Fabrication method of package structure having MEMS element
A fabrication method of a package structure having at least an MEMS element is provided, including: preparing a wafer having electrical connection pads and the at least an MEMS element; disposing lids for covering the at least an MEMS element, the lids having a metal layer formed thereon; electrically connecting the electrical connection pads and the metal layer with bonding wires; forming an encapsulant for covering the lids, bonding wires, electrical connection pads and metal layer; removing portions of the encapsulant to separate the bonding wires each into first and second sub-bonding wires, wherein top ends of the first and second sub-bonding wires are exposed, the first sub-bonding wires electrically connecting to the electrical connection pads, and the second sub-bonding wires electrically connecting to the metal layer; forming metallic traces on the encapsulant for electrically connecting to the first sub-bonding wires; forming bumps on the metallic traces; and performing a singulation process.
1. A fabrication method of a package structure having at least a Micro Electro Mechanical System (MEMS) element, comprising the steps of:
preparing a wafer having a plurality of electrical connection pads and the at least an MEMS element;
disposing a plurality of lids on the wafer for covering the at least an MEMS element, respectively, wherein each of the lids has a metal layer formed thereon;
electrically connecting the electrical connection pads and the metal layer with a plurality of bonding wires;
forming an encapsulant on the wafer for covering the lids, the bonding wires, the electrical connection pads and the metal layer;
removing a portion of the encapsulant so as to separate each of the bonding wires into a first sub-bonding wire and a second sub-bonding wire, wherein top ends of the first sub-bonding wire and the second sub-bonding wire are exposed from a top surface of the encapsulant, the first sub-bonding wires electrically connecting to the electrical connection pads, and the second sub-bonding wires electrically connecting to the metal layer;
forming a plurality of metallic traces on the encapsulant for electrically connecting to the first sub-bonding wires, respectively;
forming a plurality of bumps on the metallic traces, respectively; and
performing a singulation process to obtain a plurality of package structures each having the at least an MEMS element.
2. The method of claim 1 , wherein the electrical connection pads are disposed at an outer periphery of the lids.
3. The method of claim 1 , further comprising forming a first insulation layer on the encapsulant and the metallic traces before forming the bumps, wherein the first insulation layer has a plurality of openings for exposing the metallic traces such that the bumps are formed at the openings for electrically connecting to the metallic traces.
4. The method of claim 1 , further comprising forming a second insulation layer on the encapsulant before forming the metallic traces, wherein the second insulation layer has a plurality of openings for exposing the first sub-bonding wires.
5. The method of claim 1 , wherein each of the metallic traces has an end extending towards the corresponding MEMS element and having the corresponding bump formed thereon.
6. The method of claim 1 , wherein the metal layer is composed of a plurality of bonding pads.
7. The method of claim 1 , wherein the metal layer is formed by sputtering or evaporation.
8. The method of claim 1 , wherein the portion of the encapsulant is removed by grinding.
9. The method of claim 1 , wherein the metallic traces further electrically connect to the second sub-bonding wires.