Method of attaching components to printed cirucuit board with reduced accumulated tolerances
US9865479B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 2016 |
| Grant date | Jan 9, 2018 |
| Priority date | — |
| Expiry date | Apr 15, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/1476
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method is provided for attaching components to pads on a PCB, where total accumulated tolerances are reduced by separating accumulated tolerances into multiple processes. The method includes performing first and second processes having first and second accumulated tolerances, respectively. The first process includes placing a first stencil over the PCB, the first stencil defining first apertures corresponding to the pads; printing solder paste onto the pads using the first stencil; and reflowing the printed solder paste to form corresponding solder bumps on the pads. The second process includes placing a second stencil over the PCB, the second stencil defining second apertures corresponding to the pads; printing flux onto the solder bumps using the second stencil; placing at least one component on the printed flux; and reflowing the printed flux and the solder bumps to form corresponding solder joints between the at least one component and the first pads, respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.