Flexible sinter tool for bonding semiconductor devices
An apparatus having a seal plate which includes rigid hard portions and one or more flexible soft portions located between the hard portions is used for bonding at least one semiconductor device onto a substrate that is supported on a platform. The seal plate is movable between a first position which is spaced from the substrate and a second position whereat a first side of the seal plate is configured to be in contact with the substrate. A diaphragm covers a second side of the seal plate opposite to the first side. A fluid pressure generator exerts a fluid pressure onto the diaphragm to actuate the diaphragm to compress the one or more soft portions to transmit a bonding force onto the at least one semiconductor device during bonding.
1. Apparatus for bonding at least one semiconductor device onto a substrate that is supported on a platform, the apparatus comprising:
a seal plate including rigid hard portions and one or more flexible soft portions located between the hard portions, the seal plate having a first side which is configured to be in contact with the substrate in use when the substrate is supported on the platform;
a diaphragm covering a second side of the seal plate opposite to the first side;
a fluid pressure generator that is in fluid communication with the diaphragm, the fluid pressure generator being operative to exert a fluid pressure onto the diaphragm, the fluid pressure being further operative to actuate the diaphragm to compress the one or more soft portions, whereby to contact the at least one semiconductor device with the one or more soft portions and to apply a bonding force onto the at least one semiconductor device during bonding; and
the seal plate is movable between a first position which is spaced from the substrate, and a second position whereat a first side of the seal plate is configured to be in contact with the substrate in use whereby the fluid pressure is further configured to be applied by the diaphragm onto the hard portions of the seal plate against the substrate.
2. Apparatus as claimed in claim 1 , wherein the hard portions on the first side of the seal plate are in contact with the substrate at the second position.
3. Apparatus as claimed in claim 1 , wherein the hard portions on the first side of the seal plate are in contact with the platform and the soft portions on the first side of the seal plate are in contact with the substrate at the second position.
4. Apparatus as claimed in claim 1 , wherein the rigid hard portions are comprised in a plurality of seal inserts, each seal insert including a cutout that is sized and shaped to receive a soft portion.
5. Apparatus as claimed in claim 4 , further comprising a step at a top end of the seal insert that creates a larger cross-sectional area in the cutout than at a bottom end of the cutout, for securing the soft portion in the cutout when the soft portion is compressed during bonding.
6. Apparatus as claimed in claim 4 , wherein each seal insert is displaceable relative to another seal insert when the seal inserts are in contact with the substrate.
7. Apparatus as claimed in claim 4 , wherein the seal inserts are operative to contact both the platform and the substrate simultaneously.
8. Apparatus as claimed in claim 1 , further comprising one or more stamps arranged on the second side of the seal plate to contact the diaphragm, the or each stamp being located between the fluid pressure generator and the diaphragm for transmitting pressure from the fluid pressure generator to the one or more soft portions.
9. Apparatus as claimed in claim 8 , wherein the one or more stamps further comprise at least a first portion acted upon by the fluid pressure generator and a second portion operative to contact the diaphragm, the first portion having a larger surface area than the second portion.
10. Apparatus as claimed in claim 8 , wherein the stamp further includes a collar extending from the stamp, the collar being configured to contact top and bottom surface of a recess located within a slot along which the stamp is slidable, the recess further defining a range of motion of the collar and the stamp relative to the substrate.
11. Apparatus as claimed in claim 1 , wherein the substrate comprises a plurality of singulated substrates that are spaced from one another on the platform during bonding.
12. Apparatus as claimed in claim 11 , wherein the platform includes a recessed portion in which the singulated substrates are received, such that top surfaces of the singulated substrates are substantially at a same height as top surfaces of the platform, and the seal plate is configured to contact the singulated substrates and the platform substantially simultaneously.
13. Apparatus as claimed in claim 12 , further comprising a holding plate affixed in the recessed portion, the holding plate containing through holes for supporting the singulated substrates that are received in the recessed portion.
14. Apparatus as claimed in claim 1 , wherein the seal plate has a single cutout that is sized and shaped to receive a single unitary flat soft portion for applying a uniform bonding force onto all the semiconductor devices on the substrate.
15. Apparatus as claimed in claim 14 , wherein the rigid hard portions of the seal plate contact only the platform during bonding, whereas the unitary flat soft potion contacts the semiconductor devices and the substrate.
16. Apparatus as claimed in claim 1 , wherein the soft portions are comprised in a soft tool section, and the apparatus further includes a hard tool section incorporating a non-flexible hard tool to apply a bonding pressure onto a further one or more semiconductor devices that are mounted on the substrate.
17. Apparatus as claimed in claim 1 , further comprising a pressure sensor incorporated in the seal plate for measuring a pressure that is exerted by the seal plate.
18. Apparatus as claimed in claim 1 , further comprising a release film positioned adjacent to the seal plate between the at least one semiconductor device and the one or more soft portions.