Integrated racking structure based on three-dimensional stacked packaging and manufacturing method thereof

Abstract

The invention discloses an integrated racking structure based on three-dimensional stacked packaging and a manufacturing method of the integrated racking structure, and belongs to the field of integrated circuit packaging shells. The structure comprises an upper ceramic substrate, three stacked integrated parts and a lower ceramic substrate from top to bottom, and the upper ceramic substrate and the integrated parts, the integrated parts, and the integrated parts and the lower ceramic substrate are in brazed connection through integrated silver-copper solder layers. The invention has the following advantages: (1) the enclosure frame and guide pin integrated structure provides high alignment precision for the small-size enclosure frame and the guide pin; (2) the integrated solder reduces solder deviation and operation difficulty possibly caused by multiple times of laying of the solder; (3) the stress of layered multi-time brazing is lower than that of normal one-time brazing, and the reliability risk of the multi-layer stacked packaging structure is lower; and (4) the method is compatible with an HTCC process, and on the premise of realizing high microwave performance, miniaturization, integration and low cost, the processing and forming method is simple, and batch production is facilitated.

Description

Technical Field

[0001] The present invention belongs to the field of integrated circuit packaging shells, and in particular relates to an integrated mounting structure based on three-dimensional stacking packaging and a manufacturing method thereof. Background Art

[0002] In the field of active phased array radar, a large number of microwave components are used on the antenna array to achieve excellent beam scanning performance. The large number of microwave components used must take into account the development direction of active phased array platforms towards stealth and lightweight, so microwave components must also move towards miniaturization, high integration, and low cost. Traditional two-dimensional microwave components are all single-layer ceramic structures. On the premise of achieving electrical performance requirements, the length and width dimensions are large, which is contrary to the requirements of miniaturization and high integration. Therefore, the three-dimensional stacked packaging structure has gradually become the development direction of future integrated circuit packaging.

[0003] Through the vertical interconnection transition structure between different layers, the simple longitudinal wiring of the RF circuit in the traditional process is replaced by a combination of intra-layer horizontal wiring and inter-layer longitudinal interconnection, which significantly reduces the length and width of the ceramic component. However, the main problems with this process are: 1. The number of conductive columns (pins) for longitudinal interconnection between layers is large and small. It is difficult to ensure high alignment accuracy and mounting efficiency on the small-sized ceramic substrate during brazing, and it is difficult to ensure delivery progress and assembly accuracy during mass production; 2. Since the single-layer ceramic of the multi-layer ceramic component is relatively thin, the welding of parts adopts one-time silver-copper brazing, which has a large brazing stress and is prone to reliability problems such as ceramic cracks and air leakage after brazing. Summary of the invention

[0004] Purpose of the invention: In order to meet the needs of miniaturization, high integration and low cost of integrated circuit packaging shells, and at the same time solve the problems of assembly accuracy and mounting efficiency, the present invention optimizes the design of the metal frame and metal pin structure, optimizes the brazing mounting method, designs an integrated mounting structure based on three-dimensional stacked packaging, and provides a method for manufacturing the above-mentioned integrated mounting based on three-dimensional stacked packaging.

[0005] Technical solution: The integrated mounting structure based on three-dimensional stacking packaging described in the present invention includes an upper ceramic substrate, three stacked integrated parts and a lower ceramic substrate from top to bottom; wherein the integrated parts include a metal frame, metal pins and metal ribs, the metal pins are arranged on the upper surface of the metal frame and connected to the metal frame through the metal ribs; the lower surface of the upper ceramic substrate is divided into a metallization zone and a solder resist zone, the metallization zone is distributed in the area where the integrated parts need to be brazed to the lower ceramic substrate, and the solder resist zone is distributed between different brazing connection areas; the upper surface of the lower ceramic substrate is divided into a metallization zone and a solder resist zone, the metallization zone is distributed in the area where the integrated parts need to be brazed to the upper ceramic substrate, and the solder resist zone is distributed between different brazing connection areas; the upper ceramic substrate and the integrated parts, the integrated parts, and the integrated parts and the lower ceramic substrate are all brazed through an integrated silver-copper solder layer.

[0006] Furthermore, the upper surface of the integrated part has a nickel layer with a thickness of 0.8-2.2 μm.

[0007] Furthermore, the width of the solder resist zone 1 and the solder resist zone 2 are both 0.08-0.21 mm, and the height is both 0.03-0.08 mm, so as to prevent the solder from flowing in different soldering areas.

[0008] Furthermore, in the integrated parts, the heights of the metal frame and the metal lead pins are both 0.25-0.37 mm, and the height of the metal connecting ribs is 0.07-0.11 mm. The materials of the metal frame, the metal lead pins and the metal connecting ribs are all selected from 4J42 alloy or 4J29 alloy. The integrated structure of the metal frame and the metal lead pins can provide high alignment accuracy for small-size frames and lead pins.

[0009] Furthermore, the metallized area 1 and the metallized area 2 are both nickel layers plated by chemical plating, with a thickness of 0.8-2.2 μm, and the function is to ensure the brazing connection between the ceramic substrate and the integrated part.

[0010] Furthermore, the thickness of the integrated silver-copper solder layer is 0.06-0.12 mm, and the integrated solder layer can reduce solder deviation and operation difficulty that may be caused by multiple solder overlays.

[0011] The manufacturing method of the above-mentioned integrated mounting structure based on three-dimensional stacking packaging comprises the following steps:

[0012] (1) Preparation of metal frame, metal pins and metal connecting ribs: Prepare them into integrated parts by laser etching or chemical etching, and then anneal, clean and chemically nickel plate them for use;

[0013] (2) Preparation of integrated silver-copper solder: prepared by laser etching or chemical etching;

[0014] (3) Preparation of upper ceramic substrate and lower ceramic substrate: using Al2O3 as the main material, using metal W and Mo as metallization and hole filling materials, using high temperature multilayer co-fired ceramic process to prepare the ceramic substrate, and then chemically nickel plating for standby use;

[0015] (4) Assembling the integrated parts, the lower ceramic substrate, and the integrated silver-copper brazing material in a graphite positioning mold, and sending them to a chain brazing furnace to complete the brazing connection, which is the first-stage ceramic shell, and polishing the connecting ribs of the first-stage ceramic shell; assembling the integrated parts, the first-stage ceramic shell, and the integrated silver-copper brazing material in a graphite positioning mold, and sending them to a chain brazing furnace to complete the brazing connection, which is the second-stage ceramic shell, and polishing the connecting ribs of the second-stage ceramic shell; assembling the integrated parts, the second-stage ceramic shell, and the integrated silver-copper brazing material in a graphite positioning mold, and sending them to a chain brazing furnace to complete the brazing connection, which is the third-stage ceramic shell, and polishing the connecting ribs of the third-stage ceramic shell; assembling the third-stage ceramic shell, the upper ceramic substrate, and the integrated silver-copper brazing material in a graphite positioning mold, and sending them to a chain brazing furnace to complete the brazing connection. After the connection is completed, an integrated mounting structure based on three-dimensional stacking packaging is obtained, that is, the three-dimensional stacking packaging shell is processed.

[0016] Furthermore, in step (1), the annealing temperature is 1020-1080° C.; in step (2), the integrated silver-copper solder uses AgCu28 as raw material.

[0017] Furthermore, in step (3), the sintering temperature of the high-temperature multilayer co-fired ceramic process is 1440°C to 1630°C; in step (4), the maximum temperature of the silver-copper brazing chain furnace is 790-810°C, the chain speed is 170-215mm / min, and the insulation time in the high-temperature zone is 1-5min.

[0018] Beneficial effects: Compared with the prior art, the present invention has the following significant effects: (1) The integrated structure of the enclosure and lead pins provides high alignment accuracy for the small-sized enclosure and lead pins; (2) The integrated solder reduces the solder offset and operation difficulty that may be caused by multiple solder overlays; (3) Compared with normal single soldering, the stress of layered multiple soldering is lower, and the reliability risk of the multi-layer stacked packaging structure is lower; (4) The present invention is compatible with the HTCC process, and under the premise of achieving high microwave performance, miniaturization, integration, and low cost, the processing and molding method is simple and convenient for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of an integrated part;

[0020] Figure 2 is a schematic diagram of the structure of the upper ceramic substrate;

[0021] Figure 3 is a schematic diagram of the structure of the lower ceramic substrate;

[0022] Figure 4 It is a schematic diagram of the structure of the integrated silver-copper brazing material layer;

[0023] Figure 5 11 is a schematic diagram of the structure of the tube shell at different stages after brazing mounting, 11 is a schematic diagram of the structure of the brazing mounting one-layer integrated parts without polishing and connecting ribs, and 13 is a schematic diagram of the structure of the brazing mounting three-layer integrated parts after polishing and connecting ribs. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the embodiments and drawings.

[0025] Embodiment 1: The integrated mounting structure based on three-dimensional stacking packaging provided in this embodiment includes, from top to bottom, an upper ceramic substrate, three stacked integrated parts and a lower ceramic substrate.

[0026] like Figure 1 As shown, the integrated part includes a metal frame 1, a metal lead pin 2 and a metal connecting rib 3. The metal lead pin 2 is arranged on the upper surface of the metal frame 1 and connected to the metal frame 1 through the metal connecting rib 3. The upper surface of the integrated part has a nickel layer with a thickness of 1.6 μm. The heights of the metal frame and the metal lead pin are both 0.31 mm, and the height of the metal connecting rib is 0.09 mm. The materials of the metal frame, the metal lead pin and the metal connecting rib are all selected from 4J29 alloy.

[0027] like Figure 2 As shown, the lower surface of the upper ceramic substrate is divided into a metallization zone and a solder mask zone. The metallization zone is distributed in the area that needs to be brazed with the lower ceramic substrate through an integrated part, and the solder mask zone is distributed between different brazing connection areas. Figure 3 As shown, the upper surface of the lower ceramic substrate is divided into metallization zone 2 and solder resist zone 2. The metallization zone 2 is distributed in the area where the integrated parts need to be brazed to the upper ceramic substrate, and the solder resist zone 2 is distributed between different brazing connection areas. The width of solder resist zone 1 and solder resist zone 2 are both 0.15mm, and the height is 0.06mm. Both metallization zone 1 and metallization zone 2 are nickel layers plated by chemical plating, with a thickness of 1.6μm.

[0028] The upper ceramic substrate and the integrated parts, the integrated parts, and the integrated parts and the lower ceramic substrate are all brazed and connected by an integrated silver-copper solder layer, such as Figure 4 As shown, the thickness of the integrated silver-copper solder layer is 0.10 mm.

[0029] The steps of the manufacturing method of the above-mentioned integrated mounting structure based on three-dimensional stacking packaging are as follows:

[0030] (1) Preparation of integrated enclosure and lead pins: The enclosure and lead pins are prepared into an integrated part by laser etching or chemical etching, wherein the enclosure and lead pins are connected to each other by connecting ribs, and the integrated part is annealed, cleaned, and chemically nickel-plated before use;

[0031] (2) Preparation of upper and lower ceramic substrates: Al2O3 is used as the main material, metal W is used as the metallization and hole filling material, solder mask, metallization and hole filling slurry are printed by screen printing, and the ceramic substrate is prepared by high temperature multilayer co-fired ceramic (HTCC) process. After the ceramic substrate is sintered, it is subjected to chemical nickel plating and then set aside;

[0032] (3) Preparation of integrated brazing material: prepared by laser etching or chemical etching, wherein the silver-copper solder uses AgCu28 as raw material;

[0033] (4) Brazing assembly: After assembling the integrated parts, the lower ceramic substrate, and the integrated silver-copper brazing material, they are sent to a chain brazing furnace to complete the brazing connection. The maximum brazing temperature is 805°C, the chain speed of the brazing furnace is 207 mm / min, and the high temperature zone insulation time is 3.5 min to obtain the first stage ceramic shell. Figure 5 As shown in the left figure, the excess ribs on the tube shell are completely polished; after the integrated parts, the first-stage ceramic tube shell after polishing the ribs, and the integrated silver-copper brazing material are assembled, they are sent to the chain brazing furnace to complete the brazing connection, wherein the maximum brazing temperature is 805°C, the brazing furnace chain speed is 207mm / min, and the high temperature zone insulation time is 3.5min to obtain the second-stage ceramic tube shell, and the excess ribs on the tube shell are completely polished; after the integrated parts, the second-stage ceramic tube shell after polishing the ribs, and the integrated silver-copper brazing material are assembled, they are sent to the chain brazing furnace to complete the brazing connection, wherein the maximum brazing temperature is 805°C, the brazing furnace chain speed is 207mm / min, and the high temperature zone insulation time is 3.5min to obtain the third-stage ceramic tube shell, as shown in Figure 5 As shown in the right figure, the redundant connecting ribs on the tube shell are completely polished. After the third stage ceramic tube shell, the upper ceramic substrate, and the integrated silver-copper brazing material are assembled after the polished connecting ribs, they are sent to the chain brazing furnace to complete the brazing connection, wherein the highest brazing temperature is 805℃, the chain speed of the brazing furnace is 207mm / min, and the insulation time in the high temperature zone is 3.5min. After the connection is completed, an integrated mounting structure based on the three-dimensional stacking package is obtained, that is, the three-dimensional stacking package shell is obtained by processing.

[0034] Example 2: The difference from Example 1 is that: the material of the metal frame, metal pins and metal connecting ribs is 4J42 alloy; the thickness of the integrated silver-copper solder layer is 0.07mm; the width of the solder resist zone 1 and the solder resist zone 2 are both 0.13mm, and the thickness is 0.05mm; the metallized zone 1 and the metallized zone 2 are both nickel layers with a thickness of 1.3μm, and the upper surface of the integrated part has a nickel layer with a thickness of 1.3μm.

[0035] The steps of the manufacturing method of the above-mentioned integrated mounting structure based on three-dimensional stacking packaging are as follows:

[0036] (1) Preparation of integrated enclosure and lead pins: The enclosure and lead pins are prepared into an integrated part by laser etching or chemical etching, wherein the enclosure and lead pins are connected to each other by connecting ribs, and the integrated part is annealed, cleaned, and chemically nickel-plated before use;

[0037] (2) Preparation of upper and lower ceramic substrates: Al2O3 is used as the main material, metal W is used as the metallization material, Mo is used as the hole filling material, solder mask, metallization and hole filling slurries are printed by screen printing, and the ceramic substrate is prepared by high temperature multilayer co-fired ceramic (HTCC) process. After the ceramic substrate is sintered, it is subjected to chemical nickel plating and then set aside;

[0038] (3) Preparation of integrated brazing material: prepared by laser etching or chemical etching, wherein the silver-copper solder uses AgCu28 as raw material;

[0039] (4) Brazing assembly: After assembling the integrated parts, the lower ceramic substrate, and the integrated silver-copper brazing material, they are sent to a chain brazing furnace to complete the brazing connection, wherein the maximum brazing temperature is 801°C, the chain speed of the brazing furnace is 213 mm / min, and the holding time in the high temperature zone is 3.2 min. The first-stage ceramic shell is obtained, and the excess connecting ribs on the shell are completely polished; after assembling the integrated parts, the first-stage ceramic shell after polishing the connecting ribs, and the integrated silver-copper brazing material, they are sent to a chain brazing furnace to complete the brazing connection, wherein the maximum brazing temperature is 80 1℃, the chain speed of the brazing furnace is 213mm / min, the holding time in the high temperature zone is 3.2min, the second stage ceramic shell is obtained, and the excess ribs on the shell are completely polished; after assembling the integrated parts, the second stage ceramic shell after polishing the ribs, and the integrated silver-copper brazing material, they are sent to the chain brazing furnace to complete the brazing connection, wherein the highest brazing temperature is 801℃, the chain speed of the brazing furnace is 213mm / min, the holding time in the high temperature zone is 3.2min, the third stage ceramic shell is obtained, and the excess ribs on the shell are completely polished. After assembling the third stage ceramic shell after polishing the ribs, the upper ceramic substrate, and the integrated silver-copper brazing material, they are sent to the chain brazing furnace to complete the brazing connection, wherein the highest brazing temperature is 801℃, the chain speed of the brazing furnace is 213mm / min, and the holding time in the high temperature zone is 3.2min. After the connection is completed, an integrated mounting structure based on three-dimensional stacking packaging is obtained, that is, a three-dimensional stacking packaging shell is obtained.

Claims

1. An integrated mounting structure based on three-dimensional stacking packaging, characterized in that: From top to bottom, it includes an upper ceramic substrate, three stacked integrated parts and a lower ceramic substrate; wherein the integrated part includes a metal frame, metal pins and metal ribs, the metal pins are arranged on the upper surface of the metal frame and connected to the metal frame through the metal ribs; the lower surface of the upper ceramic substrate is divided into a metallized zone 1 and a solder resist zone 1, the metallized zone 1 is distributed in the area where the integrated part needs to be brazed to the lower ceramic substrate, and the solder resist zone 1 is distributed between different brazing connection areas; the upper surface of the lower ceramic substrate is divided into a metallized zone 2 and a solder resist zone 2, the metallized zone 2 is distributed in the area where the integrated part needs to be brazed to the upper ceramic substrate, and the solder resist zone 2 is distributed between different brazing connection areas; the upper ceramic substrate and the integrated part, the integrated parts, and the integrated part and the lower ceramic substrate are all brazed and connected through an integrated silver-copper solder layer.

2. The integrated mounting structure according to claim 1, characterized in that: The upper surface of the integrated part has a nickel layer with a thickness of 0.8-2.2 μm.

3. The integrated mounting structure according to claim 1, characterized in that: The width of the first solder resist area and the second solder resist area are both 0.08-0.21 mm, and the height is both 0.03-0.08 mm.

4. The integrated mounting structure according to claim 1, characterized in that: In the integrated part, the heights of the metal frame and the metal lead pins are both 0.25-0.37 mm, and the height of the metal connecting rib is 0.07-0.11 mm.

5. The integrated mounting structure according to claim 4, characterized in that: The materials of the metal frame, metal lead pins and metal connecting ribs are all selected from 4J42 alloy or 4J29 alloy.

6. The integrated mounting structure according to claim 1, characterized in that: The first metallization area and the second metallization area are both nickel layers plated by chemical plating, with a thickness of 0.8-2.2 μm.

7. The integrated mounting structure according to claim 1, characterized in that: The thickness of the integrated silver-copper solder layer is 0.06-0.12 mm.

8. A method for manufacturing an integrated mounting structure based on three-dimensional stacking packaging according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Preparation of metal frame, metal pins and metal connecting ribs: Prepare them into integrated parts by laser etching or chemical etching, and then anneal, clean and chemically nickel plate them for use; (2) Preparation of integrated silver-copper solder layer: prepared by laser etching or chemical etching; (3) Preparation of upper ceramic substrate and lower ceramic substrate: using Al2O3 as the main material, using metal W and Mo as metallization and hole filling materials, using high temperature multilayer co-fired ceramic process to prepare the ceramic substrate, and then chemically nickel plating for standby use; (4) Assembling the integrated parts, the lower ceramic substrate, and the integrated silver-copper brazing material in a graphite positioning mold, and sending them to a chain brazing furnace to complete the brazing connection, which is the first-stage ceramic shell, and polishing the connecting ribs of the first-stage ceramic shell; assembling the integrated parts, the first-stage ceramic shell, and the integrated silver-copper brazing material in a graphite positioning mold, and sending them to a chain brazing furnace to complete the brazing connection, which is the second-stage ceramic shell, and polishing the connecting ribs of the second-stage ceramic shell; assembling the integrated parts, the second-stage ceramic shell, and the integrated silver-copper brazing material in a graphite positioning mold, and sending them to a chain brazing furnace to complete the brazing connection, which is the third-stage ceramic shell, and polishing the connecting ribs of the third-stage ceramic shell; assembling the third-stage ceramic shell, the upper ceramic substrate, and the integrated silver-copper brazing material in a graphite positioning mold, and sending them to a chain brazing furnace to complete the brazing connection. After the connection is completed, an integrated mounting structure based on three-dimensional stacking packaging is obtained, that is, a three-dimensional stacking packaging shell is processed.

9. The preparation method according to claim 8, characterized in that: In step (1), the annealing temperature is 1020-1080° C.; in step (2), the integrated silver-copper solder uses AgCu28 as raw material.

10. The preparation method according to claim 8, characterized in that: In step (3), the sintering temperature of the high-temperature multilayer co-fired ceramic process is 1440-1630°C; in step (4), the maximum temperature of the silver-copper brazing chain furnace is 790-810°C, the chain speed is 170-215mm / min, and the insulation time in the high-temperature zone is 1-5min.

Images