Remelting process for printed circuit boards
AssigneeSiemens Aktiengesellschaft
InventorBernhard Brabetz
Life of this patent
Estimating the term…
Abstract
The appearance of stresses when remelting printed circuit boards should be avoided. The remelting process of the tin-lead layers ensues in a pressure vessel at elevated ambient gas pressure. The quantity of heat required for the remaining can be supplied on the basis of known methods (infrared irradiation, oil, etc.) or by heating the compressed gas itself. As needed, the compressed gas can be designed as a protective atmosphere. Printed circuit boards of any and all types can be remelted by this process.
Claims24
A method for remelting voltaic tin or tin-lead layers on a printed circuit board, comprising the steps:
- positioning the printed circuit board entirely within a closed vessel at least partially filled with a gas;
- elevating the ambient pressure of the gas;
- in a subsequent and separate step supplying a remelting heating to the printed circuit board at the elevated pressure.
A method for remelting voltaic tin or tin-lead layers on a printed circuit board, comprising the steps:
- positioning the printed circuit board in a closed vessel at least partially filled with a gas;
- elevating the ambient pressure of the gas;
- supplying a remelting heating to the printed circuit board by thermal radiation.
A method for remelting voltaic tin or tin-lead layers on a printed circuit board, comprising the steps:
- positioning the printed circuit board entirely within a closed vessel partially filled with a gas and partially filled with a heated liquid;
- elevating the ambient pressure of the gas;
- supplying a remelting heating to the printed circuit board by immersing said printed circuit board in said liquid.
A method for remelting metal layers on a printed circuit board, comprising the steps:
- positioning the printed circuit board entirely within a vessel at least partially filled with a gas;
- elevating the ambient pressure of the gas to at least 18 bar;
- supplying a remelting heating to the printed circuit board.
Dependencies are inferred from the claim text.