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NASA-LLIS-1202
Lessons Learned – Vibration-Induced Failures of Electronic Component Leads as a Result of Improper Mechanical Packaging Design
Year: 2002
Abstract: Description of Driving Event:
A battery charger design was reported to have experienced catastrophic component failure during vibration testing, resulting in fractured and broken component leads of heatsink-mounted power devices. A photograph of the failed assembly (Fig. 1) clearly showed a pattern of damage consistent with repeated movement and flexure of the components. The primary cause of the unwanted movement was attributed to a design decision, in which the heatsink was allowed to "float" with respect to the printed wiring assembly.
A design change, which mechanically bonded the heatsink and the printed wiring assembly together, significantly reduced the incidence of component lead failures during vibration tests.
A visual examination of sample components supplied to JSC suggested that the use of unapproved tooling and processes during the component lead forming process was a contributing factor to the observed fractured and separated leads, with numerous sample components exhibiting leads with cracks (Fig. 2). Discussions with the vendor indicated that metallic tools (including a screwdriver) were employed to form the leads. Subsequent improvement in tooling and processes resulted in smoothly formed lead bends, without fractures or significant tooling marks.
A battery charger design was reported to have experienced catastrophic component failure during vibration testing, resulting in fractured and broken component leads of heatsink-mounted power devices. A photograph of the failed assembly (Fig. 1) clearly showed a pattern of damage consistent with repeated movement and flexure of the components. The primary cause of the unwanted movement was attributed to a design decision, in which the heatsink was allowed to "float" with respect to the printed wiring assembly.
A design change, which mechanically bonded the heatsink and the printed wiring assembly together, significantly reduced the incidence of component lead failures during vibration tests.
A visual examination of sample components supplied to JSC suggested that the use of unapproved tooling and processes during the component lead forming process was a contributing factor to the observed fractured and separated leads, with numerous sample components exhibiting leads with cracks (Fig. 2). Discussions with the vendor indicated that metallic tools (including a screwdriver) were employed to form the leads. Subsequent improvement in tooling and processes resulted in smoothly formed lead bends, without fractures or significant tooling marks.
Subject: Flight Equipment
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| contributor author | NASA - National Aeronautics and Space Administration (NASA) | |
| date accessioned | 2017-09-04T16:18:12Z | |
| date available | 2017-09-04T16:18:12Z | |
| date copyright | 02/11/2002 | |
| date issued | 2002 | |
| identifier other | TEVEQCAAAAAAAAAA.pdf | |
| identifier uri | https://yse.yabesh.ir/std/handle/yse/81628 | |
| description abstract | Description of Driving Event: A battery charger design was reported to have experienced catastrophic component failure during vibration testing, resulting in fractured and broken component leads of heatsink-mounted power devices. A photograph of the failed assembly (Fig. 1) clearly showed a pattern of damage consistent with repeated movement and flexure of the components. The primary cause of the unwanted movement was attributed to a design decision, in which the heatsink was allowed to "float" with respect to the printed wiring assembly. A design change, which mechanically bonded the heatsink and the printed wiring assembly together, significantly reduced the incidence of component lead failures during vibration tests. A visual examination of sample components supplied to JSC suggested that the use of unapproved tooling and processes during the component lead forming process was a contributing factor to the observed fractured and separated leads, with numerous sample components exhibiting leads with cracks (Fig. 2). Discussions with the vendor indicated that metallic tools (including a screwdriver) were employed to form the leads. Subsequent improvement in tooling and processes resulted in smoothly formed lead bends, without fractures or significant tooling marks. | |
| language | English | |
| title | NASA-LLIS-1202 | num |
| title | Lessons Learned – Vibration-Induced Failures of Electronic Component Leads as a Result of Improper Mechanical Packaging Design | en |
| type | standard | |
| page | 2 | |
| status | Active | |
| tree | NASA - National Aeronautics and Space Administration (NASA):;2002 | |
| contenttype | fulltext | |
| subject keywords | Flight Equipment | |
| subject keywords | Hardware | |
| subject keywords | Parts Materials & Processes |