Fabricating process for package substrate
A core substrate is prepared first, a bottom redistribution layer RDL 1 is formed. Any warpage of the RDL 1 is suppressed by the core substrate. In a later process, warpage is further suppressed by a molding compound encapsulating the core substrate. A plurality of metal pillars are formed passing through the core substrate longitudinally; a top redistribution layer RDL 2 is then formed on a top surface of the metal pillars.
1. A fabricating process for package substrate, comprising a fabricating process to prepare a plurality of semi-products according to the following steps:
preparing a core substrate;
forming a bottom redistribution layer RDL 1 on a bottom surface of the core substrate; wherein the RDL 1 has a bottom redistribution circuitry embedded in bottom dielectric layers; the bottom redistribution circuitry has a plurality of first top metal pads and a plurality of first bottom metal pads;
thinning from top of the core substrate;
forming a plurality of holes from top of the core substrate;
filling metal in each of the holes to form a plurality of metal pillars passing through the core substrate; and
obtaining a plurality of semi-products through singulating.
2. A fabricating process for package substrate as claimed in claim 1 , further comprising:
preparing a temporary carrier with a release layer configured on a top surface of the temporary carrier;
arranging the plurality of semi-products on a top surface of the release layer; wherein each semi-product is placed with the metal pillars configured away from the release layer;
encapsulating the semi-products with a molding compound wrapping at least four lateral sides of the semi-products;
forming a top redistribution layer RDL 2 on a top surface of the plurality of metal pillars; wherein the top redistribution layer RDL 2 has a top redistribution circuitry embedded in top dielectric layers; the top redistribution circuitry has a plurality of second top metal pads, and has a plurality of second bottom metal pads; wherein each of the metal pillars has a top surface electrically coupled to a corresponding second bottom metal pad;
removing the temporary carrier; and
forming a plurality of bottom openings from bottom of the bottom dielectric layer to expose a bottom surface of each first bottom metal pad.
3. A fabricating process for package substrate as claimed in claim 2 , further comprising:
configuring at least one chip on a bottom surface of the plurality of first bottom metal pads.
4. A fabricating process for package substrate as claimed in claim 3 , further comprising:
filling an underfill material in a space between the chip and the bottom surface of the bottom dielectric layer.
5. A fabricating process for package substrate as claimed in claim 4 , further comprising:
applying a molding compound to encapsulate the chip or chips.
6. A fabricating process for package substrate as claimed in claim 5 , further comprising:
planting a plurality of solder balls, each on a top surface of a corresponding second top metal pad.
7. A fabricating process for package substrate as claimed in claim 6 , further comprising:
obtaining a plurality of chip package units through singulating a previous product.
8. A fabricating process for package substrate, comprising:
preparing a core substrate;
forming a bottom redistribution layer RDL 1 on a bottom surface of the core substrate; wherein the RDL 1 has a bottom redistribution circuitry embedded in bottom dielectric layers; the bottom redistribution circuitry has a plurality of first top metal pads and a plurality of first bottom metal pads;
thinning from top of the core substrate;
forming a plurality of holes from top of the core substrate;
filling metal in each of the holes to form a plurality of metal pillars passing through the core substrate;
forming a top redistribution layer RDL 2 on a top surface of the plurality of metal pillars; wherein the top redistribution layer RDL 2 has a top redistribution circuitry embedded in top dielectric layers; the top redistribution circuitry has a plurality of second top metal pads, and has a plurality of second bottom metal pads; wherein each of the metal pillars has a top surface electrically coupled to a corresponding second bottom metal pad; and
forming a plurality of bottom openings from bottom of the bottom dielectric layer to expose a bottom surface of each first bottom metal pad.
9. A fabricating process for package substrate as claimed in claim 8 , further comprising:
configuring at least one chip on a bottom surface of the plurality of first bottom metal pads.
10. A fabricating process for package substrate as claimed in claim 9 , further comprising:
filling an underfill material in a space between the chip and the bottom surface of the bottom dielectric layer.
11. A fabricating process for package substrate as claimed in claim 10 , further comprising:
applying a molding compound to encapsulate the chip or chips.
12. A fabricating process for package substrate as claimed in claim 11 , further comprising:
planting a plurality of solder balls, each on a top surface of a corresponding second top metal pad.
13. A fabricating process for package substrate as claimed in claim 12 , further comprising:
obtaining a plurality of chip package units through singulating.