LED plate structure capable of overcoming metal migration
By setting the gap and the copper foil on the back of the lead wire in the LED board, the metal migration problem caused by moisture drainage in the solid crystal area is solved, and the stability and brightness of the LED board in high temperature and high humidity environment is improved.
Patent Information
- Application Number
- CN202420550713.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-21
- Publication Date
- 2025-03-18
- Estimated Expiration
- 2034-03-21
AI Technical Summary
During the electroplating process of existing LED sheets, the leads at the edge of the copper foil in the solid crystal area drain moisture into the inside of the particles, resulting in metal migration and chip lack of brightness.
A LED plate structure is designed, in which a gap is left between the edge of the wafer copper foil and the edge of the substrate, the substrate is covered with packaging colloid, and the lead copper foil is arranged on the back of the substrate to ensure that there is no lead around the solid crystal region and prevent moisture from directly acting on the LED chip.
It effectively prevents moisture from entering the LED chip, avoids metal migration problems, and ensures the stability and brightness of LED boards in high temperature and high humidity environments.
Smart Images
Figure CN222639017U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of LED plates, and relates to an LED plate structure capable of overcoming metal migration. Background Art
[0002] As the demand for LED 2-in-1 chips in the display market increases, customers also have higher requirements for the quality of LED 2-in-1 chips. The 1707 model is one of the LED 2-in-1 chips. Because it needs to meet the requirements of the plate electroplating process, the internal circuit needs to form a network. At present, the plates on the market all use the design of connecting the chips with the front copper foil. It uses the design such as Figure 1 , Figure 2 As shown, since the front copper foil of the die-bonding area S1 is connected by leads S2, these leads S2 form drainage channels for moisture to enter the interior of the particles after the particles are cut, causing metal migration in the particles and resulting in chip dimming.
[0003] Therefore, it is necessary to improve the prior art to overcome the defects in the prior art. Utility Model Content
[0004] The utility model aims to provide an LED plate structure that overcomes metal migration and solves the problem that moisture from the edge lead of the copper foil in the crystal bonding area enters the interior of the particles, causing metal migration and resulting in chip dimming.
[0005] The purpose of the utility model is achieved through the following technical solutions:
[0006] An LED plate structure for overcoming metal migration comprises a substrate, wherein a wafer copper foil and a conductive sheet are arranged on the front side of the substrate, an LED wafer is arranged on the wafer copper foil; the LED wafer is electrically connected to the conductive sheet; the characteristic is that a gap is left between the edge of the wafer copper foil and the edge of the substrate, a packaging colloid covering the wafer copper foil and the conductive sheet is arranged on the substrate, and the gap is located in the packaging colloid; a lead copper foil is arranged on the back side of the substrate, leads are arranged on the lead copper foil, and the lead copper foil is electrically connected to the conductive sheet.
[0007] Furthermore, the conductive sheet includes at least one positive conductive sheet and one negative conductive sheet, the positive electrode of the LED chip is electrically connected to the positive conductive sheet, and the negative electrode of the LED chip is connected to the negative conductive sheet; the lead copper foil has at least two pieces and is independent of each other, and at least one of the lead copper foils is electrically connected to the positive conductive sheet, and at least one of the lead copper foils is electrically connected to the negative conductive sheet.
[0008] Furthermore, the LED chips include a blue chip, a red chip and a green chip.
[0009] Furthermore, there are four lead copper foils, and the four lead copper foils are independent of each other; one lead copper foil is electrically connected to the corresponding positive electrode conductive sheet, and three lead copper foils are electrically connected to the corresponding negative electrode conductive sheets.
[0010] Specifically, the narrowest width of the gap is D, and D≥0.08 mm.
[0011] Furthermore, the substrate is a BT substrate.
[0012] The above technical solution has the following beneficial effects: the network composed of the chip copper foil and the conductive sheet is retained to facilitate electroplating, and there are no leads around the solid crystal area, so that moisture cannot directly act on the LED chip to cause metal migration. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In order to more clearly illustrate the implementation of the utility model or the technical solution in the prior art, the following is a brief introduction to the drawings required for the implementation or the prior art description. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.
[0014] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.
[0015] Figure 1 It is a top view schematic diagram of the prior art.
[0016] Figure 2 for Figure 1 Schematic cross-section along the AA direction.
[0017] Figure 3 This is a front structural schematic diagram provided by the utility model.
[0018] Figure 4 This is a schematic diagram of the back structure provided by the utility model.
[0019] Figure 5 for Figure 3 , Figure 4 Cross-sectional view along direction BB.
[0020] In the figure: 1-substrate; 2-chip copper foil; 3-lead copper foil; 4-packaging colloid; 6-blue light chip; 7-red light chip; 8-green light chip; 9-welding wire; 10-gap. DETAILED DESCRIPTION
[0021] The specific implementation methods of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these implementation methods is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each implementation method of the present invention described below can be combined with each other as long as they do not conflict with each other. Example
[0022] See also Figure 3-Figure 5 As shown, an LED plate structure that overcomes metal migration includes a substrate 1, and the substrate 1 is a BT substrate (full name BT resin substrate material, a high-performance substrate material for PCB (printed circuit board)). The front of the substrate 1 is provided with a chip copper foil 2 and a conductive sheet, the LED chip is arranged on the chip copper foil 2, and a plurality of conductive sheets are distributed on the periphery of the chip copper foil 2 and the two are not in direct contact. In this embodiment, the number of LED chips is three, namely a blue chip 6, a red chip 7 and a green chip 8, and each LED chip has a welding wire 9; the three LED chips are electrically connected to the corresponding conductive sheets.
[0023] The above structure is the same as the LED board structure provided by the background technology, except that:
[0024] In this embodiment, a gap 10 is left between the edge of the chip copper foil 2 and the edge of the substrate 1. The substrate 1 is provided with a packaging colloid 4 covering the chip copper foil 2 and the conductive sheet. The area where the packaging colloid 4 is located is the solid crystal area in the background technology. In this embodiment, the gap 10 is also within the coverage of the packaging colloid 4, so that external moisture cannot directly contact the chip copper foil 2. At the same time, the lead of the LED board is set to the back of the substrate 1. Specifically: a lead copper foil 3 is set on the back of the substrate 1, the lead copper foil 3 is connected to the lead, and the lead copper foil 3 is electrically connected to the conductive sheet, thereby realizing power supply to the LED chip.
[0025] In this embodiment, the network composed of the wafer copper foil and the conductive sheet is retained to facilitate electroplating (the copper foil inside the plate is retained to form a network). At the same time, since there are no leads around the crystal bonding area, moisture cannot directly act on the LED wafer to cause metal migration.
[0026] Furthermore, in this embodiment, the narrowest distance D between the chip copper foil 2 and the substrate 1 needs to be maintained at more than 0.08 mm to ensure that external moisture does not penetrate the packaging colloid here to affect the chip copper foil 2.
[0027] Furthermore, in this embodiment, the conductive sheet includes a positive conductive sheet 11 and three negative conductive sheets 12 around a chip copper foil 2, the positive electrodes of the three LED chips are electrically connected to the positive conductive sheet 11, and the negative electrodes of the three LED chips are all connected to the corresponding negative conductive sheets. Similarly, around a chip copper foil 2, the number of lead copper foils 3 is at least two and they are independent of each other, and at least one of the lead copper foils is electrically connected to the positive conductive sheet, and at least one of the lead copper foils is electrically connected to the negative conductive sheet, so as to achieve the purpose of powering the three LED chips. Preferably, in this embodiment, the number of lead copper foils 3 is four, and the four lead copper foils are independent of each other; one lead copper foil is electrically connected to the corresponding positive conductive sheet, and three lead copper foils are electrically connected to the corresponding negative conductive sheet.
[0028] The utility model moves the existing front solid crystal area lead to the back to ensure that there are no leads around the front solid crystal area, cut off the path of moisture directly entering the particle body from the solid crystal area, so that moisture cannot directly act on the chip to cause metal migration. At the same time, the copper foil inside the plate is retained to form a network for easy electroplating, and there are no leads around the solid crystal area. The above design is applied to 1707 products, and the high temperature, high humidity and high pressure cooking test is in good condition, which significantly improves the previous metal migration problem.
[0029] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.
Claims
1. An LED plate structure for overcoming metal migration, comprising a substrate, a wafer copper foil and a conductive sheet are arranged on the front of the substrate, and an LED wafer is arranged on the wafer copper foil; the LED wafer is electrically connected to the conductive sheet; characterized in that: A gap is left between the edge of the chip copper foil and the edge of the substrate, a packaging colloid covering the chip copper foil and the conductive sheet is provided on the substrate, and the gap is located in the packaging colloid; a lead copper foil is provided on the back of the substrate, a lead is provided on the lead copper foil, and the lead copper foil is electrically connected to the conductive sheet.
2. The LED plate structure according to claim 1, characterized in that: The conductive sheet includes at least one positive conductive sheet and one negative conductive sheet, the positive electrode of the LED chip is electrically connected to the positive conductive sheet, and the negative electrode of the LED chip is connected to the negative conductive sheet; the lead copper foil has at least two pieces and is independent of each other, and at least one of the lead copper foils is electrically connected to the positive conductive sheet, and at least one of the lead copper foils is electrically connected to the negative conductive sheet.
3. The LED plate structure according to claim 2, characterized in that: The LED chips include a blue light chip, a red light chip and a green light chip.
4. The LED plate structure according to claim 3, characterized in that: The number of the lead copper foils is four, and the four lead copper foils are independent of each other; one lead copper foil is electrically connected to the corresponding positive electrode conductive sheet, and three lead copper foils are electrically connected to the corresponding negative electrode conductive sheets.
5. The LED plate structure according to claim 1, characterized in that: The narrowest width of the gap is D, and D≥0.08 mm.
6. The LED plate structure according to claim 1, characterized in that: The substrate is a BT substrate.