TWI393277B - Method for packaging light-emitting diode - Google Patents

Description

Light emitting diode packaging method

The invention relates to a light emitting diode packaging method, and in particular to a light emitting diode packaging method which can be mass produced.

The light-emitting diode has the advantages of small volume, long life, low power consumption, fast reaction rate, and excellent shock resistance. At present, the application of light-emitting diodes is widely used in various fields of electrical appliances and communication products, and has a tendency to replace traditional light sources. Therefore, it is necessary to develop a more efficient process in order to achieve mass production and reduce costs to increase profitability.

With the need to reduce costs and increase yields, there are many advances in packaging and testing processes that are directly related to product yield and productivity. The front-end packaging process of the conventional LED includes wafer dicing, grain inspection and grain sorting steps, and the classified dies are then subjected to post-packaging processes such as wire bonding and colloidal packaging to form a packaged finished product. Depending on the package type, the packaged products can be individually soldered to the circuit board of the preset circuit by means of pin insertion or soldering.

However, limited by the number of wire machines and the complexity of assembly of the packaged products, the production efficiency of the light-emitting diodes is still limited.

Therefore, an aspect of the present invention is to provide a light emitting diode packaging method for mass production of a light emitting diode.

The method for packaging a light emitting diode according to an embodiment of the invention includes providing a first adhesive film, placing a plurality of crystal grains on the first adhesive film, and removing a part of the crystal grains from the first adhesive film to form an array The arrangement is arranged on a stage to form an array of dies, wherein each of the dies in the array of dies has a plurality of electrodes. Moving the die array onto a substrate in a batch manner from the stage, the substrate has a plurality of pads corresponding to the electrodes of each of the die arrays, so that the pads and the electrodes of the respective die Join together separately.

According to the above, the LED package method of the embodiment of the present invention is to arrange the selected crystal grains into an array after the grain classification, so that the entire batch of crystal grains can be fixed on the substrate at the same time. The substrate is electrically connected to the wafer.

Therefore, the LED package method of the embodiment of the present invention can greatly shorten the assembly and packaging time of the LED components, and is suitable for mass production.

According to the LED package method of the embodiment of the present invention, after the wafer is cut (Die Saw), the crystal grains and the defective crystal grains are simultaneously formed, and the upper surface of each of the crystal grains may have a plurality of electrodes. A part of the crystal grains are sequentially removed from the film by the thimble, and the removed crystal grains are arranged in an array on a stage. The crystal grains arranged on the stage are attached to the other film in a batch, and the film is removed from the stage by moving the film, and then fixed on a substrate by flip chip.

Please refer to FIG. 1A-1B , which is a schematic diagram of a method for packaging a light emitting diode die according to an embodiment of the invention. Referring to FIG. 1A, the wafer attached to the first adhesive film 220 is simultaneously diced to form a plurality of good or bad crystal grains 230. Each of the crystal grains 230 has a light-emitting element body 232 and an electrode 234 formed on the light-emitting element body 232. The first adhesive film 220 is fastened and expanded by the fixing device 210 to have a large appropriate interval between the adjacent crystal grains 230. According to an embodiment of the present embodiment, the fixing device 210 can be a crystal expansion ring.

Then, the fixing device 210 is turned over so that the die 230 has one of the electrodes 234 facing downward, and then the thimble 250 is used to push down the good portion of the die 230 after the die inspection, so that the selected die 230 is separated from the first adhesive. The membrane 220 is dropped onto the lower stage 260.

The fixing device 210 can be connected to a first moving device (not shown) to perform a 2D plane movement to cause the thimble 250 to pass through the defective crystal grains. As the thimble 250 sequentially pushes down the partially selected dies 230, the stage 260 also uses a second moving device (not shown) to perform a 2D plane movement on the set array arrangement path. That is, it moves in the same direction as the moving path of the fixing device to receive a part of the die 230 dropped by the first film 220, and the selected die 230 are sequentially arranged at a predetermined position on the stage 260. At this time, the crystal grains 230 arranged on the stage 260 have one of the electrodes 234 facing downward.

The arrangement of the selected crystal grains 230 on the stage 260 may be, for example, a square matrix arrangement. In accordance with an embodiment of the present invention, the array arrangement is determined by the position and number of pads pre-set on one of the substrates corresponding to the die 230 on the stage 260.

Referring again to FIG. 1B, a second adhesive film 222 is attached to the other fixing device 212 for attaching the selected portion of the die 230 to the array 260. The second film 222 is moved to remove the die 230 from the portion of the stage 260 in a batch, so that the arrays of the crystal grains 230 can be placed in a batch on a substrate 270 at the same time. The electrodes 234 of a die 230 are respectively soldered to the corresponding substrate 270 Pad 272 is in contact.

In accordance with an embodiment of the present invention, the electrode 234 of the entire batch of die 230 can be adhered with a flux to bond the electrode 234 and the pad 272 in a reflow manner to form a power contact of the light emitting diode.

Please refer to FIG. 1C , which illustrates a cross-sectional structure of a package unit according to an embodiment of the invention. A protective layer 280 is formed on the flip chip structure completed in FIG. 1B to protect the flip chip and then cut into a plurality of package units. Each of the package units includes a substrate 270, a pad 272 on the substrate 270, and the die 230 and the pad 272 are combined to form a flip chip structure, and a protective layer 280 is coated on the outside of the flip chip structure.

According to an embodiment of the invention, the material of the protective layer 280 comprises a transparent resin, for example, an epoxy resin; the protective layer 280 further comprises a primer filling the gap between the die 230 and the substrate 270.

In accordance with another embodiment of the present invention, the die 230 can be attached to other substrates. 2A-2B, FIG. 2A is a schematic view showing a three-dimensional structure of a flip chip according to another embodiment of the present invention, and FIG. 2B is a schematic cross-sectional view showing a flip chip structure shown in FIG. 2A.

The die 332 includes a light-emitting element body 334 and two electrodes 336. The entire batch of the selected die 332 is simultaneously bonded to the plurality of conductive supports 350 in a reflow manner by a method similar to that shown in FIGS. 1A to 1C. Each of the conductive supports 350 is separated to form a separate package unit.

Although the present invention has been disclosed in the above two embodiments, it is not intended to limit the present invention, and it is obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application attached.

210‧‧‧Fixed devices

212‧‧‧Fixed devices

220‧‧‧first film

222‧‧‧second film

230‧‧‧ grain

232‧‧‧Lighting element body

234‧‧‧Electrode

250‧‧‧ thimble

260‧‧‧ stage

270‧‧‧Substrate

272‧‧‧ solder pads

280‧‧‧protection layer

332‧‧‧ grain

334‧‧‧Lighting element body

336‧‧‧electrode

350‧‧‧conductive bracket

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; Schematic diagram of the package method of the body.

FIG. 1C is a cross-sectional view showing a package unit according to an embodiment of the invention.

2A is a perspective view showing a flip chip structure according to another embodiment of the present invention.

Fig. 2B is a schematic cross-sectional view showing the flip chip structure shown in Fig. 2A.

210‧‧‧Fixed devices

220‧‧‧first film

230‧‧‧ grain

232‧‧‧Lighting element body

234‧‧‧Electrode

250‧‧‧ thimble

260‧‧‧ stage

Claims (12)

A method for packaging a light emitting diode, the method comprising: providing a first adhesive film, fixed in a fixing device; providing a plurality of crystal grains on the first adhesive film, each of the plurality of crystal grains having a plurality of electrodes; Removing a portion of the crystal grains from the first adhesive film; arranging the partial crystal grains on an array in an array to form an array of crystal grains on the stage; The partial dies are moved onto a substrate having a plurality of pads respectively corresponding to the electrodes of the partial dies; and the pads and the electrodes are respectively bonded. The method of claim 2, wherein the step of moving the partial dies from the stage in a batch process comprises: attaching the second film to the stage An array of dies; and moving the second film to remove the array of dies in bulk from the stage. The method of claim 2, wherein the removing the plurality of dies from the first film and arranging the portions of the dies on the stage comprises: using a ejector The partial grains are dropped from the first film. The method of claim 2, wherein the ejector pins are used to cause the partial dies to fall from the first film in the fixing device. When the stage is moved, the partial crystal grains that are dropped are received. The method of claim 4, wherein the fixing device is coupled to a first moving device to move the first film in one direction. The method of claim 5, wherein the stage is coupled to a second moving device, and the stage moves in the same direction as the fixed device when the fixing device moves in the direction. The method of claim 2, wherein the electrodes comprise a tin-lead electrode, a gold electrode, a conductive paste electrode or a polymer electrode. The method of claim 2, wherein each of the plurality of dies has two electrodes on an upper surface thereof. The method of claim 2, wherein the step of moving the partial dies from the stage to the substrate in a batch process comprises adhering the electrodes with a flux and reflowing The method is fixed to the substrate. The method of claim 2, wherein the substrate is a printed circuit board. The method of claim 2, wherein the substrate is a conductive support. The method of claim 2, wherein the array mode is a square matrix arrangement.