Ceramic core packaging substrate and preparation method thereof

Abstract

The invention provides a ceramic core packaging substrate and a preparation method thereof, and the preparation method comprises the steps: S1, manufacturing a ceramic core plate through a ceramic substrate sintering technology, enabling the ceramic core plate to be provided with an internal conductive wire and an internal via hole, and enabling the upper surface and / or the lower surface of the ceramic core plate to be provided with a core plate surface conductive wire; s2, preparing an intermediate bonding layer on the conductor wire on the surface of the core plate through a metal stripping process; s3, a plurality of grooves are formed in a carrier plate, and the ceramic core plates obtained in the step 2 are embedded into the grooves of the carrier plate; s4, a heating flowable medium is attached to the upper surface and / or the lower surface of the carrier plate where the ceramic core plate is embedded; s5, a semi-additive method or an improved semi-additive method is carried out on the carrier plate processed in the step S4 to prepare a layer-adding wiring layer, the layer-adding wiring layer comprises a layer-adding dielectric layer, layer-adding via holes and layer-adding conductive wires, the layer-adding conductive wires are connected with the core plate surface conductive wires through the layer-adding via holes, and middle bonding layers are arranged between the layer-adding via holes and the core plate surface conductive wires; and obtaining the ceramic core packaging substrate.

Description

Technical Field

[0001] The invention belongs to the field of microelectronic packaging substrates, and in particular relates to a ceramic core packaging substrate and a preparation method thereof. Background Art

[0002] The packaging substrate is an important component of the semiconductor package, which is used to carry the chip and provide electrical connection, protection, mechanical support and heat dissipation for the chip. With the development of semiconductor technology, in order to realize SiP microsystem integration and three-dimensional advanced packaging and other technical routes to meet the needs of high-end applications such as 5G communication, high-performance computing, and high-speed signal processing, the advanced industry has put forward higher requirements on the wiring density and heat dissipation performance of the packaging substrate.

[0003] According to the different substrate materials, packaging substrates can be mainly divided into two categories: ceramic substrates and organic substrates. Among them, ceramic substrates include low-fired ceramic substrates (LTCC) and high-fired ceramic substrates (HTCC); organic substrates include ABF boards, BT boards, PI flexible substrates, etc. Ceramic substrates have the advantages of matching the thermal expansion coefficient (CTE) of silicon, high thermal conductivity, and good heat dissipation and heat distribution performance. However, due to the limitations of the thick film sintering process, its wiring density is low (line width and line spacing are usually less than 75 microns), and the pad pitch is large (usually greater than 200 microns), which cannot meet the packaging requirements of multi-I / O and fine-pitch chips. Organic substrates are usually manufactured using thin-film wiring processes such as additive method (SAP) and modified semi-additive method (MSAP), which can obtain higher wiring density (less than 10 microns) and small pad pitch (less than 50 microns), but due to the low thermal conductivity of organic materials, the heat dissipation performance of organic substrates is relatively poor.

[0004] In order to combine the advantages of thermal conductivity, CTE and high-density wiring, the industry has proposed a thick / thin film hybrid substrate manufacturing process, that is, on a ceramic substrate with thick film wiring, a thin film wiring process is used to prepare one or more layers of high-density conductive lines. However, the current manufacturing process is incompatible with conventional substrate manufacturing processes and cannot be mass-produced with conventional substrate production equipment. Summary of the invention

[0005] The purpose of the present invention is to propose a ceramic core packaging substrate and a manufacturing method thereof in order to address the problem that the existing thick-film hybrid substrate manufacturing process is incompatible with the conventional substrate manufacturing process and cannot be mass-produced with the help of conventional substrate production equipment. The ceramic core packaging substrate proposed in the present invention is compatible with the conventional substrate manufacturing process and can be mass-produced, and the substrate structure has the advantages of the ceramic substrate's heat dissipation and thermal expansion coefficient matching and the advantage of high-density thin-film wiring.

[0006] To achieve the above object, the technical solution of the present invention is:

[0007] A method for preparing a ceramic core packaging substrate comprises the following steps:

[0008] S1: manufacturing a ceramic core plate by a ceramic substrate sintering process, wherein the ceramic core plate is provided with internal conductive wires and internal conductive holes, and the upper surface and / or the lower surface of the ceramic core plate is provided with core plate surface conductive wires;

[0009] S2: preparing an intermediate bonding layer on the conductive line on the core surface of the ceramic core board by a metal lift-off process;

[0010] S3: opening a plurality of grooves on a carrier plate, and embedding the ceramic core plate obtained in step 2 into the grooves of the carrier plate, wherein the thickness of the carrier plate is not less than the thickness of the ceramic core plate;

[0011] S4: applying a heated flowable medium to the upper surface and / or lower surface of the carrier plate embedded with the ceramic core plate, and applying pressure and heating to allow the medium to flow and fill the gap between the core plate and the carrier plate slot and level it;

[0012] S5: Implementing a semi-additive process (SAP) or a modified semi-additive process (MSAP) on the carrier board processed in step S4 to prepare at least one build-up wiring layer, wherein the build-up wiring layer includes a build-up dielectric layer, a build-up via and a build-up conductive wire, wherein the build-up conductive wire is connected to the conductive wire on the surface of the core board through the build-up via, and the intermediate bonding layer is provided between the build-up via and the conductive wire on the surface of the core board, thereby obtaining the ceramic core packaging substrate.

[0013] Preferably, the method further comprises step S6: preparing a pad on the outermost layer of the build-up wiring layer, cutting the carrier board, and releasing the ceramic core package substrate.

[0014] Preferably, the ceramic core board described in step S1 is a high-temperature co-fired ceramic substrate, and the internal conductive wires, internal conductive holes and conductive wires on the surface of the core board in the ceramic core board are sintered with gold paste.

[0015] Preferably, in step S2, the intermediate bonding layer comprises at least one adhesion layer, or the intermediate bonding layer comprises at least one adhesion layer and a seed layer located on the adhesion layer;

[0016] The material of the adhesion layer is nickel, chromium, palladium or platinum, and the seed layer is copper, gold or silver.

[0017] Preferably, the material of the carrier plate in step S3 is metal or resin-glass fiber cloth composite material.

[0018] Preferably, the step S4 specifically comprises: laminating ABF medium on the upper surface and / or lower surface of the carrier plate embedded with the ceramic core plate, and forming an ABF film after laminating and leveling, wherein the laminating method is airbag pressing, and the leveling method is mirror steel plate flattening.

[0019] Based on the same inventive concept, the present invention also provides a ceramic core package substrate, comprising a ceramic core board and a plurality of build-up wiring layers;

[0020] The ceramic core plate is provided with internal conductive wires and internal conducting holes inside, and the upper surface and / or lower surface of the ceramic core plate is provided with core plate surface conductive wires;

[0021] The build-up wiring layer is located on the upper surface and / or lower surface of the ceramic core board, and the build-up wiring layer includes a build-up dielectric layer, a build-up via and a build-up conductive wire. The build-up conductive wire is connected to the conductive wire on the surface of the core board through the build-up via, and an intermediate bonding layer is arranged between the build-up via and the conductive wire on the surface of the core board.

[0022] Preferably, the intermediate bonding layer is a multi-layer structure, including at least one adhesive layer, or the intermediate bonding layer includes at least one adhesive layer and a seed layer located on the adhesive layer;

[0023] The material of the adhesion layer is nickel, chromium, palladium or platinum, and the material of the adhesion layer is copper, gold or silver.

[0024] Preferably, the ceramic core board is a low-temperature co-fired ceramic substrate or a high-temperature co-fired ceramic substrate, and the internal conductive wires, internal conductive holes and conductive wires on the surface of the core board are formed by thick film firing.

[0025] Preferably, the build-up dielectric layer is made of ABF, polyimide or prepreg.

[0026] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0027] (1) An intermediate bonding layer is prepared at the location where the build-up vias are to be connected on the conductive line on the surface of the core board. The intermediate bonding layer can be a multilayer structure of several adhesion layers or an adhesion layer and a seed layer, which can solve the bonding problem between the thick film layer sintered by ceramic and the build-up vias prepared by SAP and MSAP processes.

[0028] (2) Since the ceramic core surface has tiny pits, it is difficult to ensure the consistency of the removal of the excess metal layer in the pits after the metal layer is prepared by sputtering or evaporation on the ceramic surface. The present invention uses the lift-off process to prepare the intermediate bonding layer on the conductive wire on the core surface, which can avoid the step of removing the metal layer on the ceramic surface.

[0029] (3) Grooves are made on the carrier board, and multiple ceramic substrates are embedded in the carrier board. Since the carrier board is made of materials such as metal, epoxy resin and glass fiber composite board, it has a certain strength and can withstand large deformation. The assembled whole board can be wired with thin films using conventional substrate thin film wiring equipment and processes to achieve mass production.

[0030] (4) A heated flowable dielectric film is laminated on one or both sides of the carrier plate embedded with the ceramic core plate. After heating, the dielectric film can flow to fill the gap between the core plate and the carrier plate slot, thereby avoiding deflection, movement and gap problems caused by the embedded structure in subsequent processes.

[0031] (5) Compared with the existing thick / thin film hybrid substrate manufacturing process, the present invention can conveniently implement double-sided processes such as double-sided lamination, double-sided flattening, and double-sided through-hole metallization with the help of SAP or MSAP equipment, thereby improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the structure of the ceramic core package substrate in Embodiment 1-2 of the present invention;

[0033] Figure 2 Schematic diagram of the structure of the ceramic core plate in Example 1-2 of the present invention;

[0034] Figure 3 A schematic diagram of the lift off process flow in the method for preparing a ceramic core packaging substrate provided in Example 2 of the present invention;

[0035] Figure 4 A schematic diagram of a build-up wiring process of a ceramic core board in a method for preparing a ceramic core package substrate provided in Example 2 of the present invention;

[0036] Description of reference numerals:

[0037] 1: Ceramic core board; 11: Internal conductive wire; 12: Internal conductive hole; 13: Conductive wire on the surface of the core board; 2: Build-up wiring layer; 21: Build-up dielectric layer; 22: Build-up via hole; 23: Build-up conductive wire; 24: Upper fixing screw hole; 3: Middle bonding layer; 31: Photoresist; 4: Carrier board. DETAILED DESCRIPTION

[0038] The following is a further detailed description of a ceramic core package substrate and a preparation method thereof proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description.

[0039] Example 1

[0040] See also Figure 1-2 , a ceramic core package substrate, comprising a ceramic core board 1 and a plurality of build-up wiring layers 2;

[0041] The ceramic core board 1 is provided with internal conductive wires 11 and internal conducting holes 12, and the upper surface and / or lower surface of the ceramic core board 1 is provided with core board surface conductive wires 13;

[0042] The build-up wiring layer 2 is located on the upper surface and / or lower surface of the ceramic core board 1. The build-up wiring layer 2 includes a build-up dielectric layer 21, a build-up via 22 and a build-up conductive wire 23. The build-up conductive wire 23 is connected to the core board surface conductive wire 13 through the build-up via 22, and an intermediate bonding layer 3 is arranged between the build-up via 22 and the core board surface conductive wire 13.

[0043] An intermediate bonding layer 3 is prepared at the position where the build-up via 22 needs to be connected on the conductive wire 13 on the surface of the core board. The intermediate bonding layer 3 can be a multilayer structure of several adhesion layers or adhesion layers and seed layers, which can solve the bonding force problem between the ceramic sintered thick film layer and the build-up via 22 prepared by SAP and MSAP processes.

[0044] Preferably, the intermediate bonding layer 3 is a multi-layer structure, including at least one adhesive layer, or the intermediate bonding layer 3 includes at least one adhesive layer and a seed layer located on the adhesive layer;

[0045] The material of the adhesion layer is nickel, chromium, palladium or platinum, and the material of the adhesion layer is copper, gold or silver; more preferably, the adhesion layer is nickel and the seed layer is copper.

[0046] Preferably, the ceramic core board 1 is a low-temperature co-fired ceramic substrate or a high-temperature co-fired ceramic substrate, and the internal conductive wires 11, the internal vias 12 and the core board surface conductive wires 13 are formed by thick film firing.

[0047] Preferably, the build-up dielectric layer 21 is made of ABF, polyimide or prepreg.

[0048] Example 2

[0049] A method for preparing a ceramic core packaging substrate comprises the following steps:

[0050] S1: a ceramic core board 1 is manufactured by a ceramic substrate sintering process, wherein an internal conductive line 11 and an internal conductive hole 12 are arranged inside the ceramic core board 1, and a core board surface conductive line 13 is arranged on the upper surface and / or the lower surface of the ceramic core board 1;

[0051] S2: preparing an intermediate bonding layer 3 on the conductive wire 13 on the core board surface of the ceramic core board 1 by a metal lift-off process;

[0052] Specific reference Figure 3 , firstly, the photoresist 31 on the ceramic core board 1 is patterned and exposed, and then the exposed photoresist 31 is removed by development, and then a film is formed, and finally the remaining photoresist 31 and the film on the photoresist 31 are peeled off, and the film remaining on the conductive line 13 on the surface of the core board is the intermediate bonding layer 3;

[0053] Continue to view Figure 4, S3: opening a plurality of grooves on the carrier board 4, and embedding the ceramic core board 1 obtained in step 2 into the grooves of the carrier board 4, wherein the thickness of the carrier board 4 is not less than the thickness of the ceramic core board 1;

[0054] S4: applying a heated flowable medium to the upper surface and / or lower surface of the carrier plate 4 embedded in the ceramic core plate 1, and applying pressure and heating to make the medium flow to fill the gap between the core plate and the slot of the carrier plate 4 and level it, so as to form a flowable medium film;

[0055] S5: Implementing a semi-additive process (SAP) or a modified semi-additive process (MSAP) on the carrier board 4 after the processing in step S4 to prepare at least one build-up wiring layer 2, wherein the build-up wiring layer 2 includes a build-up dielectric layer 21, a build-up via 22, and a build-up conductive wire 23, wherein the build-up conductive wire 23 is connected to the core board surface conductive wire 13 through the build-up via 22, and an intermediate bonding layer 3 is provided between the build-up via 22 and the core board surface conductive wire 13, and the material of the build-up dielectric layer 21 is the flowable medium in step S4;

[0056] Step S6: preparing pads on the outermost layer of the build-up wiring layer 2, cutting the carrier board 4, and releasing the ceramic core package substrate.

[0057] Preferably, the ceramic core board 1 in step S1 is a high-temperature co-fired ceramic substrate, and the internal conductive wires 11, internal vias 12 and conductive wires 13 on the surface of the core board in the ceramic core board 1 are sintered by gold paste. Usually, the ceramic powder is first added to the organic binder and mixed to form a paste-like slurry, and then the slurry is scraped into sheets with a scraper, and then the sheet-like slurry is formed into a green body through a drying process; then, the conductive holes are drilled according to the design, and the silver paste is screen-printed for wiring and filling, and finally the green body is placed in a high-temperature furnace (1600°C) for sintering to form a ceramic core board 1 with internal conductive wires 11, internal vias 12 and conductive wires 13 on the surface of the core board.

[0058] Preferably, in step S2, the intermediate bonding layer 3 includes at least one adhesion layer, or the intermediate bonding layer 3 includes at least one adhesion layer and a seed layer located on the adhesion layer;

[0059] The material of the adhesion layer is nickel, chromium, palladium or platinum, and the seed layer is copper, gold or silver; more preferably, the adhesion layer is nickel, and the seed layer is copper.

[0060] Preferably, the material of the carrier plate 4 in step S3 is metal or resin-glass fiber cloth composite material.

[0061] Preferably, step S4 specifically comprises: laminating ABF medium on the upper surface and / or lower surface of the carrier plate 4 embedded with the ceramic core plate 1, and forming an ABF film after laminating and leveling, wherein the laminating method is airbag pressing, and the leveling method is mirror steel plate flattening.

[0062] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the protection scope of the present invention.

Claims

1. A method for preparing a ceramic core packaging substrate, characterized in that: The following steps are involved: S1: manufacturing a ceramic core plate by a ceramic substrate sintering process, wherein the ceramic core plate is provided with internal conductive wires and internal conductive holes, and the upper surface and / or the lower surface of the ceramic core plate is provided with core plate surface conductive wires; S2: preparing an intermediate bonding layer on the conductive lines on the core surface of the ceramic core by a metal stripping process; S3: opening a plurality of grooves on a carrier plate, and embedding the ceramic core plate obtained in step 2 into the grooves of the carrier plate, wherein the thickness of the carrier plate is not less than the thickness of the ceramic core plate; S4: applying a heated flowable medium to the upper surface and / or lower surface of the carrier plate embedded with the ceramic core plate, and applying pressure and heating to allow the medium to flow and fill the gap between the core plate and the carrier plate slot and level it; S5: Implementing a semi-additive method or a modified semi-additive method on the carrier board processed in step S4 to prepare at least one build-up wiring layer, wherein the build-up wiring layer includes a build-up dielectric layer, a build-up via and a build-up conductive wire, wherein the build-up conductive wire is connected to the conductive wire on the surface of the core board through the build-up via, and an intermediate bonding layer is provided between the build-up via and the conductive wire on the surface of the core board, thereby obtaining the ceramic core packaging substrate.

2. The method for preparing a ceramic core package substrate according to claim 1, characterized in that: The method further includes step S6: preparing a pad on the outermost layer of the build-up wiring layer, cutting the carrier board, and releasing the ceramic core package substrate.

3. The method for preparing a ceramic core package substrate according to claim 1 or 2, characterized in that: The ceramic core board described in step S1 is a high-temperature co-fired ceramic substrate, and the internal conductive wires, internal conductive holes and conductive wires on the surface of the core board in the ceramic core board are sintered with gold paste.

4. The method for preparing a ceramic core package substrate according to claim 1, characterized in that: In step S2, the intermediate bonding layer includes at least one adhesion layer, or the intermediate bonding layer includes at least one adhesion layer and a seed layer located on the adhesion layer; The material of the adhesion layer is nickel, chromium, palladium or platinum, and the seed layer is copper, gold or silver.

5. The method for preparing a ceramic core package substrate according to claim 1, characterized in that: The material of the carrier plate in step S3 is metal or resin-glass fiber cloth composite material.

6. The method for preparing a ceramic core package substrate according to claim 1, characterized in that: The step S4 specifically includes: laminating ABF medium on the upper surface and / or lower surface of the carrier plate embedded with the ceramic core plate, and forming an ABF film after laminating and leveling, wherein the laminating method is airbag pressing, and the leveling method is mirror steel plate flattening.

7. A ceramic core package substrate, characterized in that: It includes a ceramic core board and several build-up wiring layers; The ceramic core plate is provided with internal conductive wires and internal conducting holes, and the ceramic core plate comprises a first surface and a second surface opposite to each other, and the first surface and / or the second surface are provided with core plate surface conductive wires; The build-up wiring layer is located on the first surface and / or the second surface of the ceramic core board, and the build-up wiring layer includes a build-up dielectric layer, a build-up via and a build-up conductive wire. The build-up conductive wire is connected to the conductive wire on the surface of the core board through the build-up via, and an intermediate bonding layer is arranged between the build-up via and the conductive wire on the surface of the core board.

8. The ceramic core package substrate according to claim 7, characterized in that: The intermediate bonding layer is a multi-layer structure, including at least one adhesive layer, or the intermediate bonding layer includes at least one adhesive layer and a seed layer located on the adhesive layer; The material of the adhesion layer is nickel, chromium, palladium or platinum, and the material of the adhesion layer is copper, gold or silver.

9. The ceramic core package substrate according to claim 7, characterized in that: The ceramic core board is a low-temperature co-fired ceramic substrate or a high-temperature co-fired ceramic substrate, and the internal conductive wires, internal conductive holes and conductive wires on the surface of the core board are formed by thick film firing.

10. The ceramic core package substrate according to claim 7 or 8, characterized in that: The material of the build-up dielectric layer is ABF, polyimide or prepreg.

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