KR102074456B1 - Method for preparing semiconductor package - Google Patents

Abstract

The present invention relates to a method of manufacturing a semiconductor package, comprising the steps of providing a substrate array having a plurality of semiconductor elements, manufacturing a mold having irregularities corresponding to the shape of the substrate array, Forming a first metal layer, forming an adhesive film on an exposed surface of the first metal layer, bonding a substrate array having the plurality of semiconductor elements to the adhesive film, and removing a mold from the first metal layer And forming a second metal layer on an exposed surface of the first metal layer, wherein the first metal layer is an electroless plating layer, and the second metal layer is an electrolytic plating layer.

Description

Manufacturing method of semiconductor package {METHOD FOR PREPARING SEMICONDUCTOR PACKAGE}

The present invention relates to a method for manufacturing a semiconductor package, and more particularly, to an electromagnetic shielding layer capable of preventing the outflow of electromagnetic waves generated during operation of a semiconductor device to the outside without sputtering deposition process or conductive ink treatment. It relates to a method for manufacturing a semiconductor package formed easily while having.

Recently, semiconductor manufacturing technology has been developed in a trend of high integration, thinness, and miniaturization, and there are various types of highly integrated semiconductor devices. These semiconductor packages are widely used in various fields such as smartphones, displays, home appliances, automobiles, industrial devices, and medical devices. Recently, the miniaturization, light weight, and thinness of the semiconductor package are accelerated. The importance of electromagnetic shielding to eliminate noise caused by electromagnetic shielding (electromagnetic interference, EMI / electromagnetic compatibility, EMC) of furnace semiconductor packages is increasing.

Various countermeasures for electromagnetic shielding have been proposed. For example, a metal cover is mounted on a semiconductor package, but the cost of the product, thinning, and miniaturization are raised due to the increase in the number of parts and processes. A method of forming a shielding layer using a spray method has been proposed. However, when it is not applicable to an etching solution or a package having a problem with chemical treatment, or due to a problem of poor coating efficiency and a thick and uneven film quality, the film quality is excellent, so that the thickness is 1/5 to 1/10 or less than the conventional method. A sputtering electromagnetic shielding layer has been proposed that has the same or superior electromagnetic shielding function, has excellent adhesion to package mold, and is excellent in environmental problems and forms a uniform film. The sputtering method in which a thin film is deposited on a target surface by applying a physical force to a metal material using such a plasma also has a disadvantage in that side shielding is difficult compared to top shielding and requires expensive equipment (see related Korean Patent Registration No. 10-1479248).

Accordingly, a conductive ink process in which a conductive ink is first thinly processed and a copper foil shield is formed has been proposed, but it is difficult to provide a flatness of a layer easily.

The problem to be solved by the present invention is to manufacture a method for manufacturing a semiconductor package having an electromagnetic shielding layer that can prevent the outflow of electromagnetic waves generated during operation of the semiconductor device.

In order to solve the above problems, the present invention provides a substrate array having a plurality of semiconductor devices, manufacturing a mold having irregularities corresponding to the shape of the substrate array, and a first metal layer on one surface of the mold. Forming an adhesive film, forming an adhesive film on an exposed surface of the first metal layer, bonding a substrate array having the plurality of semiconductor elements to the adhesive film, and removing a mold from the first metal layer; And forming a second metal layer on an exposed surface of the first metal layer, wherein the first metal layer is an electroless plating layer, and the second metal layer is an electrolytic plating layer. .

According to one embodiment of the present invention, the mold may be made of aluminum, copper, iron or an alloy containing the same.

According to another embodiment of the present invention, the mold may be formed of a metal mold and a mold for maintaining the form of the metal film.

According to another embodiment of the invention, the step of removing the mold from the first copper foil layer is performed by a physical peeling method, the adhesion of the mold and the metal film is higher than the adhesion of the metal film and the first metal layer. It is preferable.

The manufacturing method of the semiconductor package which concerns on this invention has the following effects.

First, there is an effect of providing a shielding copper foil without using a sputtering deposition process as an electromagnetic shielding layer that can prevent the electromagnetic waves generated during the operation of the semiconductor device to the outside.

Second, when the physical force is applied to the metal material using the plasma, the sputtering method in which the thin film is deposited on the target surface overcomes the problem that side shielding is difficult compared to the top shield and effectively provides both the top shield and the side shield.

Third, there is an effect of providing a method for forming an electromagnetic shielding layer for a plurality of semiconductor packages at one time.

Fourth, by applying the aluminum film used as a kind of conventional metal foil, there is an effect that can be used without significantly changing the structure of the conventional device.

1 is a cross-sectional view showing a layer structure of a semiconductor package manufactured by the method of manufacturing a semiconductor package of the present invention.
2 is a flowchart sequentially illustrating a method of manufacturing a semiconductor package according to an embodiment of the present invention.

The present invention relates to a method of manufacturing a semiconductor package, comprising the steps of providing a substrate array having a plurality of semiconductor elements, manufacturing a mold having irregularities corresponding to the shape of the substrate array, Forming a first metal layer, forming an adhesive film on an exposed surface of the first metal layer, bonding a substrate array having the plurality of semiconductor elements to the adhesive film, and removing a mold from the first metal layer And forming a second metal layer on an exposed surface of the first metal layer, wherein the first metal layer is an electroless plating layer, and the second metal layer is an electrolytic plating layer.

Hereinafter, a method of manufacturing a semiconductor package of the present invention will be described in detail with reference to the accompanying drawings.

The electromagnetic shielding copper foil applied to the semiconductor package according to the present invention exhibits shielding properties for blocking electromagnetic waves, near infrared rays, unwanted scattered light, and the like. Such shielded copper foil is applicable to PDP, EMI, HDI fabrication, direct laser drilling, inner layer formation, FCCL, FPC, and the like.

Hereinafter, the present invention will be described in more detail with reference to FIGS. 1 and 2. The accompanying drawings are provided for reference and illustration only and do not limit the invention.

1 is a cross-sectional view showing a layer structure of a semiconductor package manufactured by the method of manufacturing a semiconductor package of the present invention. Referring to FIG. 1, an adhesive layer 130, a first metal layer 120, and a second metal layer 140 are sequentially stacked on the substrate array 200. The substrate array 200 has a plurality of semiconductor devices mounted on a circuit board, and an electromagnetic shielding layer including the first metal layer 120 and the second metal layer 140 prevents external electromagnetic waves from entering the semiconductor device. Do it.

2 is a flowchart sequentially illustrating a method of manufacturing a semiconductor package according to an embodiment of the present invention. Referring to FIG. 2, first, a substrate array 200 having a predetermined shape and irregularities is provided (S1). In the device, a plurality of semiconductor elements are fastened to a substrate in an array method commonly used. For example, the adhesive film may be used to determine adhesion, detachment, and step difference.

Subsequently, a mold 110 having an uneven shape corresponding to the unevenness of the substrate array is manufactured (S2). The mold may be manufactured in a form in which a metal film or a molding frame capable of maintaining a shape under the metal film is combined. The metal film may be made of a metal such as aluminum, copper, iron, stainless steel, nickel, or an alloy material containing them. The mold may be made of a metal or a polymer resin, and the mold may be manufactured according to the surface irregularities of the semiconductor array, and may include a function of pressing the metal film to form the mold. The uneven shape dimension of the mold can be designed in consideration of the thickness of the metal film. The metal film may be designed in consideration of a corresponding number of concave-convex shapes such that a semiconductor device having a predetermined shape is inserted into and fixed in the inside. Specifically, the shape, structure, orthogonality and tolerance and thickness of the metal film are determined by the lower area of the semiconductor element mounted on the substrate array, the side height, the presence or absence of metal wires formed on the side, the side portion, the bottom land shape, the bottom land shape, and the bottom. It can be determined by the land protrusion step of the, the solder ball size and placement of the bottom, the compactness, or the contact area. As a result, the top surface unevenness of the metal film corresponds to the uneven shape of the substrate array.

Subsequently, the first metal layer 120 is formed on the mold 110 (S3). The first metal layer may be formed by electroless plating, and may preferably be an electroless plating layer. A release layer may be inserted into the mold and the first metal layer. In the case where the mold is made of aluminum, the release layer may be a naturally oxidized aluminum oxide layer. Although it is possible to form the first metal layer as an electroplating layer, it is preferable to form an electroless plating layer because electroplating is not well performed on the aluminum surface including the natural oxide layer. In addition, when the electroless plating layer is formed on the aluminum surface including the natural oxide layer, the natural oxide layer has an advantageous effect of functioning as a release layer. Preferably, the first metal layer has a predetermined surface roughness. For example, the first metal layer may have a surface having a surface roughness Ra of 0.2 μm or less and a surface roughness Rz of 2.5 μm or less measured using a three-dimensional surface structure analysis microscope. The surface roughness values showing such layer flatness are provided from the above-described application of the aluminum film, not the sputtering or conductive ink treatment. Here, unless otherwise specified, the surface roughnesses Ra and Rz mean surface roughness values measured at the side surfaces of the layers in which the semiconductor elements are inserted.

Subsequently, an adhesive layer 130 is formed on the first metal layer 120 (S4). The adhesive layer may be formed by spraying or a certain amount of injection by a syringe, and may be made of ultraviolet or thermosetting resin.

Subsequently, the adhesive layer 130 is brought into contact with and pressurized to bond the substrate array and the mold (S5). In the bonding process, heat, pressure, ultraviolet irradiation, etc. may be performed together. Since the uneven shapes of the first metal layer and the mold are formed to correspond to the unevenness of the substrate array, the first metal layer and the substrate array may be firmly coupled through the adhesive layer.

Subsequently, the mold 110 is separated from the first metal layer 120 (S6). Separation of the mold may be carried out by physical or chemical etching. Separation of the physical method is possible because of the relatively weak bonding between the mold and the first metal layer, and in chemical etching, it may be performed using a chemical which selectively etches only the material forming the mold.

Subsequently, a second metal layer 140 is formed on the first metal layer 120 (S7). Formation of the second metal layer may be performed by an electroplating method. It is preferable that the second metal layer has a predetermined surface roughness. For example, the surface roughness (Ra) measured using a three-dimensional surface structure analysis microscope having a surface of 0.2㎛ or less and the surface roughness (Rz) of 1.5㎛ or less, the surface roughness values showing such layer flatness are sputtered or It is provided from the application of the above-described aluminum film, not the conductive ink treatment method. Here, unless otherwise specified, the surface roughnesses Ra and Rz mean surface roughness values measured at the side surfaces of the layers in which the semiconductor elements are inserted. Further, the surface roughness difference ΔRa between the first metal layer and the second metal layer may be 0.01 to 0.5, and the surface roughness difference ΔRz between the first metal layer and the second metal layer may be within a range of 0.01 to 0.5. . Herein, the surface roughness differences ΔRa and ΔRz refer to absolute values of the differences between the surface roughness Ra and Rz unless otherwise specified.

When the second metal layer is a copper foil layer, the second metal layer has a plating bath temperature of 20 to 40 ° C., pH ≦ 2, a plating current density of 0.5 to 5 A / dm ² , and a plating time of 10 to 60 minutes in a plating bath solution containing copper. It may be formed in the range of 1 ~ 60㎛ thickness on the upper surface of the first copper foil layer by electroplating.

The plating bath solution containing copper contains a brightening agent and a carrier as water-soluble copper salts, sulfuric acid, chloride ions and additives.

The copper ion of the said water-soluble copper salt is a divalent ion. Specific examples of the copper compound include copper sulfate, copper oxide, copper chloride, copper carbonate, copper pyrophosphate, copper methanesulfonate, and copper propane sulfonate. Among these copper compounds, copper oxide (II) and copper sulfate are preferable, and copper sulfate is more preferable. The quantity of the copper ion contained in the said acidic copper plating liquid is not specifically limited, For example, 25-50 g / L is preferable.

The plating bath uses an acidic electrolyte and examples of suitable acids for the electrolyte include sulfuric acid, acetic acid, boric fluoride acid, and methane sulfonic acid. Among these electrolytes, sulfuric acid is preferred. The concentration of sulfuric acid is not limited and, for example, 50 to 200 g / L is preferable.

Although it does not specifically limit as a brightening agent, For example, 3-mercapto- 1-propanesulfonic acid or its sodium salt, bis-3 (sulfopropyl) disulfide or its bisodium salt, (3-sulfopropyl) N, Organic compounds, such as N-dimethyldithio carbamate or its sodium salt, etc. are mentioned, Preferably bis-3 (sulfopropyl) disulfide or its disodium salt is mentioned. The amount of the brightening agent is not limited, and for example, 0.01 to 50 mg / L is preferable.

Examples of the carrier include nonionic polymer surfactants such as polyether compounds such as polyethylene glycol, polypropylene glycol, polyethylene oxide, and polyoxyalkylene glycol. The quantity of a carrier is not limited, For example, 0.01-10 g / l is preferable.

Although the drawing has been described with respect to the application of the mold made of a metal film, the mold may be formed of a metal film and a mold for maintaining the shape of the metal film. The forming die may have a concave-convex shape corresponding to the concave-convex shape of the substrate array, and may also function to press the metal film to form the metal film. The molding die may be made of metal, polymer resin, or the like, and may be manufactured by a method such as press molding. Molds made of a mold and a metal film are easier to maintain a shape than a metal film alone, and the metal film may be firmly bonded along the surface irregularities of the substrate array in the process of pressurizing the substrate array and the mold. Function When the mold is made of a polymer resin having elasticity, the above effect may be maximized. The mold may be held in a bonded state to the metal film until the mold is separated into the first metal layer. In this case, the adhesion between the mold and the metal film is preferably higher than the adhesion between the metal film and the first metal layer. This is to maintain the bonding mold and the metal film in the process of separating the metal film from the first metal layer.

Hereinafter, the present invention will be described in more detail using examples.

Example

1. Preparation of the Board Array

Finally, there are two ways to uniformly arrange the package to be combined with the metal layer. The first can be provided with an array of substrates before the sawing process during the packaging process, and the second is a polyimide with adhesive coating on the individual sawed packages. , PI), polyethylene terephthalate (poly (ethylene terephthalate), PET), polyethylene naphthalate (poly (ethylene naphthalate), PEN), polycarbonate (polytcarbonate, PC) film and the like to be provided after the array.

In this embodiment, a package having dimensions of 7 mm (width) ㅧ 7 mm (length) ㅧ 1.5 mm (thickness) of QFN type is 50 μm thick with a release agent coated with a release agent of 30 gf / cm or less. Array to mid film. At this time, the columns are arranged in seven rows and seven columns, and the interval between rows is fixed at 3mm.

2. Manufacture of mold

Based on the array drawings, a molding die of a metal material (copper, stainless steel, iron, or an alloy thereof) was manufactured through a hot press method (also a cold press). Using a mold, the aluminum film having a thickness of 50 μm of series 1000 was pressed at a pressure of 100 kgf at room temperature to prepare a mold having irregularities corresponding to the array.

3. First metal layer formation

The first metal layer was formed on the die by using an electroless plating method. The electroless solution used was 100 g / L of copper sulfate (metal salt supply), 100 g / L of tartaric acid (complexing agent), 5 g / L of caustic soda (pH adjusting agent), and 10 g / L mixed solution of gluconic acid (stabilizer). It was deposited for about 30 minutes at temperature, pH 11.0 ~ 11.5 to form a copper layer of about 3㎛ thickness.

4. Adhesive layer formation

The epoxy adhesive was coated to a thickness of about 10 μm or less by using a spray method on the arrayed package as a preliminary step for stable fixation of the first metal layer and the arrayed package. At this time, the epoxy adhesive had a solid content of 30 wt.% And a viscosity of 750 cps. After drying for 2 minutes at 100 ℃ for solvent volatilization, the liquid coating layer was changed to a semi-dry B-stage state.

5. Bonding with substrate

The first metal layer was combined with the array substrate. After bonding, curing was performed for about 1 hour at a temperature of 80 ° C. to completely cure the epoxy adhesive to completely bond the first metal layer and the array substrate.

6. Separation of mold

After the complete bonding with the substrate, the mold and the first metal layer were separated by a physical method. Specific physical separation method, except for the first metal layer bonded to the package through the epoxy adhesive by fixing the bonded substrate and vacuum adsorption of the jig (jig) corresponding to each of the package array on the surface of the aluminum mold and vertically lifted. The aluminum mold was removed.

7. Second Metal Layer Formation

The second metal layer was formed on the first metal layer by the electroplating method. Plating bath solution is 35 g / L copper sulfate (water soluble copper salt), 200 g / L sulfuric acid, 50 ppm hydrochloric acid (chloride), 0.15 g / L bis-3- (sulfopropyl) disulfide (polish) and 1 g / L A solution containing polyethylene glycol (carrier) was used. The plating conditions were plating bath temperature of 30 degreeC, pH <= 2, plating current density 3A / dm <^2> , plating time 30 minutes, and the thickness of the 2nd metal layer was 30 micrometers.

The above description has been made using the embodiments of the technical idea of the present invention, and those skilled in the art to which the present invention pertains various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the embodiments described in the present invention are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

110: mold 120: first metal layer
130: adhesive layer 140: second metal layer
200: substrate array

Claims (4)

Providing a substrate array having a plurality of semiconductor devices;
Manufacturing a mold having irregularities corresponding to shapes of the substrate array;
Forming a first metal layer shielding electromagnetic waves on one surface of the mold;
Forming an adhesive film on the exposed surface of the first metal layer;
Bonding a substrate array having the plurality of semiconductor elements to the adhesive film;
Removing a mold from the first metal layer; And
And forming a second metal layer on the exposed surface of the first metal layer to shield electromagnetic waves.
The mold comprises a metal film,
The first metal layer is formed by electroless plating with an electroless plating solution containing 100 g / L copper sulfate, 100 g / L tartaric acid, 5 g / L caustic soda and 10 g / L gluconic acid,
The second metal layer is formed by electroplating with an electrolytic plating solution containing 35 g / L copper sulfate, 200 g / L sulfuric acid, 0.15 g / L bis-3- (sulfopropyl) disulfide, and 1 g / L polyethylene glycol,
The absolute value of the difference in surface roughness DELTA Ra between the first metal layer and the second metal layer is 0.01 to 0.5. The method according to claim 1,
The metal film is a method of manufacturing a semiconductor package, characterized in that made of aluminum, copper, iron, stainless steel, nickel or an alloy containing them. The method according to claim 1,
The mold is a manufacturing method of a semiconductor package, characterized in that formed in the mold for maintaining the shape of the metal film and the metal film. The method according to claim 3,
The removing of the mold from the first metal layer is performed by a physical peeling method, and the adhesion between the mold and the metal film is higher than the adhesion between the metal film and the first metal layer.

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