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An ever-growing market demand for board (second) level packages (e.g., embedded systems, system-on-a-chip, etc.) poses newer challenges for its manufacturing industry in terms of competitive pricing, higher reliability, and overall dimensions. Such packages are encapsulated for various reasons including thermal management, protection from environme...
Citations
... Transfer moulding has been the dominant process used for the encapsulation of electronic components [1]. The feasibility and the benefits of implementing thermoset injection moulding for encapsulating PCB based electronic assemblies with the help of adhesive strength tests and moulding trials is already discussed and presented in [2,3]. Previously, a good amount of research has been conducted in-house related to fibre orientation dependant material models in the direction of thermo-mechanical [4] and thermal [5] analysis for the reliability prediction of electronic components as a part of moulded interconnect devices (better known as MIDs). ...
... Definitions of levels of packages ranging from a bare chip (level 0) to a housed electronic system (level 4) are derived from [1] and are already listed out in a previous article [3]. A board-level package (level 2), with market relevant electronic components including but not limited to resistors, electrolytic capacitors, small outline packages, ball grid arrays and micro lead frames mounted on a conventional printed circuit board (PCB) (55 mm × 55 mm × 1.55 mm) was conceptualized for the purpose of reliability tests. ...
A fibre orientation dependent material model of the thermoset is implemented to predict the lifetime of electronic components as a part of 2nd level encapsulated packages. Experimental data are used in combination with coupled simulations (process simulation – fibre orientation dependant material model – thermo-mechanical simulation) for defining this lifetime prediction model. An already existing lifetime prediction model based on the Coffin-Manson relation is used initially to evaluate the prediction accuracy. The prediction model is then adjusted and fitted for the current application.
... An assessment of thermoset injection molding for the encapsulation of PCBs with surface-mounted electronic components was presented in a previous work [1]. During that assessment, mold trials were package to protect itself from external harmful media and withstand or overcome adverse environmental conditions, is brought in by means of a board-level encapsulation. ...
... An assessment of thermoset injection molding for the encapsulation of PCBs with surface-mounted electronic components was presented in a previous work [1]. During that assessment, mold trials were carried out as a part of a chalked out design of experiments (DoE) with PCBs of different transition temperatures (125 °C and 170 °C) and different encapsulation thicknesses (0.25 to 1 mm) to evaluate the implementation of thermoset injection molding as an alternative to other dominant methods for the purpose of the encapsulation of board-level packages. ...
... An example of such an encapsulated package is shown in Figure 1. The definition of levels of packaging (here, 2nd level package) is taken from [2] and was also summarized in [1]. As mentioned already in [1], extensive literature is not available on this particular topic (encapsulation of 2nd level packages with the help if thermoset injection molding). ...
A drastically growing requirement of electronic packages with an increasing level of complexity poses newer challenges for the competitive manufacturing industry. Coupled with harsher operating conditions, these challenges affirm the need for encapsulated board-level (2nd level) packages. To reduce thermo-mechanical loads induced on the electronic components during operating cycles, a conformal type of encapsulation is gaining preference over conventional glob-tops or resin casting types. The availability of technology, the ease of automation, and the uncomplicated storage of raw material intensifies the implementation of thermoset injection molding for the encapsulation process of board-level packages. Reliability case studies of such encapsulated electronic components as a part of board-level packages become, thereupon, necessary. This paper presents the reliability study of exemplary electronic components, surface-mounted on printed circuit boards (PCBs), encapsulated by the means of thermoset injection molding, and subjected to cyclic thermal loading. The characteristic lifetime of the electronic components is statistically calculated after assessing the probability plots and presented consequently. A few points of conclusion are summarized, and the future scope is discussed at the end.
