Molded Interconnect Devices Research Articles

Modeling of Thermoplastic Materials for the Process-Simulation of Press-Fit Interconnections on Moulded Interconnected Devices

This investigation is aimed at the modeling of both the fabrication process and the reliability of press-fit interconnections on moulded interconnect devices (MID). These are multifunctional three-dimensional substrates, produced by thermoplastic injection moulding for large-series applications. The assembly process and subsequently the durability of press-fit interconnections has been modeled and proved with a finite element software. Especially, a simulation tool for process optimizations was created and applied. In order to obtain realistic results, a creep model for the investigated base material, a liquid-crystal polymer (LCP), was generated and verified by experiments. Required friction coefficients between metal pin and base material were determined by adapting simulations and experiments. Retention forces of pins pressed into substrate holes during as well after the assembly process, and after temperature loads were predicted by simulations. Additionally, the decreasing extraction forces over time due to creep in the thermoplastic base material have been predicted for different storage temperatures as well with finite element analyses. Following, the numerical results of the process and reliability modeling were verified by experiments. It is concluded that the behavior of the mechanical contact of the pin-substrate system, can be suitably described time- and temperature-dependent.

Design and Simulation of 3D Layout for MID Based on Open CASCADE

Molded Interconnect Devices (MID) is an innovative technology which abandoned the conventional board and integrates the mechanical and electronic functions directly on materials. Due to the complex process, the existing MCAD and ECAD do not meet the requirements of MID, so an MID prototype system for design and simulation of 3D layout based on Open CASCADE has been developed in this paper. Through studying on the algorithm of 3D automatic routing, realized the functions of placement of 3D electronic components and 3D automatic routing. Also, simulation for 3D laser direct structuring and placement of electronic components with a six-axis robot has come true after studying manufacturing process of MID.

Aerosol-Jet Printing for Functionalization of Prototyping Materials for Electronic Applications

To meet the growing demand for adapted 3D electronic devices, e. g. for customized electronic components as well as for Molded Interconnect Devices in small batches, 3D aerosol-jet printing combined with widely-used rapid prototyping methods like stereolithography and powder bed based printing is investigated. Compared to other printing methods for fine pitch structures, the innovative contact- and maskless aerosol-jetting is advantageous for structuring of spatial substrates. This is due to the large viscosity range of processible inks, a flexible stand-off between substrate and nozzle as well as the focal length of the aerosol beam. Focus of the printing tests on stereolithography materials presented in the paper is the suitability of the nanoparticle silver inks (solvent: water and ethylene glycol, respectively) for additive manufacturing of conductor tracks concerning adhesiveness, conductivity and wettability, which can be improved by plasma treatment. Furthermore, test specimens were assembled by mounting of electronic components using isotropic conductive adhesive. Long term reliability tests of these specimens (thermal cycling at −40 °C/+125 °C; temperature humidity test 85 °C/85 % r. h.) were performed in respect of conductivity of circuit tracks and quality of the adhesive joints. Compared to stereolithography materials aerosol-jet printing on powder bed materials requires adapted processing for functionalization. Due to the rough and porous surface and the low thermal stability of the PMMA powder materials, selective sintering of silver tracks by light was examined as well as printing on PU infiltrated surfaces. Despite of reduced contour definition, good conductivity was achieved.

Research on MID Application in RFID Based on Intelligent Materials

In this paper, the three-dimensional molding mechanical and electrical integration unit Molded Interconnect Devices (MID) is introduced. It is a new type of electronic component. And the following part of the article presents the Internet of Things (IOT). From the design and manufacture process, the paper describes the possibility and necessity using MID in IOT technology, as RFID and Embedded System. In the end, the MID design process is presented.

Design and Simulation of Molded Interconnect Devices with Two Shot Molding

Three Dimensional Molded Interconnect Devices (3D-MID) has enormous potential for rationalization in both manufacturing process and the freedom to design of mechatronic products. Two shot molding is one of the most important and commonly used methods among the various MID manufacturing processes. Currently, there is a lack of effective design and simulation tools that can be used for MID with two shot molding. In this paper, an integrated product model using feature technology, some MID-specific design functions, and one special interface based on the API of Moldflow Plastics Insight (MPI) and the COM-Technology are presented. These developed product model, functions and interface increase the efficiency of the MID design process, and the design and simulation integrated environment also towards the rational and optimal design of MID products with two shot molding.

Three-dimensional automatic routing for the design of moulded interconnect devices

One of the fundamental innovations in the field of mechatronics is the direct material integration of mechanical and electronic functions through using moulded interconnect devices (MID) technology. Unlike conventional circuit boards, they are not limited to two dimensions but offer the possibility to arbitrarily lay printed circuit traces on the surfaces of the three-dimensional carrier. Traditional 2D layout function in electronic computer aided design (ECAD), especially automatic routing algorithm cannot be directly applied in MID. In this article, two 3D routing algorithms with their own advantages and disadvantages are presented. The related 3D routing functions, which are not supported by conventional mechanic CAD (MCAD) and ECAD systems, have been integrated in the design system MIDCAD. With these 3D routing functions, MIDCAD enables a more effective product design based on the MID technology.

MEMS Packaging with 3D-MID Technology

3D-MID (three dimensional molded interconnect devices) technology (which is already broadly used for 3D-MID mobile phone antennas) is also used for MEMS packaging and sensors applications. 3D-MID allows miniaturization by the integration of mechanical and electronic functions in one part. The 3D electronic circuit is integrated into a 3D plastic casing or carrier, making it possible to achieve much more compact construction and much greater function density. More and more applications involving electrical and electro-optical circuits are made using 3D-MID technology. Typical 3D-MID applications are: Sensor packaging, LED packaging, security casings, RFIDs and Antennas. The main areas of application are in the automotive, medical, industrial technology and telecommunications sectors.

Integration of 3D-Routing for the Design of Molded Interconnect Devices

One of the fundamental innovations in the field of mechatronics is the direct material integration of mechanical and electronic functions using Molded Interconnect Devices (MID technology). Unlike conventional circuit boards, they are not limited to two dimensions but offer the possibility to arbitrarily lay printed circuit traces on the surfaces of the 3D carrier, traditional 2D routing function in EDA cannot be directly applied in MID design. In this paper, two new 3D automatic routing methods are introduced. One method is based on a grid graph and extends Hadlock’s minimum detour algorithm; the other is gridless and combines the A*-algorithm and an extension of Hightower’s algorithm. The related 3D routing functions, which are not supported by conventional MCAD und ECAD systems, are integrated in the design system MIDCAD. With these 3D routing functions, MIDCAD enables a more effective product design based on the MID technology.

Two-component microinjection moulding for MID fabrication

Moulded interconnect devices (MIDs) are plastic substrates with electrical infrastructure. The fabrication of MIDs is usually based on injection moulding, and different process chains may be identified from this starting point. The use of MIDs has been driven primarily by the automotive sector, but recently, the medical sector seems more and more interested. In particular, the possibility of miniaturisation of three-dimensional components with electrical infrastructure is attractive. The present paper describes possible manufacturing routes and challenges of miniaturised MIDs based on two-component injection moulding and subsequent metallisation. This technology promises cost effective and convergent manufacturing approaches for both macro- and microapplications. This paper presents the results of industrial MID production based on two-component injection moulding and discusses the important issues for MID production that can modulate the qualities of final MID. The results and discussion presented here can be a valuable user guide for mass production of moulded interconnect devices.

Experimental investigation of the factors influencing the polymer–polymer bond strength during two-component injection moulding

Two-component injection moulding is a commercially important manufacturing process and a key technology for combining different material properties in a single plastic product. It is also one of most industrially adaptive process chain for manufacturing so-called moulded interconnect devices (MIDs). Many fascinating applications of two-component or multi-component polymer parts are restricted due to the weak interfacial adhesion of the polymers. A thorough understanding of the factors that influence the bond strength of polymers is necessary for multi-component polymer processing. This paper investigates the effects of the process conditions and geometrical factors on the bond strength of two-component polymer parts and identifies the factors which can effectively control the adhesion between two polymers. The effects of environmental conditions on the bond strength are also investigated. Investigation shows that melt and mould temperatures are vital process parameters that influence the bond strength. Besides this, surface roughness of the first-shot part and environmental factors like moisture have profound influence on the bonding of the two materials. The selections of materials and environmental conditions were done based on the suitability of MID production, but the results could be useful for two-component polymer processing for a wide range of industrial applications. The results and discussion presented in this paper are only valid for the two-component plastic parts moulded by over moulding in cavity-transfer process.

Circuit Pattern Structuring of Molded Interconnect Devices by Transmission Laser Beam

A preliminary study on laser structuring of thin metal film on shadowed surface of molded interconnect devices (MID) was carried out. For this purpose, a structuring method that removes metal film that is deposited on transparent plastic by laser irradiation shooting the film not directly but through the plastic is proposed. Several tests using copper film of 0.3μm in thickness deposited on cycloolefine copolymer (COC) plates and THG-YAG laser were performed. With respect to preciseness of structuring, the new method was not inferior to normal direct shooting. Though estimated temperature rise by absorption of the laser by the plastic is such a small value of 0.74K due to high transparency of the plastic, it was damaged along the laser flight path. The damage can be categorized into three groups. One occurs on the whole flight path. This type of damage reduces as laser power is decreased, and an intensity that eliminates the damage without sacrificing quality of structuring was found. Another occurs in places on the path. This is also reduced as the laser power is decreased, but we did not find a laser power that can prevent this damage and provides correct structuring at the same time. The other one was found on the plastic surface from which the thin film has been removed. However, this type of damage is even milder than the case of conventional laser structuring.

Horizontal and vertical integration of product data for the design of moulded interconnect devices

In this paper, a methodology for the vertical and the horizontal integration of product data fitted to the needs of Moulded Interconnect Devices (3D-MID) is presented. For that purpose, an integrated product model based on STEP and the feature technology is developed. The application objects and schemas of STEP AP210 are used and extended to support the horizontal collaboration between electronic and mechanical design. Special attention is paid to the description of the three-dimensional structure of the circuit carrier and the circuit traces running within it and on its surface. In addition, the integrated product model also supports the hierarchical collaboration between upstream MID design and downstream simulation and manufacturing. Based on this product model, an effective communication between MID design in MIDCAD and the simulation of the injection moulding process in MOLDFLOW and manufacturing utilising MID-specific automatic placement equipment could be established.

Influences on the reflow soldering process by components with specific thermal properties

PurposeThe purpose of the paper is to focus on the research into components with specific thermal properties and their influences on the reflow soldering process.Design/methodology/approachAfter a brief introduction, the paper gives an overview of the necessity of thermal management on printed circuit boards (PCBs) and the possible effects on the manufacturing of electronic devices. In the next sections, different test boards are presented for investigations into different thermal effects during soldering. The last section deals with the influences of molded interconnected devices (MIDs) on the reflow soldering process.FindingsThe investigations show that components from the thermal management influence the reflow soldering process more or less. The highest impacts on the soldering process are from components with a thermal connection to the electrical component and its solder joint. All results from the investigations have in common that the thermal influence can only be compensated by increasing the temperature during soldering. However, this significantly increases the risk of overheating the electrical components or the PCB itself.Research limitations/implicationsThis paper shows only the influence of some of the effects caused by thermal management on the reflow soldering process. Furthermore, vapour phase soldering is not considered, but actual investigations are carried out on vapour phase soldering ovens as well.Originality/valueThermal management becomes more and more important with the increasing functionality of electrical components and electronic devices. This topic has been the subject of a large number of articles. However, this paper deals with influences that thermal management has on the soldering process during the manufacturing of the electronic device.

Fabrication of Molded Interconnection Devices by Ultrasonic Hot Embossing on Thin Polymer Films

Ultrasonic hot embossing allows fabrication of metal patterns onto a polymer film with a low cost and rapid process. A polymer layer with a thin metal film on top is welded onto the polymer substrate where there are protruding micro structures on the tool. Edges around the protruding structures cut the metal layer and ensure electrical insulation. The entire process performs in a few seconds. The non-welded areas are mechanically removed after this process. An antenna of a radio frequency identification device (RFID) and a flexible membrane keyboard were fabricated by embossing 10- mum-thick conductive paths from an aluminum foil onto polypropylene films, 150 and 250 mum in thickness. Antenna circuits have been proven to show the expected resonance frequencies and the keyboard was successfully employed as an input device for a PC.

Design considerations for the hot embossing of microstrip antennas on plastic foils

In this contribution, fundamental design considerations for a novel metallization technique to realize millimeter-wave microstrip structures are presented. This hot embossing technology is a fast and economic process originating from the production of three-dimensional molded interconnect devices. Conductive structures are coated onto plastic parts or plastic foils using a heated stamp. This approach shows high potential and therefore will be investigated for the fabrication of low-cost printed antennas at millimeter-wave frequencies. The focus of this contribution is on design guidelines considering process parameters and interactions with substrate and copper foil characteristics derived from the fabrication and measurement of single microstrip patch antenna prototypes for radar applications in the industrial, scientific and medical (ISM) band at 24 GHz. Far-reaching potential lies in the utilization of the three-dimensional manufacturing technology for the construction of conformal integrated antenna systems based on the thermoforming capabilities of polymer substrates.

Comparison of methods for broadband electromagnetic characterization of Molded Interconnect Device materials

Abstract. Combining the Molded Interconnect Device technology with the Laser Direct Structuring technology exhibits the potential of designing electrical and mechanical components on three-dimensional surfaces to increase functionality, level of integration and to reduce costs. When taking advantage of this technology especially in the design of RF devices, a precise knowledge of the electromagnetic parameters of the MID material is required, as the complex permeability and permittivity strongly influence the device performance. At present time, these materials are not electromagnetically characterized in the RF frequency range. In this paper different methods are therefore presented and compared with respect to their potentials for broadband electromagnetic characterization of Molded Interconnect Device materials.

A multilayer process for the connection of fine‐pitch‐devices on molded interconnect devices (MIDs)

PurposeThe 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.Design/methodology/approachA 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.FindingsUsing 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.Research limitations/implicationsA 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.Originality/valueThe 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.

A Multilayer Process for 3D-Molded-Interconnect-Devices to Enable the Assembly of Area-Array Based Package Types

Three-dimensional molded interconnected devices (3D-MID) extend the range of classical printed circuit boards (PCB) to the third dimension. Electrical circuits can be routed over any surface forms. This enables innovative applications and new design possibilities. The combination of circuit carrier, housing, and further functions results in an increased density of integration with decreased process effort. One limitation of recent 3D-MID technologies is their incompatibility with modern area-array based electronic packages. Usually the high I/O count of such package types makes routing in only one electrical layer impossible and necessitates multilayer structures. To meet the future requirements of 3D-MID, a compatible fine-pitch multilayer process is developed. In combination with an established 3D-MID metallization process, it allows the flip-chip mounting of area-array packages. A sample device with three metallization layers is fabricated. The mechanical and electrical multilayer properties are investigated.

Process chains for the manufacturing of molded interconnect devices

Moulded interconnect device (MID) can be defined as an injection-molded plastic part that incorporates both electrical and mechanical functionalities in a single device. It is a relatively new area with enormous potential for industrial applications. At present, there are a number of available process chains for the manufacturing of MIDs. This paper presents a comparison among the MID manufacturing process chains, and it presents experimental results based on two of the most industrially adapted processes. Experiments with two-component (2k) injection molding and subsequent selective metallization show the dilemma between the polymer–polymer bond strength and selective metallization. Two new pairs of commercial polymer materials are introduced which are suitable for selective metallization and have the potential for industrial applications. Experiments with the laser direct structuring (LDS) process show that the success of the process is heavily dependant on the choice of material. It presents how the surface topographies are varied as a function of laser type and material choice. The amount of seed metal particles in the plastic material is a crucial factor that controls laser-induced metallization.

Material and processing behaviour of thermoplastics filled with low melting metals

Polymer blends filled with solid fillers such as metal fibres or carbon black can no longer fulfil the increasing demands on electrical and thermal conductivity. High levels of hard fillers increase the melt viscosity unacceptably, causing a minimised process window, high mechanical stresses on the polymer as well as an increased abrasion on both mould and machinery. The high electrical conductivity required for connectors, moulded interconnect devices or sensors can be achieved by a novel material developed by IKV, Aachen, and Siemens AG, Erlangen/Germany. It combines fibre filled polymer blends with low melting metal alloys. These alloys have the advantage of being already molten during processing and of not solidifying before the cooling phase. The result is a free flowing material that allows the injection moulding of complex geometries. A passage conductivity of the moulded parts in the range of pure metals can be achieved.