的水平。     

Simultaneous detection of lactate and glucose by integrated printed circuit board based array sensing chip

An integrated printed circuit board (PCB) based array sensing chip was developed to simultaneously detect lactate and glucose in mouse serum. The novelty of the chip relies on a concept demonstration of inexpensive high-throughput electronic biochip, a chip design for high signal to noise ratio and high sensitivity by construction of positively charged chitosan/redox polymer Polyvinylimidazole-Os (PVI-Os)/carbon nanotube (CNT) composite sensing platform, in which the positively charged chitosan/PVI-Os is mediator and electrostatically immobilizes the negatively charged enzyme, while CNTs function as an essential cross-linker to network PVI-Os and chitosan due to its negative charged nature. Additional electrodes on the chip with the same sensing layer but without enzymes were prepared to correct the interferences for high specificity. Low detection limits of 0.6 μM and 5 μM were achieved for lactate and glucose, respectively. This work could be extended to inexpensive array sensing chips with high sensitivity, good specificity and high reproducibility for various sensor applications.     

Highly reliable optical interconnection network on printed circuit board for distributed computer systems

A highly reliable interchip optical interconnection network on a printed circuit board (PCB) was designed and realized, and experiments confirmed that the data rate in each channel could reach above 3.125 Gbps and the bit error rate (BER) could be up to 1.27×10⁻¹⁸, which would be a good solution to the problem of communication bottlenecks between high-speed VLSI chips.     

ZnxCd1—xS薄膜的性质及ZnxCd1—xS／CdTe异质结太阳电池

采用丝网印刷方法制备了不同配比的ＺｎｘＣｄ１－ｘＳ多晶薄膜及异质结太阳电池，并利用Ｘ－射线衍射，光吸收分析技术和四探针测电导方法研究了薄膜的结构和性质，以及电池性能。     

铜电化学沉积在微孔金属化中的应用

以分布有微孔的印刷线路板(PCB)作为模板,按照PCB孔金属化工艺路线,研究乙醛酸化学镀铜和柠檬酸盐体系铜电沉积工艺在PCB微孔金属化中的应用.结果表明,乙醛酸化学镀铜和柠檬酸盐体系电沉积铜可以成功地应用于PCB微孔金属化加工工艺中.微孔化学镀铜金属化导电处理后,铜附着于微孔内壁,颗粒细小,但排列疏松且局部区域发生漏镀现象.微孔一经电镀铜加厚,镀层电阻显著下降;孔壁内外的铜沉积速率达到0.8:1.0;铜颗粒具有一定的侧向生长能力,能够完全覆盖化学镀铜时产生的微小漏镀区域;微孔内壁铜镀层连续、结构致密并紧密附着于内壁,大大增强了PCB上下层互连的导电性能.     

Solder joint inspection based on neural network combined with genetic algorithm

To improve the performance of automatic optical inspection (AOI), a neural network combined with genetic algorithm for the diagnosis of solder joint defects on printed circuit boards (PCBs) assembled in surface mounting technology (SMT) is presented. Six types of solder joint have been classified in respect to the reality in the manufacture. The images of solder joint under test are acquired and 14 features are extracted as input features for the classification. The neural network is easily become over-fitting because these input features are not independent of each other, so the genetic algorithm is introduced to select and remove redundant input features. The experimental results have proved that the neural network combined with genetic algorithm reduced the number of input feature and had a satisfying recognition rate.     

A low-temperature and short-annealing process for metal oxide thin film transistors using deep ultraviolet light for roll-to-roll processing

Solution-processed metal oxide semiconductors have superior electron mobility and stability than solution-processed organic semiconductors. However, their fabrication requires a very-high-temperature and long-time annealing process. In this study, we utilized deep ultraviolet (DUV) light to decrease both the temperature and time of the annealing process. High external energy is required to break the organic bonds in a metal oxide film, which is generally supplied by a high-temperature annealing process carried out for a long duration.Alternatively, the required high energy can be supplied more efficiently by irradiating the metal oxide film with DUV light for a shorter duration. In this work, we used DUV light whose peaks at 172 nm instead of the generally used mercury lamp, peaking at 254 and 185 nm. Owing to this difference, thin film transistors (TFTs) could be fabricated on silicon wafers at a lower temperature and shorter duration as compared to the conditions used in previous studies. Various conditions, such as the heating temperature, duration of DUV irradiation, and N₂ flow rate, were optimized to control the heating temperature so as to achieve a mobility of 4.44 cm²/V·s and on–off ratio of 2 × 10⁷, which are much higher than those of a transistor annealed at 300 °C for 30 min (mobility, 1.31 cm²/V·s and on–off ratio, 7 × 10⁵).     

Copper electroplating of PCB interconnects using megasonic acoustic streaming

In this research experimental and simulated analysis investigates the influence of megasonic (MS; 1 ± 0.05 MHz) acoustic-assisted electroplating techniques, with respect to the fabrication of through-hole via (THV) and blind-via (BV) interconnects for the Printed Circuit Board (PCB) industry. MS plating of copper down THV and BV interconnects was shown to produce measurable benefits such as increased connectivity throughout a PCB and cost savings. More specifically, a 700% increase of copper plating rate was demonstrated for THVs of 175 µm diameter and depth-to-width aspect ratio (ar) of 5.7:1, compared with electrodeposition under no-agitation conditions. For BVs, a 60% average increase in copper thickness deposition in 150 µm and 200 µm, ar 1:1, was demonstrated against plating under standard manufacturing conditions including bubble agitation and panel movement. Finite element modelling simulations of acoustic scattering revealed 1st harmonic influence for plating rate enhancement.