Multi-chip package (MCP) with spacer
A multi-chip package includes a substrate having first bonding pads and second bonding pads, a first chip having chip pads on an active surface, spacers attached to the substrate between the first bonding pads and the second bonding pads and having a greater thickness than that of the first chip, a second chip having chip pads on an active surface, first bonding wires, second bonding wires, external connection terminals positioned on the bottom surface of the substrate, and a package body. The first chip and the second chip are any pad types. The first and second chips may have chip pads on four edges of the active surfaces or on two opposite edges of the active surfaces. The first bonding wires and the second bonding wires are bonded to the corresponding chip pads and the corresponding first and second bonding pads by the reverse bonding method. The spacer is made of one elected from the group consisting of metal, elastomer, epoxy, and photo sensitive resist. The spacer may be discontinuously formed about a perimeter of the first chip. The multi-chip package of the present invention may further comprise a third chip mounted on the second chip.
1. A multi-chip package, comprising:
a substrate having a surface;
a spacer attached to and touching the surface;
a first chip mounted on the surface;
a second chip mounted on the spacer, such that an active surface of the first chip and an active surface of the second chip face in the same direction; and
at least one bonding wire ball bonded to the substrate and stitch bonded to one of the first chip and the second chip,
wherein the second chip is attached to insulating adhesives formed on the spacer and on only a portion of the active surface of the first chip, respectively.
2. The multi-chip package of claim 1 , wherein:
the first chip includes first chip pads on the active surface of the first chip;
the second chip includes second chip pads on the active surface of the second chip;
a back surface of the first chip is mounted on the surface;
a back surface of the second chip is mounted on the spacer; and
the spacer has a thickness greater than a thickness of the first chip.
3. The multi-chip package of claim 2 , further comprising:
first bonding pads formed on the surface;
second bonding pads formed on the surface;
first bonding wires electrically connecting the first chip pads to the first bonding pads;
second bonding wires electrically connecting the second chip pads to the second bonding pads;
external connection terminals positioned on a bottom surface of the substrate; and
a package body formed by encapsulating the first chip, the second chip, the first bonding wires, the second bonding wires, and the spacer.
4. The multi-chip package of claim 3 , wherein the second bonding wires are electrically connected to the second chip pads and the second bonding pads by a reverse bonding method.
5. The multi-chip package of claim 3 , wherein the first bonding wires are electrically connected to the first chip pads and the first bonding pads by a reverse bonding method.
6. The multi-chip package of claim 2 , wherein:
the first chip pads are positioned on a pair of opposite edges of the active surface of the first chip; and
the second chip pads are positioned on a pair of opposite edges of the active surface of the second chip.
7. The multi-chip package of claim 2 , wherein:
the first chip pads are positioned on four edges of the active surface of the first chip, and
the second chip pads are positioned on four edges of the active surface of the second chip.
8. The multi-chip package of claim 1 , wherein the spacer is made of a material selected from the group consisting of metal, elastomer, epoxy, and photo sensitive resist.
9. The multi-chip package of claim 1 , wherein the second chip is mounted on the first chip and the spacer.
10. The multi-chip package of claim 1 , further comprising a plurality of spacers attached to the surface.
11. The multi-chip package of claim 10 , wherein the spacers are on a discontinuous perimeter about the first chip.
12. The multi-chip package of claim 1 , wherein:
one of the first chip and the second chip is an edge pad type; and
the other of the first chip and the second chip is a center pad type.
13. The multi-chip package of claim 1 wherein both the first chip and the second chip are of a same pad type.
14. The multi-chip package of claim 1 , further comprising a third chip mounted on the second chip.
15. The method of claim 1 , further comprising a plurality of spacer having at least two different sizes.
16. A method of making a multi-chip package, comprising:
providing a spacer on a substrate surface so that the spacer touches the substrate surface;
mounting a first chip on the substrate surface, wherein the first chip includes an active surface on which first chip pads are provided;
mounting a second chip on the spacer, wherein the second chip includes an active surface on which second chip pads are provided, the mounting of the second chip such that the active surface of the first chip and the active surface of the second chip face in the same direction; and
ball bonding a bonding wire to the substrate and stitch bonding the bonding wire to one of the first chip and the second chip,
wherein the second chip is attached to insulating adhesives formed on the spacer and on only a portion of the active surface of the first chip, respectively.
17. The method of claim 16 , wherein the second chip is mounted above the first chip.
18. The method of claim 16 , further comprising:
forming first bonding pads on the substrate surface;
electrically connecting the first chip to the substrate by bonding the first bonding pads to the first chips pads with first bonding wires;
forming second bonding pads on the substrate surface;
electrically connecting the second chip to the substrate by bonding the second bonding pads to the second chip pads with second bonding wires; and
forming a package body by encapsulating the first chip, the second chip, the first bonding wires, the second bonding wires and the spacer.
19. The method of claim 18 , wherein:
reverse bonding is used to electrically connect the first chip; and
reverse bonding is used to electrically connect the second chip.
20. The method of claim 16 , wherein:
one of the first chip and the second chip is an edge pad type; and
the other of the first chip and the second chip is a center pad type.
21. The method of claim 16 , wherein both the first chip and the second chip are of a same pad type.
22. The method of claim 16 , wherein providing a spacer comprises etching a spacer on the substrate surface.
23. The method of claim 16 , wherein providing a spacer comprises attaching a spacer having a predetermined shape to the substrate surface.
24. The method of claim 16 , wherein the spacer is made of a material selected from the group consisting of metal, elastomer, epoxy, and photo sensitive resist.
25. The method of claim 16 , further comprising mounting an additional spacer on the substrate surface.
26. The method of claim 16 , wherein mounting the second chip further comprises mounting the second chip on the first chip.
27. The method of claim 16 , wherein the spacer is provided on a discontinuous perimeter about the first chip.
28. The method of claim 16 , wherein mounting the first chip comprises mounting a back surface of the first chip to the substrate surface.
29. The method of claim 16 , wherein mounting the second chip comprises mounting a back surface of the second chip on the spacer.
30. The method of claim 16 , further comprising mounting a third chip on the second chip.
31. The method of claim 16 , further comprising a plurality of spacer having at least two different sizes.