CN112087863A

CN112087863A - Soft and hard composite board and its making method

Info

Publication number: CN112087863A
Application number: CN201910510244.7A
Authority: CN
Inventors: 李蕙如
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-06-13
Filing date: 2019-06-13
Publication date: 2020-12-15

Abstract

The invention provides a soft and hard composite board and a manufacturing method thereof, wherein the soft and hard composite board mainly comprises a first circuit board structure, a second circuit board structure and a third circuit board structure. The first circuit board structure and the second circuit board structure are not mechanically connected, and the third circuit board structure includes an insulating link substrate, an insulating laminated substrate, and a circuit structure formed between the link substrate and the insulating laminated substrate. In particular, the surface of the connection substrate is coated with a curable adhesive material, such as a thermosetting resin. Therefore, the connection substrate can permanently connect the first circuit board structure and the second circuit board structure, so that the soft and hard composite board of the invention can simultaneously have excellent properties of good flexibility, stable connection reliability and the like.

Description

Soft and hard composite board and its making method

Technical Field

The present invention relates to a circuit board structure, and more particularly, to a soft and hard composite board and a method for manufacturing the same.

Background

The circuit board can be classified into a hard circuit board (hard board), a flexible circuit board (soft board) and a soft and hard composite board according to the hardness of the dielectric substance, wherein the soft and hard composite board is usually formed by combining the soft board and the hard board, and has the flexibility of the soft board and the strength of the hard board, so the circuit board is often applied to a component carrier of an electronic product.

In the prior art, after the soft board and the hard board form the circuit respectively, the soft board and the hard board are pressed together, wherein the hard board is provided with a slot in advance, so that the soft board and the hard board have flexibility in the slot area, and the hard board can be provided with surface mounted devices (surface mounted devices).

The soft and hard composite board in the prior art is complex and expensive in manufacturing process, and the assembling process of the surface mounting component is also complex.

Disclosure of Invention

In view of the above, the main objective of the present invention is to provide a soft and hard composite board which is easy to manufacture and a manufacturing method thereof.

To achieve the above and other objects, the present invention provides an embodiment of a soft and hard composite board, comprising:

a first circuit board structure comprising: the circuit board comprises at least one first insulating substrate, a first circuit structure formed on a first surface of the first insulating substrate, and a second circuit structure formed on a second surface of the first insulating substrate;

a second circuit board structure comprising: at least one second insulating base material, a third circuit structure formed on a third surface of the second insulating base material, and a fourth circuit structure formed on a fourth surface of the second insulating base material; and

a third circuit board structure comprising: an insulating connection substrate mechanically connected to the second surface of the first insulating substrate and the fourth surface of the second insulating substrate by a fifth surface thereof, and a fifth circuit structure formed on a sixth surface of the connection substrate;

the flexibility of the connecting base material is far greater than that of the first insulating base material and the second insulating base material, the fifth surface of the connecting base material is coated with a curable adhesive material, and the curable adhesive material is cured into a cured adhesive layer so as to form permanent connection between the third circuit board structure and the first circuit board structure and the second circuit board structure;

the plurality of hollowed-out areas penetrate through the connecting substrate and the cured adhesive layer, so that the fifth circuit structure is electrically connected with the second circuit structure and the fourth circuit structure through the hollowed-out areas, and the third circuit structure is provided with a bendable section between the first circuit structure and the second circuit structure;

wherein a portion of the fifth circuit structure is formed after the connection substrate is mechanically connected to the first and second insulating substrates.

In order to achieve the above and other objects, the present invention provides another embodiment of the soft and hard composite panel, including:

wherein the flexibility of the connecting substrate is far greater than that of the first insulating substrate and the second insulating substrate;

wherein, a solidifiable adhesive material is covered on the second circuit structure of the first circuit board structure and the fourth circuit structure of the second circuit board structure, and the solidifiable adhesive material is solidified into a solidified adhesive layer so as to form permanent connection between the third circuit board structure and the first circuit board structure and the second circuit board structure;

In order to achieve the above and other objects, the present invention also provides an embodiment of a method for manufacturing a soft and hard composite board, comprising the following steps:

providing a first circuit board structure and a second circuit board structure, wherein the first circuit board structure comprises at least a first insulating substrate, a part of a first circuit structure formed on a first surface of the first insulating substrate, and a second circuit structure formed on a second surface of the first insulating substrate, and the second circuit board structure comprises at least a second insulating substrate, a part of a third circuit structure formed on a third surface of the second insulating substrate, and a fourth circuit structure formed on a fourth surface of the second insulating substrate;

forming an uncured or semi-cured curable adhesive material on a fifth surface of an insulating connection substrate, wherein the flexibility of the connection substrate is much greater than that of the first insulating substrate and the second insulating substrate;

pressing the fifth surface of the connection substrate on which the uncured or semi-cured curable adhesive material is formed to the second surface of the first insulating substrate and the fourth surface of the second insulating substrate;

completely curing the curable adhesive material to form a cured adhesive layer;

manufacturing a plurality of hollowed-out areas on a sixth surface of the connection substrate and the cured adhesive layer, so that the second circuit structure of the first circuit board structure and the fourth circuit structure of the second circuit board structure are exposed by the hollowed-out areas; and

forming a fifth circuit structure on the sixth surface of the connection substrate, wherein a part of the fifth circuit structure is filled in the hollow area, so that the fifth circuit structure is electrically connected with the second circuit structure and the fourth circuit structure respectively;

the connecting substrate and the fifth circuit structure form a third circuit board structure, and the third circuit board structure is provided with a bendable section between the first circuit board structure and the second circuit board structure.

Since the fifth circuit structure is formed after the link substrate is mechanically connected to the first circuit board structure and the second circuit board structure, which is different from the prior art in which a circuit structure is formed on a flexible board in advance, it is expected that the present invention will have higher yield and productivity, and the process design freedom can be increased.

Other effects and embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a cross-sectional side view of a soft and hard composite panel according to the present invention;

FIG. 2 is a flow chart of a method for manufacturing a soft and hard composite board according to the present invention;

FIGS. 3A to 3I are schematic views illustrating the process of step S1;

FIG. 4 is a first process diagram of step S2;

FIGS. 5A and 5B are schematic diagrams illustrating a second process of step S2;

FIGS. 6A and 6B are schematic views illustrating the process of step S3;

FIGS. 7A to 7D are schematic views illustrating the process of step S4;

FIGS. 8A and 8B are schematic views illustrating a solder mask insulation process.

Description of the symbols

1 soft and hard composite board

10 first circuit board structure 20 second circuit board structure

30 the third circuit board structure 11 the first insulating substrate

12 first line structure 13 second line structure

111 first surface 112 second surface

12a, 13a thin copper-plated

layers

12b, 12c, 13b copper-electroplated layers

12d surface plating layer 12e solder mask

Second insulating base material of 12W solder window 21

22 third line configuration 23 fourth line configuration

211 third surface 212 fourth surface

22a, 23a thin copper-plated

layer

22b, 22c, 23b copper-plated layer

22d surface plating layer 22e solder mask

22W welding window 31 connection base material

32 laminated base material 33e solder mask

33 fifth line structure 35 hollow out area

34 bendable section 30b cured adhesive layer

30a curable adhesive material 312

311 fifth surface 10B base material

S1-S4 step 10T vias

101. 102 copper plating layers 103, 104 copper plating layers

100 double-sided copper substrate

Detailed Description

The following embodiments illustrate one method of forming a bonding pad on a light emitting diode carrier according to the present invention, which includes the following steps:

fig. 1 is a cross-sectional side view of a soft and hard composite board according to the present invention. As shown in fig. 1, the soft and hard composite board 1 of the present invention mainly includes, in terms of structural composition: a first circuit board structure 10, a second circuit board structure 20 and a third circuit board structure 30. Wherein the first circuit board structure 10 and the second circuit board structure 20 are not mechanically connected (mechanically separated). Moreover, the first circuit board structure 10 includes a first insulating substrate 11, a first circuit structure 12 formed on a first surface 111 of the first insulating substrate 11, and a second circuit structure 13 formed on a second surface 112 of the first insulating substrate 11. Engineers familiar with the design and fabrication of flexible circuit boards should know that the material of the first insulating substrate 11 can be Polyimide (PI), Polyethylene Terephthalate (PET) or Polyethylene Naphthalate (PEN).

The first circuit structure 12 includes a thin copper plating layer 12a, at least one copper electroplating layer (12b, 12c), and a surface electroplating layer 12d, and the second circuit structure 13 includes a thin copper plating layer 13a and at least one copper electroplating layer 13 b. Specifically, the thin copper plating layer 12a and the thin copper plating layer 13a may be a sputtered copper layer or a chemical copper plating layer, and the surface plating layer 12d may be one of a nickel layer, a gold layer, a silver layer, and a palladium layer or a stacked structure thereof, such as a nickel-gold plated stacked structure, a nickel-silver plated stacked structure, an electroless nickel-gold stacked structure, an electroless nickel-silver stacked structure, or a nickel-palladium-gold stacked structure. As shown in fig. 1, a solder mask layer 12e is further covered on the first circuit structure 12, and a plurality of solder windows 12W are opened on the solder mask layer 12e to expose the Surface plating layer 12d, so that Surface mounted devices (Surface mounted devices) can be easily soldered or electrically connected to the Surface plating layer 12 d.

On the other hand, the second wiring board structure 20 includes: a second insulating substrate 21, a third circuit structure 22 formed on a third surface 211 of the second insulating substrate 21, and a fourth circuit structure 23 formed on a fourth surface 212 of the second insulating substrate 21. Similarly, the material of the second insulating substrate 21 may be PI, PET, or PEN. According to the design of the present invention, the third circuit structure 22 includes a thin copper plating layer 22a, at least one copper electroplating layer (22b, 22c), and a surface electroplating layer 22d, and the fourth circuit structure 23 includes a thin copper plating layer 23a and at least one copper electroplating layer 23 b. Specifically, the thin copper plating layer 22a and the thin copper plating layer 23a may be a sputtered copper layer or a chemical copper plating layer, and the surface plating layer 22d is one of a nickel layer, a gold layer, a silver layer, a palladium layer, or a laminated structure thereof. Furthermore, as shown in fig. 1, a solder mask layer 22e is further covered on the third circuit structure 22, and a plurality of solder windows 22W are opened on the solder mask layer 22e to expose the surface plating layer 22d, so that surface mount components can be easily soldered or electrically connected to the surface plating layer 22 d.

To explain in more detail, the third wiring board structure 30 includes: an insulating connection substrate 31 and a fifth circuit structure 33; the connection substrate 31 is mechanically connected (mechanically connected to) the second surface 112 of the first insulation substrate 11 and the fourth surface 212 of the second insulation substrate 21 through a cured adhesive layer at a fifth surface 311 thereof. As shown in fig. 1, the fifth circuit structure 33 is formed on a sixth surface 312 of the connection substrate 31. According to the design of the present invention, a cured adhesive layer is formed on a fifth surface 311 of the connection substrate 31, and the cured adhesive layer is made of a curable adhesive material, such as: a thermosetting resin, a photocurable resin, or a resin that is cured by adding a curing agent. Moreover, the flexibility of the connecting substrate 31 is much larger than that of the first insulating substrate 11 and the second insulating substrate 21. The link substrate is made of, for example, a common Flexible Printed Circuit (FPC) or Polyimide (PI).

It should be noted that the fifth circuit structure 33 of the third circuit board structure 30, a portion of the first circuit structure 12 of the first circuit board structure 10 (i.e., the electroplated copper layer 12c and the surface plating layer 12d), and a portion of the third circuit structure 22 (i.e., the electroplated copper layer 22c and the surface plating layer 22d) are formed after the connection substrate 31 is mechanically connected to the first insulating substrate 11 and the second insulating substrate 21. Furthermore, a plurality of hollow areas 35 penetrate through the connection substrate 31 and the cured adhesive layer, so that the fifth circuit structure 33 is electrically connected to the second circuit structure 13 and the fourth circuit structure 23 through the plurality of hollow areas 35, and the third circuit board structure 30 has a bendable section 34 between the first circuit board structure 10 and the second circuit board structure 20. Thus, the third wiring board structure 30 has the characteristic of a soft board, while the first wiring board structure 10 and the second wiring board structure 20 have the characteristic of a hard board, and the first wiring board structure 10 and the second wiring board structure 20 can be relatively displaced.

The method for manufacturing the soft and hard composite board of the present invention will be described in detail with the aid of the accompanying drawings. Fig. 2 shows a flow chart of a method for manufacturing a soft and hard composite board according to the present invention. When the manufacturing of the soft and hard composite board 1 shown in fig. 1 is performed, step S1 is first performed: a first circuit board structure 10 and a second circuit board structure 20 are provided, wherein the first circuit board structure 10 includes a first insulating substrate 11, a portion of a first circuit structure 12 formed on a first surface 111 of the first insulating substrate 11, and a second circuit structure 13 formed on a second surface 112 of the first insulating substrate 11, and the second circuit board structure 20 includes a second insulating substrate 21, a portion of a third circuit structure 22 formed on a third surface 211 of the second insulating substrate 21, and a fourth circuit structure 23 formed on a fourth surface 212 of the second insulating substrate 21.

Fig. 3A to 3I show the process schematic diagram of step S1. As shown in fig. 3A, a substrate 10B is first taken, and then a copper plating layer 101 and a copper plating layer 102 are formed on two surfaces of the substrate 10B, so as to obtain a double-sided copper substrate 100. Both the copper plating layer 101 and the copper plating layer 102 can be a sputtered copper layer or a chemically plated copper layer. Next, as shown in fig. 3B, a drilling operation is performed to form a multi-via 10T on the double-sided copper substrate 100. As shown in fig. 3C, a copper electroplating layer 103 is formed on the surface of the double-sided copper substrate 100 and the inner wall surface of each via hole 101. As shown in fig. 3D, a hole filling operation is performed to fill the via holes 101 with an insulating material such as solder mask ink 104.

Further, as shown in fig. 3E, a grooving operation is performed on the double-sided copper substrate 100, and then the blanks of the first circuit board structure 10 and the second circuit board structure 20 are already present. Then, as shown in fig. 3F, fig. 3G, fig. 3H, and fig. 3I, dry film (dry film) pressing, exposing, developing, and etching stripping operations are sequentially performed, so that a second circuit structure 13 is formed on the second surface 112 of the first insulating substrate 11 of the first circuit board structure 10, and a fourth circuit structure 23 is formed on the fourth surface 212 of the second insulating substrate 21 of the second circuit board structure 20. As shown in fig. 3I, the second circuit structure 13 includes a thin copper plating layer 13a and at least one copper electroplating layer 13b formed in layers, and the fourth circuit structure 23 includes a thin copper plating layer 23a and at least one copper electroplating layer 23b formed in layers. It is noted that, only the prototype of the first circuit structure 12 (compare fig. 1) appears on the first surface 111 of the first insulating substrate 11, and only the prototype of the third circuit structure 22 (compare fig. 1) appears on the third surface 211 of the second insulating substrate 21.

After completing step S1, the method for manufacturing a soft and hard composite board of the present invention then performs step S2: in the case of using a cured adhesive layer, an insulating connection substrate 31 is mechanically connected to the first circuit board structure 10 and the second circuit board structure 20 at a fifth surface 311 thereof. Specifically, the step S2 includes at least two process methods. FIG. 4 shows a first process diagram of step S2. As shown in fig. 4, an uncured or semi-cured curable adhesive material 30a is formed on a fifth surface 311 of an insulating connection substrate 31, then the fifth surface 311 of the connection substrate 31 formed with the uncured or semi-cured curable adhesive material 30a is laminated on the second surface 112 of the first insulating substrate 11 and the fourth surface 21 of the second insulating substrate 21, and then the curable adhesive material 30a is completely cured into a cured adhesive layer 30 b.

Fig. 5A and 5B show a second process diagram of step S2. As shown in fig. 5A, an uncured or semi-cured curable adhesive material 30 is formed on the second circuit structure 13 of the first circuit board structure 10 and the fourth circuit structure 23 of the second circuit board structure 20, and the second surface 112 of the first circuit board structure 10 and the fourth surface 212 of the second circuit board structure 20, on which the uncured or semi-cured curable adhesive material 30a is formed, are pressed on an insulating connection substrate 31, wherein the flexibility of the connection substrate 31 is much greater than that of the first insulating substrate 11 and the second substrate 21. It should be noted that, taking an epoxy resin as an example, the glue (Varnish) of the resin is still in a monomer and diluted by a solvent, and is called uncured (a-Stage). Further, after drying with hot air and/or infrared rays, the resin state in which the molecular weight of the resin is increased to a complex or Oligomer (Oligomer) is referred to as semi-curing (B-Stage). As shown in fig. 5B, the curable adhesive material 30a is continuously cured to a cured adhesive layer 30B. Taking an epoxy resin as an example, when a resin in a semi-cured state is continuously heated and polymerized into a polymer resin, it is called complete curing (C-Stage).

After the curable adhesive material 30a is completely cured into the cured adhesive layer 30b, the fifth surface 311 of the connection substrate 31 mechanically connects the first circuit board structure 10 and the second circuit board structure 20.

With continuing reference to fig. 2, fig. 6A and 6B show the process schematic of step S3. After step S2 is completed, the method flow then executes step S3: a plurality of hollow-out areas 35 are formed on a sixth surface 312 of the connection substrate 31 and the cured adhesive layer 30b, so that the second circuit structure 13 of the first circuit board structure 10 and the fourth circuit structure 23 of the second circuit board structure 20 are exposed by the plurality of hollow-out areas 35. As can be easily understood, as shown in fig. 6A and 6B, the plurality of hollow-out regions 35 can be formed on the sixth surface 312 of the connection substrate 31 and the cured adhesive layer 30B only by performing operations such as dry film pressing (resist coating), exposure, development, and etching film stripping.

Continuously, the method flow is to execute step S4: a fifth circuit structure 33 is formed on the sixth surface 312 of the insulating connection substrate 31, wherein a portion of the fifth circuit structure 33 is filled in the hollow area 35, so that the fifth circuit structure 33 is electrically connected to the second circuit structure 13 and the fourth circuit structure 23 respectively. Specifically, the fifth circuit structure 33, a portion of the first circuit structure 12, and a portion of the third circuit structure 22 are formed in step S5. Fig. 7A to 7D show the process schematic diagram of step S4. As shown in fig. 7A, copper plating is performed to form a copper electroplated layer 105 on the copper electroplated layers 103 of the first and second

circuit board structures

10 and 20, and simultaneously to form a copper electroplated layer 106 on the sixth surface of the connection substrate 31. A part of the electroplated copper layer 106 is filled in the hollow area 35 of the insulating connection substrate 31, and the electroplated copper layer 106 is electrically connected to the second circuit structure 13 and the fourth circuit structure 23. Next, as shown in fig. 7B, 7C, and 7D, the copper electroplating layer 105 and the copper electroplating layer 106 are sequentially subjected to dry film pressing, exposure, development, and etching stripping operations, so that the copper electroplating layer 104 and the copper electroplating layer 105 are fabricated into a patterned circuit layer. As shown in fig. 7D, the connection substrate 31 and the fifth circuit structure 33 form the third circuit board structure 30, and the third circuit board structure 30 has a bendable section 34 between the first circuit board structure 10 and the second circuit board structure 20. On the other hand, the thin copper plating layer 12a, the copper electroplating layer 12b, and the copper electroplating layer 12c of the first circuit structure 12 have been completed, and the thin copper plating layer 22a, the copper electroplating layer 22b, and the copper electroplating layer 22c of the third circuit structure 22 have also been completed.

And finally, performing welding prevention insulation operation. As shown in fig. 8A and 8B, a solder mask ink 107 is coated on the first circuit structure 10 and the first circuit structure 20, and a solder mask ink 108 is coated on the third circuit structure 30. Then, a plurality of solder windows (12W, 22W) are formed in the solder resist ink 107 by dry film pressing (resist coating), exposure, development, and etching stripping. Finally, as shown in fig. 1, a surface plating process is performed at the plurality of solder windows (12W, 22W), to form the surface plating layer 12d of the first wiring structure 12 and the surface plating layer 22d of the second wiring structure 12 as shown in fig. 1. The solder mask ink 108 is connected to the sixth surface 312 of the connection substrate 31 as an insulating laminated substrate 32, so that the fifth circuit structure 33 is formed between the laminated substrate 32 and the connection substrate 31.

The solder mask ink 107 finally becomes the solder mask layer 12e, the solder mask layer 22e, and the solder mask layer 33 e. On the other hand, the first wiring board structure 10 and the second wiring board structure 20 may be a two-layer board or a multi-layer board. In short, the number of layers of the first insulating substrate 11 and the second insulating substrate 21 depends on the circuit wiring requirement; similarly, the third circuit board structure 30 can also adjust the number of stacked layers of the insulating connection substrate 31 and/or the insulating lamination substrate 32 according to the circuit wiring requirement.

In short, the present invention provides a soft and hard composite board 1, which includes a first circuit board structure 10, a second circuit board structure 20 and a third circuit board structure 30. The first circuit board structure 10 and the second circuit board structure 20 are not mechanically connected, and the third circuit board structure 30 includes an insulating connection substrate 31, an insulating laminated substrate 32, and a circuit structure formed between the connection substrate 31 and the insulating laminated substrate 32. In particular, the connection substrate 31 is made of a curable adhesive material, such as a thermosetting resin or a photo-curing resin. Therefore, the insulating connection base material 31 can permanently connect the first insulating base material 11 and the second insulating base material 21, and the soft and hard composite board 1 of the present invention can simultaneously have excellent properties such as good flexibility and stable connection reliability.

The above-described embodiments and/or implementations are only for illustrating the preferred embodiments and/or implementations of the present technology, and are not intended to limit the implementations of the present technology in any way, and those skilled in the art can make many modifications or changes without departing from the scope of the technology disclosed in the present disclosure, but should be construed as technology or implementations that are substantially the same as the present technology.

Claims

1. A soft and hard composite board, comprising:

2. A soft and hard composite board, comprising:

3. The soft-hard composite board according to claim 1 or 2, wherein the first circuit structure and the third circuit structure each comprise a thin copper plating layer, at least one copper electroplating layer, and a surface electroplating layer, which are made by layering, and the surface electroplating layer is one of nickel layer, gold layer, silver layer, palladium layer, or a layered structure thereof.

4. The soft and hard composite board according to claim 1 or 2, wherein the second circuit structure and the fourth circuit structure each comprise a thin copper plating layer and at least one copper electroplating layer which are manufactured in layers.

5. The soft-hard composite board according to claim 1 or 2, wherein the first circuit structure and the third circuit structure are respectively covered with a solder mask layer, and the solder mask layer is provided with a plurality of solder windows.

6. The manufacturing method of the soft and hard composite board is characterized by comprising the following steps:

completely curing the curable adhesive material to form a cured adhesive layer;

7. The manufacturing method of the soft and hard composite board is characterized by comprising the following steps:

forming an uncured or semi-cured curable adhesive material on the second circuit structure of the first circuit board structure and the fourth circuit structure of the second circuit board structure;

pressing the second surface of the first circuit board structure and the fourth surface of the second circuit board structure, on which the uncured or semi-cured curable adhesive material is formed, onto an insulating connection substrate, wherein the flexibility of the connection substrate is far greater than that of the first insulating substrate and the second insulating substrate;

completely curing the curable adhesive material to form a cured adhesive layer;

8. The method according to claim 6 or 7, wherein the other portion of the first circuit structure and the other portion of the third circuit structure are formed after the connection substrate is mechanically connected to the first insulation substrate and the second insulation substrate, and the first circuit structure and the third circuit structure are respectively covered with a solder mask layer, and the solder mask layer is opened with a plurality of solder windows.

9. The composite board according to claim 6 or 7, wherein the first circuit structure and the third circuit structure each comprise a thin copper plating layer, at least one copper electroplating layer, and a surface electroplating layer, and the surface electroplating layer is one of a nickel layer, a gold layer, a silver layer, a palladium layer, or a laminated structure thereof.

10. The composite soft and hard board according to claim 6 or 7, wherein the second circuit structure and the fourth circuit structure each comprise a thin copper plating layer and at least one copper electroplating layer formed in layers.