KR20160099934A - Rigid-flexible printed circuit board and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a rigid-flex board partitioned into a rigid unit and a flex unit and a manufacturing method thereof. The present invention relates to the rigid-flex board for forming a groove on a side of a first bonding member which is interposed among a plurality of soft copper foil laminate plates to be laminated to function as an insulation layer and a bonding member. The groove increases flexibility of soft copper foil laminate plates in a boundary between the rigid unit and the flex unit to prevent internal circuit layer damage and reduce a step of a protrusion unit which protrudes from an upper surface of the rigid unit of the boundary between the rigid unit and the flex unit.

Description

[0001] Rigid-flexible substrate and method for manufacturing same [0001] The present invention relates to a rigid-

The present invention relates to a rigid-flexible substrate and a method of manufacturing the same, and more particularly, to a rigid-flexible substrate in which the flexibility of the FCCL substrate of the flex portion is improved and the projecting gradient of the rigid portion is reduced.

In recent years, as the degree of integration of semiconductor elements increases, the number of connection terminals provided in semiconductor devices for connecting semiconductor devices with external circuits increases and the density of excretion also increases.

Semiconductor devices such as a semiconductor package on which such a semiconductor device is mounted are required to be reduced in size and thickness in order to improve the mounting density.

In accordance with this demand, various types of printed circuit boards have been developed, one of which is a rigid-flexible PCB that is deformable in three dimensions and spatially.

A rigid-flexible substrate is a substrate in which a rigid substrate and a flexible substrate are structurally coupled to each other and a rigid portion and a flexible portion are connected without a separate connector, and a space problem on the printed circuit board can be solved because no connector is used.

In addition, the rigid-flexible substrate has the advantages of securing the reliability that is generated in the connection of the conventional connector portion and improving the component mounting performance.

Meanwhile, the manufacturing process of the multi-layer rigid-flexible substrate has a structure in which the cover rails for protecting the flex portion are extended and stacked on the rigid portion.

In the above structure, the protruding portion is necessarily formed in the rigid portion of the rigid-flex boundary portion. Thus, the protruding portion having a high degree of inclination lifts the mask on one side in the process of printing the circuit layer on the upper surface of the rigid portion, The solder paste may be excessively printed.

That is, a pad having an excessive amount of printing causes a short between adjacent pads in a printing process or a short between adjacent pads in a reflow process after printing.

Further, there is a problem that the flex circuit of the flexible copper-clad laminate constituting the flex portion is repeated, thereby damaging the internal circuit layer of the rigid-flex boundary portion.

Korean Patent Laid-Open Publication No. 2013-0124759

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a rigid- - Flex substrates.

The above object of the present invention is achieved,

A plurality of stacked FCCL substrates, a first adhesive member formed in the rigid region and interposed between the FCCL substrates, and a cover layer formed in the rigid region and covering the outermost FCCL substrate, wherein the first adhesive member is disposed in the flex portion direction And a groove is formed to lower the inclination of the projection on the upper surface of the rigid portion.

According to another aspect of the present invention,

Attaching a coverlay to a substrate on which an inner layer circuit is formed to form a first FCCL; Stacking a first bonding member on both sides of the first FCCL and in a rigid region; Stacking a second FCCL on an upper surface of the first adhesive member; Stacking a second bonding member on the rigid region, the second bonding member being formed on the upper surface of the second FCCL; Laminating a cover layer formed on an upper surface of the second adhesive member; A method of manufacturing a rigid-flex substrate, comprising the steps of:

The first adhesive member can be punched out to the 100 mu m rigid portion region adjacent to the flex portion and the flex portion.

Since the rigid-flexible substrate according to the embodiment of the present invention can lower the slope of the protruding portion formed in the rigid portion at the boundary between the rigid portion and the flexi portion, it is possible to prevent the printing failure of the pad formed in the rigid portion and the short- There is an advantage that it can be prevented.

Further, according to the present invention, grooves are formed in a flex direction in a prepreg bonding member interposed between a plurality of FCCL substrates and formed in a rigid portion, so that the bending of the FCCL substrate of the flex portion can be made flexible, thereby preventing damage to the rigid- There is an advantage to be able to.

1 is a sectional view of a rigid-flexible substrate according to an embodiment of the present invention.
2 is a SEM photograph of the protrusion of the rigid-flex boundary;
3 is a process sectional view showing a method of manufacturing a rigid-flexible substrate according to the present invention.
4 is a view showing a process of printing an electrode pad on the upper surface of the rigid portion.

The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" include singular forms unless the context clearly dictates otherwise. Also, " comprise "and / or" comprising "when used herein should be interpreted as excluding the presence or addition of the mentioned forms, numbers, steps, operations, elements, elements and / It is not.

BRIEF DESCRIPTION OF THE DRAWINGS The objectives, specific advantages, and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. It should be noted that, in the present specification, the reference numerals are added to the constituent elements of the drawings, and the same constituent elements have the same numerical numbers as much as possible even if they are displayed on different drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. In this specification, the terms first, second, etc. are used to distinguish one element from another, and the element is not limited by the terms.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 is a sectional view of an embodiment of a rigid-flexible substrate according to the present invention, and Fig. 2 is a SEM photograph of a protrusion of a rigid-flex boundary portion.

As shown in the figure, the rigid-flex substrate 100 according to the present invention includes a plurality of FCCL substrates 110 stacked, a bonding member 120 interposed between the FCCL substrates 110, and an outermost FCCL substrate And a cover layer 130 as shown in FIG.

The FCCL (Flexible Copper Clad Laminate) substrate 110 is a flexible copper-clad laminate, which includes a base member 111 made of an insulating material, an internal circuit layer 112 patterned on the second FCCL substrate 110b, and a cover layer 113 Lt; / RTI >

The rigid portion R and the flex portion F are not clearly distinguished from each other, but they are designed arbitrarily in the manufacturing process, and the FCCL substrate 110 is not limited to the rigid portion R and the flex portion F, It can be a virtual line that appears in the finished product.

For example, polyimide, polyether imide, polyamide imide, polyamide, polyester, or the like may be used as the base member 111, and the base member 111 may be formed of a resin material having excellent flexibility. The base member 111 is not limited to the above-described material since any material can be used as long as it is an insulating material including flexibility.

The internal circuit layer 112 formed on both sides of the second FCCL substrate 110b may be formed by patterning a copper foil layer stacked on the second FCCL substrate 110b through exposure, development and etching processes.

The coverlay 113 is bonded to the upper surface of the inner circuit layer to protect the base member and the exposed inner circuit layer. The coverlay 113 may be formed of a polyimide film, a PIC (Photo Imageable Coverlay) or the like, and may have flexibility such as a base member. The coverlay 113 may be formed on the base member by touching an upper surface of the circuit layer and then removing and removing an unnecessary area, followed by pressing with a press.

Meanwhile, the base member 111 may further include a first via V1 formed in the rigid portion R for interlayer connection of the internal circuit layers. The via may be used as a ground circuit, a signal transfer circuit, or a power supply circuit. The via hole may be formed using a known method such as a laser technique or a CNC drill. The through hole may be filled with metal, As shown in FIG.

A first adhesive member 121 may be interposed between a plurality of stacked FCCL substrates 110. The first adhesive member 121 is formed on the rigid portion R, and the FCCL substrate 110 can be bonded and fixed to each other. In addition, the first adhesive member may be formed of a material having high rigidity to prevent the rigid portion R from being bent.

For example, the adhesive member 120 may use a prepreg (ppg). Prepreg is an abbreviation for pre-impregnated material, which is pre-impregnated with fabric cloth or glass cloth.

The prepreg is excellent in flowability and adhesiveness in a semi-cured state. Therefore, when the prepreg is interposed between the FCCL substrates 110 and then pressurized / heated, the FCCL substrate can be bonded while the resin is cured. At this time, the prepreg can function as an interlayer insulating layer in the rigid-flex substrate of the rigid portion (R).

The first adhesive member 121 may be formed in the rigid portion R and the groove 121a may be provided in the direction of the flex portion F. [ The groove 121a can be utilized as a space in which a part of the substrate sinks into an empty space when the coverlay, the adhesive member, the insulating layer, the circuit layer, etc. of the rigid portion R are pressed and laminated. This makes it possible to reduce the inclination of the projections formed on the upper surface of the rigid portion of the rigid-flex boundary portion.

As the inclination of the projection becomes smaller, the degree of contact between the screen mask and the upper surface of the rigid portion R is improved, so that the gap between the upper surface of the rigid portion and the screen mask can be reduced.

Therefore, it is possible to print the solder paste to be printed on the projecting portion in an appropriate amount, so that it is possible to prevent the short-circuit between the adjacent electrode pads due to electrode breakage in the printing process.

On the other hand, a cover layer 130 covering the rigid portion R may be further formed on the upper surface of the outermost FCCL substrate via a second bonding member 122. The cover layer 130 may be coated with an external circuit layer 131 formed by patterning the copper foil layer and a solder resist layer 132 covering a part of the external circuit layer. Solder paste may be printed on the external circuit layer exposed in the solder resist layer 132 to form the base of the electrode pad for die mounting.

The second adhesive member 122 may include a second via V2 for electrically connecting the external circuit layer 131 to the internal circuit layer 112 of the FCCL substrate. Since the steps of forming the second vias V2 and the external circuit layer 131 are the same as those described above, they are replaced.

Figure 2 is a SEM cross-sectional view of the rigid portion of the rigid-flex boundary. As shown in the figure, the height of the protruding portion was 185.76 탆 in the prior art, but the present invention was reduced to about 157 탆 by about 30 탆, and the inclination was significantly reduced.

Accordingly, in the process of printing the electrode pad in the upper region of the rigid portion, the solder mask can be more closely attached to the upper surface of the rigid portion, and the gap generated in the solder mask and the rigid portion can be reduced.

As a result, the print collapse of the solder is improved, and more precise pad printing can be achieved.

3 is a cross-sectional view illustrating a process for manufacturing a rigid-flex substrate according to the present invention.

The method of manufacturing a rigid-flex substrate according to the present invention includes the steps of preparing a first FCCL substrate, laminating a first bonding member on one surface of the first FCCL substrate, laminating a second FCCL substrate on the top surface of the first bonding member, Stacking a second bonding member on the first FCCL substrate and the second FCCL substrate, and forming a cover layer.

First, as shown in FIG. 3A, the first FCCL substrate 110a is a flexible copper-clad laminate, which is a base for bending the flex portion F, and may be formed by laminating a copper foil layer on the base member 111. [

The internal circuit layer 112 may be formed by selectively removing a portion of the copper foil layer. The internal circuit layer 112 may be formed by a vapor deposition method such as CVD (Chemical Vapor Deposition) or PVD (Physical Vapor Deposition) using a dry film (D / F), a subtractive method, electroless copper plating, Additive method using copper plating, Semi-Additive Process (SAP) and Modified Semi-Additive Process (MSAP).

As shown in FIG. 3B, the base member region exposed by etching can be laser-processed or CNC-processed to form a via-hole. The via hole may be subjected to a de-smear process to remove impurities remaining on the inner surface of the hole. Thereafter, the first via V1 can be formed by filling the via hole with a conductive metal material.

As shown in FIG. 3C, the cover rails 113 may be formed on both sides of the base member to protect the internal circuit layer 112. Although the cover rails 113 are shown covering the entire area of the base member in the figure, they may be formed only in the flex portion F to protect the internal circuit layers exposed to the outside.

At this time, the cover rails 113 are punched out so as to correspond to the size of the flex portion F, so as to cover the flex portion F, or remove the remaining region except the flex portion F after contacting the upper surface of the base substrate Method can be used.

As shown in Figs. 3d and 3e, adhesive members are laminated on both sides of the first FCCL substrate 110a. The adhesive member 120 formed on the first FCCL substrate may remove the rigid portion R extending from the flex portion F to form the first adhesive member 121.

The first adhesive member 121 is formed only on the rigid portion R but may be configured such that the groove 121a is formed in the direction of the flex portion F. [ At this time, the length of the groove can be varied according to the length of the flex portion. For example, if the length of the flex portion is 5 mm or less, the groove may be formed to have a thickness of 100 m, and if the flex portion length is 5 mm or more, the groove may be formed to have a thickness of 200 m.

The groove 121a may serve to lower the height of the protrusion formed on the upper portion of the rigid portion in the process of stacking the FCCL substrate, the insulating layer, the circuit layer, and the adhesive member.

In addition, the groove 121a may form a gap between the first FCCL substrate 110a and the second FCCL substrate 110b, which is a spacing space of the first bonding member thickness.

Therefore, it is possible to prevent the internal circuit layer 112 from being damaged by preventing the FCCL substrates 110 from being in contact with each other when the plurality of FCCL substrates 110 are bent, and to prevent the FCCL substrate 110 from being damaged due to the breakage of the rigid- Can be prevented.

The adhesive member formed on the lower portion of the first FCCL substrate 110a may be formed with the second adhesive member 122 by removing only the area of the flex portion F. [ The second bonding member 122 may serve to bond the cover layer 130 formed on the outermost FCCL substrate.

Next, as shown in FIG. 3F, the second FCCL substrate 110b may be laminated on the first FCCL substrate 110a, and the bonding member 120 may be bonded to the second FCCL substrate 110a. When a plurality of FCCL substrates 110 are stacked on the adhesive member 120, a groove 121a is formed in the rigid-flex boundary portion like the first adhesive member 121. In the case of the outermost FCCL substrate, Only the adhesive member of the second adhesive member and the area of the flex portion (F) can be removed.

The first adhesive member 121 and the second adhesive member 122 are punched out according to a predetermined numerical value before bonding to the FCCL substrate 110 to bond the first adhesive member 121 between the FCCL substrates, A second adhesive member 122 may be in contact with the outer surface of the substrate.

The adhesive member 120 serves to fix the FCCL substrates 110 by bonding or to fix the cover layer 130 and the FCCL substrate 110. The adhesive member 120 is formed only in the rigid portion R, So that warping of the substrate can be prevented.

As shown in FIG. 3H, the cover layer 130 may be further formed on the upper surface of the second adhesive member 122. The cover layer 130 may include an external circuit layer 131 formed by patterning a copper foil layer formed on the upper surface of the second adhesive member and a solder resist 142 to expose only a part of the external circuit layer.

The rigid-flex substrate 100 formed in this manner can prevent the FCCL substrate 110 from contacting the gap formed between the FCCL substrates 110 even if the FCCL substrate 110 is bent, .

Further, since the first adhesive member 121 has the groove 121a that forms a step from the rigid-flex boundary portion to the rigid portion R portion, the FCCL substrate 110 becomes more flexible at the rigid- It is possible to prevent (reduce) the breakage of the internal circuit layer and the base substrate due to the breakage.

4 is a view showing a process of printing an electrode pad on the upper surface of the rigid portion.

As shown, the upper surface of the rigid portion R may be formed with a protrusion at the rigid-flex boundary portion in the process of building up the rigid portion (R). That is, since the groove 121a formed in the end portion of the first adhesive member is pressed in the process of manufacturing the rigid-flex substrate, the projecting height of the rigid portion R of the rigid-flex boundary portion can be reduced.

Therefore, since the screen mask can be closely attached to the upper surface of the rigid portion R, the present invention can be applied to a die by a process of shorting and reflowing electrode pads generated in the process of printing an electrode pad on the upper surface of the rigid portion, It is possible to prevent short-circuiting of adjacent electrodes during mounting.

The foregoing detailed description is illustrative of the present invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation only as the same may be varied in scope or effect. Changes or modifications are possible within the scope. The foregoing embodiments are intended to illustrate the best mode of carrying out the invention and are not to be construed to limit the scope of the present invention to the practice of other situations known in the art for using other inventions such as the present invention, Various changes are possible. Accordingly, the foregoing description of the invention is not intended to limit the invention to the precise embodiments disclosed. It is also to be understood that the appended claims are intended to cover such other embodiments.

100. Rigid-flex substrate
110. FCCL substrate
110a. The first FCCL substrate
110b. The second FCCL substrate
111. Base member
112. Internal circuit layer
113. Coverlay
120. Adhesive member
121. First adhesive member
121a. home
122. Second adhesive member
130. Cover layer
131. External circuit layer
132. Solder resist layer
V1. The first vias
V2. Second vias
R. Rigid part
F. Flex

Claims (11)

In a rigid-flex substrate partitioned by a rigid portion and a flex portion,
A plurality of FCCL substrates stacked;
A first bonding member formed in the rigid region and interposed between the FCCL substrates;
And a cover layer formed on the rigid region and covering the outermost FCCL substrate,
Wherein the first adhesive member is provided with a groove opened in the direction of the flex portion.
The method according to claim 1,
Wherein the cover layer is bonded by a second bonding member formed on an outermost FCCL substrate.
The method according to claim 1,
In the FCCL,
A base member;
An internal circuit layer formed on the base member;
And a coverlay formed on the circuit layer.
3. The method of claim 2,
Wherein the base member is provided with a first via connecting the circuit layer.
The method according to claim 1,
Wherein the cover layer is formed by laminating an external circuit layer and a solder resist layer covering a part of an external circuit layer.
3. The method according to claim 1 or 2,
Wherein the first adhesive member and the second adhesive member are prepregs (ppg).
In a rigid-flex substrate in which a rigid portion and a flex portion are partitioned,
Preparing a first FCCL substrate;
Stacking a first bonding member on one side of the first FCCL of the rigid region and laminating a second bonding member on the other side;
Stacking a second FCCL substrate on the first FCCL substrate;
Laminating a second adhesive member on the second FCCL of the rigid region;
≪ / RTI > and laminating the cover layer.
8. The method of claim 7,
The first FCCL and the second FCCL may comprise:
Forming an internal circuit layer on the base member;
And laminating the coverlay on the internal circuit layer.
8. The method of claim 7,
Wherein the first adhesive member comprises:
Wherein the rigid portion adjacent to the flex portion and the flex portion is punched out and removed.
8. The method of claim 7,
Wherein the first adhesive member and the second adhesive member are prepregs (ppg).
9. The method of claim 8,
Wherein the base member is provided with a first via connecting the circuit layer.

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