Method for generating chip stacks
View Patent ↗Disclosed is a method for generating chip stacks during the production of chips from wafers, the chips located on the wafer being separated from one another, the wafer being ground thin and the chips being stacked to form chip stacks, the chips being checked for the purpose of a functional check, characterized in that the chips are checked in a first work step, that adhesive material is applied on the good chips, whereas the bad chips are not provided with adhesive material, that the wafer is assembled and ground thin afterwards and that the bad chips are subsequently removed and replaced by good chips.
1. A method for generating chip stacks during the production of chips from wafers, the method comprising:
a. providing a first wafer having an active side and a non-active side, wherein the first wafer has a plurality of chips;
b. testing the plurality of chips to determine a plurality of functional chips and a plurality of non-functional chips;
c. forming grooves on the active side of the first wafer to partially separate the plurality of chips;
d. creating adhesive surfaces only on the active sides of the plurality of functional chips;
e. positioning the first wafer so that the adhesive surfaces of the first wafer contacts a carrier such that chips having an adhesive surface adhere to the carrier;
f. grinding the non-active side of the first wafer down to the grooves to separate the plurality of chips so that the plurality of non-functional chips are not adhered to the carrier; and
g. replacing the non-functional chips with functional chips, wherein the function chips have adhesive surfaces which adheres to the carrier.
2. The method of claim 1 , further comprising:
h. providing a second wafer having an active side and a non-active side, wherein the second wafer has a plurality of chips;
i. testing the plurality of chips of the second wafer to determine a plurality of functional chips and a plurality of non-functional chips;
j. forming groves on the active side of the second wafer to partially separate the plurality of chips of the second wafer;
k. creating adhesive surfaces only on the active sides of the plurality of functional chips of the second wafer;
l. positioning the second wafer such that the adhesive surfaces of the second wafer adheres to the non-active side of the first wafer;
m. grinding the non-active side of the second wafer down to the grooves to separate the plurality of the chips;
n. replacing the non-functional chips with functional chips for the second wafer, wherein the function chips have adhesive surfaces which adhere to the first wafer, thus producing a plurality of chip stacks.
3. The method of claim 2 , further comprising adding additional chips to the plurality of chip stacks by repeating steps h through n for additional wafers.
4. The method of claim 1 , wherein the step of creating adhesive surfaces further comprises applying an adhesive material only to the active side of each chip of the plurality of functional chips.
5. A method for generating chip stacks during the production of chips from wafers, the method comprising:
a. providing a first wafer having an active side and a non-active side, wherein the first wafer has a plurality of chips;
b. testing the plurality of chips to determine a plurality of functional chips and a plurality of non-functional chips;
c. forming grooves on the active side of the first wafer to partially separate the plurality of chips;
d. applying an adhesive material to the plurality of functional and the plurality of non-functional chips, deactivating the adhesive material on the plurality of non-functional chips
e. positioning the first wafer so that the adhesive surfaces of the first wafer contacts a carrier such that the chips having an adhesive surface adhere to the carrier;
f. grinding the non-active side of the first wafer down to the grooves to separate the plurality of chips so that the plurality of non-functional chips are not adhered to the carrier; and
g. replacing the non-functional chips with functional chips, wherein the functional chips have adhesive surfaces which adhere to the carrier.
6. A method for generating chip stacks during the production of chips from wafers, the method comprising:
a. providing a first wafer having an active side and a non-active side, wherein the first wafer has a plurality of chips;
b. testing the plurality of chips to determine a plurality of functional chips and a plurality of non-functional chips;
c. forming grooves on the active side of the first wafer to partially separate the plurality of chips;
d. applying an adhesive material to the plurality of functional and the plurality of non-functional chips, removing the adhesive material on the plurality of non-functional chips
e. positioning the first wafer so that the adhesive surfaces of the first wafer contacts a carrier such that the chips having an adhesive surface adhere to the carrier;
f. grinding the non-active side of the first wafer down to the grooves to separate the plurality of chips so that the plurality of non-functional chips are not adhered to the carrier; and
g. replacing the non-functional chips with functional chips, wherein the functional chips have adhesive surfaces which adhere to the carrier.