A multilayer via metallized aluminum-based printed board and a method for processing the same

Abstract

The application discloses a kind of multilayer hole metallized aluminum-based printed board and processing method thereof, the printed board includes multilayer aluminum substrate, multilayer the aluminum substrate is compressed together along vertical direction and forms printed board structure, both sides of each layer the aluminum substrate are compressed with copper foil, each layer copper foil is etched with circuit, the printed board structure is also opened with multiple process holes and functional holes along vertical direction, the process hole and the functional hole are filled with insulating resin along its inner wall, the inner wall of the insulating resin and the both sides of the printed board structure are also plated with continuous copper layer.The application can realize complex circuit interconnection under the premise of guaranteeing the heat dissipation performance of the whole printed board structure.

Description

Technical Field

[0001] This invention belongs to the field of printed circuit board technology, and particularly relates to a multilayer perforated aluminum-based printed circuit board and its processing method. Background Technology

[0002] Currently, existing aluminum-based printed circuit boards are single-sided boards and double-sided boards with metallized holes, as well as pseudo-multilayer boards with FR4 PCB boards and aluminum substrates laminated together without metallized holes. The applicant found that single- or double-sided aluminum substrates have limitations in design flexibility and cannot achieve interconnection of complex circuits. Although pseudo-multilayer aluminum substrates can achieve interconnection of complex circuits, their overall heat dissipation performance is limited. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art by providing a multi-hole metallized aluminum-based printed circuit board and its processing method, which ensures the overall heat dissipation performance of the printed circuit board structure while achieving complex circuit interconnection.

[0004] The objective of this invention is achieved through the following technical solution: A multilayer perforated aluminum-based printed circuit board includes multiple aluminum substrates, which are laminated together vertically to form a printed circuit board structure. Copper foil is laminated on both sides of each aluminum substrate layer, and circuits are etched on each copper foil layer. The printed circuit board structure also has multiple process holes and functional holes vertically formed. The process holes and functional holes are filled with insulating resin along their inner walls. A continuous copper layer is plated on the inner wall of the insulating resin and on both sides of the printed circuit board structure.

[0005] In one embodiment, both sides of the aluminum substrate are pressed together with the copper foil using insulating and thermally conductive adhesive.

[0006] A method for processing a multilayer perforated aluminum-based printed circuit board includes: During the copper foil lamination stage, a double-sided aluminum substrate is formed; Etching inner layer circuitry onto a double-sided aluminum substrate; Multiple double-sided aluminum substrates are pressed together in a vertical direction to form a printed circuit board structure. Multiple through-holes and functional holes are made on the printed circuit board; The inner walls of the process holes and functional holes are filled with insulating resin. Drilling holes in the insulating resin; Metallize the holes in the printed circuit board structure; Etch the outer layer circuitry onto the printed circuit board structure.

[0007] In one embodiment, the copper foil lamination stage includes: A copper foil is pressed onto the other side of a single-sided aluminum substrate using insulating and thermally conductive adhesive to form a double-sided aluminum substrate.

[0008] In one embodiment, the inner walls of the process holes and functional holes are filled with insulating resin, including: An air guide template is attached to one side of the printed circuit board structure. The air guide template has through holes corresponding to the positions of process holes and functional holes. The diameter of the through holes on the air guide template is smaller than the diameter of the process holes and functional holes corresponding to their positions. Insulating resin is filled into the process holes and functional holes along the side of the printed circuit board structure away from the air guide template. After the insulating resin has cured, the air guide template on the printed circuit board structure is removed.

[0009] In one embodiment, the diameter of the through hole on the air guide template is 0.1 mm.

[0010] In one embodiment, drilling holes in the insulating resin includes: Drill holes along the center of the insulating resin so that the diameter of the remaining insulating resin hole wall is not less than 100μm.

[0011] In one embodiment, the thermal conductivity of the insulating thermally conductive adhesive is 3-5 W / (m•K).

[0012] In one embodiment, hole metallization of the printed circuit board structure includes: A layer of metallic copper is plated along the inner wall of the insulating resin and extends to the surface of the printed circuit board structure.

[0013] The beneficial effects of this invention are as follows: The method involves pressing multiple aluminum substrates with copper foil on both sides together vertically to achieve complex circuit interconnection while improving overall heat dissipation. At the same time, the method uses a gas-conducting template to assist in sealing the holes with insulating resin and to drill holes in the insulating resin and then perform hole metallization to ensure that the multi-layer aluminum substrate is not corroded. This solves the technical problem of pressing multiple aluminum substrates together and performing hole metallization in the existing technology. Attached Figure Description

[0014] The invention will now be described in more detail with reference to embodiments and the accompanying drawings. Figure 1 A schematic diagram of the structure of the present invention is shown; Figure 2 A schematic diagram of the processing flow of the present invention is shown; In the accompanying drawings, the same parts use the same reference numerals. The drawings are not to scale.

[0015] Figure label: 1-Aluminum substrate, 2-Copper foil, 3-Insulating resin, 4-Insulating thermally conductive adhesive, 5-Metallic copper layer. Detailed Implementation

[0016] The invention will now be further described with reference to the accompanying drawings.

[0017] This invention provides a multilayer perforated aluminum-based printed circuit board, such as... Figure 1 As shown, it includes a multilayer aluminum substrate 1, which is laminated together in a vertical direction to form a printed circuit board structure. Copper foil 2 is laminated on both sides of each layer of aluminum substrate 1, and lines are etched on each layer of copper foil 2. Multiple process holes and functional holes are also opened in the vertical direction on the printed circuit board structure. The process holes and functional holes are filled with insulating resin 3 along their inner walls. Continuous metal copper layers 5 are also plated on the inner walls of the insulating resin 3 and on both sides of the printed circuit board structure. Specifically, in this embodiment, both sides of the aluminum substrate 1 are pressed together with the copper foil 2 by insulating thermally conductive adhesive 4; It should be noted that in this embodiment, the aluminum substrate 1 is protected by insulating resin 3, and a copper layer 5 is plated on the insulating resin 3 for conductivity. This fully utilizes the excellent heat dissipation performance of the aluminum substrate 1, while avoiding damage to the aluminum substrate 1 during etching and hole metallization. This allows the overall printed circuit board structure to achieve the interconnection of complex circuits and also has excellent overall heat dissipation performance. In one embodiment, the present invention also provides a method for processing a multilayer perforated aluminum-based printed circuit board, comprising: During the copper foil lamination stage, a double-sided aluminum substrate is formed; Etching inner layer circuitry onto a double-sided aluminum substrate; Multiple double-sided aluminum substrates are pressed together in a vertical direction to form a printed circuit board structure. Multiple through-holes and functional holes are made on the printed circuit board; The inner walls of the process holes and functional holes are filled with insulating resin. Drilling holes in the insulating resin; Metallize the holes in the printed circuit board structure; Etching the outer layer circuitry onto the printed circuit board structure; Specifically, taking a single-sided aluminum substrate as an example, a printed circuit board structure with a four-layer aluminum substrate is fabricated, such as... Figure 2 As shown, it includes: (a) A single-sided aluminum substrate is provided, which is composed of an aluminum substrate and a copper foil pressed on one side thereon; (b) Copper foil is pressed onto the other side of a single-sided aluminum substrate using insulating and thermally conductive adhesive to form a double-sided aluminum substrate; (c) Etching inner layer circuits L2 and L3 on a double-sided aluminum substrate; (d) The L1-L4 aluminum substrates are laminated vertically to form a printed circuit board structure; (e) Multiple process holes and functional holes are made in the printed circuit board structure to penetrate the aluminum substrates of layers L1-L4. (f) Fill the inner walls of the process holes and functional holes with insulating resin; (g) Perform secondary drilling on the insulating resin; (h) Metallize the holes in the printed circuit board structure; (i) Etch outer layer circuits L1 and L4 on the printed circuit board structure; It should be noted that in this embodiment, multiple aluminum substrates with copper foil on both sides are pressed together in the vertical direction to achieve complex circuit interconnection while improving the overall heat dissipation performance. At the same time, the process of using a gas-conducting template to assist in sealing the holes with insulating resin and drilling holes in the insulating resin and performing hole metallization ensures that the multi-layer aluminum substrate is not corroded, thus solving the technical problem of pressing multiple aluminum substrates together and performing hole metallization in the prior art. Specifically, in this embodiment, the inner walls of the process holes and functional holes are filled with insulating resin, including: A gas guide template is attached to one side of the printed circuit board structure. The gas guide template has through holes corresponding to the positions of process holes and functional holes. The diameter of the through holes on the gas guide template is smaller than the diameter of the process holes and functional holes corresponding to their positions. Insulating resin is filled into the process holes and functional holes along the side of the printed circuit board structure away from the gas guide template. After the insulating resin has cured, the gas guide template on the printed circuit board structure is removed. It should be noted that the optimal diameter of the through hole on the air guide template is 0.1mm to prevent the insulating resin from sinking and creating voids in the hole when filling it. Specifically, in this embodiment, a hole is drilled along the center of the insulating resin so that the diameter of the remaining insulating resin hole wall is not less than 100μm, ensuring the wall thickness of the insulating resin after secondary drilling. In one embodiment, the thermal conductivity of the insulating thermally conductive adhesive is 3-5 W / (m•K). That is, for multilayer aluminum substrates, the thermal conductivity of the insulating thermally conductive adhesive used to bond different aluminum substrates must be controlled at 3-5 W / (m•K), and the filling performance of the thermally conductive adhesive must be good so that the two metal substrates can be perfectly bonded together. In one embodiment, when drilling a second hole in the insulating resin, based on equipment precision and process reliability, the diameter of the first hole needs to be larger than the diameter of the second hole, and the smaller hole is drilled out in the center compared to the larger hole. In one embodiment, due to the characteristics of aluminum, the edges of the board are sealed for protection during acid and alkali treatment steps such as etching the inner layer and metallizing the holes. The sealing material can be a tape with good corrosion resistance. In one embodiment, hole metallization of the printed circuit board structure includes: A layer of metallic copper is plated along the inner wall of the insulating resin and extends to the surface of the printed circuit board structure.

[0018] In the description of this invention, it should be understood that the terms "upper", "lower", "bottom", "top", "front", "rear", "inner", "outer", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0019] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A multilayer perforated aluminum-based printed circuit board, characterized in that, The circuit includes a multilayer aluminum substrate, wherein the multiple aluminum substrates are laminated together in a vertical direction to form a printed circuit board structure. Copper foil is laminated on both sides of each aluminum substrate layer, and circuits are etched on each copper foil layer. The printed circuit board structure also has multiple process holes and functional holes in a vertical direction. The process holes and functional holes are filled with insulating resin along their inner walls. A continuous copper layer is plated on the inner wall of the insulating resin and on both sides of the printed circuit board structure.

2. The multilayer perforated aluminum-based printed circuit board according to claim 1, characterized in that, Both sides of the aluminum substrate are pressed together with the copper foil using insulating and thermally conductive adhesive.

3. A method for processing a multi-hole metallized aluminum-based printed circuit board, used to process the multi-hole metallized aluminum-based printed circuit board as described in claim 1 or 2, characterized in that, include: During the copper foil lamination stage, a double-sided aluminum substrate is formed; Etching inner layer circuitry onto a double-sided aluminum substrate; Multiple double-sided aluminum substrates are pressed together in a vertical direction to form a printed circuit board structure. Multiple through-holes and functional holes are made on the printed circuit board; The inner walls of the process holes and functional holes are filled with insulating resin. Drilling holes in the insulating resin; Metallize the holes in the printed circuit board structure; Etch the outer layer circuitry onto the printed circuit board structure.

4. The processing method of a multilayer perforated metallized aluminum-based printed circuit board according to claim 3, characterized in that, The copper foil lamination stage includes: A copper foil is pressed onto the other side of a single-sided aluminum substrate using insulating and thermally conductive adhesive to form a double-sided aluminum substrate.

5. The processing method of a multilayer perforated aluminum-based printed circuit board according to claim 4, characterized in that, The inner walls of the process holes and functional holes are filled with insulating resin, including: An air guide template is attached to one side of the printed circuit board structure. The air guide template has through holes corresponding to the positions of process holes and functional holes. The diameter of the through holes on the air guide template is smaller than the diameter of the process holes and functional holes corresponding to their positions. Insulating resin is filled into the process holes and functional holes along the side of the printed circuit board structure away from the air guide template. After the insulating resin has cured, the air guide template on the printed circuit board structure is removed.

6. The processing method of a multilayer perforated aluminum-based printed circuit board according to claim 5, characterized in that, The diameter of the through hole on the air guide template is 0.1 mm.

7. The processing method of a multilayer perforated aluminum-based printed circuit board according to claim 6, characterized in that, Drilling holes in insulating resin includes: Drill holes along the center of the insulating resin so that the diameter of the remaining insulating resin hole wall is not less than 100μm.

8. The processing method of a multilayer perforated aluminum-based printed circuit board according to claim 4, characterized in that, The thermal conductivity of the insulating thermally conductive adhesive is 3-5 W / (m•K).

9. The processing method of a multilayer perforated aluminum-based printed circuit board according to claim 3, characterized in that, Hole metallization of printed circuit board structures includes: A layer of metallic copper is plated along the inner wall of the insulating resin and extends to the surface of the printed circuit board structure.

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