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The purpose of this paper is to present a new multilayer process for three‐dimensional molded interconnect devices (3D‐MIDs) that allows the assembly of modern area array packaged semiconductors.

A new 3D‐MID multilayer process based on local overmolding is developed. To investigate this new process, a 3D demonstrator is designed, simulated and fabricated. Various technologies such as injection molding, maskless laser assisted electroless metallization, overmolding and laser via drilling are used.

Using the new 3D‐MID multilayer process a 3D demonstrator with three metallization layers is fabricated. Injection molding simulation is utilized to ensure a feasible demonstrator design. It is shown that a surface laser treatment improves layer‐to‐layer adhesion during the process. Shear and pull tests prove the adhesion promotion. The 3D fine‐pitch‐metallization is done down to 60 μm track width. Via resistance is measured by four terminal sensing in agreement with previous results. Design rules for process compatible vias are introduced. The fabricated demonstrator is suitable for flip‐chip‐based area array packaged semiconductors.

A proof of concept is given by the fabricated demonstrator. Further, work should include reliability tests of the multilayer structures and improvement of individual process steps.

The paper describes a new multilayer process for 3D‐MIDs. It overcomes existing restrictions regarding the electrical routing on 3D‐MID surfaces. The compatibility of area array packaged semiconductors with a high‐inputs/outputs count and the 3D‐MID technology is improved.

The purpose of this paper is to propose and analyse computationally a new concept for mechanical interlocking between metal and plastics. The approach utilizes some of the ideas used in the spot‐clinching joining process and is appropriately named “clinch‐lock polymer metal hybrid (PMH) technology.”

A new approach, the so‐called “direct‐adhesion” PMH technology, is recently proposed Grujicic et al. to help meet the needs of automotive original equipment manufacturers and their suppliers for a cost‐effective, robust, reliable PMH technology which can be used for the manufacturing of load‐bearing body‐in‐white (BIW) components and which is compatible with the current BIW manufacturing‐process chain. Within this approach, the necessary level of polymer‐to‐metal mechanical interconnectivity is attained through direct adhesion and mechanical interlocking.

In an attempt to fully assess the potential of the clinch‐lock approach for providing the required level of metal/polymer mechanical interlocking, a set of finite‐element based sheet‐metal forming, injection molding and structural mechanics analyses is carried out. The results obtained show that stiffness and buckling resistance levels can be attained which are comparable with those observed in the competing injection over‐molding PMH process but with an ∼3 percent lower weight (of the polymer subcomponent) and without the need for holes and for over‐molding of the free edges of the metal stamping.

The paper presents a useful discussion of clinch‐lock joining technology's potential for fabrication of PMH load‐bearing BIW components.

This study aims to investigate the suitability of a multi-step prototyping strategy for producing pneumatic rotary vane actuators (RVAs) for the development of lightweight robots and actuation systems.

RVAs typically have cast aluminum housings and injection-molded seals that consist of hard thermoplastic cores and soft elastomeric overmolds. Using a combination of additive manufacturing (AM), computer numerical control (CNC) machining and elastomer molding, a conventionally manufactured standard RVA was replicated. The standard housing design was modified, and polymeric replicas were obtained by selective laser sintering (SLS) or PolyJet (PJ) printing and subsequent CNC milling. Using laser-sintered molds, actuator seals were replicated by overmolding laser-sintered polyamide cores with silicone (SIL) and polyurethane (PU) elastomers. The replica RVAs were subjected to a series of leakage, friction and durability experiments.

The AM-based prototyping strategy described is suitable for producing functional and reliable RVAs for research and product development. In a representative durability experiment, the RVAs in this study endured between 40,000 and 1,000,000 load cycles. Frictional torques were around 0.5 Nm, which is 10% of the theoretical torque at 6 bar and comparable to that of the standard RVA. Models and parameters are provided for describing the velocity-dependent frictional torque. Leakage experiments at 10,000 load cycles and 6 bar differential pressure showed that PJ housings exhibit lower leakage values (6.8 L/min) than laser-sintered housings (15.2 L/min), and PU seals exhibit lower values (8.0 l/min) than SIL seals (14.0 L/min). Combining PU seals with PJ housings led to an initial leakage of 0.4 L/min, which increased to only 1.2 L/min after 10,000 load cycles. Overall, the PU material used was more difficult to process but also more abrasion- and tear-resistant than the SIL elastomer.

More work is needed to understand individual cause–effect relationships between specific design features and system behavior.

To date, pneumatic RVAs have been manufactured by large-scale production technologies. The absence of suitable prototyping strategies has limited the available range to fixed sizes and has thus complicated the use of RVAs in research and product development. This paper proves that functional pneumatic RVAs can be produced by using more accessible manufacturing technologies and provides the tools for prototyping of application-specific RVAs.

This paper aims to propose a new solution for producing customized three-dimensional (3D)-printed flat-shaped splints, which are then thermoformed to fit the patient’s hand. The splint design process is automated and is available to clinicians through an online application.

Patient anthropometric data measured by clinicians are associated with variables of parametric 3D splint models. Once these variables are input by clinicians in the online app, customized stereo lithography (STL) files for both splint and half mold, in the case of the bi-material splint, are automatically generated and become available for download. Bi-materials splints are produced by a hybrid manufacturing process involving 3D printing and overmolding.

This approach eliminates the need for 3D CAD-proficient clinicians, allows fast generation of customized splints, generates two-dimensional (2D) drawings of splints for verifying shape and dimensions before 3D printing and generates the STL files. Automation reduces splint design time and cost, while manufacturing time is diminished by 3D printing the splint in a flat position.

The app could be used in clinical practice. It meets the demands of mass customization using 3D printing in a field where individualization is mandatory. The solution is scalable – it can be extended to other splint designs or to other limbs. 3D-printed tailored splints can offer improved wearing comfort and aesthetic appearance, while maintaining hand immobilization, allowing visually controlled follow-up for edema and rapidly observing the need for revision if necessary.

An online application was developed for uploading patient measurements and downloading 2D drawings and STL files of customized splints. Different models of splints can be designed and included in the database as alternative variants. A method for producing bi-materials flat splints combining soft and rigid polymers represents another novelty of the research.

This study presents a method for fabricating multi-material objects using a hybrid additive and subtractive approach. By hybridizing the material composition in addition to the fabrication process, functional requirements can be met more effectively than through homogenous material parts produced using a single manufacturing process. Development of multi-material objects consisting of dissimilar materials that have been hampered by a lack of a structural interface compatible with in-envelope hybrid additive and subtractive manufacturing.

This research presents a novel method for producing multi-material components through in-envelope hybrid additive and subtractive manufacturing. This study attempts to address the absence of a metal-polymer interface by integrating polymer additive manufacturing into a five-axis mill. The ability of the polymer additive system to reproduce overhang geometries is assessed with different levels of cooling. The relationship between structural performance, cooling and material flow rate is evaluated for the deposited carbon fiber reinforced acrylonitrile butadiene styrene.

A mechanically interlocking root structure is developed to form an interface between a machined aluminum region and a polymer region of an object. The tensile strength of the metal-polymer object is measured and found to be on the same order of magnitude as the bulk three-dimensional printed polymer.

By targeting the material properties to the local functional requirements within a part and taking advantage of both additive and subtractive manufacturing processes, this study will enable broader design options and optimization of performance metrics.

The lead‐free solder joint reliability of several printed circuit board mounted high‐density packages, when subjected to temperature cycling was investigated by finite element modelling. The packages were a 256‐pin plastic ball grid array (PBGA), a 388‐pin PBGA, and a 1657‐pin ceramic column grid array. Emphasis was placed on the determination of the creep responses (e.g. stress, strain, and strain energy density) of the lead‐free solder joints of these packages.