TWM613230U - Double-sided and multilayer fpc substrate - Google Patents

Abstract

The present invention relates to the technical field of substrate processing, in particular to a double-sided and multi-layer FPC substrate, including: a substrate, the substrate is provided with a plurality of oblique holes penetrating in the thickness direction; a sputtering layer, the sputtering layer is attached to the substrate and The surface of the oblique hole; the conductive part, the conductive part is arranged in the oblique hole, and is connected to the sputtering layer; the plural circuit copper layer, the plural circuit copper layer is located on the upper and lower surfaces of the substrate, and is connected to the sputtering layer, the plural circuit copper layer They are connected by conductive parts. The new type can reduce the production cost, reduce the difficulty of drilling, facilitate the sputtering of the inner surface of the hole, and make the sputtering ion sputter on the inner surface of the hole, avoiding sputtering to the opposite roller

Description

Substrate for double-sided and multilayer FPC

The present invention relates to the technical field of substrate processing, in particular to a double-sided and multilayer FPC substrate.

FPC: Flexible circuit board is a highly reliable and excellent flexible printed circuit board made of polyimide or polyester film as the base material. Referred to as soft board or FPC, it has the characteristics of high wiring density, light weight and thin thickness.

COF: (Chip On Flex, or, Chip On Film, often referred to as flip-chip film), is the technology of fixing the driver IC on the flexible circuit board and the die soft film packaging technology, which uses a flexible carrier board as a package chip carrier to connect the chip and the flexible substrate The technology of circuit joining, COF is a kind of FPC that requires higher precision.

The traditional way to make double-sided and multi-layer FPC through the following two ways: 1. The semi-build-up method involves the steps of drilling conductive vias, hole cleaning, shadowing, film pressing, exposure, projection, copper electroplating, film stripping, copper removal/Tiecoat removal and circuit inspection steps in sequence. 2. The etching method is followed by the steps of drilling conductive vias, hole cleaning, shadowing, copper electroplating, pre-treatment of lamination, lamination, exposure, projection/etching/stripping and line inspection steps.

The conventional technology is to drill vertical conductive through holes by purchasing FPC base copper clad foil. On the one hand, the cost of purchasing FPC base copper clad foil is higher than that of insulating film base material. On the other hand, due to FPC base The reason why the surface of the copper-clad copper foil is covered with a copper layer is that the drilling laser energy requirement is much higher, and the drilling efficiency is low, and it is easy to overheat and cause the FPC substrate copper-clad foil to deform, resulting in excessive errors;

In addition, if the insulating film substrate is drilled as a vertical hole, when the vertical hole is sputtered, it is difficult to completely cover the sputtering layer on the inner surface of the vertical hole, and when the vertical hole is sputtered, sputtering ions will pass through the vertical hole Sputtering on the opposing roller causes adhesion of the rollers, and the sputtering ions continue to adhere and accumulate and fall off to form dust pollution.

The technical problem to be solved by the new model is: to solve the problem of purchasing FPC substrate copper clad foil for drilling in the prior art, which is costly and difficult to drill, and in the prior art to drill vertical holes, it is difficult to completely cover the sputtering layer in the hole. The problem and the technical problem of the sticking of the roller caused by the vertical hole sputtering ion sputtering to the opposite roller. This model provides a method for processing double-sided and multilayer FPC substrates, which can reduce production costs, reduce drilling difficulty, facilitate the sputtering of the inner surface of the hole, and make sputtering ions sputter on the inner surface of the hole, avoiding sputtering to the opposite Inside the wheel.

The technical solution adopted by the new model to solve its technical problems is: a double-sided and multilayer FPC substrate, which includes: A substrate, the substrate is provided with a plurality of oblique holes penetrating in the thickness direction; Sputtering layer, the sputtering layer is attached to the surface of the substrate and the oblique hole; A conductive part, the conductive part is arranged in the oblique hole and connected with the sputtering layer; A plurality of circuit copper layers, a plurality of circuit copper layers are located on the upper and lower surfaces of the substrate, and are connected with the sputtering layer, and the plurality of circuit copper layers are connected through the conductive part.

In the double-sided and multilayer FPC substrate, the oblique hole is a cylindrical oblique hole.

The double-sided and multilayer FPC substrate, wherein the orthographic projection of the upper opening of the oblique hole and the orthographic projection of the lower opening of the oblique hole have no intersection, and the orthographic projection of the upper opening and the orthographic projection of the lower opening are between The straight line distance of is not greater than the longest chord of the orthographic projection of the upper opening.

In the double-sided and multilayer FPC substrate, the orthographic projection of the upper opening of the oblique hole and the orthographic projection of the lower opening of the oblique hole have no intersection. When the sputtering ions are sputtered vertically, the sputtering ions cannot be opened from the upper and lower sides. Directly pass through, further avoiding the technical problem of sputtering ions from passing through the hole and sputtering on the opposite roller, and the linear distance between the orthographic projection of the upper opening and the orthographic projection of the lower opening is not greater than the upper opening The longest chord of the orthographic projection, when the linear distance between the orthographic projection of the upper opening and the orthographic projection of the lower opening is greater than the longest chord of the orthographic projection of the upper opening, the effective area of sputtering ions on the inner wall of the oblique hole There is no guarantee that the slanted hole will be connected in the subsequent electroplating process.

In the double-sided and multilayer FPC substrate, the orthographic projection edge of the upper opening of the oblique hole is tangent to the orthographic projection edge of the lower opening of the oblique hole. When the orthographic edge of the upper opening of the oblique hole is tangent to the orthographic edge of the lower opening of the oblique hole, sputtering ions cannot be sputtered from the oblique hole to the opposing roller, while ensuring sputtering from the upper opening The sputtering ions can completely sputter the inner surface of one side of the oblique hole, further improving the effect of sputtering distribution in the hole.

In the double-sided and multilayer FPC substrate, the substrate is a PI film, and the PI film has excellent high and low temperature resistance, electrical insulation, adhesion, radiation resistance, and dielectric resistance.

According to any one of the above-mentioned methods for processing double-sided and multilayer FPC substrates, the method includes the following steps: S1. An oblique hole is formed on the surface of the substrate to penetrate along its thickness direction; S2, clean the oblique hole; S3. Sputtering a sputtering layer on the inner surface of the oblique hole and both sides of the substrate; S4. Perform electroplating and thickening treatment on the substrate and the oblique hole to form a conductive part in the oblique hole, and cover the surface of the substrate with a plurality of circuit copper layers, and the plurality of circuit copper layers are connected through the conductive part.

In the method for processing the double-sided and multilayer FPC substrate, the method for processing the double-sided and multilayer FPC substrate of the present invention is to open oblique holes in the substrate along the thickness direction, because there is no copper foil on the substrate. Copper layer, the purchase cost is low, it is convenient for drilling, avoiding the high laser energy requirement caused by the copper foil copper layer, and the drilling efficiency is low, and it is easy to overheat and cause the deformation of the substrate, which causes the technical problem of excessive error. After cleaning, perform double-sided sputtering on the inner surface of the oblique hole and the substrate. Since the oblique hole is opened, the inner surface of the oblique hole is inclined during sputtering, and the sputtering ions are more likely to be sputtered during sputtering. On the inner surface of the oblique hole, sputtering ions are more likely to adhere to the surface of the substrate, and when the inner surface of the oblique hole is inclined, it is not easy for the sputtering ions to directly pass through the hole and sputter onto the opposite roller.

In the method for processing the double-sided and multilayer FPC substrate, in order to achieve uniform distribution of metal sputtering ions on the inner wall of the positioning hole, in step S3, a part of the inner wall of the oblique hole and one side of the substrate are simultaneously A part of the sputtering layer is sputtered, and another part of the inner wall of the oblique hole and the other surface of the substrate are sputtered at the same time.

In the method for processing the double-sided and multilayer FPC substrate, in order to achieve uniform plating layer, in step S4, the inner wall of the oblique hole and both sides of the base material are simultaneously electroplated.

In the method for processing the double-sided and multilayer FPC substrate, in step S2, the oblique hole is cleaned by Plasma or Desmear.

In the method for processing a double-sided and multilayer FPC substrate, in step S1, the oblique hole is formed by a laser beam.

The new type double-sided and multilayer FPC substrate and its processing method have the following beneficial effects: 1. The base material has no metal layer, the cost is low, and the laser drilling energy is low, the drilling speed is high, the heat is small, the deformation of the base material is small, and the accuracy is relatively improved. 2. Using oblique holes for sputtering, the effect of sputtering distribution in the holes is good and it can prevent sputtering ions from passing through the oblique holes and sputtering to the opposite roller, causing roller adhesion and avoiding dust pollution caused by continuous adhesion to falling off .

The present invention will now be described in further detail in conjunction with the drawings. These drawings are all simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, so they only show the constitutions related to the present invention.

As shown in Figure 1, it is the first embodiment of the present invention, a double-sided and multilayer FPC substrate, including: The base material 10 is provided with a plurality of oblique holes 11 penetrating in the thickness direction; the oblique hole 11 is a cylindrical oblique hole, the orthographic projection of the upper opening 12 of the oblique hole 11 and the orthographic projection of the lower opening 13 of the oblique hole 11 There is no intersection, and the linear distance between the orthographic projection of the upper opening 12 and the orthographic projection of the lower opening 13 is not greater than the longest chord of the orthographic projection of the upper opening 12, and the substrate 10 is a PI film. Sputtering layer 1. The sputtering layer 1 is attached to the surface of the substrate 10 and the oblique hole 11; The conductive part is arranged in the oblique hole 11 and connected to the sputtering layer 1; A plurality of circuit copper layers 2 and a plurality of circuit copper layers 2 are located on the upper and lower surfaces of the substrate 10 and are connected to the sputtering layer 1, and the plurality of circuit copper layers 2 are connected by conductive parts.

When the orthographic projection of the upper opening 12 of the oblique hole 11 and the orthographic projection of the lower opening 13 of the oblique hole 11 have no intersection, and the linear distance between the orthographic projection of the upper opening 12 and the orthographic projection of the lower opening 13 is not greater than the orthographic projection of the upper opening 12 As shown in Figures 1 and 3, the length of the longest chord of the orthographic projection of the upper opening 12 is L. Similarly, the length of the longest chord of the lower opening 13 is also L, and the orthographic projection of the upper opening 12 is L The linear distance between the orthographic projections of the lower opening 13 is d, that is, 0<d≤L. Sputtering ions cannot be completely sputtered to the inner surface of the oblique hole 11 during sputtering, but in the subsequent electroplating process, the electroplating Filling the conductive layer on the inner surface of the oblique hole 11 can make the substrate 10 conductive on both sides.

The beneficial effects of the first embodiment are as follows: In the double-sided and multi-layer FPC substrate of the present application, oblique holes 11 are formed in the substrate 10 along the thickness direction. Since there is no copper foil copper layer on the substrate, the purchase cost is low, and it is convenient to drill and avoid copper. The copper foil layer requires high laser energy, and the drilling efficiency is low, and it is easy to overheat and cause the deformation of the substrate, which causes the technical problem of excessive error. After the inclined hole is cleaned, the inner surface of the inclined hole and the substrate are double-sided sputtering , Because the inclined hole is opened, the inner surface of the inclined hole is inclined during sputtering. During sputtering, the sputtered ions are more likely to be sputtered to the inner surface of the inclined hole, and the sputtered ions are more likely to adhere to the substrate. When the inner surface of the oblique hole is inclined, it is not easy for sputtering ions to directly pass through the hole and sputter onto the opposite roller.

As shown in Figure 2, it is the second embodiment of the present invention, a double-sided and multi-layer FPC substrate. The difference from the first embodiment is: the orthographic edge of the upper opening 12 of the inclined hole 11 and the bottom of the inclined hole 11 The orthographic projection edge of the opening 13 is tangent.

The beneficial effects of the second embodiment are as follows: When the orthographic edge of the upper opening 12 of the oblique hole 11 is tangent to the orthographic edge of the lower opening 13 of the oblique hole 11, the sputtering ions cannot be sputtered from the oblique hole to the opposing roller while ensuring the The sputtering ions sputtered by the opening 12 can be completely sputtered on the inner surface of one side of the oblique hole, which further improves the sputtering distribution effect in the hole.

According to the method for processing a double-sided and multilayer FPC substrate in the above two embodiments, the method includes the following steps: S1. An oblique hole 11 penetrating in the thickness direction is formed on the surface of the substrate 10; the oblique hole 11 is formed by a laser beam. S2, clean the oblique hole 11; in step S2, clean the oblique hole 11 by Plasma or Desmear. S3, a conductive layer is sputtered on the inner surface of the oblique hole 11 and both sides of the substrate 10; in step S3, a conductive layer is sputtered on a part of the inner wall of the oblique hole 11 and one side of the substrate 10 at the same time, and the other side of the oblique hole 11 A conductive layer is sputtered on a part of the inner wall and the other surface of the substrate 10 at the same time. S4. Perform electroplating and thickening treatment on the substrate 10, so that the surface of the substrate 10 is covered with the circuit copper layer and double-sided conduction is realized. In step S4, the inner wall of the oblique hole 11 and both sides of the substrate 10 are simultaneously electroplated.

In a word, according to the double-sided and multilayer FPC substrate and its processing method of the present invention, since the base material 10 has no metal layer, the cost is low and the laser drilling energy is low, the drilling speed is high, and the amount of heat is small. , The accuracy is relatively improved. In addition, the use of the inclined hole 11 for sputtering has a good sputtering effect and can prevent sputtering ions from passing through the inclined hole and sputtering to the opposite roller, causing the roller to stick, and avoid continuous sticking to falling off Dust pollution formed.

Taking the above-mentioned ideal embodiment according to the present invention as inspiration, and through the above-mentioned description, persons with ordinary knowledge in related fields can make various changes and modifications without departing from the scope of the technical idea of the present invention. The technical scope of this new model is not limited to the content in the specification, and its technical scope must be determined according to the requirements.

1: Sputtering layer 2: Line copper wire 10: Substrate 11: oblique hole 12: Upper opening 13: Lower opening

Fig. 1 is a schematic diagram of the first embodiment of the double-sided and multilayer FPC substrate of the present invention;

Figure 2 is a schematic diagram of a second embodiment of the double-sided and multilayer FPC substrate of the present invention;

Fig. 3 is a schematic view of the orthographic projection of the upper opening and the lower opening of the oblique hole in the method for processing the double-sided and multilayer FPC substrate of the present invention;

Fig. 4 is a schematic diagram of the cross-sectional structure of the double-sided and multilayer FPC substrate of the present invention.

10: Substrate

11: oblique hole

12: Upper opening

13: Lower opening

Claims (5)

A double-sided and multilayer FPC substrate, which includes: a substrate with a plurality of oblique holes penetrating in the thickness direction; a sputtering layer, the sputtering layer attached to the substrate and the oblique hole The surface of the hole; a conductive part arranged in the oblique hole and connected with the sputtering layer; a plurality of circuit copper layers, the circuit copper layers are located on the upper and lower surfaces of the substrate, and are connected to the sputtering layer Connected, the copper layers of these circuits are connected through the conductive portion. The double-sided and multilayer FPC substrate according to claim 1, wherein the oblique hole is a cylindrical oblique hole. The double-sided and multilayer FPC substrate according to claim 2, wherein the orthographic projection of the upper opening of one of the oblique holes and the orthographic projection of the lower opening of the oblique hole have no intersection, and the orthographic projection of the upper opening is the same as that of the lower opening. The straight line distance between the orthographic projections of the openings is not greater than the longest chord of the orthographic projections of the upper openings. The double-sided and multilayer FPC substrate according to claim 3, wherein the orthographic projection edge of the upper opening of the oblique hole is tangent to the orthographic projection edge of the lower opening of the oblique hole. The double-sided and multilayer FPC substrate according to claim 1, wherein the substrate is a PI film.

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