Packaging method for flip LED chips

Abstract

The invention relates to a packaging method for flip LED chips, which belongs to the field of LED fabrication. The packaging method at least includes the following steps that: (a) phosphor is coated on the surface of an LED chip by screen printing, and is baked to become solidified; (b) the LED chip is fixed on a chip substrate, so that the electrodes of the LED chip are bonded with the electrodes of the chip substrate; (c) the LED chip and the chip substrate are fixed on a support and the bottom of a reflective cup; (d) wires are utilized to respectively connect the positive and the negative electrodes of the fixed chip substrate with the positive and the negative electrodes of the support; (e) a sealing mould or a lens covers on the support on which the LED chip and the chip substrate are fixed, and silica gel is filled; and (f) the whole structure is backed to become solidified. Since the used LED chip is a flip chip and the phosphor is coated on the surface of the LED chip before the wires are soldered, the product yield can be increased, and the screen printing technique can ensure that the thickness of the coated phosphor is more uniform, so the distribution of phosphor powder particles is more uniform.

Description

technical field [0001] The invention relates to a packaging method for flip-chip LED chips, which belongs to the field of LED manufacturing. Background technique [0002] At present, there are mainly two conventional coating processes for phosphor powder on LED chips. The first process is to fill the holder cup with LED chips fixed with phosphor, as shown in Figure 1. This process is mature, stable and easy to operate. , but the shape of the prepared phosphor is difficult to control, and the consistency is poor, resulting in obvious light spots and yellow halos on the product. When the light is split, the distribution of the color coordinate points between the products is scattered, and there are many bins, which brings great harm to the product storage and sales. It is a big difficulty, and the amount of phosphor used is large, and the waste is serious; the second process is to only coat the phosphor on the LED chip, as shown in Figure 2, the product produced by this proces...

AI Technical Summary

Problems solved by technology

[0002] At present, there are mainly two conventional coating processes for phosphor powder on LED chips. The first process is to fill the bracket cup with LED chips fixed with phosphor, as shown in Figure 1. This process is mature, stable and easy to operate. , but the shape of the prepared phosphor is difficult to control, and the consistency is poor, resulting in obvious light spots and yellow halos on the product. When the light is split, the distribution of the color coordinate points between the products is relatively scattered, and there are many bins, which brings great harm to product storage and sales. It is a big difficulty, and the amount of phosphor used is large, and the waste is serious; the second process is to only coat the phosphor on the LED chip, as shown in Figure 2, the product produced by this process consumes less phosphor, and the fluorescent The powder excitation efficiency is high and the light spot is improved, but the operation is inconvenient and the coating efficiency is low. However, because the LED chip is a positive chip, the wire must be connected first, and then the phosphor powder can be applied, otherwise the wire cannot be soldered, and the fluorescent powder can be applied after welding the wire. The powder is easy to cause the collapse of the wire, resulting in product damage, which has a great impact on the manufacturing yield of the product

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