KR20220072634A - Multi-layered film for spacer and method of forming spacer using the same - Google Patents

Abstract

Disclosed are a multilayer film for a spacer and a method of forming a spacer using the same. The multilayer film for spacers according to the present invention is a first film having a weight reduction rate of 2% or less at 200° C. and a coefficient of linear expansion at 100° C. or less of 50 ppm/° C. or less, an adhesive layer disposed under the first film, and a lower portion of the adhesive layer It includes a first pressure-sensitive adhesive layer and a second film disposed under the first pressure-sensitive adhesive layer and having a thickness of 40 to 300 μm.

Description

Multilayer film for spacer and method of forming spacer using the same

The present invention relates to a film for a spacer for manufacturing a spacer applied to a multi-chip package.

The present invention also relates to a method of forming a spacer in a multi-chip package.

With the development of semiconductor device manufacturing technology, many studies have been made on miniaturization and multifunctionality of electronic devices.

A multi-chip package (MCP) technology is one of semiconductor chip package technologies, and is a technology for implementing the same type of semiconductor chips or different types of semiconductor chips into a single package.

The multi-chip package technology can realize high-speed transmission in a narrow package area, so it has advantages in size and weight compared to implementing each semiconductor chip as a separate package.

In order to obtain an effect of size reduction in a multi-chip package, it is necessary to stack a plurality of semiconductor chips and arrange them in one package. In this case, a spacer is used.

For example, in a package in which two semiconductor chips are stacked, one semiconductor chip is directly attached to the package substrate, but the other semiconductor chip is not directly attached to the package substrate. A spacer serves to support a semiconductor chip that is not directly attached to the package substrate.

The spacer is generally formed of a metal, a polymer, a photosensitive resist, or the like. When the spacer is formed of a metal or a photosensitive resist, a method of removing the portion other than the spacer by etching after deposition or coating of the metal or the photosensitive resist on the package substrate may be used. When the spacer is formed of a metal or a polymer, a method of manufacturing the spacer in a predetermined shape and bonding the spacer on a package substrate may be used.

A method of forming a spacer by etching after depositing or coating a metal or a photosensitive resist requires a complicated process such as photolithography and wastes materials. In the method of manufacturing a spacer having a predetermined size and bonding the spacer on a package substrate, it is not easy to accurately manufacture a spacer of a desired size, and it is difficult to accurately attach the spacer on the package substrate.

In addition, there is a method of manufacturing a spacer by using (cutting) a dummy wafer and bonding the spacer on a package substrate. In this method, waste of the dummy wafer is a problem.

An object of the present invention is to provide a multilayer film for a spacer capable of a dicing process without using a dummy wafer.

Another object to be solved by the present invention is to provide a method of forming a spacer using a dicing process without using a dummy wafer.

The technical problem to be achieved by the present invention is not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

The multilayer film for a spacer according to the present invention for solving the above problems is a first film having a weight reduction rate of 200° C. of 2% or less, a coefficient of linear expansion at 100° C. or less of 50 ppm/° C. or less; an adhesive layer disposed under the first film; a first pressure-sensitive adhesive layer disposed under the adhesive layer; and a second film disposed under the first pressure-sensitive adhesive layer and having a thickness of 40 to 300 μm.

The first film may include at least one of polyimide, polyetheretherketone, polyamideimide, polyphenylene sulfide, polyphthalamide, polysulfone, polyethersulfone, and polyetherimide.

The second film may include a polyolefin-based resin.

The first pressure-sensitive adhesive layer may include an acrylic compound.

The adhesive layer may include an acrylic compound and an epoxy resin.

An edge of the upper surface of the first pressure-sensitive adhesive layer may be exposed.

The adhesive force between the first pressure-sensitive adhesive layer and the adhesive layer may be 20 to 200 N/m before UV curing of the first pressure-sensitive adhesive layer, and 15 N/m or less after UV curing of the first pressure-sensitive adhesive layer.

a second pressure-sensitive adhesive layer disposed on the first film; and a cover film disposed on the second pressure-sensitive adhesive layer.

A method of forming a spacer according to the present invention for solving the above problems includes a fixing step of fixing the multilayer film for a spacer to a frame; a dicing step of dicing the multilayer film for spacers into individual pieces; Pick-up step of picking up a spacer made of a first film and an adhesive layer from the individualized result; and an attaching step of attaching the picked up spacers on the package substrate.

In the multilayer film for spacers, an edge of an upper surface of the first pressure-sensitive adhesive layer may be exposed, and a frame may be disposed on an edge of an upper surface of the first pressure-sensitive adhesive layer.

The multilayer film for spacers according to the present invention includes a second film having a thickness of 40 to 300 μm. Accordingly, in the dicing process for splitting the first film into individual spacers support, the second film can provide sufficient support.

Therefore, it is possible to manufacture the separated spacer of a desired size from the multilayer film for spacers according to the present invention by using the dicing process. In addition, the spacers separated through dicing can be easily attached to the package substrate through the pick-up process and the attachment process.

In addition, the present invention has an effect that a dicing process is possible without using a dummy wafer by forming a spacer.

1 is a cross-sectional view schematically illustrating an example of a multi-chip package including a spacer.
2 is a cross-sectional view schematically illustrating another example of a multi-chip package including a spacer.
3 is a cross-sectional view schematically illustrating another example of a multi-chip package including a spacer.
4 is a cross-sectional view schematically illustrating another example of a multi-chip package including a spacer.
5 is a cross-sectional view schematically illustrating a multilayer film for a spacer according to an embodiment of the present invention.
6 is a cross-sectional view schematically showing a multilayer film for a spacer according to another embodiment of the present invention.
7 schematically shows a method of forming a spacer using a dicing process according to the present invention.
8 is a plan view corresponding to (a), (b) and (c) of FIG. 7 .

The objects, 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 and preferred embodiments. In this specification, terms such as "one side", "the other side", and "both sides" are used to distinguish one component from another component, and the component is not limited by the terms. Hereinafter, in describing the present invention, detailed descriptions of related known technologies that may unnecessarily obscure the gist of the present invention will be omitted.

Hereinafter, a multilayer film for a spacer according to the present invention and a method of forming a spacer using the same will be described in detail with reference to the drawings.

1 is a cross-sectional view schematically illustrating an example of a multi-chip package including a spacer.

Referring to FIG. 1 , a first semiconductor chip unit 120 is disposed on a package substrate 110 . The first semiconductor chip unit 120 includes a first adhesive layer 121 and a first semiconductor chip 122 . The first adhesive layer 121 serves to attach the first semiconductor chip 122 to the package substrate 110 . The first semiconductor chip 122 may be electrically connected to the package substrate 110 through a wire 125 .

A spacer 130 is disposed around the first semiconductor chip unit 120 . The spacer 130 includes an adhesive layer 131 and a support 132 . The adhesive layer 131 serves to attach the support 132 to the substrate.

The second semiconductor chip unit 140 is disposed on the spacer 130 . The second semiconductor chip unit 140 includes a second adhesive layer 141 and a second semiconductor chip 142 . The second adhesive layer 141 serves to attach the second semiconductor chip 142 to the support 132 of the spacer 130 . The second semiconductor chip 142 may be electrically connected to the package substrate 110 through a wire 145 . As another example, the second semiconductor chip 142 may be electrically connected to the package substrate 110 through a via hole passing through the spacer.

The first semiconductor chip unit 120 , the spacer 130 , and the second semiconductor chip unit 140 are disposed on the package substrate 110 , and after a wire bonding process is performed, a molding unit 150 sealing them is performed. is formed The molding part 150 may be formed of an encapsulant such as an epoxy resin.

1 , the height of the spacer 130 may be higher than the height of the first semiconductor chip unit 120 . Through this, the second semiconductor chip unit 140 may be stacked using the spacer 130 as a support. As another example, the height of the spacer 130 may be the same as the height of the first semiconductor chip unit 120 . In addition, since the height of the spacer 130 is higher than the height of the first semiconductor chip unit 120 or the height of the spacer 130 is the same as the height of the first semiconductor chip unit 120 , the spacer 130 is and the effect that the first semiconductor chip unit 120 is buried by the second semiconductor chip unit 140 may be obtained.

2 to 4 are cross-sectional views schematically illustrating another example of a multi-chip package including a spacer.

2 to 4, second semiconductor chip units (140-1 to 140-4 in FIG. 2, 140-1 to 140-5 in FIG. 3, and 140-1 to 140-7 in FIG. 4) are shown in FIG. Like the illustrated example, it may be electrically connected to another second semiconductor chip unit or the package substrate 110 through a wire (not shown) or a via hole (not shown).

Even in the case of the multi-chip packages shown in FIGS. 2 to 4 , the semiconductor chip units may be stacked through the spacers 130 disposed on the package substrate 110 .

5 is a cross-sectional view schematically illustrating a multilayer film for a spacer according to an embodiment of the present invention.

Referring to FIG. 5 , the illustrated multilayer film for spacers includes a first film 510 , an adhesive layer 520 , a second film 530 , and a first pressure-sensitive adhesive layer 535 .

first film

The first film 510 is a portion that will become the support 132 of the spacer 130 of FIGS. 1 to 4 . The spacer 130 is required to have heat resistance in a semiconductor chip package manufacturing process and use of the semiconductor chip package.

Therefore, the first film 510 preferably has heat resistance. Accordingly, the first film 510 in the present invention was limited to a weight loss rate of 2% or less at 200°C and a coefficient of linear expansion at 100°C or less of 50 ppm/°C or less. When the weight loss rate of 200°C exceeds 2% or the coefficient of linear expansion at 100°C or lower exceeds 50 ppm/°C, it can be considered that the heat resistance is not good.

The first film 510 having the above heat resistance includes at least one of polyimide, polyetheretherketone, polyamideimide, polyphenylene sulfide, polyphthalamide, polysulfone, polyethersulfone, and polyetherimide. can do. Among these, it is more preferable to use polyimide or polyether ether ketone which is more excellent in heat resistance as a material of a 1st film.

The first film 510 may have a single-layer structure. As another example, the first film 510 may have a multilayer structure.

The thickness of the first film 510 may be determined according to the thickness of the target spacer support ( 132 in FIG. 1 ).

adhesive layer

The adhesive layer 520 is a portion to be the adhesive layer 131 of the spacer 130 of FIGS. 1 to 4 .

The adhesive layer 520 is disposed under the first film 510 . The adhesive layer 520 may have a thickness of about 3 to 60 μm, but is not limited thereto.

In the present invention, the adhesive layer 520 may include an acrylic compound. In addition, the adhesive layer 520 may include an epoxy resin for curing. As an epoxy resin, bisphenol A type, bisphenol F type, bisphenol S type, bisphenol AF type, biphenyl type, naphthalene type, fluorene type, phenol novolak type, orthocresol novolak type, glycidylamine type, etc. are 1 More than one species can be used.

In addition, one or more additives may be additionally included in the adhesive layer 520 . The additive may include, but is not limited to, a curing agent (phenolic resin, amines, etc.), inorganic particles (silica, aluminum hydroxide, alumina, titanium dioxide, calcium carbonate, etc.), a curing accelerator, and a silane coupling agent.

The acrylic compound usable for the adhesive layer 520 and the first pressure-sensitive adhesive layer 535 and the second pressure-sensitive adhesive layer 545 to be described later preferably includes a monomer derived from (meth)acrylic acid ester.

As the (meth)acrylic acid ester for forming the monomer of the acrylic compound, (meth)acrylic acid alkyl ester, (meth)acrylic acid cycloalkyl ester, (meth)acrylic acid aryl ester, etc. may be presented.

The acrylic compound may further include a carboxyl group-containing monomer, an acid anhydride monomer, a hydroxyl group-containing monomer, a glycidyl group-containing monomer, a sulfonic acid group-containing monomer, a phosphoric acid group-containing monomer, an acrylonitrile-containing monomer, and the like.

In addition, the acrylic compound may further include one or more polyfunctional monomers. The polyfunctional monomer is hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol Di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy (meth) acrylate (ie, polyglycy dil (meth) acrylate), polyester (meth) acrylate, urethane (meth) acrylate, and the like may be presented.

second film

The second film 530 is disposed under the adhesive layer 520 . A first pressure-sensitive adhesive layer 535 is disposed between the second film 530 and the adhesive layer 520 . The first pressure-sensitive adhesive layer 535 may be formed by casting coating and drying directly on the second film 530 , or may be formed by laminating the second film 530 .

The second film 530 serves as a support in the dicing process. Accordingly, in the present invention, the thickness of the second film 530 is limited to 40 μm or more. When the thickness of the second film 530 is less than 40 μm, it is difficult to secure expanding and pickup properties. In addition, when the thickness of the second film 530 exceeds 300 μm and is excessively thick, there is a possibility that an expansion failure and a pickup failure may occur. Therefore, the thickness of the second film 530 is preferably 300 μm or less. The thickness range of the second film 530 may be 40 to 300 μm, preferably 50 to 250 μm, more preferably 60 to 200 μm, and most preferably 70 to 150 μm.

The second film 530 may use a polyolefin-based resin. Specifically, the second film 530 is a low-density polyethylene, medium-density polyethylene, high-density polyethylene, ultra-low-density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homo polypropylene, polybutene, polymethylpentene, ethylene-vinyl acetate copolymer It may be formed of a material including at least one of a copolymer, an ionomer resin, an ethylene-(meth)acrylic acid copolymer, an ethylene-(meth)acrylic acid ester copolymer, an ethylene-butene copolymer, and an ethylene-hexene copolymer.

The second film 530 may have a single-layer structure, or as another example, a multi-layer structure.

The first pressure-sensitive adhesive layer 535 may be formed to a thickness of about 5 to 30 μm, but is not limited thereto. The first pressure-sensitive adhesive layer 535 may include an acrylic compound. However, unlike the adhesive layer 520 , the first pressure-sensitive adhesive layer 535 may not include an epoxy resin.

In addition, one or more additives may be additionally included in the first pressure-sensitive adhesive layer 535 . The additive may be a thermal curing agent such as an isocyanate curing agent or a photoinitiator such as benzophenone, but is not limited thereto.

The first pressure-sensitive adhesive layer 535 may exist in a B-stage state until UV curing in the dicing process.

On the other hand, the adhesive force between the first pressure-sensitive adhesive layer 535 and the adhesive layer 520 may represent 20 to 200 N/m before UV curing of the first pressure-sensitive adhesive layer, and 15 N/m or less after UV curing. . This is to ensure that only the separated first film 510 and the adhesive layer 520 are picked up in the pickup process after dicing. The control of the adhesion of the first pressure-sensitive adhesive layer 535 may be performed, for example, by controlling the pressure-sensitive adhesive component. For example, the acrylic compound of the first pressure-sensitive adhesive layer 535 is based on 100 parts by weight of acrylic acid-2-ethylhexyl, 10 to 40 parts by weight of acrylic acid-2-hydroxyethyl, 2-methacryloyloxyethyl isocyanate 10 to 45 parts by weight of the copolymer may be one comprising a copolymerized reaction.

Meanwhile, referring to FIG. 5 , the edge of the upper surface of the first pressure-sensitive adhesive layer 535 may be exposed. This is to facilitate fixing of the film for spacers to the ring frame in the dicing process. This will be described later with reference to FIG. 7 .

6 is a cross-sectional view schematically showing a multilayer film for a spacer according to another embodiment of the present invention.

The multilayer film for spacers shown in FIG. 6 includes a first film 510 , an adhesive layer 520 , a second film 530 , and a first pressure-sensitive adhesive layer 535 , like the multilayer film for spacers shown in FIG. 5 . include In the multilayer film for spacers shown in FIG. 6 , the first film 510 , the adhesive layer 520 , the second film 530 , and the first pressure-sensitive adhesive layer 535 are the same as those described in FIG. 5 , and thus descriptions thereof will be omitted. decide to do

Meanwhile, the multilayer film for spacers shown in FIG. 6 further includes a cover film 540 and a second pressure-sensitive adhesive layer 545 .

cover film

The cover film 540 acts as a protective film for protecting the first film 510 before the dicing process. The cover film 540 is previously removed in the dicing process. The cover film 540 may be formed of a material such as polyethylene terephthalate, polyethylene, polypropylene, polyvinyl chloride, polycarbonate, polyimide, etc., but is not limited thereto.

A second pressure-sensitive adhesive layer 545 may be disposed between the cover film 540 and the first film 510 .

The second pressure-sensitive adhesive layer 545 may be formed to a thickness of about 3 to 30 μm, but is not limited thereto. Like the first pressure-sensitive adhesive layer 535 , the second pressure-sensitive adhesive layer 545 may include an acrylic compound but not an epoxy resin. The second pressure-sensitive adhesive layer 545 may further include one or more additives such as a curing agent such as a phenol-based resin and amines, or a silane coupling agent.

Meanwhile, referring to FIG. 6 , the edge of the lower surface of the second pressure-sensitive adhesive layer 545 may be exposed. This is to facilitate the removal of the cover film 540 and the second pressure-sensitive adhesive layer 545 immediately before the dicing process.

How to form a spacer

7 schematically shows a method of forming a spacer using a dicing process according to the present invention. 8 is a plan view corresponding to (a), (b) and (c) of FIG. 7 , which is referred to when describing the method of FIG. 7 .

Referring to FIG. 7 , the method for forming a spacer according to the present invention includes a fixing step, a dicing step, a picking step and an attaching step.

First, as in the example shown in FIG. 7 (a), a multilayer for spacers including a first film 510, an adhesive layer 520, a first pressure-sensitive adhesive layer 535 and a second film 530 from above. prepare the film For example, by removing the second pressure-sensitive adhesive layer 545 and the cover film 540 from the multilayer film for spacers shown in FIG. 6 , a multilayer film for spacers such as the example shown in (a) of FIG. 7 can be prepared. have.

Then, as in the examples shown in FIGS. 7 (b) and 8 (b), the multilayer film for spacers is fixed. A frame 610 such as a ring frame may be used to fix the multilayer film for spacers. On the other hand, when the edge of the upper surface of the first pressure-sensitive adhesive layer 535 is exposed in the multilayer film for spacers, the frame 610 can be easily disposed on the edge of the upper surface of the first pressure-sensitive adhesive layer 535 . have.

Thereafter, as in the example shown in FIG. 7C , the multilayer film for spacers is diced along a predetermined cutting line SL using a dicing saw 601 or a laser to separate into pieces. do. As described above, in the case of the multilayer film for a spacer according to the present invention, the second film 530 having a thickness of 40 to 300 μm is included separately from the first film 510 serving as a support for the spacer. The second film 530 having a thickness of 40 to 300 μm included in the multilayer film for spacers may provide sufficient support in the dicing process.

Thereafter, as in the example shown in (d) of FIG. 7 , a spacer consisting of a first film 510 and an adhesive layer 520 in the resultant fragmented using a pushing means 620 and an adsorption means 630 is removed. pick up

Thereafter, as in the example shown in FIG. 7E , a spacer formed of the first film 510 and the adhesive layer 520 is attached to the package substrate 110 .

<Example>

Hereinafter, preferred examples are presented to help the understanding of the present invention. However, the following examples are only provided for easier understanding of the present invention, and the contents of the present invention are not limited by the following examples.

Preparation of adhesive film for spacer

A first film (polyimide), an acrylic-epoxy adhesive layer, an acrylic pressure-sensitive adhesive layer, and a second film (polyethylene film) were prepared from above to prepare multilayer films for spacers (refer to FIG. 7 (a)), and the second film Only the thickness of was changed. After that, the ring frame was bonded to the upper edge of the acrylic pressure-sensitive adhesive layer to fix the multilayer film for spacers, and then, using a dicing device, DFD-6361 (manufactured by Disco), each specimen was individually measured to be 9mm × 12mm. After the dicing process of dividing the spacers into spacers, the individual spacers were expanded and picked up using a pickup equipment SPA-300 (manufactured by Shinkawa Co., Ltd.).

The following evaluations were performed, and are shown in Table 1.

Expanding evaluation: After dicing, in the pickup equipment, the expanding process of expanding the second film is performed in order to distinguish between chips and to facilitate pickup. was measured

Pick-up evaluation: The height of the needle pin of the pickup equipment was picked up at 0.35 mm and 0.45 mm, and when the pickup success rate was more than 95%, it was evaluated as good (O), and when it was less than 95%, it was evaluated as bad (X).

[Table 1]

Referring to Table 1, in the case of specimens 2 to 6 having a thickness of 40 to 300 μm of the second film, no defects were observed in the expanding process and the pickup process. In contrast, in the case of Specimen 1 having a thickness of less than 40 μm of the second film, the expanding process did not proceed due to tearing of the film, and as a result, the pickup process did not proceed either. On the other hand, in the case of Specimen 7 in which the thickness of the second film exceeds 300 μm, the expandable range was only 1 mm, and pickup failure was confirmed at the needle pin height of 0.45 mm of the pickup equipment.

Therefore, it is preferable that the thickness of the second film is 40 to 300 μm.

Although the present invention has been described as described above, the present invention is not limited by the embodiments disclosed herein, and it is apparent that various modifications may be made by those skilled in the art within the scope of the technical idea of the present invention. In addition, even if the effect of the configuration of the present invention is not explicitly described and described while describing the embodiment of the present invention, it is natural that the effect predictable by the configuration should also be recognized.

110: package substrate
120: first semiconductor chip unit
130: spacer
131: adhesive layer
132: support
140: second semiconductor chip unit
150: molding part
510: first film
520: adhesive layer
530: second film
535: first pressure-sensitive adhesive layer
540: cover film
545: second pressure-sensitive adhesive layer
601: Saw for dicing
610: frame
620: pushing means
630: means of adsorption

Claims (10)

A first film having a weight loss rate of 2% or less at 200° C. and a coefficient of linear expansion at 100° C. or less of 50 ppm/° C. or less;
an adhesive layer disposed under the first film;
a first pressure-sensitive adhesive layer disposed under the adhesive layer; and
and a second film disposed under the first pressure-sensitive adhesive layer and having a thickness of 40 to 300 μm.
The method of claim 1,
The first film is a multilayer for a spacer, characterized in that it comprises at least one of polyimide, polyether ether ketone, polyamide imide, polyphenylene sulfide, polyphthalamide, poly sulfone, polyether sulfone and polyether imide. film.
According to claim 1,
The second film is a multilayer film for spacers, characterized in that it comprises a polyolefin-based resin.
According to claim 1,
The first pressure-sensitive adhesive layer is a multilayer film for spacers, characterized in that it includes an acrylic compound.
According to claim 1,
The adhesive layer is a multilayer film for spacers, characterized in that it comprises an acrylic compound and an epoxy resin.
According to claim 1,
The multilayer film for spacers, characterized in that the edge of the upper surface of the first pressure-sensitive adhesive layer is exposed.
According to claim 1,
The adhesive force between the first pressure-sensitive adhesive layer and the adhesive layer is 20 to 200 N/m before UV curing of the first pressure-sensitive adhesive layer, and 15 N/m or less after UV curing of the first pressure-sensitive adhesive layer. Spacer, characterized in that for multilayer films.
According to claim 1,
a second pressure-sensitive adhesive layer disposed on the first film; and
The multilayer film for spacers, characterized in that it further comprises a cover film disposed on the second pressure-sensitive adhesive layer.
A fixing step of fixing the multilayer film for spacers according to claim 1 to a frame;
a dicing step of dicing the multilayer film for spacers into individual pieces;
Pick-up step of picking up a spacer made of a first film and an adhesive layer from the individualized result;
and an attaching step of attaching the picked up spacers onto a package substrate.
10. The method of claim 9,
The multilayer film for the spacer has an exposed edge of the upper surface of the first pressure-sensitive adhesive layer,
A method for forming a spacer, characterized in that a frame is disposed on an edge of the upper surface of the first pressure-sensitive adhesive layer.

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