| 摘要 |
<p>An improved means and method is provided for encapsulating electronic devices (30) and other objects by transfer molding. The mold cavities (22) are arranged in rows, disposed adjacent to and parallel with slot-shaped encapsulant reservoirs (24), and coupled to the reservoirs by short feeder channels (25) of uniform length.</p><p>Preferably, a row of cavities (22) is located in a mirror symmetric fashion on either side of and parallel with each slot-shaped reservoir (24). A tightly fitting blade (23) moves in each slot-shaped reservoir (24) to compress and liquify the plastic encapsulant charge, injecting it into the mold cavities (22) containing the component (30) to be encapsulated. Plastic utilization can exceed 90%, and better control over molding conditions can be obtained because the plastic material reaches each mold cavity at the same stage of the liquification-solidification cycle. More cavities can be fitted in a given mold area because the usual central material pot (15) and runner-tree (14) are eliminated.</p> |
