All manufacturers rush into the Micro LED, which holds the key technology patents

In recent years shows that quite a hot topic in the panel market is probably Micro LED (micro light emitting diode), many manufacturers as can subvert the market blue ocean killer technology, major or start-up companies are competing in this area, in the relevant technology patent applications also began in 2013 the rapid surge.

If you want to use a simple word that Micro LED, its volume is about LED one percent, size and pixel spacing are reduced to micron level.

In the production process of Micro LED, the components of the miniature, there are many problems to be overcome or improved, and the technology transfer process is the key whether the standard production and commercial products.

On the basis of the display substrate size is different, can be divided into two kinds of transfer forms, the first is the small size of the display substrate, the integration technology used in semiconductor manufacturing, the LED will be directly bonded to the substrate, technology vendors on behalf of Taiwan ITRI, second is used for large size (or no size limit) display substrate using pick-and-place Micro technology, a LED array of pixels were transferred to the board, on behalf of manufacturers for the Apple (LuxVue), X-Celeprint, such as Sony, eLux and other manufacturers also have relevant technology transfer.

The Micro LED related patents

The Taiwan Industrial Technology Research Institute

(A) patent name: transfer method of light emitting element and a light emitting element array

Announcement number: TW I521690

Priority: US 61/511137

This article is about the patent transfer method of the light emitting element, comprises the steps of forming a plurality of LED arrays arranged before the substrate 1, an array as a color of LED, for example in Figure 1 red, green and blue respectively for an array.

Transfer process through multiple steps of welding, in order to a predetermined position on the LED 1 substrate transferred to the substrate 2 so, as shown in Figure 2, every time before welding with a protective layer to cover up to the transfer of the LED, and then transferred to the conductive convex block and the LED substrate 2 bonding pads, the most after 1 LED of substrate will be transferred to the substrate 2.

Figure 1. TW I521690 patent Figure 3 (source: TIPO)

Figure 2. TW I521690 H-J patent (source: TIPO)

In this article the patent seems to have no special mention of LED or Micro LED size is related to the word, but in the case of the United States is corresponding to the same priority, mentioned light emitting element is 1 to 100 microns, and spacing (pitch) according to the actual demand of the products is adjusted, as in Figure 3. And the text is shown in the table.

Figure 3. US 14/583594 patent (source: USPTO)

(B) patent name: light emitting element and method for manufacturing display

Announcement number: TW I590433

This patent is about Micro / Taiwan LED manufacturing technology, but the method with a different. First of all, the LED array is formed on the substrate, wherein the semiconductor epitaxial structure, a first electrode and a second electrode composed of light emitting diode chip and light emitting element comprises a light emitting diode chip and a spherical electrode extension, after the completion of the light emitting element is removed from the substrate

Then through the nozzle ejected by the light emitting element, light emitting element and the friction of the nozzle, the spherical electrode extends with electrostatic charge, contact and receiving substrate through the circuit structure of the transmission signal but also with the electrostatic charge in the embodiment of the spherical electrode in manual extension with a positive charge and contacts with negative charge.

As shown in Figure 4, for example, through the shaking sieve method, the light emitting element into the receiving substrate in the opening hole, because the ball extension electrode is greater than the size of the light emitting diode chip size, so in the process of falling, the light ball falls into the hole to extend electrode in contact with all points.

Figure 4. TW I590433 patent map P, S, T (source: TIPO)

The Apple (LuxVue)

LuxVue in 2014 by Apple Micro merger, LED related patents owned is the largest of all manufacturers, in the transfer of technology which is massive technology transfer by electrostatic adsorption.

Patent name: Micro device transfer head array

Announcement No.: US 9548233 B2

In order to achieve better transfer efficiency, the use of massive transfer technology manufacturers continue to develop every kind of transfer head, and special Apple the patent is the transfer of the bipolar structure has a head, can give positive and negative voltage.

The platform structure transfer head by the dielectric layer on the separation of the formation of a silicon electrode on the substrate, when you want to grab LED, on a silicon electrode through positive, another silicon electrode can be charged through the target LED pickup.

Figure 5. US 9548233 Figs. 1B, 34, 35 (source: USPTO)

The X-Celeprint

Patent name: Micro device transfer head array

Public number: US 2017-0048976 A1

The massive transfer technology of Micro-Transfer-Printing X-Celeprint (TP) is used in the LED stamping head pressure, using van der Waals let LED attached to the imprinting head after, from the source of the substrate will pick up a predetermined position to the target substrate after the imprinting head together with LED pressure to the target substrate, so that the connection on LED column insert the back contact pad after the completion of the LED transfer.

Figure 6. Figs. US2017-0048976 5-6 patent (source: USPTO)

The eLux

According to reports, Foxconn will acquire Micro LED startup eLux, the company has two points in the patent. The first is the transfer of technology and the mainstream of the market, followed by its patents in America, using CIP series of Sharp and a large number of its own patent (Fig. 8).

Patent name: System and Method f