JP2957747B2 - Method of manufacturing circuit board with circuit component mounting terminals - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a circuit board having terminals for mounting circuit components such as ICs. More specifically, in the present invention, a required circuit wiring pattern is formed on an insulating base material, one end of which is electrically connected to the circuit wiring pattern, and the other end of which is formed as described above. Insulation base
The present invention relates to a method for manufacturing a circuit board having a circuit component mounting terminal that can be formed so as to have a reliable connection pad or bump for a circuit component that penetrates and protrudes to the outside.

[0002]

2. Description of the Related Art As a method for manufacturing a circuit board having terminals for mounting circuit components such as an IC of this type, there is a method shown in FIG. In this method, as shown in FIG. 3A, first, a required circuit wiring pattern 22 is formed on one surface of a flexible or hard insulating base material 21, and the insulating base material 21 is formed. On the other surface, a metal mask 23 for shielding excimer laser light is formed. In this metal mask 23,
The circuit wiring pattern 22 is processed so as to form a hole 24 at a corresponding position, and a protective film 26 made of a polyimide film or the like is adhered to the surface of the circuit wiring pattern 22 using an adhesive 25. Thus, a surface protection layer 27 is formed.

[0003] Next, as shown in FIG.
The conductive hole 28 reaching the circuit wiring pattern 22 is formed by irradiating the excimer laser light A from the side 3. Therefore,
After the unnecessary metal mask 23 is removed by means such as etching as shown in FIG. 3 (3), one end of the conductive hole 28 is electrically connected to the circuit wiring pattern 22 as shown in FIG. 4 (4). And connection pads or bumps 29 for a circuit component such as an IC having such a shape that the other end protrudes outside from the insulating base material 21 are formed by filling processing such as solder.

[0004]

In the above-described method, in the step of removing the metal mask 23, a part of the circuit wiring pattern 22 is also exposed to the etching solution and is damaged to form a recess 22A. In extreme cases, the circuit wiring pattern 22
There is also a risk that a through hole may be formed in the hole. The degree of the damage is determined by the processing layer applied to the back surface of the copper foil which is usually applied to improve the adhesion when the copper foil forming the circuit wiring pattern 22 and the polyimide film used for the insulating base material 21 are bonded. Of the metal mask 23, variations in the thickness of the metal mask 23 layer, variations in the degree of renewal of the etching solution inside the conductive holes 28, and the like.

The above-mentioned variation in the degree of damage to the circuit wiring pattern 22 located in the conduction hole 28 causes a variation in the size and height of the connection pads or bumps 29. It is not preferable because it causes connection failure when mounting circuit components.

[0006]

SUMMARY OF THE INVENTION The present invention reliably prevents a situation in which a circuit wiring pattern is damaged during an etching process for removing a metal mask. An object of the present invention is to provide a method of manufacturing a circuit board having a high-precision circuit component mounting terminal capable of suitably preventing a connection failure when mounting a component.

Therefore, according to the method of manufacturing a circuit board provided with circuit component mounting terminals of the present invention, a required circuit wiring pattern is formed on one surface of an insulating base material and the insulating base is formed. A metal mask is formed on the other surface of the base material, a hole is formed in the metal mask at a corresponding location where the circuit wiring pattern is located, and a separation groove hole having a shape adapted to the outer shape of the circuit board is formed. And then irradiating excimer laser light from the metal mask side to form a conduction hole reaching the circuit wiring pattern from the hole portion, and forming the conduction hole located at the separation groove hole. A separating groove is formed to penetrate the insulating base material, and then a conductive metal layer having high corrosion resistance is formed on the circuit wiring pattern exposed at the bottom of the conductive hole. And a resist on the conductive metal layer by an electrodeposition method. After the metal mask is removed by etching and the resist layer is peeled off, one end of the conductive hole is connected to the circuit wiring pattern via the corrosion-resistant conductive metal layer. Each step of forming connection pads or bumps for circuit components that are electrically joined together and whose other end protrudes outside the insulating base material is employed.

Here, when the back surface of the circuit wiring pattern is raised with a conductive metal layer, when the electrodeposition resist layer is selectively formed on the surface of the conductive metal layer, the conductive hole is formed. Because the electrodeposition resist liquid inside the inside of the electrodeposition renewal can be satisfactorily performed, air bubbles generated on the surface to be adhered, which is a problem at the time of using the electrodeposition resist, can be suitably removed, and therefore, the resist caused by air bubble entrapment can be removed. The occurrence of pinholes can be reliably suppressed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in further detail with reference to the illustrated embodiments. FIG. 1 is an enlarged cross-sectional view conceptually showing a main part of a circuit board provided with circuit component mounting terminals manufactured according to an embodiment of the present invention. A circuit wiring pattern 2 is formed at a required position on one side of the substrate, the pertinent portion of the back side being covered with a conductive metal layer 6 having corrosion resistance. A conductive hole 10 is formed in the insulating base material 1 at a corresponding position where the circuit wiring pattern 2 is located and reaches the conductive metal layer 6 from the upper surface of the insulating base material 1. One end of the conduction hole 10 is electrically connected to the circuit wiring pattern 2 via the conductive metal layer 6 and the other end projects outside the insulating base material 1.
It is configured to form connection pads or bumps 11 for circuit components such as. A protective film 8 such as a polyimide film is adhered to the surface side of the circuit wiring pattern 2 with an adhesive 7 to form a surface protective layer 9.
The surface protective layer 9 is not limited to the film member as described above, and may be formed by printing and applying a varnish-like polyimide resin, an insulating cover coat ink, or the like.

FIGS. 2 (1) to 2 (4) show a manufacturing process diagram for this purpose. First, as shown in FIG. 2 (1), for example, an adhesive or non-adhesive type flexible member is used. A material such as a double-sided copper-clad laminate, which is hard or hard, is prepared and subjected to a photo-etching process to form a required circuit wiring pattern 2 on one surface of the insulating base material 1; A metal mask 3 is formed on the side. The metal mask 3 is formed by etching so as to have a hole 4 at a corresponding position where the circuit wiring pattern 2 is located as shown in the figure and to have a separation groove 5 formed along the outer shape of the product. A surface protective layer 9 is formed on the surface of the circuit wiring pattern 2 by attaching a protective film 8 such as a polyimide film using an adhesive 7.

Therefore, as shown in FIG.
The light A is irradiated from the side of the metal mask 3 to form an IC to be described later.
Holes 1 for forming mounting terminals for circuit components such as
Ablation is formed with the separation groove 5A. As a result, the conduction hole 10 exposes a part of the circuit wiring pattern 2, and the separation groove 5A includes the insulating base material 1, the adhesive 8
And the protective film 8 is penetrated.

Next, as shown in FIG.
A conductive metal layer 6 such as gold, which is rich in corrosion resistance, is formed by plating or other means on the portion of the circuit wiring pattern 2 exposed at the bottom of the metal wiring pattern 2 and is further deposited on the surface of the conductive metal layer 6 by an electrodeposition method. A resist layer 12 is formed.

Then, as shown in FIG. 1D, the unnecessary metal mask 3 is removed by etching means, and the resist layer 12 formed by electrodeposition is peeled off. Next, by filling the conduction hole 10 with solder or the like, one end is electrically connected to the circuit wiring pattern 2 via the corrosion-resistant conductive metal layer 6 and the other end is insulated. It becomes possible to form connection pads or bumps 11 for circuit components such as ICs protruding outside the base material 1.

[0014]

According to the method of manufacturing a circuit board provided with circuit component mounting terminals according to the present invention, electrodeposition is performed with the back surface of the circuit wiring pattern raised with a corrosion-resistant conductive metal layer. Since the resist is selectively formed on the surface of the conductive metal layer, the renewal of the electrodeposition resist solution inside the conductive holes can be performed satisfactorily. Resist pinholes caused by the incorporation of bubbles generated on a certain adherend surface can be suitably suppressed, and there is no possibility that the circuit wiring pattern will be damaged when the metal mask is removed by etching. Variations in the depth of conduction holes for forming connection pads or bumps can be suitably suppressed.

Therefore, when connecting to a circuit component such as an IC,
To provide a circuit board having circuit component mounting terminals with extremely high connection reliability, because it is possible to reliably eliminate the variation in size and height in connection pads or bumps that cause connection failure. Is possible.

[Brief description of the drawings]

FIG. 1 is a conceptual enlarged cross-sectional configuration view of a principal part of a circuit board having circuit component mounting terminals manufactured according to an embodiment of the present invention.

FIG. 2 is a manufacturing process diagram of a circuit board provided with circuit component mounting terminals according to an embodiment of the present invention.

FIG. 3 is a manufacturing process diagram of a circuit board provided with circuit component mounting terminals according to a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulation base material 2 Circuit wiring pattern 3 Metal mask 4 Hole 5 Separation groove 5A Separation groove 6 Conductive metal layer 7 Adhesive 8 Protective film 9 Surface protective layer 10 Conducting hole 11 Connection pad or Bump 12 resist layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-323893 (JP, A) Patent 2539287 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) H05K 3/40 H05K 3/24 H01L 21/60

Claims (1)

(57) [Claims] A required circuit wiring pattern is formed on one surface of an insulating base material, and a metal mask is formed on the other surface of the insulating base material. In addition, a hole is formed at a corresponding position where the pin is located, and a separating groove hole having a shape conforming to the outer shape of the circuit board is formed. Then, excimer laser light is irradiated from the metal mask side to form the hole. Forming a conduction hole reaching the circuit wiring pattern from the portion, forming a separation groove penetrating the insulating base material portion located in the separation groove hole portion, and then forming the conduction hole; A conductive metal layer having high corrosion resistance is formed on the circuit wiring pattern exposed at the bottom, and a resist layer is formed on the conductive metal layer by an electrodeposition method. Etch and remove metal mask
After the resist layer is peeled off, one end of the conductive hole is electrically connected to the circuit wiring pattern via the corrosion-resistant conductive metal layer and the other end is connected to the insulating base. A method of manufacturing a circuit board having circuit component mounting terminals including a step of forming connection pads or bumps for circuit components protruding out of a material.