An HTCC ceramic tube structure and electronic component

Abstract

This utility model discloses an HTCC ceramic housing structure and electronic component, belonging to the field of ceramic housing technology. The specific structure includes a ceramic body and a gold-tin cover plate. The ceramic body has an opening at the top for mounting the chip. Multiple semi-circular grooves are arranged around the outer circumference of the ceramic body, each groove containing a first conductive layer. Multiple bonding fingers corresponding to the semi-circular grooves are arranged around the inner circumference of the cavity, electrically connected to the corresponding first conductive layer. The lower end of the first conductive layer connects to a second conductive layer at the bottom of the ceramic body. A sealing ring is arranged around the upper circumference of the ceramic body, and the gold-tin cover plate is placed on top of it. A first conductive post is positioned between the sealing ring and the grounded bonding finger. This utility model connects the grounded bonding finger and the sealing ring via the first conductive post, enhancing GND shielding, reducing electromagnetic leakage, ensuring better shielding of high-frequency signals and less electric field leakage, and improving signal transmission quality.

Description

Technical Field

[0001] This utility model relates to the field of ceramic tube shell technology, specifically to an HTCC ceramic tube shell structure, and also to an electronic component containing an HTCC ceramic tube shell structure. Background Technology

[0002] HTCC (High-Temperature Co-fired Ceramic) technology holds a crucial position in packaging technology due to its unique advantages. Compared to traditional PCB substrates, HTCC high-temperature ceramic substrates offer superior heat dissipation, rapidly dissipating chip heat and maintaining stable chip operation; they possess extremely high mechanical strength, effectively resisting external mechanical shocks and vibrations, ensuring the reliability of the packaging structure; and they also exhibit stable dielectric constants and good chemical compatibility, making them widely used in aerospace equipment, high-end consumer electronics, communication base stations, and other fields with extremely high reliability and performance requirements. Currently, HTCC ceramic packaging structures mainly include the CSOP, CLCC, and CDFN series, which can meet the packaging needs of different application scenarios.

[0003] However, current mainstream quad flat leadless co-fired ceramic packaging technology (such as single-channel transmission systems) has significant drawbacks in high-frequency signal transmission: in existing packaging designs, the internal bonding fingers and sealing ring are electrically isolated and do not achieve conductivity. This design flaw leads to severe signal shielding failure and electric field leakage problems in applications at 30GHz and above, seriously affecting the high-frequency signal transmission quality and overall system performance. With the popularization of high-frequency communication and precision electronic systems, the signal transmission bottleneck caused by this packaging design urgently needs to be addressed. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide an HTCC ceramic tube shell structure and electronic components that can achieve high-frequency applications of 30-35GHz, avoid serious signal shielding failure and electric field leakage problems, and improve the high-frequency signal transmission quality and overall system performance.

[0005] The technical solution adopted by this utility model is as follows: an HTCC ceramic tube shell structure, including a ceramic body and a gold-tin cover plate. The ceramic body is provided with an accommodating cavity with an opening at the top for installing chips. Multiple semi-circular grooves are provided around the outer circumference of the ceramic body. Each semi-circular groove is provided with a first conductive layer. Multiple bonding fingers corresponding to the semi-circular grooves are provided around the inner circumference of the accommodating cavity. The multiple bonding fingers are electrically connected to the first conductive layer at the corresponding position. The lower end of the first conductive layer is connected to the bottom of the ceramic body to provide a second conductive layer. A sealing ring is provided around the upper circumference of the ceramic body. The gold-tin cover plate is covered on the gold-tin cover plate. A first conductive post is provided between the sealing ring and the grounded bonding finger.

[0006] Furthermore, the diameter of the first conductive post is 0.1-0.2 mm.

[0007] Furthermore, the diameter of the first conductive post is 0.15 mm.

[0008] Furthermore, the first conductive post is made of tungsten, molybdenum, or a combination of both.

[0009] Furthermore, a chip bonding area is provided at the bottom of the aforementioned cavity, and the chip bonding area is connected to the back ceramic bonding area provided in the middle of the bottom surface of the ceramic body through a second conductive post.

[0010] Furthermore, the number of the aforementioned second conductive pillars is 4 to 12.

[0011] Furthermore, the diameter of the semi-circular groove on the side wall is 0.18~0.35mm.

[0012] Furthermore, a third conductive post is provided between the aforementioned bonding finger and the second conductive layer.

[0013] An electronic component includes the aforementioned HTCC ceramic housing structure and a chip mounted within the HTCC ceramic housing structure.

[0014] The beneficial effects of this utility model are as follows: Compared with the prior art, this utility model connects the grounded bonding finger and the sealing ring through the first conductive post, and combines it with a metal cover plate to effectively solve the problems of poor signal shielding and electric field leakage in the high-frequency band, thereby improving the signal transmission quality. In particular, it can maintain good signal transmission quality in the 30-35GHz high-frequency band. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the HTCC ceramic tube shell structure in Example 1;

[0016] Figure 2 This is a schematic diagram of the pin definition of the HTCC ceramic housing structure in Example 1;

[0017] Figure 3 This is a schematic diagram of the manufacturing process of HTCC ceramic tube shell structure;

[0018] Figure 4 The insertion loss S of the HTCC ceramic tube shell structure in Example 1 is... 21 Line graph;

[0019] Figure 5 This is a schematic diagram of an HTCC ceramic housing structure that uses only internal through-holes to connect the GND bonding fingers and the sealing ring (the chip bonding area and the back ceramic bonding area are not connected).

[0020] Figure 6 yes Figure 5Insertion loss S of HTCC ceramic tube shell structure 21 Line graph;

[0021] Figure 7 This is a schematic diagram of the HTCC tube shell structure in Comparative Example 1;

[0022] Figure 8 The insertion loss S of the HTCC shell structure in Comparative Example 1 21 Line graph. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0024] Quad Flat No-Lead (CQFN) high-temperature co-fired ceramic packaging technology can be applied to multiple transmission systems. However, in the design of this packaging structure, there is no electrical connection between the internal bonding fingers and the sealing ring. This often leads to poor signal shielding and electric field leakage in high-frequency applications, thus affecting signal transmission performance at high frequencies. To address this problem, Embodiment 1 of this invention proposes an HTCC ceramic tube shell structure that electrically connects the grounded bonding fingers to the sealing ring via a first conductive post, and combines this with a metal cover plate to form shielding. This effectively solves the problems of poor signal shielding, signal discontinuity caused by electric field leakage, core signal distortion, and poor transmission quality in the 30GHz frequency band of the ceramic substrate.

[0025] Example 1: As Figure 1-3 As shown, an HTCC ceramic housing structure includes a ceramic body 1 and a gold-tin cover plate 8. The ceramic body 1 has an opening at the top for receiving a chip. Multiple semi-circular grooves 3 are provided around the outer circumference of the ceramic body 1, and a first conductive layer 7 is provided in each semi-circular groove 3. Multiple bonding fingers 5 corresponding to the semi-circular grooves 3 are provided around the inner circumference of the receiving cavity 10. The multiple bonding fingers 5 are electrically connected to the first conductive layer 7 at their corresponding positions. The lower end of the first conductive layer 7 is connected to a second conductive layer 6 at the bottom of the ceramic body 1. A sealing ring 9 is provided around the upper circumference of the ceramic body 1. The gold-tin cover plate 8 is placed on the gold-tin cover plate 8. A first conductive post 11 is provided between the sealing ring 9 and the grounded bonding finger 5. The ceramic body 1 is mounted on a PCB board 15, and the lead-out end (second conductive layer) at the bottom of the ceramic body 1 is electrically connected to the corresponding position on the PCB board 15.

[0026] The gold-tin cover plate is made of Kovar alloy (4J42 + gold-tin solder). The main ceramic components are one or more of aluminum nitride, aluminum oxide, silicon carbide, silicon nitride, and beryllium oxide. The co-fired metal material is tungsten, and the metal surface is electroplated with nickel and gold. The signal is input from PCB board 1 and transmitted to the core area through the semi-circular hole 3 on the side wall of the ceramic body 1 of the ceramic shell. A through hole (filled with the second conductive post 14) is set between the chip bonding area 12 and the back ceramic bonding area 13. At the same time, the sealing ring 9 and the bonding finger 5 connected to the ground terminal GND are electrically connected through the first conductive post 11. As a key link to improve the transmission performance of the ceramic shell, the structural schematic diagram is shown in Figure 1, and the pin definition diagram is shown in Figure 2. In the figure, the bonding finger 5 connected to the ground terminal GND is provided with the first conductive post 11 connected to the sealing ring 9. The metal pattern in the bottom surface of the ceramic is co-fired by metal and ceramic. The pattern extends into the interior of the ceramic body through the boundary line between the side wall and the bottom surface, and is connected to the outer pad of the shell through the through hole and internal circuit.

[0027] This invention, by retaining the side wall holes connected to the lead-out ends on the flat ceramic shell, adds an internal through hole (filled with conductive material to achieve electrical connection) between the bonding finger and the sealing ring. The introduction of the internal through hole filled with conductive material enhances GND shielding, reduces electromagnetic leakage, and effectively solves the problem of poor transmission performance caused by signal integrity issues when transmitting high-frequency signals in the 35GHz frequency range. It ensures better shielding of high-frequency signals and less electric field leakage, thereby improving signal transmission quality.

[0028] The diameter of the first conductive post 11 is 0.1-0.2 mm; the preferred diameter of the first conductive post 11 is 0.15 mm; the first conductive post 11 is made of tungsten, molybdenum or a combination of the two.

[0029] To ensure superior signal transmission performance in the 35GHz band, a chip bonding area 12 is provided at the bottom of the cavity 10. The chip bonding area 12 is connected to the back ceramic bonding area 13 located in the center of the bottom surface of the ceramic body 1 via a second conductive post 14. Figure 6 It can be seen that within the DC~35GHz signal band, the introduction of the GND hole enhances the integrity of high-frequency signals. Within this band, the insertion loss S21 is consistently less than -1dB, reaching a maximum of 0.9dB at 17.5GHz, with only about 18.7% power loss, demonstrating the excellent signal transmission performance of this enclosure in the 35GHz band; the number of second conductive posts 14 ranges from 4 to 12.

[0030] The diameter of the semi-circular groove 3 on the side wall is 0.18~0.35mm; a third conductive post 2 is provided between the bonding finger 5 and the second conductive layer 6. The third conductive post 2, together with the first conductive layer of the semi-circular hole on the side wall, effectively improves the return loss and solves the problem of poor signal transmission performance in the 35GHz frequency range due to impedance mismatch in a single signal transmission mode.

[0031] Example 2: As Figure 3 As shown, a method for preparing an HTCC ceramic tube shell structure includes the following steps:

[0032] Step 1: Laser Aperture and Cavities: Corresponding cavities, through-holes, and sidewall holes are engraved on each layer of green ceramic tape. Laser aperture enables highly precise hole diameter and location, and produces smooth hole walls, which helps improve adhesion and conductivity in subsequent metallization processes. Compared with traditional mechanical drilling, laser aperture is faster and more efficient, making it suitable for mass production. It minimizes the heat-affected zone of the substrate, reducing damage and stress to surrounding materials. Complex cavity and through-hole structures can be easily fabricated to meet special design requirements. The process is easily automated, reducing manual intervention and improving production consistency.

[0033] Step 2, Hole Filling: A stencil is used for hole filling. The purpose is to ensure that the conductive paste is accurately and evenly filled into the vias on the circuit board, enabling signal transmission between layers. Using a stencil improves production efficiency, reduces material waste, and ensures consistent hole filling quality.

[0034] Step 3: Printing: The corresponding pattern for each layer of green ceramic tape is printed onto the corresponding green ceramic tape using screen printing, including printing the sidewall holes. Screen printing technology can accurately print conductive paste or other functional materials onto the green ceramic tape to form the required circuit pattern. The steps include preparing the green ceramic tape, preparing the conductive paste, making the screen template, performing screen printing, and drying. It has the advantages of low cost, simple operation, strong adaptability, and good repeatability.

[0035] Step 4: Shaping: Stack and press the green ceramic strips together in a preset order; then cut them one by one with a hot cutting machine to form individual green ceramic semi-finished products.

[0036] Step 5: Place the green ceramic semi-finished product in a high-temperature sintering furnace and heat it to 500~600℃ within 38 hours at a heating rate of 0. After the organic components are completely burned off, depending on the type of ceramic and thick film metal used, continue to heat it to 1375~1650℃ after 15 hours, and hold it at the highest temperature for 1-2 hours for sintering; after sintering, cool the ceramic substrate to room temperature within 48 hours.

[0037] Step 6: Nickel plating: Apply a nickel layer of 1.3µm to 8.9µm to the sintered ceramic using chemical plating or electroplating methods; avoid plating creep and missed plating.

[0038] Step 7: Gold Plating: Clean the HTCC ceramic substrate with a suitable solvent to remove surface oil and dust; immerse the cleaned substrate in an acidic solution for pickling to remove the oxide layer; after pickling, treat the substrate surface with an activator to improve the adhesion of the plating layer. Plate a layer of gold on the nickel plating layer, the thickness of which depends on actual needs; after gold plating, thoroughly clean the substrate with deionized water to remove residual chemicals; place the cleaned substrate in an oven to dry, ensuring the substrate surface is dry; finally, inspect the gold plating layer to ensure it is uniform, defect-free, and meets technical requirements, and select qualified products as finished products.

[0039] Example 3: As Figure 1-3 As shown, an electronic component includes the aforementioned HTCC ceramic housing structure and a chip mounted within the HTCC ceramic housing structure.

[0040] Specific example 1: such as Figure 1 The structure shown employs a first conductive post connecting the sealing ring and the bonding fingers of GND, simultaneously connecting the chip bonding area and the back ceramic bonding area in a ceramic shell structure. The ceramic material is 92% black alumina, the co-fired metal is tungsten, and the metal surface is plated with nickel, palladium, and gold. The ceramic cavity contains bonding fingers (chip signal input ports within the core area). The shell interior utilizes 0.15mm diameter internal through-holes filled with conductive material as the signal transmission medium, and retains 0.25mm diameter sidewall holes.

[0041] As shown in Figure 4, within the DC~35GHz signal band, the introduction of the GND hole enhances the integrity of high-frequency signals. Within this band, the insertion loss S... 21 Always less than -1dB, at 17.5G, S 21 With a maximum value of 0.9dB and only about 18.7% power loss, this enclosure demonstrates excellent signal transmission performance in the 35GHz band.

[0042] Specific example 2: such as Figure 5 As shown, the chip bonding area and the back ceramic bonding area are not connected. Only an internal through-hole connects the GND bonding fingers and the sealing ring in an HTCC ceramic shell structure. The ceramic material is 92% black alumina, the co-fired metal is tungsten, and the metal surface is electroplated with nickel and gold. The ceramic cavity contains bonding fingers (chip signal input ports inside the core area). A 0.15mm diameter through-hole (filled with conductive material) on the sealing ring serves as the signal transmission medium, connecting to the GND bonding fingers. Figure 1 As shown. By Figure 6 It can be seen that the signal is within the frequency band of DC~17 GHz, and the insertion loss S 21 <-1dB indicates good transmission performance. However, insertion loss deteriorates rapidly after 20GHz, resulting in high-frequency signal loss and significant distortion.

[0043] Comparative Example: The difference from Example 1 lies in, for example... Figure 7 As shown, instead of using the bonding fingers for grounding and the top metal cover plate, an HTCC ceramic shell structure is used, employing internal through-holes to connect the chip bonding area and the back ceramic bonding area. The ceramic material is 92% black alumina, the co-fired metal is tungsten, and the metal surface is plated with nickel, palladium, and gold. The ceramic cavity contains bonding fingers (chip signal input ports within the core area), utilizing 0.15mm diameter holes (filled with conductive material) as the GND signal transmission medium. Figure 8 As shown.

[0044] Depend on Figure 8 It can be seen that the insertion loss S is within the frequency band of DC~32G. 21 It gradually increases with increasing frequency, although the overall insertion loss S 21 <1dB, but electric field leakage occurs in many places, and insertion loss fluctuates, resulting in unstable transmission.

[0045] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. An HTCC ceramic package structure, characterized by, The ceramic body (1) and the gold-tin cover plate (8) are included. The ceramic body (1) is provided with an accommodating cavity (10) with an opening at the top. The accommodating cavity (10) is used to install the chip. Multiple side wall semicircular grooves (3) are provided around the outer perimeter of the ceramic body (1). Each side wall semicircular groove (3) is provided with a first conductive layer (7). Multiple bonding fingers (5) corresponding to the side wall semicircular grooves (3) are provided around the inner perimeter of the accommodating cavity (10). The multiple bonding fingers (5) are electrically connected to the first conductive layer (7) at the corresponding position. The lower end of the first conductive layer (7) is connected to the bottom of the ceramic body (1) and a second conductive layer (6) is provided. A sealing ring (9) is provided around the upper perimeter of the ceramic body (1). The gold-tin cover plate (8) is covered on the gold-tin cover plate (8). A first conductive post (11) is provided between the sealing ring (9) and the grounded bonding finger (5).

2. A HTCC ceramic package structure according to claim 1, characterized in that, The diameter of the first conductive post (11) is 0.1-0.2 mm.

3. A HTCC ceramic package structure according to claim 2, characterized in that, The diameter of the first conductive post (11) is 0.15 mm.

4. A HTCC ceramic package structure according to claim 1, wherein, The first conductive post (11) is made of tungsten, molybdenum or a combination of the two.

5. A HTCC ceramic package structure according to claim 1, wherein, The bottom of the cavity (10) is provided with a chip bonding area (12), and the chip bonding area (12) is connected to the back ceramic bonding area (13) provided in the middle of the bottom surface of the ceramic body (1) through a second conductive post (14).

6. A HTCC ceramic housing structure according to claim 5, characterized in that The number of the second conductive pillars (14) is 4 to 12.

7. A HTCC ceramic package structure according to claim 5, wherein The diameter of the semi-circular groove (3) on the side wall is 0.18~0.35mm.

8. A HTCC ceramic package structure according to claim 1, wherein, A third conductive post (2) is provided between the bonding finger (5) and the second conductive layer (6).

9. An electronic component, characterized by Includes an HTCC ceramic housing structure as described in any one of claims 1-8 and a chip installed within the HTCC ceramic housing structure.

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