An integrated circuit can be fabricated on a semiconductor die. The die can also be referred to as a chip, and the die can be a so-called “flip chip.” A flip chip has a surface that includes conductive protrusions, which can be referred to as “bumps.” The die can be fragile and vulnerable to damage during handling. The die may be protected by a coating of epoxy or plastic. The die can also be mounted on an interposer, and the interposer can be handled instead of or in addition to the die.
An integrated circuit on the die can generate heat during operation, and a heat sink may be necessary to transfer heat from the die to a surrounding environment. A heat sink can be attached to the die with a thermal pad between the heat sink and the die. The thermal pad can be made removable upon removal of the heat sink. Compression of the thermal pad can facilitate thermal conductivity between the die and the heat sink. Some thermals pads include a metal core or a metal layer.
Corners and edges of the die, in particular, may be fragile and easily damaged due to stress concentration and heightened pressure. For example, the corners and edges of the die are likely to have a relatively small contact area with objects that contact the die, as compared to flat surfaces of the die. In particular, contact between a heat sink and the die may damage the die. Placement of the thermal pad may need to be precise for the pad to protect the entire die from damage by the heat sink during attachment.
The die can be mounted on an interposer, and the conductive leads can be electrically connected to wire leads of the interposer. The die can be bonded to the interposer mechanically or by an adhesive or thermosetting plastic that encases the die.
USPTO Backgrounds
USPTO Backgrounds