Measurement of Effective Cure Shrinkage of Epoxy Molding Compound and Induced In-line Warpage during Molding Process
| dc.contributor.advisor | Han, Bongtae | en_US |
| dc.contributor.author | Kim, Changsu | en_US |
| dc.contributor.department | Mechanical Engineering | en_US |
| dc.contributor.publisher | Digital Repository at the University of Maryland | en_US |
| dc.contributor.publisher | University of Maryland (College Park, Md.) | en_US |
| dc.date.accessioned | 2023-10-12T05:39:52Z | |
| dc.date.available | 2023-10-12T05:39:52Z | |
| dc.date.issued | 2023 | en_US |
| dc.description.abstract | Cure shrinkage accumulated only after the gel point is known as effective cure shrinkage (ECS), which produces residual stresses inside molded components. The ECS of an epoxy-based molding compound (EMC) is measured by an embedded fiber Bragg grating (FBG) sensor. Under a typical molding condition, a high mold pressure inherently produces large friction between EMC and mold inner surfaces, which hinders EMC from contracting freely during curing. A two-stage curing process is developed to cope with the problem. In the first stage, an FBG sensor is embedded in EMC by a molding process, and the FBG-EMC assembly is separated from the mold at room temperature. The molded specimen is heated to a cure temperature rapidly in the second stage using a constraint-free curing fixture. The ECS of an EMC with a filler content of 88 wt% is measured by the proposed method, and its value is 0.077%. The measured ECS can be used to predict the warpage caused by molding processes. The validity of the prediction can be verified only by measuring the warpage during molding. A point-based measurement technique utilizing uniquely-generated multiple beams and binarization-based beam tracing method is developed to cope with the challenges associated with the warpage measurement during molding. The proposed method is implemented successfully to measure the warpage of a bimaterial disk that consists of aluminum and EMC as a function of time during molding process. Measurements are repeated to establish the measurement accuracy of the proposed method. | en_US |
| dc.identifier | https://doi.org/10.13016/dspace/wqsy-6j3n | |
| dc.identifier.uri | http://hdl.handle.net/1903/30973 | |
| dc.language.iso | en | en_US |
| dc.subject.pqcontrolled | Mechanical engineering | en_US |
| dc.title | Measurement of Effective Cure Shrinkage of Epoxy Molding Compound and Induced In-line Warpage during Molding Process | en_US |
| dc.type | Dissertation | en_US |
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