Method of fabricating a semiconductor package having through holes for molding back side of package
A portable memory card and methods of manufacturing same are disclosed. The portable memory includes a substrate having a plurality of holes formed therein. During the encapsulation process, mold compound flows over the top surface of the substrate, through the holes, and down into a recessed section formed in the bottom mold cap plate to form a projection of mold compound on the bottom surface of the substrate.
1. A method of forming a semiconductor package having a substrate including first and second surfaces and one or more semiconductor die on the first surface of the substrate, the substrate including one or more holes between the first and second surfaces, the method comprising the steps of:
(a) positioning the substrate within a molding chamber including at least one mold plate having a recessed section adjacent the one or more holes formed through the substrate; and
(b) injecting a mold compound over the first surface of the substrate, the mold compound encapsulating the one or more semiconductor die and flowing through the one or more holes into the recessed section of the at least one mold plate to form a finger grip on the second surface of the substrate to facilitate removal of the semiconductor package from a slot in a host device in which the semiconductor package is used.
2. A method as recited in claim 1 , wherein said step (b) of injecting a mold compound over the first surface of the substrate comprises the step of injecting an epoxy resin over the first surface of the substrate.
3. A method as recited in claim 1 , wherein said step (b) of injecting a mold compound over the first surface of the substrate and flowing through the one or more holes comprises the step of injecting the mold compound to exert a first pressure on the first surface and a second pressure, lower than the first pressure, on the recessed section of the mold plate.
4. A method as recited in claim 1 , wherein said step (b) of injecting a mold compound over the first surface of the substrate and flowing through the one or more holes comprises the step of controlling a pressure exerted by the mold compound within the recessed section of the molding plate by controlling the number and diameter of the one or more holes.
5. A method as recited in claim 1 , further comprising the step (c) of forming a plurality of contact fingers on the second surface of the substrate, adjacent a first edge of the package.
6. A method as recited in claim 5 , wherein said step (b) of injecting a mold compound over the first surface of the substrate and flowing through the one or more holes to form a projection on the second surface comprises the step of forming the projection adjacent a second edge of the package opposite the first edge of the package.
7. A method as recited in claim 6 , wherein said step (b) of injecting a mold compound over the first surface of the substrate and flowing through the one or more holes to form a projection on the second surface comprises the step of forming the projection to end less than ½ inch from the second edge of the package.
8. A method as recited in claim 6 , wherein said step (b) of injecting a mold compound over the first surface of the substrate and flowing through the one or more holes to form a projection on the second surface comprises the step of forming the projection across substantially the entire second surface except over the plurality of contact fingers.
9. A method of forming a semiconductor package having a substrate including first and second surfaces, one or more semiconductor die on the first surface of the substrate and contact fingers along a first edge of the second surface, the method comprising the steps of:
(a) forming one or more holes through the substrate between the first and second surfaces of the substrate, the one or more holes positioned adjacent a second edge opposite the first edge;
(b) positioning the substrate within a molding chamber including at least one mold plate having a recessed section adjacent the one or more holes formed in said step (a); and
(c) injecting a mold compound over the first surface of the substrate, the mold compound encapsulating the one or more semiconductor die and flowing through the one or more holes formed in said step (a) into the recessed section of the at least one mold plate to form a finger grip on the second surface of the substrate, the finger grip being gripped when removing the semiconductor package from a slot of a host device.
10. A method as recited in claim 9 , wherein said step (a) of forming one or more holes through the substrate comprises the step of drilling one or more holes through the substrate.
11. A method as recited in claim 9 , wherein said step (a) of forming one or more holes through the substrate comprises the step of forming one or more holes through the substrate using a laser.
12. A method as recited in claim 9 , wherein said step (a) of forming one or more holes through the substrate is performed prior to mounting of the one or more semiconductor die on the substrate.
13. A method as recited in claim 9 , wherein said step (a) of forming one or more holes through the substrate comprises the step of forming between 10 and 20 holes in the substrate.
14. A method as recited in claim 13 , wherein said step of forming between 10 and 20 holes in the substrate comprises the step of forming between 10 and 20 holes having a diameter of less than ½ mm.
15. A method as recited in claim 9 , wherein said step (a) of forming one or more holes through the substrate comprises the step of forming two rows of holes.
16. A method as recited in claim 9 , wherein said step (c) of injecting a mold compound over the first surface of the substrate comprises the step of injecting an epoxy resin over the first surface of the substrate.
17. A method as recited in claim 9 , wherein said step (c) of injecting a mold compound over the first surface of the substrate and flowing through the one or more holes comprises the step of injecting the mold compound to exert a first pressure on the first surface and a second pressure, lower than the first pressure, on the recessed section of the mold plate.
18. A method as recited in claim 9 , wherein said step (c) of injecting a mold compound over the first surface of the substrate and flowing through the one or more holes comprises the step of controlling a pressure exerted by the mold compound within the recessed section of the molding plate by controlling the number and diameter of the one or more holes.
19. A method as recited in claim 9 , further comprising the step (d) of forming a plurality of contact fingers on the second surface of the substrate, adjacent a first edge of the package.
20. A method as recited in claim 19 , wherein said step (c) of injecting a mold compound over the first surface of the substrate and flowing through the one or more holes to form a projection on the second surface comprises the step of forming the projection adjacent a second edge of the package opposite the first edge of the package.
21. A method as recited in claim 20 , wherein said step (c) of injecting a mold compound over the first surface of the substrate and flowing through the one or more holes to form a projection on the second surface comprises the step of forming the projection to end less than ½ inch from the second edge of the package.
22. A method as recited in claim 20 , wherein said step (c) of injecting a mold compound over the first surface of the substrate and flowing through the one or more holes to form a projection on the second surface comprises the step of forming the projection across substantially the entire second surface except over the plurality of contact fingers.
23. A method as recited in claim 9 , further comprising the step (e) of encasing the die and substrate encapsulated in said steps (b) and (c) within a lid.
24. A method of forming a semiconductor package having a substrate including first and second surfaces and one or more semiconductor die on the first surface of the substrate, the method comprising the steps of:
(a) forming a plurality of holes through the substrate between the first and second surfaces of the substrate;
(b) positioning the substrate within a molding chamber including at least one mold plate having a recessed section adjacent the plurality of holes formed in said step (a); and
(c) injecting a mold compound over the first surface of the substrate, the mold compound encapsulating the one or more semiconductor die and flowing through the plurality of holes formed in said step (a) into the recessed section of the at least one mold plate to form a finger grip on the second surface of the substrate to facilitate removal of the semiconductor package from a host device, the mold compound is injected with a force allowing the mold compound to encapsulate the one or more semiconductor die on the first surface, and the number and diameter of the plurality of holes prevent flash on the second surface outside of the recessed section.
25. A method as recited in claim 24 , wherein said step (a) of forming the plurality of holes through the substrate comprises the step of forming between 10 and 20 holes in the substrate.
26. A method as recited in claim 25 , wherein said step of forming between 10 and 20 holes in the substrate comprises the step of forming between 10 and 20 holes having a diameter of less than ½ mm.
27. A method as recited in claim 24 , wherein said step (a) of forming the plurality of holes through the substrate comprises the step of forming two rows of holes.
28. A method as recited in claim 24 , further comprising the step (d) of forming a plurality of contact fingers on the second surface of the substrate, adjacent a first edge of the package.
29. A method as recited in claim 28 , wherein said step (c) of injecting a mold compound over the first surface of the substrate and flowing through the plurality of holes to form a projection on the second surface comprises the step of forming the projection adjacent a second edge of the package opposite the first edge of the package.
30. A method as recited in claim 24 , further comprising the step (e) of encasing the die and substrate encapsulated in said steps (b) and (c) within a lid.