A packaging structure for a SiP module based on a ceramic material

Abstract

This invention discloses a SiP module packaging structure based on ceramic materials. The packaging structure uses ceramic material as the outer shell, with a recessed, staggered layer structure on the substrate to facilitate the assembly of chips and passive devices of different sizes and heights. Due to the complex internal circuitry and numerous interface pins of the SiP module, a ball grid array (BGA) pin configuration is adopted on the outer shell. Metallization layout design on the ceramic substrate enables chip mounting pads and partial circuit wiring. Vias filled with metallized paste between the substrates connect the internal metallized pads to the external BGA pins. By assembling specific chips and passive devices at different locations and interconnecting them with wire bonding, the complete packaging process of a specific circuit SiP module is achieved. This invention features excellent insulation performance, ultra-high integration, ultra-light weight, rapid heat dissipation, and high reliability, making it highly valuable for widespread application.

Description

Technical Field

[0001] This utility model relates to the field of integrated circuits, specifically a SiP module packaging structure based on ceramic materials. Background Technology

[0002] The semiconductor industry is closely related to defense, the internet, automobiles, and industrial manufacturing. Currently, my country's semiconductor industry is in a period of rapid development. However, with the rapid development of semiconductor technology, integrated circuits have entered the post-Moore's Law era. Existing processes and equipment are insufficient to bring integrated circuits to a new level, so semiconductor computing is gradually moving towards SiP (System-in-Package) technology. Simultaneously, the packaging requirements for integrated circuits are becoming increasingly stringent. Metal-ceramic hermetic packaging structures are entering the market. Ceramic components, due to their high strength, low density, high temperature resistance, and corrosion resistance, are attracting significant attention in the aerospace field and have broad application prospects. In recent years, SiP products have gained recognition from numerous users, with upgrades and development often taking the form of multi-chip modules (MCMs) and hybrid integrated circuits (HICs), achieving "PCB board componentization (deviceization)." However, developing plastic-packaged SiP products is difficult and costly, requiring complex molds and processes, making mass production challenging. This utility model mainly provides a packaging structure and method for SiP modules based on ceramic materials. Using ceramic materials as the packaging substrate, its advantages include product miniaturization, high performance, short development cycle, high reliability, and reduced costs. This packaging structure features high integration and high reliability. Utility Model Content

[0003] To address the aforementioned technical problems, this utility model provides a SiP module packaging structure based on ceramic materials to meet the overall requirements of electronic component system integration technology in scientific research and production.

[0004] The technical solution of this utility model is as follows: a packaging structure for a SiP module based on ceramic materials, including a ceramic substrate, which is formed by stamping multiple layers of ceramic. The outer substrate portion of the ceramic substrate has a recessed staggered structure for assembling chips and passive devices of different sizes and heights. Metallization is performed on the ceramic substrate to meet the requirements of chip mounting pads and some circuit wiring. The metallized areas are composed of multiple layers of metal materials. The first layer is tungsten metal, printed in a specific shape using a paste method. After curing, nickel is electroplated on its surface as the second metal layer. The third and outermost metal layer is electroplated with pure gold. A ball grid array (BGA) pin is used on the outside of the ceramic substrate, with lead-free or lead-containing solder balls melted and solidified on the surface metallization layer. Vias are designed between the ceramic substrates and filled with metallization paste to connect the internal metallized pads to the external BGA pins. Specific chips and passive devices are assembled at different positions, supplemented by wire bonding interconnection, to achieve complete packaging of a specific circuit SiP module.

[0005] Furthermore, the internal metallization includes the welding area, bonding area and electrical connection traces of active and passive devices. The welding process of the passive devices includes high-temperature solder vacuum sintering and conductive adhesive bonding. The welding of the active devices includes conductive adhesive bonding and eutectic bonding.

[0006] Furthermore, in the layered structure of the ceramic matrix, passive devices are welded together using solder.

[0007] Preferably, the ceramic substrate has metallized wiring between internal layers, and then through-hole metallization paste is designed to fill the holes, thereby realizing the connection between the internal metallized pads and the external ball grid array pins.

[0008] The ceramic matrix is ​​alumina ceramic.

[0009] Preferably, the ceramic substrate has blank spaces inside for logos or anti-counterfeiting designs.

[0010] The principle of this utility model is as follows: Alumina ceramic material is used as the outer shell of the packaging substrate. The substrate of the outer shell is designed with a recessed staggered structure to facilitate the assembly of chips and passive devices of different sizes and heights. Since the internal circuit of the SiP module is complex and has many interface pins, the outer shell adopts the ball grid array (BGA) pin pattern. By performing metallization layout design on the ceramic substrate, chip mounting pads and some circuit wiring are realized. At the same time, vias are designed between the substrates and filled with metallization paste to realize the connection between the internal metallized pads and the external ball grid array pins. Then, by assembling specific chips and passive devices at different positions and connecting them with wire bonding, the complete packaging process of the SiP module for a specific circuit is realized.

[0011] The beneficial effects of this utility model are:

[0012] This invention is designed from the perspective of reducing parasitic parameters. It comprehensively considers factors such as the product's later functions, performance parameters, packaging process, and integration level, which greatly reduces the impact of parasitic parameters on the product during packaging and reduces the process difficulty of packaging the product in the later stages.

[0013] (2) This utility model uses ceramic material as the packaging shell, and realizes the assembly of chips and other devices and partial circuit routing between devices through metallized wiring. The assembly of devices is achieved by dispensing, eutectic bonding, and soldering. Then, the complete circuit connection function is realized by wire bonding with gold wire as the lead material. The external pins adopt ball grid array packaging technology to ensure 100-pin external output interface while improving the soldering reliability of the product. Finally, multiple active and passive electronic components with different functions and other types of chips are assembled in the same package to form a system or subsystem with multiple functions.

[0014] (3) The staggered design on the ceramic substrate is mainly for the safe welding of thicker passive components such as resistors and capacitors. Welding is carried out in the pit, and the passive devices and active devices are physically isolated. When the passive devices are soldered, the excess solder will accidentally overflow into the bonding area of ​​the active devices.

[0015] (4) The metallization layout on the ceramic substrate adopts the nickel-gold electroplating process, with the outermost layer metallized as gold, which solves the problems of low resistance and low inductance of the wiring of ceramic parts, and at the same time facilitates the homogeneous metal bonding process of gold wire bonding. This improves the overall reliability.

[0016] (5) A metal frame made of Kovar is mounted on the substrate and sealed with a cover plate made of the same Kovar material under an inert protective gas by parallel seam welding process to meet the high reliability requirements of hermetic encapsulation.

[0017] This invention features excellent insulation, ultra-high integration, ultra-light weight, rapid heat dissipation, and high reliability. It can be widely used in hybrid integrated products such as functional circuit modules or systems with high reliability requirements. This invention has already been promoted and applied to various products in our company, demonstrating significant advantages and wider applicability compared to existing plastic-encapsulated products. It also has high promotional value for other products with similar form factor requirements. Attached Figure Description

[0018] Figure 1 This is a diagram of the internal cavity of the SiP module's package housing;

[0019] Figure 2 This is the package pin diagram of the SiP module;

[0020] Figure 3 This is a side view of the SiP module.

[0021] Figure 4 This is a partial assembly diagram of the SiP module;

[0022] Figure 5 This is a schematic diagram of the internal and external connections of the SiP module casing;

[0023] Figure 6 This is a diagram of the SiP module housing cover.

[0024] In the diagram: 1-Internal metallization I; 2-Internal metallization II; 3-Internal recessed layer; 4-Internal metallization IV; 5-Metallization break; 6-Internal blank; 7-Internal metallization VII; 8-Internal metallization VIII; 9-Metal sealing ring; 10-Ceramic substrate; 11-Ball grid array pin; 12-First pin identifier; A1-Surface metallization; A2-Wire bond alloy wire; A3-Solder; A4-Chip; B1-Metallization; B2-Paste. Detailed Implementation

[0025] This embodiment discloses a packaging structure and packaging method for a SiP module based on ceramic materials.

[0026] like Figure 1 , Figure 2 and Figure 3 As shown, a ceramic planar pad array package has external dimensions of 25.0mm × 25.0mm × 3.0mm and an internal enclosed space of 22.8mm × 22.8mm × 1.3mm. It mainly includes a ceramic substrate 10, a metal sealing ring 9, including but not limited to internal metallization, ball grid array pins 11, and first and second pin identifiers 12.

[0027] Internal metallization includes the soldering area, bonding area and electrical connection traces of active and passive devices. The metallization area is composed of multiple layers of metal materials. The first material is tungsten metal, which is printed in a specific shape using a paste method. After curing, nickel metal is electroplated on its surface as the second metal layer. Finally, the third and outermost metal layer is electroplated with pure gold.

[0028] The internal recessed layer 3 is for assembling chips and passive devices of different sizes and heights.

[0029] Metallization interruption 5 involves first electrically connecting all metallized areas to facilitate nickel-gold plating. After nickel-gold plating is completed, the parts that cannot be connected are laser-cut according to the circuit connection requirements to achieve complete circuit wiring.

[0030] The ceramic matrix is ​​alumina ceramic.

[0031] The blank space inside the ceramic substrate (6) is for the placement of a logo or anti-counterfeiting design.

[0032] The metal sealing ring 9 is made of Kovar alloy, grade: 4J42 / 4J29.

[0033] The ball grid array pins 11 are located outside the ceramic substrate. Lead-free or lead-containing tin balls are melted and solidified on the surface metallization layer, and the surface metallization composition is the same as that of the internal metallization of the ceramic.

[0034] The ceramic substrate 10 is formed by stamping multiple layers of ceramic. Metallization B1 wiring is performed between the internal layers, and through-hole metallization paste B2 is designed to fill the holes, thereby realizing the connection between the internal metallized pads B1 and the external ball grid array pins 11.

Claims

1. A packaging structure for a SiP module based on ceramic materials, characterized in that: The ceramic substrate (10) is formed by stamping multiple layers of ceramic. The outer shell substrate of the ceramic substrate has a recessed staggered structure for assembling chips and passive devices of different sizes and heights. Metallization is performed on the ceramic substrate. The metallization area is composed of multiple layers of metal materials. The first layer is tungsten metal, which is printed in a specific shape using a paste method. After curing, nickel is electroplated on its surface as the second metal layer. The third and outermost metal layer is electroplated with pure gold. Ball grid array pins (11) are used on the outside of the ceramic substrate, and lead-free or lead-containing tin balls are melted and solidified on the surface metallization layer. Through-hole metallization paste is designed between ceramic substrates to connect internal metallized pads with external ball grid array pins. Then, specific chips and passive devices are assembled at different positions, and wire bonding interconnection is used to achieve complete packaging of specific circuit SiP modules.

2. The packaging structure of the SiP module based on ceramic materials according to claim 1, characterized in that: The internal metallization includes the soldering area, bonding area and electrical connection traces of active and passive devices. The soldering process of the passive devices includes high-temperature solder vacuum sintering and conductive adhesive bonding. The soldering of active devices includes conductive adhesive bonding and eutectic bonding.

3. The packaging structure of the SiP module based on ceramic materials according to claim 1, characterized in that: In the layered structure of the ceramic matrix, passive devices are welded together using solder.

4. The packaging structure of the SiP module based on ceramic materials according to claim 1, characterized in that: The ceramic substrate is wired with metallization B1 between internal layers, and then the via metallization paste B2 is designed to fill the holes, so as to realize the connection between the internal metallization pads B1 and the external ball grid array pins 11.

5. The packaging structure of the SiP module based on ceramic materials according to claim 1, characterized in that: The ceramic substrate has blank spaces inside for logos or anti-counterfeiting designs.

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