Ceramic substrate capable of effectively buffering stress

Abstract

The utility model discloses a ceramic substrate capable of effectively buffering stress. The ceramic substrate comprises a ceramic base layer, an upper circuit layer, a lower circuit layer and a metal box dam, a via hole is formed in the surface of the ceramic base layer in a penetrating manner, a via column is formed in the via hole, a groove is concavely formed in the upper surface of the ceramic base layer, and a mounting position and a glue injection position which are communicated with each other are arranged in the groove; the metal box dam comprises a bottom layer part and a main body part integrally extending upwards from the upper surface of the bottom layer part. The stress relief holes are formed in the edge of the ceramic base layer, so that the internal stress of the ceramic base layer is effectively reduced, the elastic rubber pieces are filled in the rubber injection positions, the inner side faces of the grooves and the peripheral side face of the bottom layer part are tightly attached to the elastic rubber pieces, the elasticity of the elastic rubber pieces can absorb expansion deformation of the grooves and the bottom layer part, and the situation that the stress is too large is effectively prevented; dark cracks of the ceramic base layer cannot be caused, so that the service life and the reliability of the ceramic substrate are improved.

Description

Ceramic substrates for effective stress buffering Technical Field

[0001] This utility model relates to the field of ceramic substrate technology, and in particular to a ceramic substrate that effectively buffers stress. Background Technology

[0002] Ceramic substrates are special process boards where copper foil is directly bonded to the surface of an alumina or aluminum nitride ceramic substrate at high temperatures. The resulting ultra-thin composite substrates possess excellent electrical insulation properties, high thermal conductivity, excellent solderability, and high adhesion strength. Like PCB boards, they can be etched with various patterns and have a large current-carrying capacity. Therefore, ceramic substrates have become a fundamental material for high-power power electronic circuit structure technology and interconnection technology. Ultraviolet (UV) light-emitting diodes (LEDs) offer advantages such as energy saving, environmental friendliness, long lifespan, small size, and controllable wavelength. Deep UV LEDs, with an emission wavelength less than 300nm, can be applied in sterilization, water purification, and biochemical detection. UV LEDs are typically packaged using ceramic substrates. To facilitate the packaging of the UV chip, the ceramic substrate has metal dams forming a packaging cavity to house and encapsulate the UV chip.

[0003] Currently, to prevent aging, traditional ceramic substrates for packaging have abandoned the traditional molding process and adopted metal dam packaging. This design can effectively avoid aging problems. However, the thermal expansion coefficient of metal differs greatly from that of ceramic, which can lead to excessive stress during the packaging process, causing microcracks in the substrate and thus reducing the lifespan and reliability of the ceramic substrate. Therefore, it is necessary to improve the existing metal dam packaging substrates. Summary of the Invention

[0004] In view of this, the present invention addresses the deficiencies of the existing technology, and its main purpose is to provide a ceramic substrate that effectively buffers stress. This effectively solves the problem that excessive stress occurs in the packaging process of existing ceramic substrates, which causes dark cracks in the substrate and reduces the lifespan and reliability of the ceramic substrate.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A ceramic substrate for effectively buffering stress includes a ceramic base layer, an upper circuit layer, a lower circuit layer, and a metal dam.

[0007] The surface of the ceramic base layer has a through hole, and a through post is formed in the through hole. The upper surface of the ceramic base layer is recessed with a groove. The groove has an installation position and an injection position that are interconnected. An elastic rubber element is injected and filled in the injection position. The elastic rubber element is tightly fitted to the inner side of the groove. Stress relief holes are opened at the edge of the ceramic base layer.

[0008] The upper circuit layer is formed on the upper surface of the ceramic substrate and is electrically connected to the upper end of the conductive post; the lower circuit layer is formed on the lower surface of the ceramic substrate and is electrically connected to the lower end of the conductive post.

[0009] The metal dam includes a bottom part and a main part extending upward integrally from the upper surface of the bottom part. The bottom part is installed and fixed in the mounting position. The peripheral side of the bottom part is tightly fitted with an elastic rubber part. The main part extends upward into a groove and forms a receiving cavity. The aforementioned upper circuit layer is located in the receiving cavity.

[0010] As a preferred embodiment, the groove has an interconnected mounting position and two injection positions, wherein one injection position is located outside the mounting position and the other injection position is located inside the accommodating cavity and inside the mounting position, providing elastic support for the inner and outer sides of the metal dam.

[0011] As a preferred embodiment, the surface of the ceramic substrate is provided with a storage groove, which is located in the receiving cavity and is located between the upper circuit layer and another glue injection position. The storage groove is used to collect the glue that overflows during glue injection and prevent the glue from flowing onto the upper circuit layer.

[0012] As a preferred embodiment, the bottom surface of the storage groove is arc-shaped, which can buffer stress and further reduce stress concentration.

[0013] As a preferred embodiment, the lower surface of the ceramic substrate is formed with a heat dissipation layer, and there are two lower circuit layers, which are located on both sides of the heat dissipation layer. The space between the two lower circuit layers and the heat dissipation layer is filled with ink to form a solder resist layer.

[0014] As a preferred embodiment, the lower surface of the ceramic substrate is provided with heat dissipation holes. The heat dissipation layer includes an integrally formed longitudinal portion and a transverse portion. The longitudinal portion extends into the heat dissipation holes and is in contact with the inner wall of the heat dissipation holes. The transverse portion is in contact with the lower surface of the ceramic substrate. This design can significantly improve heat dissipation efficiency.

[0015] As a preferred embodiment, the through hole is a vertical through hole.

[0016] As a preferred embodiment, the inner periphery of the main body is recessed to form an embedding groove, which is used to embed a glass cover plate. The glass cover plate can effectively protect the encapsulating resin from scratches and damage.

[0017] As a preferred embodiment, the elastic component is made of silicone.

[0018] Compared with the prior art, this utility model has obvious advantages and beneficial effects. Specifically, as can be seen from the above technical solution:

[0019] By creating stress relief holes at the edge of the ceramic substrate, the internal stress of the ceramic substrate is effectively reduced. In addition, elastic adhesive is injected into the injection position. The inner side of the groove and the peripheral side of the bottom layer are closely attached to the elastic adhesive. The elasticity of the elastic adhesive can absorb the expansion deformation of both, effectively preventing excessive stress and preventing the ceramic substrate from cracking. This improves the lifespan and reliability of the ceramic substrate.

[0020] To more clearly illustrate the structural features and effects of this utility model, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments: Attached Figure Description

[0021] Figure 1 is a cross-sectional view of a preferred embodiment of the present invention.

[0022] Explanation of reference numerals in the attached diagram:

[0023] 10. Ceramic base layer 11. Through hole

[0024] 12. Conductor post; 13. Groove

[0025] 131. Installation position; 132. Adhesive injection position

[0026] 14. Stress relief hole 15. Storage groove

[0027] 16. Heat dissipation holes; 20. Upper circuit layer

[0028] 30. Lower line layer; 40. Metal cofferdam

[0029] 401. Receptacle cavity; 41. Bottom layer

[0030] 42. Main body 421. Embedding groove

[0031] 50. Elastic rubber parts; 60. Heat dissipation layer

[0032] 61. Longitudinal section 62. Transverse section

[0033] 70. Solder resist layer. Detailed Implementation

[0034] Please refer to Figure 1, which shows the specific structure of a preferred embodiment of the present invention, including a ceramic base layer 10, an upper circuit layer 20, a lower circuit layer 30, and a metal dam 40.

[0035] A through hole 11 is formed through the surface of the ceramic base layer 10, and a through post 12 is formed in the through hole 11. A groove 13 is recessed on the upper surface of the ceramic base layer 10. The groove 13 has an interconnected mounting position 131 and a glue injection position 132. The glue injection position 132 is filled with an elastic glue element 50, which is tightly fitted to the inner side of the groove 13. Stress relief holes 14 are formed at the edge of the ceramic base layer 10. In this embodiment, the groove 13 has an interconnected mounting position 131 and two glue injection positions 132. One glue injection position 132 is located outside the mounting position 131, and the other glue injection position 132 is located inside the accommodating cavity 401 and inside the mounting position 131, providing elastic support for the inner and outer sides of the metal dam 40. A receiving groove 15 is formed on the surface of the ceramic base layer 10. The receiving groove 15 is located in the accommodating cavity 401 and is formed on the upper circuit layer 20. Between the injection point 132 and another injection position 132, a receiving groove 15 is used to collect the glue overflowing during injection, preventing the glue from flowing onto the upper circuit layer 20; in addition, the bottom surface of the receiving groove 15 is arc-shaped, which can buffer stress and further reduce stress concentration; a heat dissipation layer 60 is formed on the lower surface of the ceramic base layer 10, and there are two lower circuit layers 30, which are located on both sides of the heat dissipation layer 60. The space between the two lower circuit layers 30 and the heat dissipation layer 60 is filled with ink to form a solder resist layer 70; and a heat dissipation hole 16 is provided on the lower surface of the ceramic base layer 10. The heat dissipation layer 60 includes an integrally formed longitudinal portion 61 and a transverse portion 62. The longitudinal portion 61 extends into the heat dissipation hole 16 and is attached to the inner wall of the heat dissipation hole 16, and the transverse portion 62 is attached to the lower surface of the ceramic base layer 10. This design can greatly improve the heat dissipation efficiency; the through hole 11 is a vertical through hole; the elastic plastic part 50 is made of silicone.

[0036] The upper circuit layer 20 is formed on the upper surface of the ceramic base layer 10 and is electrically connected to the upper end of the conductive post 12; the lower circuit layer 30 is formed on the lower surface of the ceramic base layer 10 and is electrically connected to the lower end of the conductive post 12.

[0037] The metal dam 40 includes a bottom portion 41 and a main body portion 42 integrally extending upward from the upper surface of the bottom portion 41. The bottom portion 41 is fixedly mounted on the mounting position 131, and its peripheral side surface is tightly fitted with the elastic rubber part 50. The main body portion 42 extends upward from the groove 13, forming a receiving cavity 401, within which the aforementioned upper circuit layer 20 is located. In this embodiment, the inner periphery of the surface of the main body portion 42 is recessed to form an embedding groove 421 for embedding a glass cover plate, which can effectively protect the encapsulating resin from scratches and damage.

[0038] The key design feature of this invention is that by creating stress relief holes at the edge of the ceramic substrate, the internal stress of the ceramic substrate is effectively reduced. Furthermore, an elastic adhesive component is injected into the injection position, and the inner side of the groove and the peripheral side of the bottom layer are in close contact with the elastic adhesive component. The elasticity of the elastic adhesive component can absorb the expansion deformation of both, effectively preventing excessive stress and preventing the ceramic substrate from cracking. This improves the lifespan and reliability of the ceramic substrate.

[0039] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the technical scope of the present utility model. Therefore, any minor modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A ceramic substrate for effectively buffering stress, characterized in that: The device includes a ceramic substrate, an upper circuit layer, a lower circuit layer, and a metal dam. A through-hole is formed on the surface of the ceramic substrate, and a conductive post is formed within the through-hole. A groove is recessed on the upper surface of the ceramic substrate, containing interconnected mounting positions and injection positions. An elastic adhesive element is injected and filled into the injection position, tightly fitting the inner side of the groove. Stress-relieving holes are formed at the edge of the ceramic substrate. The upper circuit layer is formed on the upper surface of the ceramic substrate and is conductively connected to the upper end of the conductive post. The lower circuit layer is formed on the lower surface of the ceramic substrate and is conductively connected to the lower end of the conductive post. The metal dam includes a bottom layer and a main body extending integrally upward from the upper surface of the bottom layer. The bottom layer is fixedly mounted on the mounting position, and its peripheral side is tightly fitted with the elastic adhesive element. The main body extends upward from the groove, forming a receiving cavity, within which the aforementioned upper circuit layer is located.

2. The ceramic substrate for effectively buffering stress according to claim 1, characterized in that: The groove has an installation position and two injection positions that are interconnected. One injection position is located outside the installation position, and the other injection position is located inside the accommodating cavity and inside the installation position.

3. The ceramic substrate for effectively buffering stress according to claim 2, characterized in that: The surface of the ceramic base layer is provided with a storage groove, which is located in the receiving cavity and is located between the upper circuit layer and another injection position.

4. The ceramic substrate for effectively buffering stress according to claim 3, characterized in that: The bottom surface of the storage slot is arc-shaped.

5. The ceramic substrate for effectively buffering stress according to claim 1, characterized in that: The lower surface of the ceramic substrate is formed with a heat dissipation layer. There are two lower circuit layers, which are located on both sides of the heat dissipation layer. The space between the two lower circuit layers and the heat dissipation layer is filled with ink to form a solder resist layer.

6. The ceramic substrate for effectively buffering stress according to claim 5, characterized in that: The lower surface of the ceramic base layer is provided with heat dissipation holes. The heat dissipation layer includes an integrally formed longitudinal part and a transverse part. The longitudinal part extends into the heat dissipation holes and is attached to the inner wall of the heat dissipation holes. The transverse part is attached to the lower surface of the ceramic base layer.

7. The ceramic substrate for effectively buffering stress according to claim 1, characterized in that: The through hole is a vertical through hole.

8. The ceramic substrate for effectively buffering stress according to claim 1, characterized in that: The inner periphery of the surface of the main body is recessed to form an embedding groove.

9. The ceramic substrate for effectively buffering stress according to claim 1, characterized in that: The elastic component is made of silicone.

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