Ceramic packaging structure and semiconductor device

Abstract

The invention discloses a ceramic packaging structure and a semiconductor device. The ceramic packaging structure comprises a ceramic base; the slot structure is arranged at the bottom pin welding position of the ceramic base, and metallization layers are arranged on the periphery of the bottom and the inner wall of the slot structure; and one end of the metal pin is inserted into the slot structure, and the ceramic base is welded with the metal pin through the metallization layer by using a welding flux so as to realize electrical and mechanical connection. According to the ceramic packaging structure, the welding firmness of the metal pins and the ceramic base is improved, the reliability of the structure is enhanced, the risk that the pins fall off is greatly reduced, and welding flux is effectively prevented from overflowing. In addition, due to the optimal design of the metal pins, the welding stability and the overall reliability of the device are further improved while the packaging size of the pins is not increased.

Description

Technical Field

[0001] The present invention relates to semiconductor device packaging technology, in particular to a ceramic packaging structure and a semiconductor device. Background Art

[0002] With the continuous development of power devices, semiconductor devices are gradually developing in multiple directions such as high power, miniaturization, and integration. Ceramic packaging devices made using multi-layer co-fired ceramic technology are receiving more and more attention. Among various packaging materials, ceramic packaging uses high-temperature sintered ceramic materials such as alumina and aluminum nitride, which are increasingly widely used in the integration of various semiconductor devices due to their excellent mechanical strength, thermal conductivity, and insulation properties.

[0003] Wire bonding is a key technology for achieving the connection between chips and package pins in semiconductor packaging. In recent years, the semiconductor industry's urgent demand for higher integration, higher reliability and lower cost has put forward higher requirements for wire bonding technology.

[0004] In order to realize device packaging, the existing ceramic packaging structure often uses a sintered ceramic base + pin structure, in which a pin matrix is ​​welded to the bottom of the ceramic base; the ceramic base is made of ceramic materials such as alumina and aluminum nitride + tungsten metal slurry after high-temperature co-firing, and the pins are brazed and bonded to the bottom of the base through silver-copper solder. However, the contact area between the pins of the existing ceramic packaging structure and the bottom surface of the base is relatively small, which is easy to cause welding voids during the pin brazing process. After a certain degree of temperature cycling, the pins are prone to fall off.

[0005] It should be noted that the information disclosed in the above background technology section is only used for understanding the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0006] The main purpose of the present invention is to overcome the defects existing in the above-mentioned background technology and provide a ceramic packaging structure and a semiconductor device.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A ceramic packaging structure, comprising:

[0009] Ceramic base;

[0010] A slot structure is arranged at the bottom pin welding position of the ceramic base, and the bottom and inner wall of the slot structure are provided with a metallized layer;

[0011] One end of the metal pin is inserted into the slot structure. The ceramic base is welded to the metal pin through the metallization layer using solder. The metal pin forms an electrical connection with the metallization layer through the solder. At the same time, the metal pin cooperates with the slot structure to achieve mechanical connection.

[0012] Further:

[0013] The metal pin comprises a pin elongated portion and an end head with a diameter larger than that of the pin elongated portion, and the end head is inserted into the slot structure.

[0014] The slot structure depth is ≤1 times the slot diameter, and the slot spacing is greater than 1 times the slot diameter.

[0015] The material of the metal pin is Kovar alloy, and the difference between the diameter of the metal pin and the diameter of the ceramic base slot is greater than 0.05 mm.

[0016] The metallization layer is selected from tungsten, molybdenum, manganese and alloy materials thereof, and has a thickness of ≥5 μm.

[0017] The ceramic base is a multi-layer co-fired ceramic base.

[0018] The ceramic base is formed by co-firing a ceramic body and a metal slurry. The main material of the ceramic body is selected from alumina, aluminum nitride, silicon nitride, silicon carbide, beryllium oxide and their composite materials; the metal material is selected from silver, copper, gold, platinum, palladium, nickel, tungsten, molybdenum, manganese and their alloys.

[0019] The solder is selected from gold, silver, copper and composite materials thereof and gold-tin composite materials.

[0020] The plurality of metal pins are arranged on the ceramic base in a pin grid matrix.

[0021] A semiconductor device has the ceramic packaging structure.

[0022] The present invention has the following beneficial effects:

[0023] The present invention proposes a ceramic packaging structure, which significantly improves the welding firmness between the pin and the base by providing a metallized slot structure at the pin welding position at the bottom of the ceramic base. The ceramic packaging structure designed by the present invention enables one end of the pin to be inserted into the slot inside the ceramic base, and the bottom and surrounding of the slot are metallized, and the welding contact area between the ceramic base and the pin is significantly increased. After brazing, one end of the pin is firmly anchored inside the base, which significantly enhances the reliability of the structure, including greatly reducing the risk of pin falling off due to temperature cycling. Moreover, when brazing is performed in a high-temperature molten state, the ceramic packaging structure can more effectively fix the solder and prevent the solder from overflowing during the brazing process.

[0024] Furthermore, the ceramic packaging structure of the present invention further expands the welding contact area by designing the end diameter of the metal pin to be larger than its slender part without increasing the overall packaging size of the pin, effectively enhancing the welding firmness and mechanical connection strength between the pin and the base, and improving stability and reliability.

[0025] In general, the ceramic packaging structure of the present invention exhibits significant advantages in terms of enhancing reliability, reducing costs and improving integration, and provides an efficient and reliable solution for the semiconductor packaging field.

[0026] Other beneficial effects of the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of a ceramic packaging structure according to an embodiment of the present invention.

[0028] Figure 2 FIG. 4 is an exploded view of a ceramic packaging structure according to an embodiment of the present invention.

[0029] Figure 3 It is a three-dimensional cross-sectional view of the ceramic packaging structure after the pins of the embodiment of the present invention are welded.

[0030] Figure 4 It is a front cross-sectional view of the ceramic packaging structure after the pins are welded according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

[0032] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for fixing as well as for coupling or communication.

[0033] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] See also Figures 1 to 4 An embodiment of the present invention provides a ceramic packaging structure, including a ceramic base 1, a slot structure 3 arranged at the bottom pin welding position of the ceramic base 1, and a metal pin 2, the bottom and inner wall of the slot structure 3 are surrounded by a metallization layer 5, one end of the metal pin 2 is inserted into the slot structure 3, the ceramic base 1 is welded to the metal pin 2 through the metallization layer 5 using solder 4, the metal pin 2 forms an electrical connection with the metallization layer 5 through the solder 4, and the metal pin 2 cooperates with the slot structure 3 to achieve mechanical connection.

[0036] The ceramic packaging structure of the present invention significantly improves the welding firmness between the pin and the ceramic base 1 by providing a metallized slot structure 3 at the pin welding position at the bottom of the ceramic base 1. The designed ceramic packaging structure enables one end of the metal pin 2 to be inserted into the slot inside the ceramic base 1. The bottom and surrounding of the slot are metallized, and the welding contact area between the ceramic base 1 and the pin is significantly increased. After brazing, one end of the pin is firmly anchored inside the base 1, which greatly enhances the reliability of the structure, including greatly reducing the risk of pin falling off due to temperature cycling. Moreover, when brazing is performed in a high-temperature molten state, the solder 4 can be more effectively fixed to prevent the solder 4 from overflowing during the brazing process.

[0037] like Figure 1 and Figure 2 As shown, in some embodiments, the plurality of metal pins 2 are arranged on the ceramic base 1 in a pin grid matrix.

[0038] like Figures 2 to 4 As shown, in some embodiments, the metal pin 2 includes a pin elongated portion 22 and an end 21 with a diameter larger than the pin elongated portion, and the end 21 is inserted into the slot structure 3, and the whole is in the shape of a nail with an inverted nail head. In this embodiment, the diameter of the end 21 of the metal pin 2 is designed to be larger than the elongated portion 22, and the size of the slot structure 3 is adapted to the end 21 of the metal pin 2, thereby further expanding the welding contact area without increasing the overall package size of the pin, effectively enhancing the welding firmness and mechanical connection strength between the pin and the base 1, and improving stability and reliability.

[0039] In some embodiments, the metal pin 2 is made of Kovar alloy, and the difference between the diameter of the metal pin 2 and the diameter of the slot of the ceramic base 1 is greater than 0.05 mm.

[0040] In some embodiments, the depth of the slot structure 3 is ≤ 1 times the slot diameter, and the slot spacing is greater than 1 times the slot diameter.

[0041] In some embodiments, the metallization layer 5 is selected from tungsten, molybdenum, manganese and alloy materials thereof, and has a thickness of ≥5 μm. The ceramic base 1 is a multi-layer co-fired ceramic base. The ceramic base 1 is formed by co-firing a ceramic body and a metal slurry, and the main material of the ceramic body is selected from aluminum oxide, aluminum nitride, silicon nitride, silicon carbide, beryllium oxide and composite materials thereof; the metal material is selected from silver, copper, gold, platinum, palladium, nickel, tungsten, molybdenum, manganese and alloys thereof. The solder 4 is selected from gold, silver, copper and composite materials thereof and gold-tin composite materials.

[0042] An embodiment of the present invention further provides a semiconductor device having the ceramic packaging structure of any of the above embodiments.

[0043] Embodiment 1

[0044] A ceramic packaging structure, the main structure includes a multi-layer co-fired ceramic base and a metal pin, the two are connected by brazing with Ag-Cu solder at 810°C.

[0045] The metal pin material used is Kovar alloy, with a tip height of 100 μm and a tip diameter of 240 μm; the solder thickness used is 50 μm;

[0046] The co-fired ceramic base is made of 92 black alumina and tungsten paste. A slot structure is set at the pin pad at the bottom of the ceramic base. The slot depth is 120μm and the diameter is 300μm. Tungsten is used for metallization around the bottom and inner wall of the slot. The diameter of the metallized area is 250μm and the metallized thickness is 10μm.

[0047] The ceramic packaging structure of the embodiment of the present invention has improved reliability after brazing, and the pins do not fall off.

[0048] In summary, the ceramic packaging structure proposed in the present invention improves the welding firmness between the metal pins and the ceramic base, enhances the reliability of the structure, greatly reduces the risk of pins falling off, and effectively prevents solder overflow. In addition, the optimized design of the metal pins further improves the welding stability and the overall reliability of the device without increasing the pin and package size.

[0049] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of the reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In the absence of mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A ceramic packaging structure, characterized in that: include: Ceramic base; A slot structure is arranged at the bottom pin welding position of the ceramic base, and the bottom and inner wall of the slot structure are provided with a metallized layer; One end of the metal pin is inserted into the slot structure. The ceramic base is welded to the metal pin through the metallization layer using solder. The metal pin forms an electrical connection with the metallization layer through the solder. At the same time, the metal pin cooperates with the slot structure to achieve mechanical connection.

2. The ceramic packaging structure according to claim 1, characterized in that: The metal pin comprises a pin elongated portion and an end head with a diameter larger than that of the pin elongated portion, and the end head is inserted into the slot structure.

3. The ceramic packaging structure according to claim 1 or 2, characterized in that: The slot structure depth is ≤1 times the slot diameter, and the slot spacing is greater than 1 times the slot diameter.

4. The ceramic packaging structure according to any one of claims 1 to 3, characterized in that: The material of the metal pin is Kovar alloy, and the difference between the diameter of the metal pin and the diameter of the ceramic base slot is greater than 0.05 mm.

5. The ceramic packaging structure according to any one of claims 1 to 4, characterized in that: The metallization layer is selected from tungsten, molybdenum, manganese and alloy materials thereof, and has a thickness of ≥5 μm.

6. The ceramic packaging structure according to any one of claims 1 to 5, characterized in that: The ceramic base is a multi-layer co-fired ceramic base.

7. The ceramic packaging structure according to claim 6, characterized in that: The ceramic base is formed by co-firing a ceramic body and a metal slurry. The main material of the ceramic body is selected from alumina, aluminum nitride, silicon nitride, silicon carbide, beryllium oxide and their composite materials; the metal material is selected from silver, copper, gold, platinum, palladium, nickel, tungsten, molybdenum, manganese and their alloys.

8. The ceramic packaging structure according to any one of claims 1 to 7, characterized in that: The solder is selected from gold, silver, copper and composite materials thereof and gold-tin composite materials.

9. The ceramic packaging structure according to any one of claims 1 to 8, characterized in that: The plurality of metal pins are arranged on the ceramic base in a pin grid matrix.

10. A semiconductor device, characterized in that: A ceramic packaging structure as claimed in any one of claims 1 to 9.

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