CN-122028316-A - Circuit layer conduction copper-based circuit board manufacturing method and circuit board

CN122028316ACN 122028316 ACN122028316 ACN 122028316ACN-122028316-A

Abstract

The invention relates to the field of circuit boards and discloses a circuit board manufacturing method for conducting a copper base through a circuit layer and the circuit board, wherein the manufacturing method comprises the steps of forming a plurality of cavities at preset positions on a substrate structure formed by a copper plate, a dielectric layer and a copper foil, wherein the cavities penetrate through the dielectric layer and expose the surface of the copper plate; the method comprises a step of filling conductive paste into a cavity to form a filled conductive body for connecting the copper plate and the copper foil, a step of flattening, wherein the surface treatment is carried out on the area filled with the conductive paste to enable the upper surface of the filled conductive body and the upper surface of the copper foil to reach preset flatness, and a step of forming a circuit pattern on the copper foil. The circuit board is manufactured by the manufacturing method. The invention has the beneficial effects of successfully breaking through the contradiction that efficiency, cost and quality are difficult to be compatible in the prior art.

Inventors

LI PEICAN
JIANG JUNLIN
JIANG WEIHONG
CHEN XUDONG
WU ZURONG

Assignees

广东依顿电子科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260211

Claims (10)

1. The manufacturing method of the circuit board with the copper base conducted by the circuit layer is characterized by comprising the following steps of: A cavity forming step, namely forming a plurality of cavities at preset positions on a substrate structure formed by a copper plate, a dielectric layer and a copper foil, wherein each cavity penetrates through the dielectric layer and the copper foil and exposes the upper surface of the copper plate; a step of filling the cavity with conductive paste to form a filled type conductor connecting the copper plate and the copper foil; a flattening step, namely carrying out surface treatment on the area filled with the conductive paste to enable the upper surface of the filled conductive body and the upper surface of the copper foil to reach preset flatness; And a circuit forming step of forming a predetermined circuit pattern on the copper foil.
2. The method of manufacturing a circuit board with a copper-based circuit layer as defined in claim 1, wherein the cavity forming step includes forming a first opening at a predetermined position of the copper foil and removing all of the dielectric layer directly under the first opening to expose the copper plate surface, and the lower end of the filled via is in direct contact with the upper surface of the copper plate.
3. The method for manufacturing a circuit board with a copper base on which a circuit layer is conducted according to claim 1, wherein the cavity forming step comprises the steps of forming a first opening at a preset position of the copper foil, removing all the dielectric layers right below the first opening, drilling a groove on the copper plate by adopting laser, wherein the groove is located right below the first opening, the depth of the groove is larger than the thickness of the dielectric layers, and the lower end of the filled type conduction body is embedded into the copper plate.
4. The method for manufacturing a circuit board with a copper base on a circuit layer according to any one of claims 1 to 3, wherein in the step of filling the paste, the conductive paste is copper paste with a solid content of not less than 80%, and the cured copper paste forms the filled conductive body.
5. The method of manufacturing a circuit board with a copper-based circuit layer as defined in claim 4, wherein the planarizing step includes polishing the filled via, and a difference in height between an upper end surface of the filled via and an upper end surface of the copper foil is not more than 30 μm.
6. The method for manufacturing a circuit board with a copper base for conducting a circuit layer according to claim 3, wherein the bottom of the groove is provided with at least one step hole, and the filled conducting body is filled in the step hole.
7. The method of claim 1, further comprising a step of electroplating and thickening between the planarizing step and the circuit forming step, wherein the step of electroplating and thickening is performed on the copper foil surface and the filled conductive body surface once to uniformly thicken the surface copper layer.
8. A circuit board with a copper-based circuit layer, manufactured by the method for manufacturing the circuit board with the copper-based circuit layer according to any one of claims 1 to 7, comprising: Copper plate; The dielectric layer is arranged on the copper plate and is a prepreg; a copper foil disposed over the dielectric layer, the copper foil having a predetermined circuit pattern formed thereon; at least one filled conductor penetrating the dielectric layer and connecting the copper plate and the copper foil; The filling type conductive body is formed by solidifying conductive slurry filled in the cavity, and the height difference between the upper end surface of the filling type conductive body and the upper surface of the copper foil is not more than 30 mu m.
9. The circuit board of claim 8, wherein the copper plate is provided with a groove, at least one step hole is arranged in the groove, and the lower end of the filling type conduction body is embedded in the groove of the copper plate.
10. The wiring layer on copper-based wiring board according to claim 8, wherein a lower end of the filled via is in direct contact with an upper surface of the copper plate.

Description

Circuit layer conduction copper-based circuit board manufacturing method and circuit board Technical Field The invention relates to the field of circuit boards, in particular to a circuit board manufacturing method for conducting copper-based circuit layers and a circuit board. Background In electronic devices involving high-power heat dissipation (e.g., LED lighting, power modules), the use of a circuit board in which a circuit layer is electrically connected to a metal substrate (e.g., copper-based) is a key technology. The core of such boards is to build reliable vertical conductive structures (commonly referred to as bumps) in the dielectric layer to achieve electrical connection and heat dissipation between the upper layer wiring and the underlying copper base. The main technical idea of manufacturing such conductive structures in the industry is that pits/through holes are formed by etching or laser processing, or protrusions are formed by deforming a substrate by mechanical rolling, and the core step of finally realizing electrical connection is dependent on a selective electroplating thickening process, i.e. a copper layer is gradually accumulated in a specific area by chemical deposition and electroplating until a required conductor is formed or connected. However, this technical paradigm relying on selective plating thickening suffers from the following drawbacks. Firstly, the process is necessarily lengthy, and in order to fill a groove with a larger depth-width ratio or cover the side surface of a boss, repeated electroplating cycles are often needed, so that the production period is obviously prolonged. And secondly, the cost is high, the material utilization rate is low, a large amount of energy and chemical materials are consumed by multiple electroplating, and if the whole plate is adopted for electroplating, copper is also required to be etched for reducing, so that serious copper metal waste is caused. Furthermore, the intractable quality is derived, copper whiskers which are difficult to thoroughly remove are extremely easy to generate in the electroplating process, so that the copper whiskers become potential hidden hazards for causing short circuit of a circuit, meanwhile, the requirements of the process on the alignment precision, etching uniformity or rolling stress control of a previous pattern are extremely strict, and any deviation is easy to cause incomplete lamination or unreliable connection, so that the yield and long-term reliability of the product are finally reduced. Therefore, the prior art is always limited by the contradiction that the efficiency, the cost and the quality are difficult to be compatible. Disclosure of Invention In order to solve the technical problems, the invention aims to provide a circuit board manufacturing method for conducting copper-based circuit layers and a circuit board, which can reduce cost and improve material utilization rate, thoroughly avoid copper whiskers and improve cost and quality of products. The invention is realized by the following technical scheme: A method for manufacturing a circuit board with a circuit layer conducting copper base comprises a cavity forming step of forming a plurality of cavities at preset positions on a substrate structure formed by a copper plate, a dielectric layer and a copper foil, wherein the cavities penetrate through the dielectric layer and expose the surface of the copper plate, a slurry filling step of filling conductive slurry into the cavities to form a filled type conducting body for connecting the copper plate and the copper foil, a flattening step of carrying out surface treatment on a region filled with the conductive slurry to enable the upper surface of the filled type conducting body and the upper surface of the copper foil to reach preset flatness, and a circuit forming step of forming a preset circuit pattern on the copper foil. The invention has the beneficial effects that the novel process paradigm of filling the prefabricated cavity and the conductive paste is adopted, so that the rule avoids the traditional selective electroplating thickening technical route. The method comprises the steps of firstly filling slurry into a cavity to replace a lengthy multiple electroplating cycle, obviously shortening the production period, improving the efficiency, secondly obviously reducing the cost, improving the material utilization rate, avoiding the energy consumption and the material consumption of multiple electroplating, avoiding the metal waste caused by etching copper reduction after the whole plate electroplating, and eliminating the quality chronic diseases derived from the electroplating process. In some embodiments, the cavity forming step includes forming a first opening at a predetermined position of the copper foil and removing all of the dielectric layer directly under the first opening to expose the copper plate surface, the lower end of the filled via being in direct contact with t