TWM580798U - LED carrier board having preset conductive bump - Google Patents

Abstract

An LED carrier board, having preset bumps, includes a substrate, a circuit layer and multiple bumps. The substrate has an LED carrier surface on which the circuit layer is formed. The circuit layer has multiple contacting pads atop which the bumps are formed, respectively. The bumps are used for electrically connecting to multiple LED chips, respectively. Thereby, the yield of the overall preparation procedure can be enhanced.

Description

Light-emitting diode carrier board pre-equipped with conductive bumps

The present invention relates to a light emitting diode carrier, and more particularly to a surface mount type light emitting diode (SMD LED) carrier.

The process of LED (hereinafter referred to as LED) can be divided into upstream epitaxial fabrication, midstream wafer fabrication and downstream packaging testing and system assembly. When the LED die is completed, the LED die will be adhered to the LED. On the body carrier board (hereinafter referred to as the LED carrier board), after a series of production processes such as solid crystal, curing, wire bonding, sealing, and cutting, a light-emitting diode component (hereinafter referred to as an LED component) is fabricated.

The existing packaging technology is to electrically connect the bumps of the LED die with the electrical contacts of the substrate by solder, but due to the smaller and smaller size of the LED die, the process of forming bumps on the LED die is performed. The difficulty is significantly increased and the yield is difficult to increase.

In view of this, the main purpose of the present invention is to provide a light-emitting diode carrier that contributes to the improvement of the LED die package yield.

In order to achieve the above object, the present invention provides a light-emitting diode carrier plate pre-equipped with conductive bumps, comprising a substrate, a circuit layer and a plurality of conductive bumps, the substrate having a light-emitting diode bearing surface (below Referring to the LED bearing surface, the circuit layer is formed on the LED bearing surface, and the circuit layer has a plurality of electrical contacts, the conductive bumps are respectively formed on the top surfaces of the electrical contacts, and the conductive bumps are respectively provided A plurality of LED dies are electrically connected.

By presetting the conductive bumps on the LED carrier, there is no need to form additional bumps on the LED die, and the process of forming bumps on the carrier is much less difficult than forming bumps on the LED die. Therefore, the novel can solve the problem that the LED die bump process yield is poor in the previous LED packaging process, thereby improving the overall process yield.

Referring to FIG. 1 , in one embodiment of the present invention, the LED carrier board includes a substrate 10 , a circuit layer 20 , a plurality of conductive bumps 30 , and a solder resist layer 40 . The LED carrier can be applied, for example, to a packaging process of an SMD LED component.

The substrate 10 itself has one or more insulating layers, such as epoxy, woven glass, polyester, or other materials commonly used in the fabrication of circuit board substrates. In addition, the substrate 10 has an LED carrying surface 11 on the LED carrying surface 11 which may have one or more LED carrying regions (not shown) for mounting a plurality of LED dies.

The circuit layer 20 is formed on the LED carrying surface 11 , and the circuit layer 20 has a plurality of electrical contacts 21 . The number of electrical contacts 21 depends on the number of LED dies that the LED carrying surface 11 needs to carry, and a part of the electrical The contact 21 is electrically connected to the p-pole of the LED die through the conductive bump 30, and the other electrical contact 21 is electrically connected to the n-pole of the LED die through the conductive bump 30. The circuit layer 20 is made of a conductive material such as copper. In order to provide sufficient current transmission capability, the electrical contact 21 may further have a surface plating layer 211, and the surface plating layer 211 may be made of, for example, nickel, gold, silver, palladium or an alloy thereof.

The conductive bumps 30 are respectively formed on the top surfaces of the electrical contacts 21. Since the electrical contacts 21 have a surface plating layer 211 in this embodiment, the conductive bumps 30 are formed on the top surface of the surface plating layer 211. The conductive bumps 30 are electrically connected to the plurality of LED dies, respectively. The material of the conductive bumps 30 is, for example, tin.

The solder resist layer 40 is formed on the LED bearing surface 11 , and the solder resist layer 40 partially covers the circuit layer 20 , but the electrical contact 21 and the conductive bump 30 are not covered by the solder resist layer 40 , wherein the top of the conductive bump 30 is higher than the solder resist The top surface of layer 40 is electrically connected to the LED die. The solder resist layer 40 is an insulating layer, and the material thereof may be epoxy resin, enamel resin, polyimide resin, phenol resin, fluororesin, cerium oxide or aluminum oxide. In the embodiment illustrated in Figure 1, the solder mask 40 has a substantially flush top surface. In other possible embodiments, the height of the solder resist layer between the two electrical contacts 21 as shown in FIG. 1 is equal or slightly lower than the top surface of the electrical contact.

Figures 2 through 4 illustrate one embodiment of a process for preparing a front LED strip. First, as shown in FIG. 2, one to several copper layers are formed on the LED carrying surface 11 of the substrate 10, and then the copper layer is patterned to form the circuit layer 20; then, as shown in FIG. 3, The LED bearing surface 11 forms a solder resist layer 40, and a window 41 is formed at the corresponding electrical contact 21 to expose the electrical contact 21; and then, as shown in FIG. 4, the surface of the electrical contact 21 is surface-treated. The surface plating layer 211 is provided, and the conductive bump 30 is formed on the top surface of the surface plating layer 211, that is, the LED carrier board as shown in FIG.

5 and 6 are schematic diagrams showing the process of mounting the LED die on the LED carrier board, that is, the electrodes 2 of the LED die 1 are respectively aligned with the conductive bumps 30, and then the LED die 1 is reflowed by reflow soldering. The conductive bumps 30 are electrically connected to facilitate subsequent LED packaging processes.

In summary, since the process of forming bumps on the carrier is much less difficult than forming bumps on the LED die, the present invention can solve the problem of poor LED chip bump process yield in the prior LED packaging process. To improve the overall process yield.

1‧‧‧LED dies

2‧‧‧electrode

10‧‧‧Substrate

11‧‧‧LED bearing surface

20‧‧‧ circuit layer

21‧‧‧Electrical contacts

211‧‧‧ surface coating

30‧‧‧Electrical bumps

40‧‧‧ solder mask

41‧‧‧Opening the window

Figure 1 is a schematic cross-sectional view showing one embodiment of the present invention.

2 to 4 are schematic views showing a process of one embodiment of the present invention.

5 and 6 are schematic views showing a process of mounting an LED die in one embodiment of the present invention.

Claims (4)

A light-emitting diode carrier board pre-equipped with a conductive bump comprises: a substrate having a light-emitting diode carrying surface; a circuit layer formed on the light-emitting diode carrying surface, the circuit layer having a plurality of electricity a plurality of conductive bumps are respectively formed on the top surfaces of the electrical contacts, and the conductive bumps are respectively electrically connected to the plurality of light emitting diodes. The light-emitting diode carrier board provided with the conductive bumps as claimed in claim 1 further includes a solder resist layer formed on the light-emitting diode carrying surface, the solder resist layer partially covering the circuit layer, and the electrical connections The dots and the conductive bumps are not covered by the solder resist layer. The light-emitting diode carrier board provided with the conductive bumps as claimed in claim 2, wherein the conductive bumps are higher than the top surface of the solder resist layer. The light-emitting diode carrier board provided with the conductive bumps according to claim 1, wherein each of the electrical contacts further has a surface plating layer, and the conductive bumps are respectively formed on the top surface of the surface plating layer.