| 摘要 |
The invention is a lead frame that has leads formed in two levels during the etching process in which the lead frame is formed. A lead frame form (40), or continuous strip of lead frame material, is coated on two sides with a photo resist material (41,43). Each photo resist coated side is patterned to define leads on the lead frame. The lead patterns (41,43, 42,44) on the two sides are offset from each other so that patterns on one side of the lead frame material alternate with the patterns on the other side of the lead frame material. Both sides of the photo resist patterned lead frame material are etched to a depth exceeding the thickness of a lead. The photo resist (41,43) material is then removed. The resulting lead frame has leads (50-56) that are in two levels, each level having leads offset by a lead width from the other level, but with an effective zero distance between leads horizontally. |
