TWM568019U - Rigid-flex circuit board - Google Patents

Abstract

A soft and hard composite board includes a first circuit board structure, a second circuit board structure and a third circuit board structure. The first circuit board structure includes a first substrate and a first circuit structure, and the second circuit board structure includes a second substrate and a second circuit structure, the third circuit board structure comprises a third connecting substrate, a third laminated substrate and a third circuit structure; the third connecting substrate is made of a photo-sensing dielectric and the flexibility is much larger than The first and second substrates, the third connecting substrate is mechanically connected to the first and second circuit board structures, and the third circuit board structure has a bendable between the first circuit board structure and the second circuit board structure The folded portion, the third circuit structure is formed after the third joint substrate is mechanically coupled to the first and second circuit board structures.

Description

Soft and hard composite board

The present invention relates to a circuit board structure, and more particularly to a soft and hard composite board.

The circuit board can be divided into a hard circuit board (referred to as a hard board), a flexible circuit board (soft board), and a soft and hard composite board according to the softness and hardness of the dielectric material, wherein the soft and hard composite board is usually composed of a soft board and a hard board. They are combined and combine the flexibility of a flexible board with the strength of a hard board, so they are often used in parts carriers for electronic products.

The soft and hard composite board of the prior art usually forms a circuit after the soft board and the hard board respectively form a circuit, and then presses the soft and hard boards together, wherein the hard board is pre-formed into a slot, so that the soft and hard composite board has the slotted area. Flexible, while the hard board area can be fitted with surface mounted devices.

The prior art soft and hard composite board processes are both complicated and expensive, and the assembly process of the surface mount components is also complicated. In addition, the conventional soft boards are generally made of FR-4 or PI materials, which are generally not resistant to high temperatures and affect the design freedom of subsequent processes.

In view of this, the main purpose of the present invention is to provide a soft and hard composite board which is easy to manufacture.

In order to achieve the above and other objects, the present invention provides a soft and hard composite board comprising a first circuit board structure, a second circuit board structure and a third circuit board structure, the first circuit board structure having a first surface and An opposite second surface, the first circuit board structure includes at least one insulating first substrate and a first circuit structure formed on the at least one first substrate, the second circuit board structure having a third surface and a In a reverse fourth surface, the second circuit board structure comprises an insulated second substrate and a second circuit structure formed on the at least one second substrate, the third circuit board structure having a fifth surface and a reverse a sixth surface, the third circuit board structure comprising an insulated third connecting substrate, at least one insulating third laminated substrate, and a third circuit formed on the third connecting substrate and the at least one third laminated substrate The third connecting substrate is located on the fifth surface of the third circuit board structure; wherein the flexibility of the third connecting substrate is much larger than the first substrate and the second substrate, and the third connecting substrate is light Sense imaging dielectric; The third connecting substrate is mechanically connected to the first surface of the first circuit board structure and the third surface of the second circuit board structure, and the third circuit structure is electrically connected to the first and second circuit structures respectively, and the third circuit board The structure has a bendable section between the first circuit board structure and the second circuit board structure; wherein the third circuit structure is only distributed between the fifth surface and the sixth surface, and at least one of the third circuit structures The portion is formed after the third bonding substrate is mechanically connected to the first and second wiring board structures.

Since the third bonding substrate is made of a photo-sensing dielectric, the third circuit structure can be formed after the third bonding substrate is mechanically connected to the first and second circuit board structures, which is required to be soft in advance with the prior art. The formation of the circuit structure on the board is different. It is expected that the new model will have higher yield and productivity, and the degree of freedom in process design can also be increased.

Please refer to FIG. 1 , which is a soft and hard composite board according to an embodiment of the present invention. The soft and hard composite board 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 has a first surface 11 and a reverse second surface 12, and the first circuit board structure 10 includes two insulating first substrates 13a, 13b and is formed on the first substrate 13a, 13b. The first circuit structure 14, wherein the first substrate 13a is made of, for example, PP, and the second substrate 13b is made of, for example, a solder resist material, and the first circuit structure 14 illustratively includes a layered electroless copper plating layer 14a. The electroplated copper layers 14b and 14c and the surface plating layer 14d, wherein the surface plating layer 14d may be, but not limited to, one of a nickel layer, a gold layer, a silver layer, and a palladium layer or a laminated structure thereof, such as an electroplated nickel-gold laminated structure, electroplating Nickel silver gold laminated structure, electroplated nickel silver laminated structure, chemical nickel gold laminated structure, chemical nickel silver laminated structure or nickel palladium gold laminated structure.

The second circuit board structure 20 has a third surface 21 and a reversed fourth surface 22, and the second circuit board structure 20 has two insulating second substrates 23a, 23b and the second substrate 23a, 23b. The second circuit structure 24, wherein the second substrate 23a is made of, for example, PP, the second substrate 23b is made of, for example, a solder resist material, and the second circuit structure 24 illustratively includes a layered electroless copper plating layer 24a. The electroplated copper layers 24b, 24c and the surface plating layer 24d, wherein the surface plating layer 24d may be, but not limited to, one of a nickel layer, a gold layer, a silver layer, a palladium layer or a laminated structure thereof, such as an electroplated nickel-gold laminated structure, electroplating a nickel-silver-gold laminated structure, an electroplated nickel-silver laminated structure, an electroless nickel-gold laminated structure, an electroless nickel-silver laminated structure or a nickel-palladium-gold laminated structure, and these surface plating layers 14d, 24d can be used, for example, to be attached to surface mount components or joints. . Wherein, the first and second circuit board structures 10, 20 are mechanically separated.

The third circuit board structure 30 has a fifth surface 31 and a reverse sixth surface 32, and the third circuit board 30 includes an insulated third connecting substrate 33, an insulated third laminated substrate 34, and a The third circuit structure 35 is formed on the third connection substrate 33 and the third laminate substrate 34. Wherein, the third connecting substrate 33 is made of a photoimageable dielectric having photosensitivity to light of a specific wavelength range (for example, ultraviolet light), and the photosensitive in the photo sensing dielectric The agent (for example, a photosensitive polymer) has a photosensitizing group, and the photosensitizing group undergoes a photochemical reaction when irradiated with light of a specific wavelength range; the photo-sensing dielectric may be a positive photo-sensing dielectric, and the photosensitive region thereof Dissolving in the developer; the photo-sensing dielectric may also be a negative-sensitivity imaging dielectric, the non-photosensitive region of which may be dissolved in the developer; the third laminate substrate 34 may be a photo-sensing dielectric or other flexible Made of a dielectric or insulating material, wherein the flexibility of the third connecting substrate 33 and the third laminated substrate 34 is preferably much larger than the first substrates 13a, 13b and the second substrates 23a, 23b, so The three-circuit board structure 30 has a bendable section 36 interposed between the first circuit board structure 10 and the second circuit board structure 20, so that the third circuit board structure 30 has the characteristics of a soft board, and The first and second circuit board structures 10, 20 have the characteristics of a hard board, and the first and second circuit board structures 10, 20 are relatively displaceable.

In addition, the third connecting substrate 33 is located on the fifth surface 31 of the third wiring board structure 30, and the third connecting substrate 33 is mechanically connected to the first surface 11 of the first wiring board structure 10 and The third surface 21 of the second circuit board structure 20. On the other hand, the sixth surface 32 of the third wiring board structure 30 is not connected to other wiring board structures, particularly hard boards.

The third circuit structure 35 is formed on the third connecting substrate 33 and the third laminated substrate 34. The third circuit structure 35 illustratively includes an electroplated copper layer 35a, and a portion of the third circuit structure 35 extends over the bendable portion. Section 36, preferably, the third circuit structure 35 electrically connects at least a portion of the circuitry in the first circuit structure 14 to at least a portion of the circuitry in the second circuit structure 24.

Figures 2 to 21 disclose a manufacturing process of a soft and hard composite board, which is described as follows:

As shown in FIG. 2, a double-sided copper substrate 100 is first taken, and then a drilling operation is performed as shown in FIG. 3, and a via hole 101 is formed on the double-sided copper substrate 100, and then, as shown in FIG. In the copper plating operation, the electroplated copper layer 102 is formed on the surface of the double-sided copper substrate 100 and the via hole 101, and the plugging operation is performed as shown in Fig. 5, and the insulating material such as the solder resist ink 103 is filled in the via hole 101.

Next, as shown in FIG. 6, the grooving operation is performed so that the double-sided copper base material 100 has substantially the prototype of the first wiring board structure 10 and the second wiring board structure 20. Then, as shown in FIGS. 7 to 10, the filming, exposure, development, and etching stripping operations are sequentially performed to form a patterned circuit layer on the double-sided copper substrate 100.

So far, the structure on the left side of the double-sided copper substrate 100 is the basic configuration of the first circuit board structure 10, and the structure on the right side of the double-sided copper substrate 100 is the basic configuration of the second circuit board structure 20, that is, the first configuration is provided. The circuit board structure 10 and the second circuit board structure 20.

Next, as shown in FIG. 11, the film bonding operation is performed again, and the third joint substrate 33 is mechanically connected to the first surface 11 of the first wiring board structure 10 and the third surface 21 of the second wiring board structure 20, wherein The third joining substrate 33 is made of a photo-sensitive imaging dielectric.

Then, as shown in Figs. 12 and 13, the exposure and development operations are sequentially performed, and a plurality of hollow regions 33a which allow the first circuit structure or the second circuit structure to be exposed are formed on the third connecting substrate 33.

As shown in FIG. 14, a copper plating operation is performed to form an electroplated copper layer 104 on the second surface 12 and the fourth surface 22 of the first and second wiring board structures 10, 20, and on the surface of the third bonding substrate 33. An electroplated copper layer 105 is also formed. A portion of the electroplated copper layer 105 is filled in the hollow region 33a of the third connecting substrate 33 to electrically connect the electroplated copper layer 105 to the first and second circuit structures.

Next, as shown in Figs. 15 to 18, the electroplated copper layers 104 and 105 are sequentially subjected to press-drying, exposure, development, and etching stripping operations, and the electroplated copper layers 104 and 105 are patterned into circuit layers.

Then, as shown in FIG. 19 to FIG. 21, a solder resist insulation operation, an exposure, and a development operation are performed, and a solder resist layer 106 and a photo-sensing dielectric layer 107 are further formed on the surfaces of the electroplated copper layers 104 and 105, respectively. The solder resist layer 106 is formed into a window, and finally a surface plating treatment is performed at the window opening of the solder resist layer 106 to obtain a soft and hard composite panel as shown in Fig. 1. In this embodiment, the entirety of the third circuit structure is formed after the third joint substrate is mechanically coupled to the first and second circuit board structures.

It should be noted that the first and second circuit board structures may be two-layer boards or multi-layer boards, and the number of layers of the first substrate and the second substrate depends on circuit wiring requirements; likewise, the third layer structure The number of layers can also be adjusted depending on the circuit wiring requirements of the third circuit board structure. It should be noted that the third circuit structure referred to herein refers to a circuit structure completely located on the fifth and sixth surfaces, and other circuit structures extending beyond the fifth surface (for example, extending to the first and third lines) The vias between the plate structures and the conductive layers on the vias are not the third circuit structure referred to herein.

10‧‧‧First circuit board structure

11‧‧‧ first surface

12‧‧‧ second surface

13a, 13b‧‧‧ first substrate

14‧‧‧First circuit structure

14a‧‧‧Electrochemical copper plating

14b, 14c‧‧‧ electroplated copper layer

14d‧‧‧Surface plating

20‧‧‧Second circuit board structure

21‧‧‧ third surface

22‧‧‧ fourth surface

23a, 23b‧‧‧second substrate

24‧‧‧Second circuit structure

24a‧‧‧Electrochemical copper plating

24b, 24c‧‧‧ electroplated copper layer

24d‧‧‧Surface plating

30‧‧‧ Third circuit board structure

31‧‧‧ fifth surface

32‧‧‧ sixth surface

33‧‧‧ Third joining substrate

33a‧‧‧ Short-cut area

34‧‧‧ Third laminate substrate

35‧‧‧ Third circuit structure

35a‧‧‧Electroplated copper layer

36‧‧‧ bendable section

100‧‧‧Double-sided copper substrate

101‧‧‧through holes

102‧‧‧Electroplated copper layer

103‧‧‧ soldering ink

104, 105‧‧‧Electroplated copper layer

106‧‧‧ solder mask

107‧‧‧Photosensitive imaging dielectric layer

Fig. 1 is a schematic cross-sectional view showing an embodiment of a novel soft and hard composite panel.

2 to 21 are schematic cross-sectional views showing a manufacturing process of one embodiment of the novel soft and hard composite panel.

Claims (6)

A soft and hard composite board comprising: a first circuit board structure having a first surface and a reverse second surface, the first circuit board structure comprising at least one insulating first substrate and one formed on the at least a first circuit structure of a first substrate; a second circuit board structure having a third surface and a reverse fourth surface, the second circuit board structure including at least one insulating second substrate and a formation a second circuit structure of the at least one second substrate; and a third circuit board structure having a fifth surface and a reverse sixth surface, the third circuit board structure including an insulated third joint a third laminated substrate having at least one insulation and a third circuit structure formed on the third connecting substrate and the at least one third laminated substrate, the third connecting substrate being located in the third circuit board structure a fifth surface; wherein the flexibility of the third bonding substrate is much larger than the first substrate and the second substrate, and the third bonding substrate is made of a photo-sensing dielectric; The third connecting substrate is mechanically connected to the first line a first surface of the structure and a third surface of the second circuit board structure, the third circuit structure being electrically connected to the first and second circuit structures, respectively, the third circuit board structure having a first circuit board structure And a bendable section between the second circuit board structure; wherein the third circuit structure is only distributed between the fifth surface and the sixth surface, and at least a portion of the third circuit structure is The third joint substrate is formed after the first and second circuit board structures are mechanically connected. The soft and hard composite panel according to claim 1, wherein the flexibility of the at least one third laminate substrate is much larger than the first substrate and the second substrate. The soft and hard composite board according to claim 1, wherein the first circuit structure has at least one surface plating layer on the second surface, the surface plating layer being one of a nickel layer, a gold layer, a silver layer and a palladium layer. Or its laminated structure. The soft and hard composite board according to claim 1, wherein the second circuit structure has at least one surface plating layer on the fourth surface, the surface plating layer being one of a nickel layer, a gold layer, a silver layer and a palladium layer. Or its laminated structure. The soft and hard composite board of claim 1, wherein a portion of the first circuit structure is formed after the third joint substrate is mechanically coupled to the first and second circuit board structures. The soft and hard composite board of claim 1, wherein a portion of the second circuit structure is formed after the third joint substrate is mechanically coupled to the first and second circuit board structures.