Method and apparatus for connecting at least one chip to an external wiring configuration
View Patent ↗An electrically conductive connection is produced between a chip and an external wiring configuration that is kept at a distance from the chip by spacers. Electrically conductive contact material is introduced into recesses in the external wiring configuration in order to produce the electrically conductive connection. This can be carried out economically, and allows a mechanically very robust electrical connection from the chip pads to the external wiring planes.
1. A method for connecting at least one chip to an external wiring configuration, which comprises:
providing a chip with chip pads;
forming conductor tracks and recesses in an external wiring configuration;
spacing the chip at a distance away from the external wiring configuration by placing spacer cushions between a surface of the chip and the external wiring configuration to keep the chip pads at a distance from the external wiring configuration and to form a gap between the chip and the external wiring configuration; and
forming electrically conductive connections between the chip and the external wiring configuration by introducing an electrically conductive contact material into the recesses in the external wiring configuration such that the electrically conductive contact material is in physical contact with the chip pads and the conductor tracks of the external wiring configuration, and such that the chip is not in physical contact with the external wiring configuration in areas other than the electrically conductive contact material and spacer cushions, thus forming a cavity between the chip and the wiring configuration in the areas other than the electrically conductive contact material and spacer cushions, and the electrically conductive contact material providing a mechanically robust electrical connection between the chip pads and the conductor tracks of the external wiring configuration.
2. The method according to claim 1 , wherein: contact is made between a number of chips and corresponding external wiring configurations in one process step.
3. The method according to claim 2 , wherein: when contact is made, the chips are still located on a wafer.
4. The method according to claim 1 , wherein: the contact material is a paste.
5. The method according to claim 1 , wherein: the contact material is an electrically conductive adhesive.
6. The method according to claim 1 , wherein: the contact material is a curing material.
7. The method according to claim 1 , wherein: the recesses are holes in the external wiring configuration.
8. The method according to claim 1 , wherein: the recesses are holes in a substrate.
9. The method according to claim 1 , wherein: the external wiring configuration and the chip form a fine pitch ball grid array product.
10. The method according to claim 1 , wherein: the external wiring configuration and the chip form a chip size package product.
11. The method according to claim 1 , wherein: the external wiring configuration and the chip form a wafer scale assembly product.
12. The method according to claim 1 , wherein: the external wiring configuration and the chip form a module assembly product.
13. The method according to claim 1 , wherein: the external wiring configuration and the chip form a chip on board product.
14. The method according to claim 1 , which comprises: using a print process to introduce the electrically conductive contact material into recesses.
15. The method according to claim 1 , which comprises: dispensing the electrically conductive contact material into recesses.
16. An apparatus for connecting at least one chip to an external wiring configuration, the apparatus comprising:
chip pads provided on the chip;
conductor tracks and recesses formed in the external wiring configuration;
spacer cushions for keeping the chip at a distance away from the external wiring configuration, said spacer cushions being placed on a surface of the chip to keep said chip pads at a distance from the external wiring configuration and to form a gap between the chip and the external wiring configuration; and a device for forming electrically conductive connections between the chip and the external wiring configuration by introducing an electrically conductive contact material into recesses in the external wiring configuration such that said electrically conductive contact material is in physical contact with said chip pads and said conductor tracks of the external wiring configuration, and such that the chip is not in physical contact with the external wiring configuration in areas other than said electrically conductive contact material and spacer cushions, thus a cavity being formed between the chip and the wiring configuration in said areas other than said electrically conductive contact material and spacer cushions;
said electrically conductive contact material providing a mechanically robust electrical connection between said chip pads and said conductor tracks of the external wiring configuration.