(A) Field of the Invention
The present invention relates to a package structure of a compound semiconductor device and fabricating method thereof, and more particularly, to a thin package structure and fabricating method of a photoelectric semiconductor device.
(B) Description of the Related Art
Because the light emitting diode (LED) pertaining to the photoelectric device has advantages of a small body, high efficiency and long lifetime, it is deemed as an excellent illuminant source for the next generation. Furthermore, LCD (liquid crystal display) technology is developing rapidly and full color is the current trend in electronic product displays. Therefore, the white series LEDs are not only applicable to indication lights and large size display screens but also to most consumer electronic products such as mobile phones and personal digital assistants (PDA).
The LED device 10 utilizes a common printed circuit board (PCB) as the substrate 13. The total thickness of the LED device 10 is limited by the insulation layer 13c of the substrate 13, hence it cannot be reduced further. However, the trend of consumer electronic products is towards a light, thin, short and small body in recent years. Accordingly, each of the internal devices of the consumer electronic product and its shell needs to be miniaturized. On the other hand, the insulation layer 13c is made mostly of epoxy resin with poor heat dissipation, and therefore is not suitable for a high power chemical compound semiconductor as a heat-transferring path.
In view of the above, the consumer electronic products market is in urgent need of a photoelectric compound semiconductor device with a thin type package. The device not only needs to have a reduced thickness for saving space, but also needs to address the heat dissipation problem. With such a device, reliable, high power electronics products will be more easily manufactured.
One aspect of the present invention provides the package structure of a compound semiconductor device and fabricating method thereof. The semiconductor device has external electrodes or contacts uncovered by an encapsulation material. There is no printed circuit board between a die and external electrodes for transmitting electrical signals, so the heat dissipation of the device is improved.
Another aspect of the present invention provides the package structure of very thin semiconductor device and fabricating method thereof. The thickness of the device can be reduced for saving space because of the use of a thin substrate.
According the aforesaid aspects, the present invention discloses the package structure of a compound semiconductor device comprising a conductive film with a pattern, a die and a transparent encapsulation material. The die is mounted on a first surface of the conductive film. The encapsulation material is overlaid on the first surface of the conductive film and die. A second surface of the conductive film is not covered by the encapsulation material, wherein the second surface is opposite to the first surface.
The die is electrically connected to the conductive film through at least one metallic wire, or is electrically connected to the conductive film through a plurality of bumps.
The second surface of the conductive film is uncovered by encapsulation material. The material of the conductive film is silver, nickel, copper, tin, aluminum or the alloy of the aforesaid metals. Indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium oxide (IGO) and indium tungsten oxide (IWO) also are suitable for the material of the conductive film.
The conductive film comprises an N type electrode and a P type electrode.
The transparent encapsulation material is further mixed with fluorescent powders.
The die is mounted on the first surface of the conductive film through die bonding paste or eutectic bonding.
The present invention discloses the package method of a compound semiconductor device comprising the steps of: providing a temporary substrate; forming a conductive film with a pattern on the temporary substrate, wherein the conductive film has a first surface and a second surface opposite the first surface; mounting a die to the first surface of the conductive film; overlaying a transparent encapsulation material on the first surface of the conductive film and the die; and removing the temporary substrate.
The present invention further comprises a step of electrically connecting the die to the conductive film through a plurality of metallic wires.
Alternatively, the present invention also discloses a step of electrically connecting the die to the conductive film through a plurality of bumps.
The conductive film is formed on the temporary substrate through printing, screen printing, electroforming, chemical plating or sputtering.
The temporary substrate is removed by bending, separating, etching, laser cutting or grinding.
The present invention discloses the package structure of a compound semiconductor device comprising a thin film substrate with a pattern, a die and a transparent encapsulation material. The thin film substrate comprises an upper conductive film, an insulation film including a plurality of openings, and a lower conductive film, wherein the insulation film is sandwiched between the upper conductive film and lower conductive film. The die is mounted on the upper conductive film. The encapsulation material is overlaid on the upper conductive film and the die.
Each of the upper conductive film and lower conductive film comprises an N type electrode and a P type electrode. The N type electrodes of the upper conductive film and lower conductive film contact each other through the plurality of openings, and the P type electrodes of the upper conductive film and lower conductive film also contact each other through the plurality of openings.
The thickness of the insulation layer is preferably between 0.01 mm and 0.1 mm. The material of the insulation layer is polyimide, PV (polyvinyl), PC (polycarbonate), PVC (polyvinyl chloride), PMMA (polymethylmethacrylate) or acrylic.
The present invention discloses the package method of a compound semiconductor device comprising the steps of: providing an insulation film including a plurality of openings; forming an upper conductive film and a lower conductive film respectively on two surfaces of the insulation film, wherein the upper conductive film and the lower conductive film contact each other through the plurality of openings; mounting a die on the upper conductive film; and overlaying a transparent encapsulation material on the upper conductive film and the die.
The present invention further comprises two steps of forming the insulation film on a plate and forming the plurality of openings on the insulation film.
The insulation film is formed on the plate through dispensation, dip or sol gel.
The plurality of openings are formed on the insulation film through mechanical drilling, laser drilling or plasma etching.
The upper conductive film and the lower conductive film are formed on the insulation film through electroplating, printing or copper foil pressing.
The present invention further discloses the package structure of a compound semiconductor device comprising a thin substrate having a first electrode and a second electrode, a chemical compound semiconductor die on the thin substrate; means for mounting the semiconductor die on the thin substrate; and a transparent encapsulation material overlaying the semiconductor die.
The semiconductor die is a light emitting diode die, a laser diode die or a photo sensor die.
The means comprise wire bonding and flip chip bonding for mounting the semiconductor die on the thin substrate. The die is mounted on the thin substrate through die bonding paste or eutectic bonding before the wire bonding.
The package structure further comprises a color conversion material mixed with the transparent encapsulation material, and the color conversion material is fluorescent powder. The transparent encapsulation material is epoxy resin or silicone.
The package structure further comprises a reflective layer around the transparent encapsulation material.
The present invention discloses the package method of a compound semiconductor device comprising the steps of: providing a thin film substrate having a first electrode and a second electrode; mounting a semiconductor die on the thin film substrate whereby a positive electrode of the semiconductor die is connected to a first electrode and a negative electrode of the semiconductor die is connected to the second electrode; and overlaying a transparent encapsulation material on the semiconductor die.
The thin film substrate with a pattern is a patterning conductive layer formed on a temporary substrate. The temporary substrate is removed after the semiconductor die is covered with the transparent encapsulation material.
The conductive film is formed on the temporary substrate through printing, screen printing, electroforming, chemical plating or sputtering. The temporary substrate is removed by bending, separating, etching, laser cutting or grinding.
The conductive film substrate comprises a first conductive layer with a pattern, an insulation film with a plurality of holes and a second conductive layer with a pattern.
The manufacturing method of the conductive film substrate comprises the steps of: providing an insulation film having a plurality of holes; fixing the first conductive layer with a first pattern and the second conductive layer respectively with a second pattern on two opposite surfaces of the insulation film with a plurality of holes whereby the first conductive layer with a pattern and the second conductive layer with a pattern are electrically connected to each other through the plurality of holes.
The objectives and advantages of the present invention will become apparent upon reading the following description and upon reference to the accompanying drawings in which:
As shown in
After the transparent encapsulation material 26 is hardened, the substrate 21 is removed by bending, separating, etching, laser cutting or grinding. Therefore, a second surface 224 of the conductive film 22 appears on the encapsulation material 26. Accordingly, the package structure of the compound semiconductor device 20 is completed, as shown in
For directing and concentrating the light from the semiconductor die 23 to emit from the top surface of the encapsulation material 26, a reflection layer 28 can cover the sides of the encapsulation material 26, as shown in
Because the second surface 224 of N type electrode 221 and P type electrode 222 are not covered by the transparent encapsulation material 26, they can serve as outer contacts for surface mounting. Furthermore, the heat generated from the die 23 is directly transferred by the thin conductive film 22 with a superior conductive coefficient so that the heat dissipation efficiency of the package structure is improved. Compared with prior arts, the compound semiconductor device 20 does not need a printed circuit board for the whole package structure, and, therefore, the thickness of the package structure can be reduced to 0.2 mm-0.15 mm. In this embodiment, the die 23 can be an LED, a laser LED or a photocell.
For directing and concentrating the light from the semiconductor die 33 to emit from the top surface of the encapsulation material 36, a reflection layer 38 can cover the sides of the encapsulation material 36, as shown in
The above-described embodiments of the present invention are intended to be illustrative only. Those skilled in the art may devise numerous alternative embodiments without departing from the scope of the following claims.
Number | Date | Country | Kind |
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096126300 | Jul 2007 | TW | national |