LED packaging process and packaging ceramic substrate

Abstract

The invention relates to the technical field of LED packaging, in particular to an LED packaging technology and a packaging ceramic substrate, a groove matched with the installation direction of an LED chip is formed between a first heat conduction ceramic layer and a second heat conduction ceramic layer, and a heat pipe is bent into a shape matched with the groove, so that the heat pipe is matched with the heating position of the LED chip, the heat dissipation effect on the LED chip is guaranteed, and the heat dissipation efficiency of the LED chip is improved. The use area of the heat pipe is reduced, the structural strength of the packaging ceramic substrate is ensured, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of LED packaging technology, specifically to an LED packaging process and a packaging ceramic substrate. Background Technology

[0002] LED chips generate a significant amount of heat during operation, making heat dissipation a key factor limiting the performance improvement and lifespan extension of LED lighting products. Traditional LED packaging processes and ceramic substrates have shortcomings in heat dissipation structure design. In most cases, the design of heat dissipation channels or structures lacks specificity and fails to effectively match the heat generation and conduction paths of the LED chips. For example, the heat dissipation trench layout of some ceramic substrates is arbitrary, or the heat dissipation structure is too large, without taking into account the distribution of LED chips, thus affecting the stability of the packaging structure. Summary of the Invention

[0003] To address the problems in the prior art, this invention provides an LED packaging process and a packaging ceramic substrate, which effectively reduces the occupancy of the heat dissipation structure while ensuring the heat dissipation effect of the packaging ceramic substrate and ensuring the structural stability of the packaging ceramic substrate.

[0004] The technical solution adopted by this invention to solve its technical problem is: an LED packaging process and a packaging ceramic substrate, comprising the following steps: S1. Determine the shape of the trench according to the LED chip mounting direction, and use this to open the mold for the first thermally conductive ceramic layer and the mold for the second thermally conductive ceramic layer. S2. Place the ceramic powder into the mold of the first thermally conductive ceramic layer and the mold of the second thermally conductive ceramic layer respectively, and perform dry pressing to prepare the first ceramic blank and the second ceramic blank with grooves on the surface. S3. The first ceramic blank and the second ceramic blank formed by dry pressing are sintered at high temperature to obtain the first thermally conductive ceramic layer and the second thermally conductive ceramic layer respectively. S4. Bend the cut heat pipe into the shape of matching groove, weld positioning blocks to the outer wall of the heat pipe, place the middle part of the heat pipe into the groove of the first thermally conductive ceramic layer, and splice the second thermally conductive ceramic layer with the first thermally conductive ceramic layer. S5. After evacuating the heat pipe and filling it with working fluid, seal the ends of the heat pipe by welding. S6. Adhere a ceramic substrate with a circuit layer to the bottom of the second thermally conductive ceramic layer, and install an LED chip on the ceramic substrate.

[0005] Specifically, the grooves are arc-shaped, and after the first and second thermally conductive ceramic layers are bonded together, the adjacent grooves are combined to form a circular channel.

[0006] Specifically, a positioning groove is formed at the bottom of the trench.

[0007] Specifically, the working fluid is purified water.

[0008] Specifically, the first thermally conductive ceramic layer and the second thermally conductive ceramic layer are bonded together with a ceramic adhesive.

[0009] Specifically, the thickness of the first thermally conductive ceramic layer and the second thermally conductive ceramic layer is 3.0 mm to 6.35 mm.

[0010] Specifically, the heat pipe has a diameter of 1.5 mm to 2.0 mm.

[0011] Specifically, the positioning block includes two sets of arc-shaped copper sheets welded to the outer wall of the heat pipe, with an aluminum sheet placed between the two sets of arc-shaped copper sheets.

[0012] A ceramic substrate for packaging, prepared using the aforementioned LED packaging process, includes a first thermally conductive ceramic layer, a second thermally conductive ceramic layer, and a ceramic substrate with a circuit layer arranged sequentially from top to bottom. Grooves are formed on the opposing surfaces of the first and second thermally conductive ceramic layers. A heat pipe is disposed in the grooves formed by the upper and lower layers. A positioning groove is provided on the inner wall of the grooves. A positioning block that engages with the positioning groove is installed on the outer wall of the heat pipe.

[0013] The beneficial effects of this invention are: 1. The LED packaging process and packaging ceramic substrate of the present invention form grooves matching the mounting direction of the LED chip on the first and second thermally conductive ceramic layers through a dry pressing process, and bend the heat pipe into the shape matching the grooves, thereby matching the heat dissipation position of the LED chip, ensuring the heat dissipation effect of the LED chip, reducing the area of ​​the heat pipe, ensuring the structural strength of the packaging ceramic substrate, and reducing production costs.

[0014] 2. The LED packaging process and packaging ceramic substrate described in this invention ensure the stability of the heat pipe within the trench by engaging the positioning block with the positioning groove. The positioning block is composed of arc-shaped copper and aluminum sheets. When the temperature rises, the aluminum sheet expands, causing the two sets of arc-shaped copper sheets to gradually expand outward under thermal stress, making the arc-shaped copper sheets fit more tightly against the positioning groove. This further improves the stability of the engagement between the positioning block and the positioning groove, and also improves the stability of the heat pipe installation. This ensures that the heat pipe can maintain a good heat dissipation position and maintain efficient heat dissipation performance under high-temperature operating conditions. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] Figure 1 This is a process flow diagram of the present invention; Figure 2 This is an isometric view of the ceramic substrate for packaging according to the present invention; Figure 3 This is an exploded view of the ceramic substrate for packaging according to the present invention; Figure 4 for Figure 3 Enlarged view of region A; In the figure: 1. First thermally conductive ceramic layer; 2. Second thermally conductive ceramic layer; 3. Ceramic substrate; 4. LED chip; 5. Trench; 6. Heat pipe; 7. Positioning block; 71. Arc-shaped copper sheet; 72. Aluminum sheet; 8. Positioning groove. Detailed Implementation

[0017] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0018] In order to effectively ensure the stability of LEDs during operation, maintain luminous efficiency, and improve lifespan, as an embodiment of the present invention, an LED packaging process includes the following steps: S1. Determine the shape of the trench 5 according to the mounting direction of the LED chip 4, and make molds for the first thermally conductive ceramic layer 1 and the second thermally conductive ceramic layer 2 accordingly. S2. Place ceramic powder into the mold of the first thermally conductive ceramic layer 1 and the mold of the second thermally conductive ceramic layer 2 respectively, and perform dry pressing to prepare the first ceramic blank and the second ceramic blank with grooves 5 on the surface. S3. The first ceramic blank and the second ceramic blank formed by dry pressing are sintered at high temperature to obtain the first thermally conductive ceramic layer 1 and the second thermally conductive ceramic layer 2 respectively. S4. Bend the cut heat pipe 6 into the shape of matching groove 5, and weld positioning block 7 on the outer wall of heat pipe 6. Place the middle part of heat pipe 6 into the groove 5 of the first thermally conductive ceramic layer 1, and assemble the second thermally conductive ceramic layer 2 with the first thermally conductive ceramic layer 1. S5. After evacuating the heat pipe 6 and filling it with working fluid, seal and weld the ends of the heat pipe 6. S6. A ceramic substrate 3 with a circuit layer is bonded to the bottom of the second thermally conductive ceramic layer 2, and an LED chip 4 is installed on the ceramic substrate 3.

[0019] To facilitate the connection between the heat pipe 6 and the groove 5, in one embodiment of the present invention, the groove 5 is arc-shaped, and after the first thermally conductive ceramic layer 1 and the second thermally conductive ceramic layer 2 are bonded together, the adjacent grooves 5 are assembled into a circular channel.

[0020] The arc-shaped groove 5 is designed to easily match the shape of the heat pipe 6, ensuring the stability of the heat pipe 6 within the circular channel. It should be noted that the orientation of the groove 5 should be determined according to the mounting orientation of the LED chip 4, including but not limited to serpentine paths, arc paths, and S-shaped paths.

[0021] To improve the stability of the heat pipe 6 within the groove 5, a positioning groove 8 is formed at the bottom of the groove 5. It should be noted that when the molds for the first thermally conductive ceramic layer 1 and the second thermally conductive ceramic layer 2 are made, the positions of the positioning grooves 8 should be matched to ensure that the groove 5 and the positioning grooves 8 are formed simultaneously during the dry pressing of the first and second ceramic blanks. Furthermore, the spacing between adjacent positioning grooves 8 should be set at 30-60 mm to avoid excessive spacing that would compromise the positioning effect, and to prevent insufficient spacing that would affect the structural strength of the first and second thermally conductive ceramic layers 1 and 2.

[0022] In one embodiment of the present invention, the working medium is purified water. It should be noted that the working medium is not limited to purified water; it can also be methanol or ethanol. Methanol is suitable for operation in a temperature range of -20 to 120°C. In low ambient temperatures, methanol's low-temperature performance ensures that the heat pipe 6 can still start and operate normally at lower temperatures. Ethanol, on the other hand, generally operates in a temperature range of -40 to 150°C, which can meet the heat dissipation needs of some LEDs with wider operating temperature range requirements.

[0023] As an embodiment of the present invention, the first thermally conductive ceramic layer 1 and the second thermally conductive ceramic layer 2 are bonded together by a ceramic adhesive. This installation method can effectively reduce processing costs and reduce the impact on the structure and performance of the heat pipe 6 during the connection process.

[0024] In one embodiment of the present invention, the thickness of the first thermally conductive ceramic layer 1 and the second thermally conductive ceramic layer 2 is 3.0 mm to 6.35 mm. The diameter of the heat pipe 6 is 1.5 mm to 2.0 mm. Designing the thickness of the first and second thermally conductive ceramic layers 2 to be between 3.0 mm and 6.35 mm effectively reduces the difficulty of dry pressing and high-temperature sintering processes, while ensuring the structural strength and heat dissipation performance of the first and second thermally conductive ceramic layers 2. This gives the encapsulated ceramic substrate 3 good pressure and impact resistance, making it less prone to cracking or deformation. The diameter of the heat pipe 6, between 1.5 mm and 2.0 mm, ensures the heat dissipation efficiency of the heat pipe 6, matches the size requirements of the first and second thermally conductive ceramic layers 2, and reduces material costs.

[0025] To improve the stability of the heat pipe 6 within the groove 5, in one embodiment of the invention, the positioning block 7 includes two sets of arc-shaped copper sheets 71 welded to the outer wall of the heat pipe 6, with an aluminum sheet 72 positioned between the two sets of arc-shaped copper sheets 71. During use, since the aluminum sheet 72 is positioned between the two sets of arc-shaped copper sheets 71, its thermal expansion exerts an outward pushing force on the arc-shaped copper sheets 71. As the temperature rises, the expansion of the aluminum sheet 72 causes the two sets of arc-shaped copper sheets 71 to gradually expand outward under thermal stress, making the arc-shaped copper sheets 71 fit more tightly against the positioning groove 8. This further improves the stability of the connection between the positioning block 7 and the positioning groove 8, and simultaneously enhances the stability of the heat pipe 6 installation, ensuring that the heat pipe 6 maintains a good heat dissipation position and high-efficiency heat dissipation performance even under high-temperature operating conditions. It should be noted that the arc length of the arc-shaped copper sheet 71 is 1 / 3 to 1 / 2 of the circumference of the heat pipe 6, so as to provide sufficient contact area to generate friction to fix the heat pipe 6. The thickness of the positioning block 7 should be set to 1 / 2 of the first thermally conductive ceramic layer 1 or the second thermally conductive ceramic layer 2, that is, 1.5-3.175 mm, to avoid causing excessive damage to the ceramic layer structure.

[0026] The present invention also provides a ceramic substrate 3 for packaging, which is prepared by the above-mentioned LED packaging process. It includes a first thermally conductive ceramic layer 1, a second thermally conductive ceramic layer 2, and a ceramic substrate 3 arranged sequentially from top to bottom. Grooves 5 are formed on the opposite surfaces of the first thermally conductive ceramic layer 1 and the second thermally conductive ceramic layer 2. A heat pipe 6 is arranged in the groove 5 formed by the upper and lower parts. A positioning groove 8 is arranged on the inner wall of the groove 5. A positioning block 7 that is engaged with the positioning groove 8 is installed on the outer wall of the heat pipe 6.

[0027] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An LED packaging process and a packaging ceramic substrate, characterized in that, Includes the following steps: S1. Determine the shape of the trench according to the LED chip mounting direction, and use this to open the mold for the first thermally conductive ceramic layer and the mold for the second thermally conductive ceramic layer. S2. Place the ceramic powder into the mold of the first thermally conductive ceramic layer and the mold of the second thermally conductive ceramic layer respectively, and perform dry pressing to prepare the first ceramic blank and the second ceramic blank with grooves on the surface. S3. The first ceramic blank and the second ceramic blank formed by dry pressing are sintered at high temperature to obtain the first thermally conductive ceramic layer and the second thermally conductive ceramic layer respectively. S4. Bend the cut heat pipe into the shape of matching groove, weld positioning blocks to the outer wall of the heat pipe, place the middle part of the heat pipe into the groove of the first thermally conductive ceramic layer, and splice the second thermally conductive ceramic layer with the first thermally conductive ceramic layer. S5. After evacuating the heat pipe and filling it with working fluid, seal the ends of the heat pipe by welding. S6. Adhere a ceramic substrate with a circuit layer to the bottom of the second thermally conductive ceramic layer, and install an LED chip on the ceramic substrate.

2. The LED packaging process and packaging ceramic substrate according to claim 1, characterized in that, The groove is an arc-shaped groove. After the first and second thermally conductive ceramic layers are bonded together, the adjacent grooves are combined to form a circular channel.

3. The LED packaging process and packaging ceramic substrate according to claim 2, characterized in that, A positioning groove is formed at the bottom of the trench.

4. The LED packaging process and packaging ceramic substrate according to claim 3, characterized in that, The working medium is purified water.

5. The LED packaging process and packaging ceramic substrate according to claim 4, characterized in that, The first thermally conductive ceramic layer and the second thermally conductive ceramic layer are bonded together with a ceramic adhesive.

6. The LED packaging process and packaging ceramic substrate according to claim 5, characterized in that, The thickness of the first thermally conductive ceramic layer and the second thermally conductive ceramic layer is 3.0 mm to 6.35 mm.

7. The LED packaging process and packaging ceramic substrate according to claim 6, characterized in that, The heat pipe has a diameter of 1.5 mm to 2.0 mm.

8. The LED packaging process and packaging ceramic substrate according to claim 7, characterized in that, The positioning block includes two sets of arc-shaped copper sheets welded to the outer wall of the heat pipe, with an aluminum sheet placed between the two sets of arc-shaped copper sheets.

9. A ceramic substrate for packaging, characterized in that, The LED packaging process described in any one of claims 1 to 8 includes a first thermally conductive ceramic layer, a second thermally conductive ceramic layer, and a ceramic substrate arranged sequentially from top to bottom. Grooves are formed on the opposite surfaces of the first and second thermally conductive ceramic layers. A heat pipe is arranged in the grooves formed by the upper and lower layers. A positioning groove is provided on the inner wall of the groove. A positioning block that engages with the positioning groove is installed on the outer wall of the heat pipe.

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