TWI843681B - Method for welding an electronic element, and method for manufacturing a light-emitting diode display - Google Patents

Abstract

A device configured to weld an electronic element includes a carrying platform, a pressing element, a hermetic space generating mechanism, a gas extracting mechanism, and an energy generating mechanism. The carrying platform is configured to support a substrate. The pressing element is made of a flexible material. The hermetic space generating mechanism is capable of putting the pressing element on the carrying platform, so as to form a hermetic space between the pressing element and the carrying platform. The gas extracting mechanism is configured to extract gas from the hermetic space. The energy generating mechanism is disposed adjacent to the carrying platform, and capable of generating energy on the carrying platform. A method for welding an electronic element and a method for manufacturing a light-emitting diode display are also provided.

Description

Method for welding electronic components and method for manufacturing light emitting diode display

The present invention relates to a device for joining electronic components, a method for joining electronic components and a method for manufacturing a display, and in particular to a device for welding electronic components, a method for welding electronic components and a method for manufacturing a light-emitting diode display.

Semiconductor components are usually grown on a growth substrate using epitaxial growth. However, as the various applications of semiconductor components change, the semiconductor components may not remain on the original growth substrate when they are finally formed into a finished product, but may be transferred to a transfer substrate, and finally transferred to a target substrate to form a final product.

When a semiconductor device is to be transferred from a transfer substrate to a target substrate, one method is to place the front surfaces of the transfer substrate and the target substrate facing each other and press the transfer substrate and the target substrate together.

The use of micro light-emitting diodes (micro-LEDs) in displays is already a future trend in the display industry. The manufacturing process uses technology to transfer micro-LED chips from a transfer substrate to a target substrate. Currently, this industry is still mainly used to produce small and medium-sized displays. Considering future development, it is bound to develop towards large-size displays.

The future challenges of large-size displays lie in large-area pressing accuracy, laser type, production yield, selection of related materials, and bad spot repair methods. Therefore, the development and research of large-size production equipment is also imperative.

The present invention provides a device for welding electronic components, which can uniformly press two substrates.

The present invention provides a method for welding electronic components, which can uniformly press a carrier substrate and a target substrate.

The present invention provides a method for manufacturing a light emitting diode display, which can manufacture the light emitting diode display by uniformly pressing a carrier substrate and a target substrate.

An embodiment of the present invention provides a device for welding electronic components, which includes a supporting platform, a pressure element, a closed space generating mechanism, an exhaust mechanism and an energy generating mechanism. The supporting platform is used to support a substrate. The pressure element is made of a flexible material. The closed space generating mechanism can place the pressure element on the supporting platform to form a closed space between the pressure element and the supporting platform. The exhaust mechanism is used to exhaust the closed space. The energy generating mechanism is arranged near the supporting platform and can generate energy on the supporting platform.

An embodiment of the present invention provides a method for welding electronic components, which includes: providing a carrier substrate, on one surface of which an electronic component selectively having a solder is carried; providing a target substrate, which has a welding surface, on which a desired welding position is provided, and when there is no solder on the above-mentioned electronic component, applying a solder to the desired welding position; making a surface of the carrier substrate bearing the electronic component face the welding surface of the target substrate, and making the electronic component face the desired welding position; placing the facing carrier substrate and the target substrate into a closed space, wherein the closed space is close to an end surface of the carrier substrate that is made of a flexible material; evacuating the closed space so that the end surface of the flexible material presses against a surface of the carrier substrate that does not bear the electronic component; and applying energy to melt the solder so that the electronic component is welded to the desired welding position.

An embodiment of the present invention provides a method for manufacturing a light emitting diode display, which includes welding an electronic component using the above method, and the electronic component is a light emitting diode chip.

In the device for welding electronic components, the method for welding electronic components and the method for manufacturing a light-emitting diode display of the embodiments of the present invention, since a flexible material is used in combination with a method for exhausting air in a closed space, two substrates can be pressed evenly to achieve a good welding effect, thereby improving the yield rate of manufacturing a light-emitting diode display.

Figures 1 to 5 are cross-sectional schematic diagrams for illustrating the process of a method for welding electronic components of an embodiment of the present invention. Please refer to Figures 1 to 5. The method for welding electronic components of this embodiment includes the following steps. First, please refer to Figure 1, and provide a carrier substrate 100. On one surface 102 of the carrier substrate 100, an electronic component 110 selectively having a solder 112 thereon is carried. In this embodiment, the carrier substrate 100 is, for example, a glass substrate or a transparent substrate of other materials. However, in other embodiments, the carrier substrate 100 can also be a metal substrate or an opaque substrate of other materials. In one embodiment, a plurality of electronic components 110 can be fixed on the carrier substrate 100 through an adhesive layer 120. In this embodiment, the electronic component 110 is, for example, a light emitting diode chip or other electronic components, and has at least one pad 114 thereon, and the solder 112 is disposed on the pad 114 .

In addition, a target substrate 200 is provided, which has a welding surface 202, and a desired welding position 212 is provided on the welding surface 202, and when there is no solder 112 on the electronic component 110, the solder 112 is applied to the desired welding position 212. In this embodiment, the target substrate 200 is a thin film transistor (TFT) substrate, and a pad 210 connected to a conductive line of the thin film transistor substrate is provided on the welding surface 202, and the surface of the pad 210 forms the desired welding position 212. In other embodiments, the target substrate 200 can also be a silicon substrate, a circuit board or other appropriate substrates.

Afterwards, the surface 102 of the carrier substrate 100 carrying the electronic component is made to face the welding surface 202 of the target substrate 200, and the electronic component 110 is made to face the desired welding position 212. In this embodiment, a suction platform 300 can be used to suction the carrier substrate 100, for example, by suctioning a surface 104 of the carrier substrate 100 that does not carry the electronic component 110 by vacuum suction, wherein the surface 104 faces the surface 102. In addition, in this embodiment, an image sensor 310 can be used to sense the alignment mark on the carrier substrate 100 through the through hole 302 of the suction platform 300, and to sense the alignment mark on the target substrate 200 below the carrier substrate 100, so as to align the electronic component 110 with the desired welding position 212.

Next, the adsorption platform 300 is placed on a supporting platform 400 for supporting the target substrate 200 to form a closed space S1 between the adsorption platform 300 and the supporting platform 400. Then, the closed space S1 is evacuated, for example, by vacuuming. In the present embodiment, the supporting platform 400 has an exhaust channel 410, one end of which is connected to the closed space S1, and the other end is connected to an exhaust mechanism 420, for example, an exhaust pump. The exhaust mechanism 420 exhausts the gas in the closed space S1 to the outside through the exhaust channel 410, so that the closed space S1 reaches a vacuum state. When the closed space S1 is evacuated, the gravity of the carrier substrate 100 is greater than the adsorption force of the adsorption platform 300, so that the carrier substrate 100 falls onto the target substrate 200 and causes the closed space S1 to be broken, as shown in FIG3 . In this embodiment, when the carrier substrate 100 falls onto the target substrate 200 and faces the target substrate 200, the electronic component 110 contacts the desired welding position 212 of the target substrate 200 through the solder 112.

Afterwards, please refer to FIG. 4 , the facing carrier substrate 100 and the target substrate 200 are placed in a closed space S2, wherein one end surface of the closed space S2 close to the carrier substrate 100 is made of a flexible material, i.e., a pressing element 510 having a flexible material. In this embodiment, the pressing element 510 is a flexible film, such as a silicone film. Then, please refer to FIG. 5 , the closed space S2 is evacuated so that the end surface of the flexible material (i.e., the pressing element 510) presses against the surface 104 of the carrier substrate 100 that does not carry the electronic component 110. At this time, due to the significant drop in air pressure in the closed space S2, the atmospheric pressure above the pressure element 510 will cause the pressure element 510 to deform downward and bear against the surface 104 of the carrier substrate 100, so as to uniformly press the carrier substrate 100. In addition, when the pressure element 510 presses against the surface 104 of the carrier substrate 100, an energy 522 is applied to melt the solder 112, so that the electronic component 110 is soldered to the desired soldering position 212. In this embodiment, the energy 522 is, for example, a laser beam. However, in other embodiments, the energy 522 may also be thermal energy or an incoherent beam (i.e., a non-laser beam).

Please refer to Figures 4 and 5. An embodiment of the present invention provides a device 500 for welding electronic components, which includes a supporting platform 400, a pressure element 510, a closed space generating mechanism 530, an exhaust mechanism 420 and an energy generating mechanism 520. The supporting platform 400 is used to support a substrate, such as a target substrate 200. The closed space generating mechanism 530 can place the pressure element 510 on the supporting platform 400, so that a closed space S2 is formed between the pressure element 510 and the supporting platform 400. The exhaust mechanism 420 is used to exhaust the closed space S2. In this embodiment, the exhaust mechanism 420 exhausts air through the supporting platform 400, for example, exhausts the closed space S2 through the exhaust channel 410 in the supporting platform 400.

The energy generating mechanism 520 is disposed adjacent to the carrier platform 400 and can generate energy 522 on the carrier platform 400. In the present embodiment, the energy generating mechanism 520 is a laser generator for providing energy 522 (a laser beam in the present embodiment). The energy generating mechanism 520 can move laterally to scan different electronic components 110. Alternatively, in another embodiment, the energy generating mechanism 520 can provide an energy beam with a large cross-sectional area to irradiate multiple electronic components 110 at the same time. However, in other embodiments, the energy generating mechanism 520 can also be a heater or a non-coherent light source. In the present embodiment, the laser generator (i.e., the energy generating mechanism 520) projects a laser beam (i.e., energy 522) onto the carrier platform 400 through the pressure element 510 to melt the solder 112. However, in another embodiment, as shown in FIG6 , the laser generator (i.e., energy generating mechanism 520) projects a laser beam (i.e., energy 522) onto the carrier platform 400 through the carrier platform 400 to melt the solder 112. The carrier platform 400 may be penetrated by the laser beam, or may have a window that is penetrated by the laser beam.

The method of soldering electronic components in FIG. 1 to FIG. 5 or FIG. 6 can also be used as a method for manufacturing a light-emitting diode display, wherein the electronic component 110 is a light-emitting diode, such as a micro light-emitting diode, and the target substrate 200 is used as a display substrate of the terminal product. The electronic component 110 (i.e., the light-emitting diode) is disposed on the target substrate 200 and is electrically connected to the target substrate 200. After the electronic component 110 is soldered to the target substrate 200, the adhesive layer 120 and the carrier substrate 100 can be removed, and the remaining target substrate 200 and the electronic component 110 thereon become a light-emitting diode display.

In the device 500 for welding electronic components, the method for welding electronic components, and the method for manufacturing a light-emitting diode display of the present embodiment, since a flexible material is used in combination with a method for exhausting the closed space S2, the two substrates can be evenly pressed together to achieve a good welding effect, thereby improving the yield rate of manufacturing a light-emitting diode display. In the steps of FIG. 2 to FIG. 3, the closed space S1 is evacuated to allow the carrier substrate 100 to fall onto the target substrate 200, so that it is not easy to form a bubble space between the carrier substrate 100 and the target substrate 200 to affect the manufacturing yield rate. In the step of FIG. 5, the closed space S2 is evacuated to allow the pressure element 510 to be subjected to atmospheric pressure so that the carrier substrate 100 can be evenly pressed together. Since a negative pressure method is adopted, the equipment load does not need to consider the compression load. Since the pressing element maintains uniform compression of the carrier substrate 100 when the electronic component 110 is welded to the target substrate 200 with energy 522, good welding quality can be achieved.

In addition, in this embodiment, the area of the carrier substrate 100 is larger than the area of the target substrate 200, so a dummy sheet 220 may be placed around the target substrate 200. In this way, when the carrier substrate 100 falls on the target substrate 200, the dummy sheet 220 may support the edge of the carrier substrate 100 to prevent the edge of the carrier substrate 100 from bending. However, in another embodiment, when the area of the carrier substrate 100 is smaller than or equal to the area of the target substrate 200, it is not necessary to place the dummy sheet 220 around the target substrate 200.

In summary, in the device for welding electronic components, the method for welding electronic components, and the method for manufacturing a light-emitting diode display of the embodiments of the present invention, since a flexible material is used in combination with a method for exhausting air in a closed space, two substrates can be pressed evenly to achieve a good welding effect, thereby improving the yield rate of manufacturing a light-emitting diode display.

100: Carrier substrate 102, 104: Surface 110: Electronic component 112: Solder 114: Pad 120: Adhesive layer 200: Target substrate 202: Soldering surface 210: Pad 212: Position to be soldered 220: Dull sheet 300: Adsorption platform 302: Through hole 310: Image sensor 400: Carrier platform 410: Exhaust channel 420: Exhaust mechanism 500: Device for soldering electronic components 510: Pressure element 520: Energy generating mechanism 522: Energy 530: Enclosed space generating mechanism S1, S2: Enclosed space

Figures 1 to 5 are cross-sectional schematic diagrams for illustrating the process of a method for welding electronic components according to one embodiment of the present invention. Figure 6 is a cross-sectional schematic diagram of an apparatus for welding electronic components according to another embodiment of the present invention.

100: Carrier substrate 102, 104: Surface 110: Electronic component 112: Solder 114: Pad 120: Adhesive layer 200: Target substrate 202: Soldering surface 210: Pad 212: Position to be soldered 220: Dull sheet 400: Carrier platform 410: Exhaust channel 420: Exhaust mechanism 500: Device for soldering electronic components 510: Pressure element 520: Energy generating mechanism 522: Energy 530: Enclosed space generating mechanism S2: Enclosed space

Claims (6)

A method for soldering electronic components, comprising: Providing a carrier substrate, on one surface of which an electronic component with a solder selectively applied thereon is carried; Providing a target substrate, which has a soldering surface, on which a desired soldering position is provided, and when there is no solder on the electronic component, applying a solder to the desired soldering position; Making one surface of the carrier substrate carrying the electronic component face the soldering surface of the target substrate, and making the electronic component face the desired soldering position; Placing the facing carrier substrate and the target substrate into a closed space, wherein the closed space is close to an end surface of the carrier substrate which is made of a flexible material; Evacuating the closed space so that the end surface of the flexible material presses against a surface of the carrier substrate which does not carry the electronic component; and Apply energy to melt the solder so that the electronic component is soldered to the desired soldering location. A method for soldering electronic components as described in claim 1, wherein when the carrier substrate is made to face the target substrate, the electronic component is brought into contact with the desired soldering position of the target substrate through the solder. A method for welding electronic components as described in claim 1, wherein the energy is a laser beam. A method for welding electronic components as described in claim 1, wherein the electronic component is a light emitting diode chip. A method for welding electronic components as described in claim 1, wherein the target substrate is a thin film transistor substrate. A method for manufacturing a light-emitting diode display comprises soldering a light-emitting diode chip using the method described in claim 4.

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