Semiconductor package having light-emitting-diode solder-bonded on first and second conductive pads separated by at least 75 UM
A semiconductor package and a fabrication method thereof are disclosed, which is characterized in that a solder material is used to bond an LED chip and a substrate so as to provide a thick joint between the substrate and the LED chip and hence reduce stresses generated between the LED chip and the substrate due to their CTE mismatch, thereby preventing delamination from occurring between the LED chip and the substrate after a reliability test.
1. A semiconductor package, comprising:
a substrate having a first conductive pad and a second conductive pad;
a solder material formed on the first and second conductive pads and having a thickness of 5 to 40 um, wherein a distance between the solder material on the first conductive pad and the solder material on the second conductive pad is at least 75 um; and
an Light-Emitting-Diode(LED) chip having a first electrode pad and a second electrode pad and attached to the substrate by bonding via the solder material the first electrode pad and second electrode pad to the first and second conductive pads, respectively.
2. The package of claim 1 , wherein the substrate has a plurality of reflective portions and circuits.
3. The package of claim 2 , wherein the substrate comprises a base layer, an insulating layer formed on the base layer, and a metal layer formed on the insulating layer, wherein the metal layer comprises the reflective portions, the circuits and the first and second conductive pads.
4. The package of claim 2 , wherein a reflective layer is formed over the reflective portions.
5. The package of claim 4 , wherein a surface treatment layer is formed between the reflective portions and the reflective layer.
6. The package of claim 1 , wherein a surface treatment layer is formed between the first conductive pad and the solder material and between the second conductive pad and the solder material.
7. The package of claim 1 , wherein the solder material has a thickness of 5 to 20 um.
8. The package of claim 1 , wherein a reflective layer is formed on the first electrode pad.
9. The package of claim 1 , wherein a bonding material is formed on the first and second electrode pads for being bonded with the solder material.
10. The package of claim 9 , wherein the bonding material is made of Au—Sn, Au or Ag.
11. A fabrication method of a semiconductor package, comprising the steps of:
forming a solder material on a first conductive pad and a second conductive pad of a substrate, wherein a distance between the solder material on the first conductive pad and the solder material on the second conductive pad is at least 75 um; and
attaching an LED chip having a first electrode pad and a second electrode pad to the substrate with the first and second electrode pads bonded to the solder material on the first and second conductive pads, respectively, via the solder material, wherein the solder material has a thickness of 5 to 40 um.
12. The method of claim 11 , wherein the substrate has a plurality of reflective portions and circuits.
13. The method of claim 12 , wherein the substrate comprises a base layer, an insulating layer formed on the base layer, and a metal layer formed on the insulating layer, wherein the metal layer comprises the reflective portions, the circuits and the first and second conductive pads.
14. The method of claim 12 , wherein a reflective layer is formed over the reflective portions.
15. The method of claim 14 , wherein a surface treatment layer is formed between the reflective portions and the reflective layer.
16. The method of claim 11 , wherein a surface treatment layer is formed between the first conductive pad and the solder material and between the second conductive pad and the solder material.
17. The method of claim 11 , wherein the solder material has a thickness of 5 to 20 um.
18. The method of claim 11 , wherein a reflective layer is formed on the first electrode pad.
19. The method of claim 11 , wherein a bonding material is formed on the first and second electrode pads being bonded with the solder material.
20. The method of claim 19 , wherein the bonding material is made of Au—Sn, Au or Ag.