Automated Assembly Technologies Research Articles

Modular ceramic scaffolds for individual implants

Ideal artificial bone grafts aim for multiscale porosity, high mechanical strength and ensure rapid vascularization for bone ingrowth. In this work modular ceramic arteriovenous loops (AV-loops) with a hierarchical porosity approach were designed and manufactured to meet these criteria and to exceed the poor mechanical strength of monolithic scaffolds. Bioactive building blocks (β-TCP, HAp, BCP) with dimensions of 1.5–3.0 mm were prepared by injection molding and assembled to complex AV-loop scaffolds using a customized automated assembly technology (pick and place). The building blocks were bonded with a biocompatible adhesive. Single building blocks are characterized by a compressive strength of 112.4–134.5 MPa with a residual sintering porosity of 32.2–41.5%, matching the strength of cortical bone of 100–230 MPa. The compressive strength of the modular assemblies varied between 22.3 and 47.6 MPa primary depending on the building block arrangement. The achieved compressive strengths are superior to current monolithic AV-scaffolds and sufficient for the implantation as non-load-bearing AV-loop scaffolds in isolation chambers. The modular AV-loop scaffolds provide a hierarchical interconnected pore network (P = 58.8%) combining small macropores of 4.1–4.3 µm size for possible enhanced protein absorption and large gradient macropores of 200–1700 µm size for optimum vascularization and complete bone ingrowth. The modular building block approach allows to design patient individualized scaffolds with complex hierarchical pore networks. The pore volume, size and geometry as well as the biological response can effectively be tuned by changing the dimensions, shape and placing gap of the bioactive building blocks. Statement of SignificanceGold standard of bone replacement in case of surgery or cancer is still own bone material usually taken from the hip/arm or leg in second surgery with poor mechanical properties and limited amount. To avoid a second surgery and provide mechanical strong scaffold structures for fast patient regeneration a novel modular building block approach is used. This allows complex scaffold geometry with a hierarchical interconnection porosity for blood vessel ingrowth. The pore volume, size and geometry as well as the biological response can effectively be tuned by changing the dimensions, shape and placing gap of the bioactive building blocks.

Using two feed-forward layers for fault detection of hole

Automated assembly technology is a major component of modern aerospace manufacturing. Hole-Making Robot (HMR)s can significantly improve the efficiency of the aircraft manufacturing and can also ensure reliability of processing. The machining accuracy of the HMR depends on the precision of the mechanism, the accuracy of hole-positioning, and the vertical degree of the hole. Evaluating the precision of the hole system requires a complete set of inspection systems to measure the relevant hole parameters. Visual detection technology can provide more information on the object, which in theory is better suited to simulate real world applications. Due to the rapid development of current visual technology and the actual demand of aviation holes, this paper attempts to apply Convolution Neural Network (CNN) technology to the concrete task of visual inspection and improve the performance of visual inspection systems. Hole classification and hole flaw detection are realized via two feed-forward layers. We created a dataset of 1300 images of holes for testing. These were collected from various sources. The highest accuracy was 98.15% and was achieved using the two feed-forward neural network algorithm.

An automated assembly technology for large mobile radar antenna

Purpose Large-scale mobile radars are still erected manually by using lifting equipment, which often fails to meet the requirements on precision, quality and efficiency in the erecting process. This paper aims to introduce techniques for automatic assembly of large mobile radar antenna. Design/methodology/approach A large-scale metrology system for accurate identification of the positions and orientation of the radar antenna components is presented. A novel three-degree-of-freedom parallel mechanism is designed to realize orientation adjustment of three axes synchronous, and, thus guarantees the efficiency and accuracy of positioning process. Findings The system described in this paper is practicable in outdoor environment and provides a holistic solution that gives full consideration of the operation conditions and the environmental influences. In performance evaluation tests, the measured absolute accuracy is less than ±1 mm and repeatability is less than ±0.5 mm in the positioning task for 10 × 3 m large antenna. Originality/value This paper presents a new concept of an automatic assembly technology for the large radar antenna application.

Wafer Level Solder Bumping and Flip Chip Assembly with Solder Balls Down to 30μm

The most important technology driver in the electronics industry is miniaturization mainly driven by size reduction on wafer level and cost. One of the interconnection technologies for fine pitch applications with the potential for highest integration and cost savings is Flip Chip technology. The commonly used method of generating fine pitch solder bumps is by electroplating the solder. This process is difficult to control or even impossible if it comes to ternary or quaternary alloys. The work described in this study addresses the limitations of existing bumping technologies by enabling low-cost, fine pitch bumping and the use of a very large variety of solder alloys. This flexibility in the selection of the solder materials and UBM stacks is a large advantage if it is essential to improve temperature cycling resistance, drop test resistance, or to increase electromigration lifetime. The technology allows rapid changeover between different low melting solder alloys. Tighter bump pitches and a better bump quality (no flux entrapment) are achievable than with screen printing of solder paste. Because no solder material is wasted, the material costs for precious metal alloys like Au80Sn20 are much lower than with other bumping processes. Solder bumps with a diameter between to date 30 μm and 500 μm as well as small and large batches can be manufactured with one cost efficient process. To explore this potential, cost-efficient solder bumping and automated assembly technologies for the processing of Flip Chips have been developed and qualified. Flip Chips used in this study are 10 mm by 10 mm in size, have a pitch of 100 μm and a solder ball diameter of 30 μm, 40 μm or 50μm, respectively. Wafer level solder application has been done using wafer level solder sphere transfer process or solder sphere jetting technology, respectively. The latter tool has been used for many years in the wafer level packaging industry for both Flip Chip and chip scale packaging applications. It is commonly known in the industry as a solder ball bumping equipment. For the described work the process was scaled down for processing solder spheres with a diameter of 30 μm what was never done before that way worldwide. The research has shown that the underfill process is one of the most crucial factors when it comes to Flip Chip miniaturization for high reliability applications. Therefore, high performance underfill material was qualified initially [1]. Final long term reliability testing has been done according to MIL-STD883G, method 1010.8, condition B up to thirteen thousand cycles with excellent performance of the highly miniaturized solder joints. SEM/EDX and other analysis techniques will be presented. Additionally, an analysis of the failure mechanism will be given and recommendations for key applications and further miniaturization will be outlined.

Machine tools become much more than just a lathe or milling machine

PurposeTo review the International Manufacturing Technology Show in Chicago with emphasis on innovations in applying automation to manufacturing and assembly.Design/methodology/approachIn‐depth interviews with exhibitors of automated assembly and manufacturing technology.FindingsBuilding of production machinery is moving toward offering automated assembly or production cells and away from building single purpose equipment. Robots are married to machine tools for much more than just tending.Practical implicationsUsers in almost any manufacturing realm will find that automated assembly technologies are now addressing all types of production requirements. No longer is it necessary to think only million off part runs can be produced in an automated manner. Machine tool builders are including testing, finishing, marking, assembly and other secondary operations within the basic machining unit for a wide range of production volumes.Originality/valueIllustrates that automation can even be applied to “made to order” type production.

Robots great and small at Hanover

Reports from the Hanover Fair on new developments in automated assembly technology, particularly robotic assembly, outlines the latest robot hardware and software innovations to be launched on the market, describes new applications being taken up by industry.

Autumn shows roundup

A report on three major American automation shows where innovative products and automated assembly technologies formed a focus. Products reviewed include grippers, actuators, assembly modules, dispensing controller and pneumatic components from a number of suppliers.