A method for preparing a ceramic high-density carrier board

Abstract

The present invention discloses a method for preparing a ceramic high-density carrier board, comprising: depositing copper foil on the ceramic carrier board; generating copper pillars on the copper foil; etching and removing the copper foil other than the copper pillars; using ABF laminating adhesive to press the ceramic carrier board so that the copper pillars are located in the ABF laminating adhesive; drilling holes on the side of the ceramic carrier board away from the copper pillars; depositing copper in the holes to form a circuit pattern connected to the copper pillars; bonding the circuit pattern to a chip. The present invention provides a method for preparing a ceramic high-density carrier board, using ABF laminating adhesive to press the ceramic carrier board to resist soldering.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor carriers, and in particular to a method for preparing a ceramic high-density carrier. Background Art

[0002] Semiconductor packaging technology continues to develop in the direction of miniaturization, light weight, high performance, multi-function and high reliability to meet the application needs of electronic information, power systems, national defense and military industries. The semiconductor packaging form has developed from the dual in-line package technology (DIP) invented in the 1960s to the present. Due to the increase in the number of chip I / Os, it has gone through the packaging forms of quad flat package (QFP), pin grid array package (PGA), ball grid array package (BGA) and system-level package (SiP). The package pin pitch has developed from 2.54mm to the current 15μm. In the future, the spacing between package pins will be further reduced to 10μm, or even lower.

[0003] The reduction in the gap between the package pins means that the density of the interconnection structure in the substrate increases. As the density of the interconnection structure in the substrate increases and the spacing between the pins in the substrate decreases, the difficulty in preparing the interconnection structure of the high-density interconnection substrate also increases. Conventional interconnection methods cannot ensure effective circuit connection of the high-density interconnection substrate, affecting the performance stability of the high-density interconnection substrate product. Summary of the invention

[0004] The present invention aims to solve at least one of the problems in the related art to a certain extent. To this end, the present invention aims to provide a method for preparing a ceramic high-density carrier board, using ABF lamination adhesive lamination to perform solder resistance on the ceramic carrier board.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical solution: a method for preparing a ceramic high-density carrier board, comprising:

[0006] depositing copper foil on a ceramic carrier;

[0007] Generating copper pillars on copper foil;

[0008] Etching to remove the copper foil except for the copper pillar;

[0009] ABF lamination adhesive is used to press the ceramic carrier board so that the copper pillar is located in the ABF lamination adhesive;

[0010] Drill holes on the side of the ceramic carrier away from the copper pillars;

[0011] Copper is deposited in the hole to form a circuit pattern connected to the copper column;

[0012] The circuit pattern is bonded to the chip.

[0013] Further, a copper pillar is generated on the copper foil, specifically comprising:

[0014] The copper foil on the protective film is laminated, exposed and developed to define the copper column area;

[0015] A copper pillar is formed by horizontal electroplating on the copper pillar area.

[0016] Furthermore, when the ABF laminating adhesive is pressed against the ceramic carrier, shaping plates are provided at the upper and lower ends of the pressing mold, and the end surfaces of the two shaping plates abutting against the ABF laminating adhesive or the ceramic carrier are parallel to each other.

[0017] Furthermore, a circuit pattern is formed in the hole by copper electroplating.

[0018] Furthermore, a circuit pattern is formed in the hole by copper electroplating, which specifically includes:

[0019] Drilling is performed by laser etching;

[0020] depositing a first copper layer horizontally within the hole;

[0021] forming a second copper layer by horizontal electroplating on the first copper layer;

[0022] The second copper layer protruding from the ceramic carrier is subjected to circuit etching to form a circuit pattern.

[0023] Furthermore, before depositing the first copper layer, the method further includes: plasma cleaning the ceramic carrier.

[0024] Furthermore, a solder resist is screen printed on the circuit pattern surface of the ceramic carrier.

[0025] Furthermore, the silk screen printing of solder resist also includes exposure and development to form solder resist windows.

[0026] Furthermore, an immersion gold treatment is performed at the position of the solder resist opening.

[0027] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art: the preparation method of the ceramic high-density carrier of the present application includes: depositing copper foil on the ceramic carrier; generating copper pillars on the copper foil; etching and removing the copper foil other than the copper pillars; using ABF laminating glue to press the ceramic carrier so that the copper pillars are located in the ABF laminating glue; drilling holes on the side of the ceramic carrier away from the copper pillars; depositing copper in the holes to form a circuit pattern connected to the copper pillars; bonding the circuit pattern to the chip. In the present application, ABF laminating glue is used to perform solder mask packaging on the ceramic carrier, and the chip is packaged using a ceramic carrier, and copper pillars and circuit patterns are formed on both sides of the ceramic carrier, respectively, the circuit pattern is used to bond with the chip, and the circuit pattern and copper pillars are used to lead out the signal in the chip; the method for forming copper pillars and circuit patterns in the present application is suitable for ceramic high-density carriers with small pin gaps, which improves the signal transmission stability of ceramic high-density carriers. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0030] In the attached figure:

[0031] Figure 1 Flow chart of the preparation method in Example 3. DETAILED DESCRIPTION

[0032] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings, are constructed and operated in a specific direction, and are only for the convenience of describing the present technical solution, rather than indicating that the mechanism or element referred to must have a specific direction, and therefore cannot be understood as a limitation to the present invention.

[0033] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intermediate elements. The terms "first", "second", "third", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third", etc. can explicitly or implicitly include one or more of the features. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0034] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, mechanisms, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0035] Example 1

[0036] The present application provides a method for preparing a ceramic high-density carrier board, comprising:

[0037] depositing copper foil on a ceramic carrier;

[0038] Generating copper pillars on copper foil;

[0039] Etching to remove the copper foil except for the copper pillar;

[0040] ABF lamination adhesive is used to press the ceramic carrier board so that the copper pillar is located in the ABF lamination adhesive;

[0041] Drill holes on the side of the ceramic carrier away from the copper pillars;

[0042] Copper is deposited in the hole to form a circuit pattern connected to the copper column;

[0043] The circuit pattern is bonded to the chip.

[0044] In the present application, ABF lamination glue is used to perform solder mask packaging on the ceramic carrier, the chip is packaged on the ceramic carrier, and copper pillars and circuit patterns are formed on both sides of the ceramic carrier, respectively. The circuit pattern is used for bonding with the chip, and the circuit pattern and copper pillars are used to lead out the signal in the chip; the method for forming the copper pillars and circuit patterns in the present application is suitable for high-density ceramic carriers with small pin gaps, which improves the signal transmission stability of high-density ceramic carriers.

[0045] Specifically, when the signal in the chip needs to be led out, the ABF laminate glue can be ground to expose the internal copper pillars.

[0046] Example 2

[0047] The present application provides a method for preparing a ceramic high-density carrier board, comprising:

[0048] S1: depositing copper foil on a ceramic carrier; specifically, the copper foil may be deposited on the ceramic carrier by using a copper electroplating method, or the copper foil may be directly pasted on the ceramic carrier.

[0049] S2: generating a copper pillar on the copper foil; specifically, the method of forming the copper pillar may include the following two methods:

[0050] First method:

[0051] The copper foil on the protective film is laminated, exposed and developed to define the copper pillar area. After exposure and development, the area where the copper pillar needs to be formed will be exposed, and the area where the copper pillar does not need to be formed will be covered by the dry film. The copper pillar area refers to the location where the copper pillar needs to be formed.

[0052] The copper pillars are formed by horizontal electroplating on the copper pillar area. Since the area where the copper pillars are not required to be formed is covered by the dry film, the copper pillars can be grown in the copper pillar area by horizontal electroplating.

[0053] The method of the present application adopts the exposure and development method to define the copper pillar area, which can ensure the accuracy of the position and size of the copper pillar area. The cross-sectional size of the copper pillar area defined by the exposure and development is equal to the size of the copper pillar grown subsequently. The copper pillar is generated on the copper pillar area by means of horizontal electroplating, which can further ensure the accuracy of the size and position of the copper pillar.

[0054] Second method:

[0055] Copper pillar areas are defined on the auxiliary film in sequence. The copper pillar areas here refer to the location areas where copper pillars need to be formed later. Defining the copper pillar areas refers to making special marks on the auxiliary film to facilitate confirmation of the subsequent copper pillar locations.

[0056] The copper paste is melted by laser, so that the molten copper paste drops dropwise onto the copper column area and solidifies to form a copper column.

[0057] The copper column formed by solidification and accumulation of the copper slurry is laser polished to form a cylindrical copper column.

[0058] The present application adopts a method of laser melting slurry to form the copper pillar, which can ensure the accuracy of the position of the copper pillar. Laser polishing of the formed copper pillar can ensure the accuracy of the size of the copper pillar.

[0059] In the present application, the height of the copper pillar can be specifically designed according to the packaging requirements.

[0060] S3: Etching to remove the copper foil outside the copper pillar; while stripping and flash etching to remove the dry film, etching to remove the copper foil outside the copper pillar.

[0061] S4: ABF lamination adhesive is used to press the ceramic carrier board so that the copper column is located in the ABF lamination adhesive.

[0062] In the present application, the ABF laminating adhesive is initially in a molten state and can be solidified and formed under a specific environment. In actual operation, the molten ABF laminating adhesive and the copper foil after the copper pillars are grown are pressed together, and the ABF laminating adhesive is solidified and wraps the copper pillars.

[0063] When the ABF laminating adhesive is pressed with the copper foil, shaping plates are arranged at the upper and lower ends of the pressing mold, and the end surfaces of the two shaping plates abutting against the ABF laminating adhesive or the protective film are parallel to each other, and the surfaces of the shaping plates contacting the ABF laminating adhesive or the protective film are smooth.

[0064] Specifically, both sides of the shaping plate have smooth surfaces, and the two shaping plates are respectively arranged at the upper and lower ends of the pressing mold. The ceramic carrier plate is placed on one of the shaping plates, and the copper column extends toward the other shaping plate. The molten ABF laminating glue is filled on the ceramic carrier plate and the copper column, and pressed at a set temperature so that the ABF laminating glue solidifies and wraps around the copper column.

[0065] The ABF lamination adhesive after lamination in this application completely wraps the copper pillar.

[0066] The flatness of the product end after lamination can be ensured by laminating with the help of a shaping plate. After lamination, the ABF laminating adhesive is solidified and the copper column is wrapped by the ABF laminating adhesive. At the same time, the top of the ABF laminating adhesive and the bottom of the protective film are parallel to each other and have good smoothness.

[0067] S5: drilling a hole on a side of the ceramic carrier away from the copper pillar; the drilling may be performed by laser etching.

[0068] S6: depositing copper in the hole to form a circuit pattern connected to the copper pillar; specifically including:

[0069] Plasma cleaning of the ceramic substrate to remove dust residue from laser drilling.

[0070] The first copper layer is deposited horizontally in the hole; specifically, the first copper layer can be deposited by a horizontal copper deposition process. The first copper layer is relatively thin and is a global deposition process. The first copper layer is located at the bottom of the hole and can be connected to the copper column.

[0071] The second copper layer is formed by horizontal electroplating on the first copper layer; the second copper layer is grown on the first copper layer in the hole by horizontal electroplating. The second copper layer needs to fill the hole. The first copper layer is deposited first, and then the second copper layer is deposited, which is conducive to the rapid and firm growth of the second copper layer. The second copper layer will overflow from the hole during the deposition process and deposit on the outside of the ceramic carrier.

[0072] The second copper layer protruding from the ceramic carrier is subjected to circuit etching to form a circuit pattern. Thus, the circuit pattern, the second copper layer, the first copper layer and the copper pillar in the ceramic carrier form an interconnection structure.

[0073] In this application, the circuit pattern is used for bonding with the chip.

[0074] In this application, the ceramic substrate is used to package the chip, and the ABF laminated adhesive further packages the chip and the ceramic substrate, and the ABF laminated adhesive also has the function of solder resistance. When the signal in the chip needs to be led out, the side of the ABF laminated adhesive away from the chip can be ground to expose the copper column.

[0075] In order to protect the circuit pattern, in the present application, solder mask can be screen-printed on the circuit pattern surface of the ceramic carrier, the solder mask layer can be exposed and developed to form solder mask windows, and then gold processing can be performed at the positions of the solder mask windows.

[0076] Example 3

[0077] like Figure 1 As shown, the present application provides a method for preparing a ceramic high-density carrier, comprising:

[0078] S1: depositing copper foil on a ceramic carrier. In the present application, the ceramic carrier may be HTCC (Low Temperature co-fired Ceramic) or LTCC (High Temperature co-fired Ceramic).

[0079] HTCC contains Al2O3, AlN, SiC, etc., and the sintering temperature is 1500~1900℃.

[0080] Advantages of Al2O3: low price, good comprehensive performance, good air tightness, good reliability, thermal conductivity is only 20W / m·K, dielectric constant is about 10, needs to be improved. It is easy to realize multilayering, mainly used for high-speed device packaging, such as high-frequency device input and output boards, optical communication devices, hybrid integrated circuits, etc.

[0081] AlN, with a thermal conductivity 20 times that of Al2O3 and a CTE matching that of silicon, has the advantages of high mechanical strength and small mass, and is a ceramic substrate for high-density, high-power electronic packaging. It is used in high-frequency devices, high-brightness LEDs, semiconductor laser devices, and high-power transistor devices.

[0082] SiC has mechanical strength second only to diamond, has excellent wear resistance and corrosion resistance, has the same thermal conductivity as Cu, CTE close to silicon, and a high dielectric constant, making it suitable for low-voltage circuits and high-heat dissipation devices.

[0083] LTCC: sintering temperature 850~950℃. Gold, silver and copper can be selected as conductor metals to form a more refined circuit pattern and achieve high-density wiring. It has a low dielectric constant, CTE close to silicon, and high mechanical strength. It is an important component for manufacturing complex integrated circuit chip products.

[0084] S2: Laminating, exposing and developing the copper foil to define the copper column area.

[0085] S3: Horizontally electroplating the copper pillar region to form a copper pillar.

[0086] S4: Etching to remove the copper foil except for the copper pillar.

[0087] S5: Use ABF build-up adhesive and copper foil to press together so that the copper pillar is located in the ABF build-up adhesive.

[0088] In the present application, the ABF laminating adhesive is initially in a molten state and can be solidified and formed under a specific environment. In actual operation, the molten ABF laminating adhesive and the copper foil after the copper pillars are grown are pressed together, and the ABF laminating adhesive is solidified and wraps the copper pillars.

[0089] When the ABF laminating adhesive is pressed with the copper foil, shaping plates are arranged at the upper and lower ends of the pressing mold, and the end surfaces of the two shaping plates abutting against the ABF laminating adhesive or the protective film are parallel to each other, and the surfaces of the shaping plates contacting the ABF laminating adhesive or the protective film are smooth.

[0090] Specifically, both sides of the shaping plate have smooth surfaces, and the two shaping plates are respectively arranged at the upper and lower ends of the pressing mold. The ceramic carrier plate is placed on one of the shaping plates, and the copper column extends toward the other shaping plate. The molten ABF laminating glue is filled on the ceramic carrier plate and the copper column, and pressed at a set temperature so that the ABF laminating glue solidifies and wraps around the copper column.

[0091] The ABF lamination adhesive after lamination in this application completely wraps the copper pillar.

[0092] The flatness of the product end after lamination can be ensured by laminating with the help of a shaping plate. After lamination, the ABF laminating adhesive is solidified and the copper column is wrapped by the ABF laminating adhesive. At the same time, the top of the ABF laminating adhesive and the bottom of the protective film are parallel to each other and have good smoothness.

[0093] S6: Laser drilling is performed on the side of the ceramic carrier away from the copper pillar.

[0094] S7: Plasma cleaning is performed on the ceramic carrier.

[0095] S8: Horizontally deposit copper in the hole to form a first copper layer.

[0096] S9: forming a second copper layer by horizontal electroplating on the first copper layer. The second copper layer and the first copper layer form an integrated interconnection layer.

[0097] S10: Etching the second copper layer to form a circuit pattern. The circuit pattern is used for bonding with the chip.

[0098] S11: Screen printing solder mask is performed on the circuit pattern surface of the ceramic substrate, and the solder mask layer is used to protect the circuit pattern.

[0099] S12: Expose and develop the solder resist layer to form solder resist openings, and then perform gold immersion treatment at the positions of the solder resist openings. The ceramic high-density carrier formed in this application is stored after testing.

[0100] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. A method for preparing a ceramic high-density carrier board, characterized in that: include: depositing copper foil on a ceramic carrier; Generating copper pillars on copper foil; Etching to remove the copper foil except for the copper pillar; ABF lamination adhesive is used to press the ceramic carrier board so that the copper pillar is located in the ABF lamination adhesive; Drill holes on the side of the ceramic carrier away from the copper pillars; The method of electroplating copper is used to form a circuit pattern in the hole, and a circuit pattern connected to the copper column is formed; specifically, the method includes: drilling a hole by laser etching; horizontally depositing a first copper layer in the hole; horizontally electroplating a second copper layer on the first copper layer; and performing circuit etching on the second copper layer protruding from the ceramic carrier to form a circuit pattern. The circuit pattern is bonded to the chip.

2. The method for preparing a ceramic high-density carrier board according to claim 1, characterized in that: Generate copper pillars on copper foil, including: The copper foil on the protective film is laminated, exposed and developed to define the copper column area; A copper pillar is formed by horizontal electroplating on the copper pillar area.

3. The method for preparing a ceramic high-density carrier according to claim 1, characterized in that: When the ABF laminating adhesive is pressed together with the ceramic carrier, shaping plates are arranged at the upper and lower ends of the pressing mold, and the end surfaces of the two shaping plates abutting against the ABF laminating adhesive or the ceramic carrier are parallel to each other.

4. The method for preparing a ceramic high-density carrier board according to claim 1, characterized in that: Before depositing the first copper layer, the method further includes: plasma cleaning the ceramic carrier.

5. The method for preparing a ceramic high-density carrier board according to claim 1, characterized in that: Screen printing solder mask is performed on the circuit pattern surface of the ceramic substrate.

6. The method for preparing a ceramic high-density carrier board according to claim 5, characterized in that: The silk screen printing solder resist also includes exposure and development to form solder resist windows.

7. The method for preparing a ceramic high-density carrier board according to claim 6, characterized in that: Perform immersion gold treatment at the location of the solder mask opening.

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