Circuit board structure without black oxide treatment and manufacturing method thereof

Abstract

A method for manufacturing a brown-free circuit board structure includes: providing a circuit board having a substrate and a circuit layer disposed on the substrate, wherein the circuit layer has circuit segments, the circuit segments having a circuit top surface and circuit sidewalls; using a pressing roller to lay a low-dielectric sheet on the circuit top surface of the circuit segments of the circuit layer, the low-dielectric sheet having a first insulating film; hot-pressing the low-dielectric sheet such that a first surface of the first insulating film adheres to the circuit top surface, circuit sidewalls, and substrate surface not covered by the circuit layer of the circuit segment; and pressing a prepreg sheet onto a second surface of the first insulating film, the prepreg sheet having glass fiber filaments, the first insulating film being disposed between the glass fiber filaments and the circuit layer to prevent the glass fiber filaments from contacting the circuit layer.

Claims

1. A method for manufacturing a brown-free circuit board structure, comprising: A circuit board (110) is provided, wherein the circuit board (110) has a substrate (112) and a circuit layer (114) disposed on the substrate (112), and the circuit layer (114) has a circuit segment (113), the circuit segment (113) has a circuit top surface (115) and a circuit sidewall (117) adjacent to the circuit top surface (115); a low dielectric sheet (210) is laid on the circuit top surface (115) of the circuit segment (113) of the circuit layer (114) using a pressing roller (200), wherein the low dielectric sheet (210) has a first insulating film (120) and a carrier film (220) attached to one side of the first insulating film (120) away from the circuit top surface (115); The low-dielectric sheet (210) is hot-pressed so that a first surface (122) of the first insulating film (120) of the low-dielectric sheet (210) is attached to the top surface (115) of the circuit section (113), the sidewall (117) of the circuit section (113), and a substrate surface (111) of the substrate (112) not covered by the circuit layer (114). The first insulating film (120) located on the sidewall (117) of the circuit section (113) is vertically connected to the top surface (115) of the circuit section (113) and the substrate (112). The substrate surface (111) of the first insulating film (120) has a thickness between 6 micrometers and 10 micrometers; and a semi-cured sheet (130) is pressed onto a second surface (124) of the first insulating film (120) relative to the first surface (122), wherein the semi-cured sheet (130) has a glass fiber filament (132), and the first insulating film (120) is disposed between the glass fiber filament (132) and the circuit layer (114) to prevent the glass fiber filament (132) from contacting the circuit segment (113) of the circuit layer (114).

2. The method for manufacturing a brown-free circuit board structure as described in claim 1 further includes: Before pressing the semi-cured sheet (130), the carrier film (220) of the low dielectric sheet (210) is removed to expose the second surface (124) of the first insulating film (120).

3. The method for manufacturing a brown-free circuit board structure as described in claim 1, wherein pressing the prepreg sheet (130) onto the second surface (124) of the first insulating film (120) further comprises: A second insulating film (140) and a copper foil layer (150) are pressed onto the side of the prepreg (130) away from the first insulating film (120), such that the glass fiber filaments (132) of the prepreg (130) are located between the first insulating film (120) and the second insulating film (140) to avoid the glass fiber filaments (132) from contacting the copper foil layer (150).

4. A method for manufacturing a brownless circuit board structure as described in claim 1, wherein before the low dielectric sheet (210) is thermo-pressed, the first insulating film (120) of the low dielectric sheet (210) does not contact the line sidewall (117) of the line segment (113) and the substrate surface (111) of the substrate (112).

5. The method for manufacturing a brownless circuit board structure as described in claim 1, wherein the heat-pressing process of the low dielectric sheet (210) is between 10 seconds and 150 seconds.

6. A method for manufacturing a brown-free circuit board structure as described in claim 1, wherein the temperature for hot-pressing the low-dielectric sheet (210) is between 100 and 160 degrees Celsius.

7. A brown-free circuit board structure, comprising: A circuit board (110) has a substrate (112) and a circuit layer (114) disposed on the substrate (112), wherein the circuit layer (114) has a circuit segment (113), the circuit segment (113) has a circuit top surface (115) and a circuit sidewall (117) adjacent to the circuit top surface (115); a first insulating film (120) has a first surface (122) and a second surface (124) opposite to the first surface (122), wherein the first surface (122) is attached to the circuit top surface (115) of the circuit segment (113), the circuit sidewall (117) and a substrate surface (111) of the substrate (112) not covered by the circuit layer (114). The first insulating film (120) located on the sidewall (117) of the circuit section (113) is vertically connected to the top surface (115) of the circuit section (113) and the substrate surface (111) of the substrate (112), and the thickness of the first insulating film (120) is between 6 micrometers and 10 micrometers; and a semi-cured sheet (130) is pressed onto the second surface (124) of the first insulating film (120) and has a glass fiber filament (132), wherein the first insulating film (120) is disposed between the glass fiber filament (132) and the circuit layer (114) to prevent the glass fiber filament (132) from contacting the circuit section (113) of the circuit layer (114).

8. The non-brown-coated circuit board structure as described in claim 7 further includes: A second insulating film (140) is pressed onto the side of the semi-cured sheet (130) away from the first insulating film (120); A copper foil layer (150) is disposed on the side of the second insulating film (140) away from the semi-cured sheet (130), wherein the glass fiber filaments (132) of the semi-cured sheet (130) are located between the first insulating film (120) and the second insulating film (140) to prevent the glass fiber filaments (132) from contacting the copper foil layer (150).

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