CN216218446U

CN216218446U - Ceramic substrate with thermal stress releasing box dam

Info

Publication number: CN216218446U
Application number: CN202122597177.2U
Authority: CN
Inventors: 袁广; 罗素扑; 黄嘉铧; 陈志敏
Original assignee: Huizhou Xinci Semiconductor Co ltd
Current assignee: Huizhou Xinci Semiconductor Co ltd
Priority date: 2021-10-27
Filing date: 2021-10-27
Publication date: 2022-04-05
Anticipated expiration: 2031-10-27

Abstract

The utility model discloses a ceramic substrate with a thermal stress releasing dam, which comprises a ceramic substrate, wherein an upper circuit layer is arranged on the upper surface of the ceramic substrate, a lower circuit layer is arranged on the lower surface of the ceramic substrate, a plurality of dam layers are stacked on the upper circuit layer and are of a closed annular structure, the dam layers are stacked to form a dam, the width of the outer ring of the dam layers is gradually reduced from top to bottom, a stepped structure is formed on the outer side surface of the dam, and an avoiding groove for releasing thermal stress is formed between the outer peripheral side of the dam and the upper surface of the upper circuit layer. This ceramic substrate of area release thermal stress box dam through form the groove of dodging of release thermal stress between the periphery side of box dam and the upper surface on last circuit layer, and the thermal expansion stress that the box dam produced after the solid brilliant is released through dodging the groove, reduces the expansion stress between ceramic substrate and the box dam, prevents that ceramic substrate is because the thermal expansion stress of box dam is too big and is pulled apart.

Description

Ceramic substrate with thermal stress releasing box dam

Technical Field

The utility model relates to the technical field of ceramic substrates, in particular to a ceramic substrate with a thermal stress relief box dam.

Background

Good device heat dissipation capability depends on optimized heat dissipation structure design, packaging material selection, packaging manufacturing process, and the like. Ceramic substrates are increasingly used in electronic packaging, particularly in power electronic devices such as insulated gate bipolar transistors, laser diodes, light emitting diodes, and focused photovoltaic packaging, due to their good thermal conductivity, heat resistance, insulation properties, low thermal expansion coefficient, and continuous reduction in cost.

The existing DPC ceramic dam board is generally a direct plating 3D DPC ceramic dam board, namely: and directly making a vertical dam on the circuit layer of the ceramic substrate. However, the vertical box dam on a single ceramic substrate is too small in size, and the box dam is easily attached to the ceramic substrate after being formed, which causes the following problems: the vertical box dam cannot be milled, the box dam and the ceramic substrate which are formed by milling cannot be aligned, and a welding part is easy to fall off due to the fact that the welding area of the outer side face of the vertical box dam is small. In addition, the box dam of the DPC ceramic box dam board of the direct plating 3D is a vertical structure made of copper plating materials, after the DPC ceramic box dam board is processed through subsequent die bonding, the ceramic substrate is pulled to crack and deform due to overlarge thermal expansion stress of the vertical copper layer on the outer side of the vertical box dam, and the thermal shock circulation test cannot be passed.

Therefore, a new technical solution is needed to solve the above problems.

SUMMERY OF THE UTILITY MODEL

In view of the above, the present invention provides a ceramic substrate with a thermal stress relief dam, which is configured to form an avoidance groove for relieving thermal stress between an outer peripheral side of the dam and an upper surface of an upper circuit layer, so that thermal stress generated by the dam after die bonding is relieved through the avoidance groove, thereby reducing expansion stress between the ceramic substrate and the dam and preventing the ceramic substrate from being pulled apart due to excessive thermal stress of the dam.

In order to achieve the purpose, the utility model adopts the following technical scheme:

the utility model provides a ceramic substrate of area release thermal stress dam, includes ceramic substrate, ceramic substrate's upper surface is provided with the upper line layer, ceramic substrate's lower surface is provided with down the line layer, it is provided with a plurality of box dam layers to pile up on the upper line layer, and a plurality of box dam layers are closed loop configuration, and a plurality of box dam layers pile up and form the box dam, and the outer loop width on a plurality of box dam layers reduces the setting from top to bottom gradually, the lateral surface of box dam forms the echelonment structure, form the groove of dodging that is used for releasing thermal stress between the periphery side of box dam and the upper surface on line layer.

As a preferred scheme, the inner side surface of the box dam and the upper surface of the upper line layer are perpendicular to each other.

As a preferred scheme, the dam layer is provided with more than two layers.

As a preferable scheme, the dam layer is made of metal.

Preferably, the box dam layer is made of copper.

Preferably, the substrate of the ceramic substrate is an aluminum nitride ceramic, an aluminum oxide ceramic, a silicon nitride ceramic, or an aluminum silicon carbon ceramic.

Compared with the prior art, the utility model has obvious advantages and beneficial effects, and concretely, according to the technical scheme, the ceramic substrate with the thermal stress release dam is mainly characterized in that the outer ring width of a plurality of dam layers is gradually reduced from top to bottom, the plurality of dam layers are stacked to form the dam, and the outer side surface of the dam forms a step-shaped structure, so that: an avoiding groove for releasing thermal stress is formed between the outer peripheral side of the box dam and the upper surface of the upper circuit layer, thermal expansion stress generated by the box dam after crystal solidification is released through the avoiding groove, expansion stress between the ceramic substrate and the box dam is reduced, and the ceramic substrate is prevented from being pulled and cracked due to overlarge thermal expansion stress of the box dam; the structure is simple and the production is easy.

Meanwhile, the top box dam layer is designed to be relatively large, so that the welding area of subsequent welding parts (such as lenses and cover plates) can be increased, and the risk of falling of the welding parts is reduced. Because the avoiding groove is formed between the peripheral side of the box dam and the upper surface of the upper circuit layer, the avoiding groove can be skillfully utilized as a buckling position when the lens or the cover plate is assembled, and the assembling stability of the lens or the cover plate is improved.

To more clearly illustrate the structural features and effects of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Drawings

FIG. 1 is a schematic diagram of a first embodiment of the present invention;

FIG. 2 is a partial schematic view of a first embodiment of the present invention;

FIG. 3 is a schematic diagram of a second embodiment of the present invention;

FIG. 4 is a partial schematic view of a second embodiment of the present invention.

The attached drawings indicate the following:

10. ceramic substrate 21, upper wiring layer

22. Lower line layer 30 and first dam layer

40. Second and

third dam layers

50 and 50

60. Avoidance groove 61, first step

62. Second step 63, lateral groove

64. Third step 65, fourth step

70. And a fourth dam layer.

Detailed Description

Referring to fig. 1 to 4, specific structures of the embodiments of the present invention are shown.

In the description of the present invention, it should be noted that, for the orientation words, such as the terms "upper", "lower", "front", "rear", "left", "right", etc., indicating the orientation and positional relationship based on the orientation or positional relationship shown in the drawings, are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation and operation, and should not be construed as limiting the specific scope of the present invention.

A ceramic substrate with a thermal stress relief dam comprises a ceramic substrate 10, wherein an upper circuit layer is arranged on the upper surface of the ceramic substrate 10, a lower circuit layer 22 is arranged on the lower surface of the ceramic substrate 10, a plurality of dam layers are stacked on the upper circuit layer 21 and are of a closed annular structure, the dam layers are stacked to form a dam, and the outer ring widths of the dam layers are gradually reduced from top to bottom; wherein, the outer side surface of the box dam forms a ladder-shaped structure, and an avoiding groove 60 for releasing thermal stress is formed between the outer peripheral side of the box dam and the upper surface of the upper circuit layer 21. The box dam layer is made of metal materials, and preferably, the box dam layer is made of copper materials. Preferably, the base material of the ceramic substrate 10 is an aluminum nitride ceramic, an aluminum oxide ceramic, a silicon nitride ceramic, or an aluminum silicon carbon ceramic.

Fig. 1 and fig. 2 show a schematic view and a partial schematic view of a first embodiment, respectively. In the first embodiment, three dam layers are disposed on the ceramic substrate 10. Wherein, the inner side surfaces of the plurality of dam layers are perpendicular to the upper surface of the upper circuit layer 21. Specifically, the upper circuit layer 21 is provided with a first dam layer 30, the outer ring width of the first dam layer 30 is smaller than that of the upper circuit layer 21, a first step 61 is formed between the outer side surface of the first dam layer 30 and the upper circuit layer 21, the first dam layer 30 is provided with a second dam layer 40, the outer ring width of the second dam layer 40 is larger than that of the first dam layer 30, a second step 62 is formed between the bottom surface of the second dam layer 40 and the outer side surface of the first dam layer 30, the bottom surface of the second dam layer 40, the outer side surface of the first dam layer 30 and the top surface of the upper circuit layer 21 form a transverse groove 63, the second dam layer 40 is provided with a third dam layer 50, and a third step 63 is formed between the bottom surface of the third dam layer 50 and the outer side surface of the second dam layer 40. The transverse groove 63, the third step 63 enclose an escape groove 60 which forms a relief for thermal stresses.

Fig. 3 and 4 show a schematic view and a partial schematic view of the second embodiment, respectively. In the second embodiment, four dam layers are provided on the ceramic substrate 10, and specifically, in addition to the first embodiment, the fourth dam layer 70 is provided on the upper end of the third dam layer 50. Wherein, the outer ring width of the fourth dam layer 70 is larger than the outer ring width of the third dam layer 50, a fourth step 65 is formed between the bottom surface of the fourth dam layer 70 and the outer side surface of the third dam layer 50, and the transverse groove 63 and the fourth step 65 form an avoiding groove 60 for releasing thermal stress. The outer side surfaces of the plurality of dam layers form a step-shaped structure, so that: the outer side surface of the box dam layer is increased, so that the welding area of a welding part is increased, and the risk of falling of the welding part is reduced; meanwhile, the peripheral side of the dam layer and the upper circuit layer 21 form an avoiding groove 60 for releasing thermal stress, so that the ceramic substrate 10 forms a three-dimensional stress structure. In the die bonding processing process, the stress generated by the box dam is released through the avoiding groove 60 for releasing the thermal stress, so that the thermal expansion stress accumulation generated by the contraction of the packaging adhesive of the ceramic substrate 10 can be prevented from pulling the box dam layer to shift, and further, the stress concentration formed on the outer side of the box dam is prevented from causing fracture, thereby being beneficial to improving the strength of the box dam. Meanwhile, when the lens or the cover plate is assembled, the avoiding groove 60 can be skillfully utilized as a buckling position, so that the assembling stability of the lens or the cover plate is improved. In practical implementation, the dam layer is provided with more than two layers, and the dam layer can also be provided with more than two layers.

Next, taking the first embodiment as an example, the process flow of the present invention is detailed as follows: respectively plating an upper circuit layer 21 and a lower circuit layer 22 on the upper surface and the lower surface of the ceramic substrate 10; then, plating a first dam layer 30 on the upper circuit layer 21; then, plating a second dam layer 40 with a wider outer ring width on the first dam layer 30; then, plating a third dam layer 50 with wider outer ring width on the second dam layer 40; an escape groove 60 for releasing thermal stress is formed between the upper line layer 21 and the first, second and

third dam layers

30, 40 and 50.

Preferably, the dam layer is a copper material, and accordingly, in actual practice, it is produced using a DPC process, and the dam layer is plated on the ceramic substrate 10.

The design key point of the utility model is that the ceramic substrate with the thermal stress relief box dam is mainly arranged by adopting the way that the width of the outer ring of a plurality of box dam layers is gradually reduced from top to bottom, a plurality of box dam layers are arranged in a stacking way to form the box dam, and the outer side surface of the box dam forms a step-shaped structure, so that: an avoiding groove for releasing thermal stress is formed between the outer peripheral side of the box dam and the upper surface of the upper circuit layer, thermal expansion stress generated by the box dam after crystal solidification is released through the avoiding groove, expansion stress between the ceramic substrate and the box dam is reduced, and the ceramic substrate is prevented from being pulled and cracked due to overlarge thermal expansion stress of the box dam; the structure is simple and the production is easy.

Claims

1. The utility model provides a ceramic substrate of area release thermal stress box dam, includes ceramic substrate, ceramic substrate's upper surface is provided with the upper line layer, ceramic substrate's lower surface is provided with down the line layer, it is provided with a plurality of box dam layers to pile up on the upper line layer, and a plurality of box dam layers are closed loop configuration, and a plurality of box dam layers pile up and form box dam, its characterized in that: the outer ring width of a plurality of box dam layers reduces the setting from top to bottom gradually, the lateral surface of box dam forms the echelonment structure, form the groove of dodging that is used for releasing thermal stress between the periphery side of box dam and the upper surface on line layer.

2. The ceramic substrate with a thermal stress relief dam of claim 1, wherein: the inner side surface of the box dam is perpendicular to the upper surface of the upper line layer.

3. The ceramic substrate with a thermal stress relief dam of claim 1, wherein: the box dam layer is provided with more than two layers.

4. The ceramic substrate with a thermal stress relief dam of claim 1, wherein: the box dam layer is made of metal materials.

5. The ceramic substrate with a thermal stress relief dam of claim 4, wherein: the box dam layer is made of copper.

6. The ceramic substrate with a thermal stress relief dam according to any of claims 1 to 5, wherein: the base material of the ceramic substrate is aluminum nitride ceramic or aluminum oxide ceramic or silicon nitride ceramic or aluminum silicon carbon ceramic.