CN205491438U - A new multi-layer flexible circuit board structure - Google Patents

Abstract

The utility model discloses a novel multilayer flexible circuit board structure, it includes from last to the first copper foil layer of stacking arrangement in proper order down, FR4 reinforcement sheet layer, first AD glue film, first PI reinforcement sheet layer, second AD glue film, second copper foil layer, second PI reinforcement sheet layer, third copper foil layer, third AD glue film, third PI reinforcement sheet layer, fourth copper foil layer, the thickness value of second PI reinforcement sheet layer is 12.5 microns, the thickness value of third copper foil layer is 18 microns, the thickness value of third AD glue film is 25 microns, the thickness value of third PI reinforcement sheet layer is 12.5 microns, the thickness value of fourth copper foil layer is 12 microns; the lower surface of the fourth copper foil layer is provided with a first blind hole and a second blind hole, the depth value of the first blind hole is 49.5 micrometers, the depth value of the second blind hole is 80 micrometers, and the diameter values of the first blind hole and the second blind hole are 100 micrometers respectively. Through the design, the utility model has the advantages of reasonable in design, yields are high and the steady quality.

Description

A new multi-layer flexible circuit board structure

technical field

The utility model relates to the technical field of flexible circuit boards, in particular to a novel multilayer flexible circuit board structure.

Background technique

As an important type of circuit board structure, flexible circuit board (FPC) is widely used in electronic products; and with the gradual development of electronic products in the direction of thinning and miniaturization, the application of flexible circuit boards is becoming more and more extensive .

For the existing multi-layer flexible circuit board, because the depth of the blind hole is too deep, the activity of the electroplating solution is too weak to fill the blind hole with copper, and the defective rate of the manufactured FPC product is extremely high and there are quality risks.

Utility model content

The purpose of the utility model is to provide a novel multi-layer flexible circuit board structure in view of the deficiencies in the prior art. The novel multi-layer flexible circuit board structure has reasonable design, high yield rate and stable quality.

In order to achieve the above object, the utility model is realized through the following technical solutions.

A new multi-layer flexible circuit board structure, including the first copper foil layer, the FR4 reinforcement layer, the first AD adhesive layer, the first PI reinforcement layer, and the second AD adhesive layer that are stacked sequentially from top to bottom layer, the second copper foil layer, the second PI reinforced layer, the third copper foil layer, the third AD adhesive layer, the third PI reinforced layer, the fourth copper foil layer, the second PI reinforced layer The thickness value is 12.5 microns, the thickness of the third copper foil layer is 18 microns, the thickness of the third AD adhesive layer is 25 microns, the thickness of the third PI reinforcing plate layer is 12.5 microns, and the thickness of the fourth copper foil layer The value is 12 microns;

The lower surface of the fourth copper foil layer is provided with a first blind hole and a second blind hole beside the first blind hole, the depth of the first blind hole is 49.5 microns and the first blind hole is formed from the fourth copper foil The lower surface extends to the lower surface of the third copper foil layer, the depth of the second blind hole is 80 microns and the second blind hole extends from the lower surface of the fourth copper foil layer to the lower surface of the second copper foil layer, the first The diameters of the blind hole and the second blind hole are respectively 100 microns.

Wherein, the thickness of the first copper foil layer is 35 microns.

Wherein, the thickness of the FR4 reinforcing plate layer is 700 microns.

Wherein, the thickness of the first AD adhesive layer is 25 microns.

Wherein, the thickness of the first PI reinforced plate layer is 25 microns.

Wherein, the thickness of the second AD adhesive layer is 15 microns.

Wherein, the thickness of the second copper foil layer is 18 microns.

The beneficial effects of the utility model are: a novel multi-layer flexible circuit board structure described in the utility model, which includes the first copper foil layer, the FR4 reinforcing plate layer, the first AD glue, which are sequentially stacked from top to bottom layer, the first PI reinforced layer, the second AD adhesive layer, the second copper foil layer, the second PI reinforced layer, the third copper foil layer, the third AD adhesive layer, the third PI reinforced layer, The fourth copper foil layer, the thickness of the second PI reinforcing plate layer is 12.5 microns, the thickness of the third copper foil layer is 18 microns, the thickness of the third AD adhesive layer is 25 microns, the third PI reinforcing plate The thickness of the fourth copper foil layer is 12.5 microns, the thickness of the fourth copper foil layer is 12 microns; the first and second blind holes are opened on the lower surface of the fourth copper foil layer, the depth of the first blind hole is 49.5 microns, and the depth of the second blind hole The depth value is 80 microns, and the diameter values of the first and second blind holes are respectively 100 microns. Through the above structural design, the utility model has the advantages of reasonable design, high yield and stable quality.

Description of drawings

The utility model is further described below using the drawings, but the embodiments in the drawings do not constitute any limitation to the utility model.

Fig. 1 is the structural representation of the utility model.

In Figure 1 are included:

1——The first copper foil layer 2——FR4 reinforcement layer

3——The first AD adhesive layer 4——The first PI reinforcement layer

5——The second AD glue layer 6——The second copper foil layer

7——The second PI reinforcement layer 8——The third copper foil layer

9——The third AD adhesive layer 10——The third PI reinforcement layer

11——The fourth copper foil layer 12——The first blind hole

13—the second blind hole.

detailed description

The utility model will be described below in conjunction with specific embodiments.

As shown in Figure 1, a new multi-layer flexible circuit board structure includes a first copper foil layer 1, an FR4 reinforcement layer 2, a first AD adhesive layer 3, and a first PI laminated layer from top to bottom. Reinforced laminate layer 4, second AD adhesive layer 5, second copper foil layer 6, second PI reinforced laminate layer 7, third copper foil layer 8, third AD adhesive layer 9, third PI reinforced laminate layer 10. The fourth copper foil layer 11, the thickness of the second PI reinforcing plate layer 7 is 12.5 microns, the thickness of the third copper foil layer 8 is 18 microns, and the thickness of the third AD adhesive layer 9 is 25 microns, The thickness of the third PI reinforcing plate layer 10 is 12.5 microns, and the thickness of the fourth copper foil layer 11 is 12 microns.

Further, the lower surface of the fourth copper foil layer 11 is provided with a first blind hole 12 and a second blind hole 13 located beside the first blind hole 12, the depth of the first blind hole 12 is 49.5 microns and the first blind hole 12 is The hole 12 extends from the lower surface of the fourth copper foil layer 11 to the lower surface of the third copper foil layer 8, the depth value of the second blind hole 13 is 80 microns and the second blind hole 13 extends from the lower surface of the fourth copper foil layer 11 The surface extends to the lower surface of the second copper foil layer 6, and the diameters of the first blind hole 12 and the second blind hole 13 are respectively 100 microns.

It should be further pointed out that the thickness of the first copper foil layer 1 is 35 microns, the thickness of the FR4 reinforcement layer 2 is 700 microns, the thickness of the first AD adhesive layer 3 is 25 microns, and the first PI reinforcement layer The thickness of 4 is 25 microns, the thickness of the second AD adhesive layer 5 is 15 microns, and the thickness of the second copper foil layer 6 is 18 microns.

The utility model includes four layers of copper foil layers, and consists of the first copper foil layer 1, the FR4 reinforcing plate layer 2, the first AD adhesive layer 3, the first PI reinforcing plate layer 4, the second AD adhesive layer 5, The second copper foil layer 6, the second PI reinforcing plate layer 7, the third copper foil layer 8, the third AD adhesive layer 9, the third PI reinforcing plate layer 10, and the fourth copper foil layer 11 are stacked in sequence, The whole structure is novel in design.

In addition, for the first blind hole 12 and the second blind hole 13, the ratio of their diameter to depth can meet the requirements of the blind hole diameter and blind hole depth of 1:0.8 in the electroplating process, and the electroplating is stable and reliable.

Based on the above circumstances, it can be seen that through the above structural design, the utility model has the advantages of reasonable design, high yield rate and stable quality.

The above content is only a preferred embodiment of the present utility model. For those of ordinary skill in the art, according to the idea of the present utility model, there will be changes in the specific implementation and scope of application. The content of this specification should not be understood as Limitations on the Invention.

Claims (7)

1. A new multi-layer flexible circuit board structure, characterized in that it includes a first copper foil layer (1), an FR4 reinforcing plate layer (2), and a first AD adhesive layer ( 3), the first PI reinforcement layer (4), the second AD adhesive layer (5), the second copper foil layer (6), the second PI reinforcement layer (7), the third copper foil layer (8 ), the third AD adhesive layer (9), the third PI reinforcement layer (10), the fourth copper foil layer (11), the thickness of the second PI reinforcement layer (7) is 12.5 microns, the third The thickness of the copper foil layer (8) is 18 microns, the thickness of the third AD adhesive layer (9) is 25 microns, the thickness of the third PI reinforcing plate layer (10) is 12.5 microns, and the fourth copper foil layer ( 11) The thickness value is 12 microns; The lower surface of the fourth copper foil layer (11) is provided with a first blind hole (12) and a second blind hole (13) next to the first blind hole (12), and the depth value of the first blind hole (12) is is 49.5 microns and the first blind hole (12) extends from the lower surface of the fourth copper foil layer (11) to the lower surface of the third copper foil layer (8), and the depth value of the second blind hole (13) is 80 microns And the second blind hole (13) extends from the lower surface of the fourth copper foil layer (11) to the lower surface of the second copper foil layer (6), the first blind hole (12), the second blind hole (13) The diameter values were 100 μm. 2. A novel multi-layer flexible circuit board structure according to claim 1, characterized in that: the thickness of the first copper foil layer (1) is 35 microns. 3. A novel multi-layer flexible circuit board structure according to claim 2, characterized in that: the thickness of the FR4 reinforcement layer (2) is 700 microns. 4. A novel multi-layer flexible circuit board structure according to claim 3, characterized in that: the thickness of the first AD adhesive layer (3) is 25 microns. 5. A novel multi-layer flexible circuit board structure according to claim 4, characterized in that: the thickness of the first PI reinforcement layer (4) is 25 microns. 6. A novel multi-layer flexible circuit board structure according to claim 5, characterized in that: the thickness of the second AD adhesive layer (5) is 15 microns. 7. A novel multi-layer flexible circuit board structure according to claim 6, characterized in that the thickness of the second copper foil layer (6) is 18 microns.