Active solid-state devices (e.g. – transistors – solid-state diode – Incoherent light emitter structure – With housing or contact structure
Reexamination Certificate
2002-07-09
2003-09-02
Jackson, Jerome (Department: 2815)
Active solid-state devices (e.g., transistors, solid-state diode
Incoherent light emitter structure
With housing or contact structure
C257S100000, C257S098000
Reexamination Certificate
active
06614058
ABSTRACT:
FIELD OF THE INVENTION
The present invention generally relates to a light emitting semiconductor device with a flip-chip package structure, especially to a light emitting semiconductor device with a surface-mounted and flip-chip package structure.
DESCRIPTION OF THE RELATED ART
Traditionally, the package structures of light emitting semiconductor devices include “lead-types” and “chip-types”. A lead-type package structure of a light emitting semiconductor device is shown in FIG.
1
. The light emitting diode
100
includes a light emitting component
102
, a mount lead
105
and an inner lead
106
. The mount lead
105
includes a cup
105
a
and a lead
105
b
. The light emitting component
102
is installed on the recess of the cup
105
a,
which is filled with an epoxy coating resin
101
. In this way, the light emitting component
102
can be sealed in the coating resin
101
. Then, the N-type electrode and the P-type electrode (not shown) of the light emitting component
102
are connected to the mount lead
105
and the inner lead
106
via the conductive wires
103
, respectively. Finally, the light emitting component
102
and part of the mount lead
105
and the inner lead
106
are encapsulated in the molding material
104
.
FIG. 2
shows the sectional view of a structure of a conventional LED.
The LED
200
is a GaN-based light emitting diode. As shown in the figure, the LED
200
includes a sapphire substrate
201
and a multi-layer structure consisted of an N-type GaN semiconductor layer
202
and a P-type GaN semiconductor layer
203
. The N-type GaN semiconductor layer is formed on the surface of the sapphire substrate and the P-type GaN semiconductor layer is formed on the surface of the N-type GaN semiconductor layer. The P-type GaN semiconductor layer
203
is etched to form a exposed area
206
on the surface of the N-type GaN semiconductor layer
202
, and an N-type electrode
205
is set up thereon. Meanwhile, a transparent P-type electrode
204
is formed on the surface of the P-type GaN semiconductor layer
203
. A P-type electrode area (not shown) is defined on the transparent electrode
204
to expose part of the surface of the P-type GaN semiconductor layer
203
. A P-type electrode
207
is then formed on the exposed area of the P-type GaN semiconductor layer
203
and electrically connected to the transparent electrode
204
. Then, a traditional lead-type LED is formed.
Similarly, a chip-type LED package structure is shown as FIG.
3
. In
FIG. 3
, the light emitting semiconductor device
300
includes an LED dice
303
fixed on a lead frame
302
with silver paste. The lead frame
302
is formed on the insulating substrate
301
. Then, the steps of wire-bonding, encapsulating and dicing are processed in sequence. As to the wire-bonding step, the connecting points
304
of the LED dice
303
are connected to the lead frame
302
by gold leads
305
. For the encapsulating step, the lead frame
302
is preheated on a framework and transferred into a laminator with the framework. In the laminator, an epoxy resin is filled into the framework and a hardening step is processed. After the encapsulating step, the LED dice
303
is encapsulated in a plastic cube
306
filled with an epoxy resin.
According to the package structure of the traditional light emitting semiconductor devices described above, all of the packaging steps, such as die bonding, wire bonding and encapsulating, are required in both the lead type structure and the chip-type structure. These manufacturing steps make it difficult to minimize the size of the device, and the manufacturing cost of the device cannot be reduced. Hence, it is required to simplify the packaging processes of the light emitting semiconductor devices.
SUMMARY OF THE INVENTION
Therefore, one object of the present invention is to provide an improved light emitting semiconductor device with simplified package structure.
Another object of the present invention is to provide an improved light emitting semiconductor device with a lower manufacturing cost.
Moreover, another object of the present invention is to provide an improved light emitting semiconductor device with higher light-emitting efficiency.
The light emitting semiconductor device of the present invention comprises: an insulating substrate; an LED, which includes a substrate, a first-type semiconductor layer formed on the substrate surface, a first electrode formed on part of the first-type semiconductor layer surface, a second-type semiconductor layer formed on the surface of the first-type semiconductor layer but does not cover the first electrode, and a second electrode formed on the surface of the second-type semiconductor layer; two bumps, formed on the insulating substrate; and two electrode layers, formed on the two sides of the insulating substrate and extend upwardly and downwardly to the upper and lower surface of the insulating substrate. The first and second electrodes of the LED are connected to the insulating substrate via the two bumps respectively. Meanwhile, the upper parts of the two electrode layers are connected with the first and second electrode of the LED via the two bumps.
According to the package structure described above, the light emitting semiconductor device of the present invention has both of the advantages of the flip-chip package structure and the surface-mounting process.
Meanwhile, the insulating substrate of the light emitting semiconductor device of the present invention has a thermal-expansion coefficient similar to an LED and a thermal-conductivity similar to a metal material. Hence, the device of the present invention possess a lower stress and better reliability, and can be operated with high power.
Further, the light emitting semiconductor device of the present invention is backside light-emitted type. Therefore, the device can reduce the light shelter effect caused by the electrodes and have higher light-emitted efficiency than the conventional light emitting semiconductor devices. Moreover, the device of the present invention is packaged with Surface-Mounting technology. This method simplifies the manufacturing process of the device and minimizes the size thereof.
Further, the packaging material of the present invention is cheaper than the traditional LED packaging materials. Hence, the manufacturing cost of the device is reduced.
REFERENCES:
patent: 5814837 (1998-09-01), Okazaki
patent: 5990500 (1999-11-01), Okazaki
patent: 6111272 (2000-08-01), Heinen
patent: 6169294 (2001-01-01), Biing-Jye et al.
patent: 6268618 (2001-07-01), Miki et al.
patent: 6355946 (2002-03-01), Ishinaga
patent: 6365429 (2002-04-01), Kneissl et al.
patent: 6474531 (2002-11-01), Ozawa
Lin Ming-der
Wang Kwang-ru
Highlink Technology Corporation
Martine & Penilla LLP
LandOfFree
Light emitting semiconductor device with a surface-mounted... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Light emitting semiconductor device with a surface-mounted..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Light emitting semiconductor device with a surface-mounted... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3073232