KR100704921B1 - Method for manufacturing substrate using cushion sheet for staking multilayer substrate and substrate manufactured thereby - Google Patents

Abstract

By varying the configuration of the cushion paper, the pressure applied to the flexible part or the cavity of the multilayer board can be reduced, thereby improving the cupping or warping during lamination and unnecessary sticking between the substrate and the cover lay. Provided are a method of manufacturing a substrate using laminated cushion paper, and a substrate thereof. As a result, it is possible to provide an excellent substrate having improved bending reliability of the entire substrate and preventing cracks in the internal circuits, thereby reducing the defective rate. In the present invention, in the cushioning paper used for the uniform transmission of pressure when the multilayer board is laminated, the cushion paper uses a cushioning paper for stacking the multilayer board including a soft portion and a hard portion.

Cushion paper, soft part, hard part, flexible multi-layer board, semiconductor mounting board

Description

Method for manufacturing substrate using cushion sheet for staking multilayer substrate and substrate manufactured thereby

1 is a cushion paper according to a preferred embodiment of the present invention;

2 is a view showing a substrate manufacturing method according to an embodiment of the present invention; And

3 is a view showing a substrate manufacturing method according to another preferred embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10: hard part 15: soft part

110: base material 120: conductive layer

130: cover lay 140: prepreg

150: cushion paper 151: hard part

153: soft part

160: kraft sheet 165: release paper

170: cavity

200: pressure

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate manufacturing method using a cushion paper used for multilayer substrate stacking and a substrate thereof, and more particularly, to a method for manufacturing a substrate using cushion paper for stacking a multilayer board including a flexible multilayer board or a cavity.

When manufacturing a printed circuit board, a lamination process is performed using a constant temperature and pressure to bond a pre-flag of B-stage to a blackened CCL (Copper Clad Layer). Kraft paper is typically used for some cushioning during the hot press and even distribution of pressure on the substrate during this process. Cushion paper is used together with kraft paper to more evenly distribute the pressure on the substrate when stacking several layers of substrates having different stacking areas at the same time.

Due to the light weight, small size, high density, and high production speed of electronic devices, required parts are becoming smaller, lighter, and thinner. In addition, in order to increase the flexibility of exterior design design through the flexibility of components, flexible substrates having the advantages of both rigid and flexible substrates are needed. Also, a package for semiconductor mounting generally refers to a multilayer printed circuit board having a cavity in a substrate for mounting a semiconductor device.

When stacking a semiconductor mounting package including a multi-layered substrate or a cavity having a flexible portion and a rigid portion at the same time as the flexible substrate, it serves to uniformly transmit pressure, absorb damping vibration, and absorb layer space. The role of cushion paper becomes more important.

However, when the multilayer substrate is laminated, a cupping or warpage phenomenon may occur due to the application and pressure of non-uniform pressure. In addition, when pressurizing the laminated substrate conventionally, the same pressure is applied to the flexible portion and the rigid portion, and the laminated portion and the cavity portion, so that an undesirable sticking phenomenon occurs between the cover layer and the substrate forming the flexible portion. There is a problem. This leads to the generation of cracks in the internal circuit due to the reduced bending reliability of the entire substrate. That is, it may cause a problem in shape, conductivity, etc., which may be a cause of increasing the defective rate of the product.

The present invention provides a method for manufacturing a substrate that can reduce the failure rate by increasing the flexural reliability of the entire substrate and preventing cracks in the internal circuit by using a cushioning layer for stacking the multilayer substrate that can reduce the pressure applied to the flexible portion or the cavity of the multilayer substrate. to provide.

In addition, the present invention provides a substrate manufactured by the manufacturing method.

According to one aspect of the invention,

a) laminating a multilayer board;

b) laminating cushion papers on top and bottom of the laminated substrate;

c) stacking kraft paper on top of the cushion paper; And

d) applying pressure to the substrate passed through step c),

The cushion paper includes a soft portion and a hard portion,

The multilayer board is a flexible multilayer board including a flexible portion and a rigid portion,

The soft part of the cushion paper may propose a method of manufacturing a substrate laminated so as to be placed on top of the flexible part of the flexible multilayer board.

According to another aspect of the invention,

a) laminating a multilayer board;

b) laminating cushion papers on top and bottom of the laminated substrate;

c) stacking kraft paper on top of the cushion paper; And

d) applying pressure to the substrate passed through step c),

The cushion paper includes a soft portion and a hard portion,

The multilayer board is a flexible multilayer board including a flexible portion and a rigid portion,

The multilayer board is a package for semiconductor mounting including the cavity,

The soft part of the cushion paper may provide a substrate manufacturing method of stacking the upper portion of the cavity of the package for semiconductor mounting.

According to a preferred embodiment, the cushioning paper is a cushioning paper for multi-layer substrate lamination including polyvinyl chloride (PVC) resin, wherein the polyvinyl chloride resin may include a plasticizer.

Here, the plasticizer is a phthalic acid ester plasticizer, a trimellitic acid ester plasticizer, a phosphite acid ester plasticizer, an epoxy plasticizer, a polyester plasticizer, an aliphatic (aliphatic acid ester) plasticizer and chlorinated paraffin plasticizer may be one or more compounds selected from the group consisting of.

Here, the hard part may include 10 to 20 parts by weight of the plasticizer based on 100 parts by weight of the polyvinyl chloride resin, and the soft part may include 20 to 60 parts by weight of the plasticizer based on 100 parts by weight of the polyvinyl chloride resin. can do.

According to a preferred embodiment, the thickness of the cushion paper is 200 to 300㎛.

According to another aspect of the present invention, it is possible to provide a multi-layer substrate manufactured by the above-described substrate manufacturing method.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the substrate manufacturing method using a cushioning substrate for multilayer substrate stacking according to the present invention will be described in detail. In addition, prior to describing in detail the preferred embodiments of the present invention will be described with respect to the cushion paper.

Cushion paper used for lamination of multi-layered substrates is to be placed between kraft paper and the substrate in order to uniformly transmit pressure to the entire laminated substrate, and to sufficiently transmit pressure to each layer inside the substrate having different layers. As such cushioning paper, thermoplastic resins such as fluoropolymer (teflon), polyethylene, polypropylene, polystyrene, and polyvinyl chloride are used. Among them, polyvinyl chloride resin is preferably used as a cushioning paper because of good pressure transmission, damping vibration and shock absorption.

Polyvinyl chloride (PVC) resin is an amorphous polymer having a glass transition temperature (Tg) of 80 to 82 ° C. and a crystallinity of 10% or less. The theoretical melting point of the crystal part is 225 ° C., but a true melt state cannot be obtained. Resin. Thus, PVC flow is not a flow of molecules but rather a very small particle flow, such as domains or primary particles that form during polymerization. Because of this, PVC resin is low in glass transition temperature, but even at high temperatures, it can balance shock absorption or impact dispersion, and thus has suitable properties to be used as a cushion paper.

The degree of polymerization of the polyvinyl chloride resin may be selected from a conventional range in the art, for example, may be about 1000 to 1300 degree of polymerization.

In order to achieve the desired performance, the thermoplastic resin is mixed with various additives to make a final product that meets the characteristics. For example, PVC resin is a hard and brittle glassy material at room temperature, but when a plasticizer is added thereto, the melting temperature and the melt viscosity are lowered, which leads to a molding process. This removal of vertical breaks and ease of plastic working is called plasticization.

Taking PVC as an example, the action of this plasticizer will be described in more detail. The plasticizer is infiltrated between the PVC molecules and solvated at the polar part of the molecular chain and the polar part of the plasticizer, thereby preventing access of the molecular chain and simultaneously It enables micro-brown movement so that a flexible resin can be obtained at room temperature. When modeling the intermolecular plasticization mechanism of PVC resin by a polar plasticizer, it can be divided into the hinge type by a polar aromatic compound and the screen type by a polar aliphatic compound.

These plasticizers are classified by chemical structure, such as phthalic acid ester, trimellitic acid ester, phosphite acid ester, epoxy, polyester, and aliphatic. (aliphatic acid ester) and chlorinated paraffin. According to a preferred embodiment of the present invention, the plasticizer can be used without limitation within the usual range, and is not limited to the examples of specific plasticizers below. Phthalic acid ester is preferable as a plasticizer of double PVC resin, and its phthalic acid ester of 4-10 carbon atoms is more preferable.

(1) Phthalic acid-based plasticizer is the most commonly used plasticizer with excellent usability with PVC. It is DBP (Di-butyl-phthalate), DOP (Di-2-ethylhexyl phthalate), DINP (Di-isononyl phthalate), DIDP (Di- isodecyl phthalate) and BBP (Butyl benzyl phthalate), and DBP and BBP are mixed with other plasticizers according to their use rather than solely due to poor physical properties due to plasticizer loss (Loss). DINP and DIDP are low volatility. It is a plasticizer.

(2) Trimellitic acid esters have a low incompatibility and plasticization efficiency compared to phthalic acid plasticizers, while low volatility, oil resistance, heat resistance, etc. are particularly used for heat resistant wires. Specific examples include Tri-ethylhexyl trimellitate (TOTM), Tri-isononyl trimellitate (TINTM), and Tri-isodecyl trimellitate (TIDTM).

3) Phosphoric Acid Ester plasticizers have excellent flame retardancy, oil resistance, and electrical insulation, but they are used in combination with primary plasticizers because they have lower heat, light stability, and cold resistance than phthalic acid. Specific examples include Tri-cresyl phosphate (TCP), Tri-2-ethylhexyl phosphate (TOP), and cresyl diphenyl phosphate (CDP).

4) As an epoxy plasticizer, the double bond of unsaturated fatty acid glycerol ester is epoxidized with hydrogen peroxide or peracetic acid and classified into ESO (epoxidized soybean oil) and ELO (epoxidized linseed oil). These epoxy groups contain hydrochloric acid and improve the thermal stability due to synergistic effects in combination with metal soap stabilizers. In addition, it has an excellent plasticizing effect and is used as a cold resistant, non-toxic plasticizer.

4) Polyester plasticizers are used a lot of low-polymerization polyester having an average molecular weight of about 1,000 to 8,000. Since the molecular weight is larger than that of general plasticizers, there is almost no volatilization, extraction, or transition phenomenon, and thermal stability is good, but weather resistance is poor. Care must be taken when mixing due to the high viscosity.

5) Aliphatic Acid Ester plasticizers are secondary plasticizers prepared by reacting linear dicarboxylic acids with branched alcohols, and esters tend to crystallize at high temperatures. DOA (di-2-ethylhexyl adipate), DOZ (di-2-ethylhexyl azelate), DIDA (di-isodecyl adipate), etc. belong to this and are widely used as cold-resistant plasticizers due to low temperature flexibility.

6) Chlorinated paraffin plasticizer is a compound having a PVC-like structure and has a chlorine content of 35 to 70%. It is conventionally used as a low cost secondary plasticizer. Cereclor S-45 (chlorine content 43-45%) and S-52 (chlorine content 50-52%) are widely used and used in combination with phthalate and phosphate plasticizers. It is inferior in cold resistance, thermal stability and weather resistance, and the higher the chlorine content, the better the flame retardancy, compatibility and performance.

The addition of such plasticizers can impart flexibility to thermoplastic resins, such as PVC resins, and lower the glass transition temperature (Tg). Therefore, by adjusting the content of the plasticizer added to the resin such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), it is possible to manufacture a cushioning paper including a soft portion. Among them, a PVC resin which is inexpensive in manufacturing cost and which can control fine viscosity and pressure is preferable.

1 is a cushion paper according to a preferred embodiment of the present invention. Referring to FIG. 1, the cushion paper 150 of the present invention includes a soft part 153 having improved flexibility and elasticity by adjusting the content of the hard part 151 and the plasticizer as in the related art. The amount of the plasticizer contained in the soft portion 132 is greater than the amount contained in the hard portion 151, so that the cushioning paper 150 can achieve the desirable purpose of the present invention. However, the preferred amount of plasticizer added to the soft portion depends on the thickness of the layer, the components of the layer, the strength of the external pressure 200 upon lamination, the external temperature, and the like. According to a preferred embodiment of the present invention, in the PVC cushion paper, the hard part contains 10 to 20 parts by weight of a plasticizer with respect to 100 parts by weight of the PVC resin, the soft part of the hard part 20 to 60 parts by weight of plasticizer with respect to 100 parts by weight of PVC resin It is included in wealth. According to a preferred embodiment of the present invention, the thickness of the cushion paper is preferably 200 to 300 μm.

As described above, the resin composition included in the soft portion and the resin composition contained in the hard portion may be discharged onto a release paper and pressed together, thereby manufacturing the cushion paper of the present invention. Here, the press conditions are the same as in the case of manufacturing a cushion paper made of a hard portion in the art, for example, the press temperature may be carried out at about 160 ℃.

In addition, the cushion composition of the present invention may be produced by supplying and molding the resin composition included in the soft portion and the resin composition included in the hard portion, respectively, on a mold.

The manufacturing method of such a cushion paper can be carried out by a conventional method of manufacturing a cushion paper made of a hard portion.

In the present invention, the release paper 165 may be selected within a conventional range in the art, and is not particularly limited.

In addition to the plasticizer in the usual range in the art, additives that may be included in the cushion paper may be further added.

In addition, the cushion paper 150 of the present invention is to relatively reduce the pressure that is loaded when laminated on the flexible portion or the cavity of the multilayer substrate, for example, a flexible multilayer substrate or a semiconductor mounting substrate compared with the rigid portion or the substrate stacking portion. Therefore, the soft portion 153 of the cushion paper 150 is preferably manufactured to have the same size as the size of the flexible portion or the cavity of the substrate.

The cushion paper 150 of the present invention has been described above. Hereinafter, a method of manufacturing a substrate using the cushion paper will be described.

According to a preferred embodiment of the present invention, a substrate manufacturing method includes the steps of a) laminating a multi-layer substrate, b) laminating the cushion paper 150 of the present invention on the upper and lower portions of the laminated substrate; c) laminating the kraft paper 160 on top of the cushion paper 150, and d) applying pressure to the substrate passed through step c). In addition, the release paper 165 may be further stacked on the upper and lower portions of the cushion paper 150 within the conventional range of the art, and a duooil may be further stacked on the kraft paper. It is also possible to omit some layers within the usual scope of the art.

2 shows a method of manufacturing a substrate according to a preferred embodiment of the present invention. Referring to FIG. 2, the multi-layer substrate shows one embodiment of a flexible substrate, but the flexible substrate of the present invention is not limited thereto. In this case, the multilayer substrate includes a hard part 10 and a flexible part 15. Here, the hard part 10 may have a structure having a mechanical strength, such as a conventional hard board in the art. According to an embodiment, the prepreg 140 and the substrate 110 reinforced with glass fibers are sequentially stacked on a core substrate such as a copper clad laminate (CCL). Herein, a polyimide substrate may be used to impart a predetermined strength.

The flexible portion 15 may also have the same structure as a flexible substrate including a conventional FCCL in the art. According to an embodiment, the conductive layer 120 is formed on the substrate 110 by a connecting means such as an adhesive, and the coverlay 120 is bonded to protect the exposed conductive layer 120. A cavity 170 is included between the substrate 110 and the coverlay. This coverlay may comprise, for example, acrylate, epoxy or polyimide.

In order to compress the flexible substrate, the cushion paper 150 is stacked on upper and lower portions of the stacked substrate, and the kraft paper 160 is stacked on the cushion paper 170 to apply a pressure 200 to manufacture a multilayer board. Here, in order to apply less pressure to the flexible portion 15 of the substrate, it is preferable to press the soft portion 153 of the cushion paper 150 to correspond to the upper portion of the flexible portion 15. A suitable temperature for producing the flexible substrate through these steps is 120 to 200 ℃. Release paper 165 is stacked on the upper and lower portions of the cushion paper 150.

3 is a view showing a substrate manufacturing method according to another preferred embodiment of the present invention. Referring to FIG. 3, a multi-layer substrate including a cavity, for example, a package for semiconductor mounting is shown. However, the multilayer board or the package for semiconductor mounting including the cavity of the present invention is not limited thereto and refers to a conventional one of the art. Several substrates including the cavity 170 are laminated on the core substrate 110 such as a conventional copper clad laminate using an adhesive such as the prepreg 140.

In order to compress the semiconductor package package, the cushion paper 150 is stacked on upper and lower portions of the stacked substrates, and the kraft paper 160 is stacked on the cushion paper 170 to apply pressure 200. Here, in order to apply less pressure to the cavity 17 of the substrate, it is preferable to press the soft part 153 of the cushion paper 150 to be positioned above the cavity 17. Release paper 165 is stacked on the upper and lower portions of the cushion paper 150.

In the above, the cushioning paper for multi-layer substrate stacking and the method of manufacturing the substrate using the same are described below.

<Example 1>

15 g of DOP was added to 100 g of polyvinyl chloride resin having a degree of polymerization of 1000 ± 50 to prepare a composition corresponding to the hard part. Also, 25 g of DOP was added to the same resin to prepare a composition corresponding to the soft portion. It is increased when the soft part and the hard part are pressed between the soft part and the hard part while laminating the hard part composition to a size corresponding to the hard part of the substrate on the release paper and laminating the soft part composition to the size corresponding to the soft part of the substrate. The space was given at regular intervals. This was pressed at 160 ° C. to prepare 0.25 mm cushion paper combined with release paper.

<Example 2>

The hard part composition and the soft part composition of Example 1 were separated, respectively, and fed into a mold of the corresponding area, and press molded to prepare 0.25 mm cushion paper.

The present invention is not limited to the above embodiments, and many variations are possible by those skilled in the art within the spirit of the present invention.

As described above, the present invention provides a cushioning paper for stacking multilayer boards which can reduce the pressure applied to the flexible portion or the cavity of the multilayer board by varying the configuration of the cushioning paper. In another aspect, the present invention provides a cushioning paper for multi-layer substrate stacking to improve the cupping or twisting phenomenon, unnecessary sticking phenomenon between the substrate and the coverlay.

In addition, the present invention provides a substrate manufacturing method that can increase the bending reliability of the entire substrate and prevent the cracks in the internal circuit to reduce the defective rate and an excellent substrate manufactured thereby.

Claims (10)

a) laminating a multilayer board; b) laminating cushion papers on top and bottom of the laminated substrate; c) stacking kraft paper on top of the cushion paper; And d) applying pressure to the substrate passed through step c), The cushion paper includes a soft portion and a hard portion, The multilayer board is a flexible multilayer board including a flexible portion and a rigid portion, And stacking the soft portion of the cushion paper so as to lie on top of the flexible portion of the flexible multilayer board. a) laminating a multilayer board; b) laminating cushion papers on top and bottom of the laminated substrate; c) stacking kraft paper on top of the cushion paper; And d) applying pressure to the substrate passed through step c), The cushion paper includes a soft portion and a hard portion, The multilayer board is a flexible multilayer board including a flexible portion and a rigid portion, The multilayer board is a package for semiconductor mounting including the cavity, And the soft portion of the cushion paper is laminated so as to be placed on an upper portion of the cavity of the semiconductor mounting package. The method according to claim 1 or 2, The cushioning paper is a substrate manufacturing method of the cushioning paper for multilayer boards containing polyvinyl chloride (PVC) resin. The method according to claim 3, The polyvinyl chloride resin is a substrate manufacturing method comprising a plasticizer. The method according to claim 4, The plasticizer is a phthalic acid ester plasticizer, a trimellitic acid ester plasticizer, a phosphiteic acid ester plasticizer, an epoxy plasticizer, a polyester plasticizer, an aliphatic acid ester) and at least one compound selected from the group consisting of chlorinated paraffin plasticizers. The method according to claim 4, The hard part is a substrate manufacturing method comprising 10 to 20 parts by weight of the plasticizer with respect to 100 parts by weight of the polyvinyl chloride resin. The method according to claim 4, The soft part is a substrate manufacturing method comprising 20 to 60 parts by weight of the plasticizer with respect to 100 parts by weight of the polyvinyl chloride resin. The method according to claim 1 or 2, The substrate manufacturing method of the cushion paper has a thickness of 200 to 300㎛. A multilayer substrate prepared by the method of manufacturing a substrate of claim 1. A multilayer substrate manufactured by the substrate manufacturing method of claim 2.

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