KR20060013027A - Apparatus for reflow semiconductor - Google Patents

Abstract

Disclosed is a semiconductor reflow apparatus capable of reducing the failure of a semiconductor package due to thermal damage. A semiconductor reflow apparatus according to an embodiment of the present invention, the reflow cover for applying a solder ball on the back of the semiconductor package, providing a reflow space as a semiconductor reflow apparatus for reflowing the solder ball, the semiconductor package Cooling unit for cooling the to a predetermined temperature, and a heating unit for heating the semiconductor package so that the solder ball is reflowed.

Solder Balls, Reflow, Cooling Units, Heating Units.

Description

Semiconductor reflow device {Apparatus for reflow semiconductor}

1 is a cross-sectional view of a semiconductor reflow apparatus according to an embodiment of the present invention.

2 is a cross-sectional view of a semiconductor reflow apparatus according to another embodiment of the present invention.

The present invention relates to a semiconductor reflow apparatus, and more particularly to a solder ball reflow apparatus that can reduce the thermal damage of the semiconductor package.

As electronic devices, including personal portable electronic products, have increased in capacity and speed, and their sizes have also become smaller, semiconductor packages are also becoming larger, faster, and lighter and smaller.

Currently, in order to reduce the size of the package, a ball grid array package using a ball instead of a pin (BGA package) and a chip scale package that can be assembled within a large range without exceeding the chip size ( Chip scale package (CSP) has been proposed.

Conventionally, a stacked package has been proposed to perform a plurality of functions as one package while increasing the mounting density per unit semiconductor package, and an example thereof is disclosed in US Pat. No. 6,268,649. US Patent 6,268, 649 discloses a structure in which a plurality of BGA packages are stacked up and down. In the patent, the unit BGA package includes a substrate, a molded semiconductor chip disposed in the center of the upper portion of the substrate, and solder balls disposed on the bottom surfaces of both substrates around the semiconductor chip, and the stacked package of the patent includes Unit BGA packages are stacked up and down using solder balls as electrical medium.

At this time, the solder ball is applied to the back of the printed circuit board (surface where the semiconductor chip is not attached), and then reflowed by a predetermined thermal process and attached to the back of the solder ball.

However, when manufacturing the stacked package as described above, the solder ball reflow process must be performed for each layer package, and thus, the first package (base package) must be subjected to at least two reflow processes. As a result, the base package is subjected to thermal damage, thereby increasing the probability of failing.

In this way, if any one of the base package or the other package fails, the entire stacked package malfunctions and must be disposed of. Therefore, the yield of the semiconductor package is lowered.

Accordingly, the technical problem to be achieved by the present invention is to provide a semiconductor reflow apparatus capable of reducing the failure of a semiconductor package due to thermal damage.

Other objects and novel features thereof, as well as the objects of the present invention, will be apparent from the description and the accompanying drawings. Among the inventions disclosed herein, an outline of representative features is briefly described as follows.

A semiconductor reflow apparatus according to an embodiment of the present invention, the reflow cover for applying a solder ball on the back of the semiconductor package, providing a reflow space as a semiconductor reflow apparatus for reflowing the solder ball, the semiconductor package Cooling unit for cooling the to a predetermined temperature, and a heating unit for heating the semiconductor package so that the solder ball is reflowed.

The cooling unit is installed under the semiconductor package to support the semiconductor package.

In addition, the semiconductor package may be a single package in which a single semiconductor chip is integrated. In this case, a pusher is installed on the semiconductor package to fix the semiconductor package to the cooling unit.

In addition, when the semiconductor package is a stacked package in which a plurality of semiconductor packages are stacked, a cooling unit may be further installed on the stacked package to fix the stacked semiconductor packages while cooling the upper semiconductor package.

The cooling unit may be a water cooling plate or TEC. In addition, when the cooling units are arranged up and down, the cooling units may be the same type or different from each other. In addition, the cooling unit and the semiconductor package may be attached by a thermal interface material (TIM).

The heating unit may be installed on one side or both sides of the semiconductor package. Such heating unit may be an IR lamp or a laser gun.

When the heating units are installed at both sides of the semiconductor package, the heating units may be the same or different from each other. The heating unit is preferably surrounded by a peripheral support to thermally separate from the cooling unit.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. However, embodiments of the present invention may be modified in many different forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Accordingly, the shape and the like of the elements in the drawings are exaggerated to emphasize a more clear description, and the elements denoted by the same reference numerals in the drawings means the same elements.

1 is a cross-sectional view of a semiconductor reflow apparatus according to an embodiment of the present invention. This embodiment shows an apparatus for reflowing solder balls in a single package in which one semiconductor chip is mounted.

As shown in FIG. 1, a cooling unit 120 is disposed in a reflow cover 100 that provides a reflow space, and a semiconductor chip 110a and a printed circuit board are disposed on the cooling unit 120. The semiconductor package 110 including the 110a is disposed. The cooling unit 120 serves to cool the semiconductor package 110 during solder ball reflow, and may be, for example, a water cooling plate or a thermo electric cooler (TEC). At this time, the semiconductor package 110 is disposed such that the surface on which the solder ball is attached (the back side of the printed circuit board) is exposed to the outside. The semiconductor package 110, more specifically, the semiconductor chip 110a and the cooling unit 120 are attached by a thermal interface material 115 (TIM). TIM is provided to ensure the reliability of solder joint process and to maximize the cooling efficiency by minimizing mechanical damage. The thickness of the TIM is preferably in the range of about 0.2 to 0.4 mu m in consideration of the surface state and flatness of the package.

A pusher 130 is disposed on the semiconductor package 110 to fix the semiconductor package 110. The pusher 130 is disposed to press the center portion of the semiconductor package 110 to which the solder ball is not applied.

A local heating unit 140 is disposed on one side or both sides of the semiconductor package 110. The local heating unit 140 is disposed on one side or both sides of the printed circuit board 110 to locally apply heat for reflowing the solder balls. The heating unit 140 may be an infrared (IR) lamp or a laser gun. In addition, the local heating unit 140 is surrounded by a peripheral support to be thermally separated from the cooling unit 120.

Such a semiconductor reflow apparatus is operated as follows.

The solder ball 160 is discharged from a solder ball ejector (not shown) to a predetermined portion of the back surface of the semiconductor package 110. The heating unit 140 is driven so that the solder balls 160 are easily seated on the back surface of the semiconductor package 110. The heating unit 140 heats the semiconductor package 110 to a temperature at which the solder balls 160 can be reflowed, for example, 220 to 250 ° C. At this time, since the heating unit 140 is locally installed on one side or both sides of the printed circuit board 110, the solder ball 160 is disposed at the edge of the semiconductor package 110 without heating the semiconductor package 110 as a whole. ) Can be effectively reflowed.

In addition, since the cooling unit 120 is operated at the same time when the heating unit 140 is operated, thermal damage to the semiconductor package 110 may be further reduced. The cooling unit is preferably operated so that the semiconductor package 110 can maintain a constant temperature, such as in the range of 150 to 190 ° C.

2 is a cross-sectional view of a semiconductor reflow apparatus according to another embodiment of the present invention. This embodiment shows a reflow apparatus for attaching solder balls to a stacked package.

First, referring to FIG. 2, the first cooling unit 210a and the second cooling unit 210b are disposed to face up and down in the reflow cover 100 that provides a reflow space. The first and second packages 220 and 230 are stacked between the first and second cooling units 210a and 210b. The first package 220 is arranged such that its semiconductor chip 220a faces the first cooling unit 210a, and the second package 230 has its semiconductor chip 220 connected to the first package 220. It is arranged to face the back side (back side of the printed circuit board). The first package 220, the second package 230, the second package 230, and the second cooling unit 210b may be attached by the adhesive layer 240, respectively. In addition, a TIM 250 is interposed between the first cooling unit 210a, the first package 220, and the second cooling unit 210b and the second package 230. The TIM 250 plays the same role as the above-described embodiment and may be formed to the same thickness. In this case, the first and second cooling units 210a and 210b may be identical to or different from each other. The first and second cooling units 210a and 210b serve to cool the semiconductor packages 220 and 230, that is, the respective semiconductor chips and the printed circuit board, when solder balls reflow into the semiconductor packages 220 and 230. For example, it may be a water cooling plate or TEC. In addition, the first cooling unit 210a serves to support the semiconductor packages 220 and 230, and the second cooling unit 210b serves to press and fix the stacked semiconductor packages 220 and 230.

Local heating units 260a and 260b are disposed on one side or both sides of the semiconductor packages 220 and 230. The local heating units 260a and 260b may be infrared (IR) lamps or laser guns as in the above-described embodiment, and may be the same or different when installed on both sides of the semiconductor package 220 or 230. have. The local heating units 260a and 260b are wrapped by the peripheral support 270 to be thermally separated from the cooling units 210a and 210b, and the peripheral support 270 serves to guide the package arrangement when stacking the packages. Do it.

Like the single package, in the case of the stacked package, the solder balls 280 are attached by locally applying heat to both sides of the semiconductor packages 220 and 230 to reflow the solder balls when the solder balls are discharged. At the same time, in the stacked package of the present embodiment, the cooling units 210a and 210b are disposed above and below the semiconductor packages 220 and 230, thereby effectively cooling the stacked semiconductor packages 220 and 230.                     

The present invention is not limited to the above embodiment. Although the exemplary embodiments have been described with respect to the solder ball reflow apparatus, all of the semiconductor reflow apparatuses to be reflowed in addition to the solder balls may be applied.

As described in detail above, according to the present embodiment, a heating unit for reflowing the solder balls in an apparatus for reflowing the solder balls on the bottom surface of the semiconductor package, and cooling for cooling the semiconductor package heated by the heating unit. Install each unit.

The heating unit is disposed locally on one side of the semiconductor package to locally heat the semiconductor package. Accordingly, the thermal damage of the semiconductor package can be reduced.

In addition, the cooling unit installed in the reflow apparatus continuously cools the semiconductor package to maintain a constant temperature, thereby reducing the failure due to thermal damage of the semiconductor package. Accordingly, the yield of the semiconductor package is improved.

Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to the above embodiments, and various modifications may be made by those skilled in the art within the scope of the technical idea of the present invention. .

Claims (14)

A semiconductor reflow apparatus for applying solder balls to a back surface of a semiconductor package and reflowing the solder balls, A reflow cover to provide a reflow space; A cooling unit cooling the semiconductor package to a predetermined temperature; And And a heating unit for heating the semiconductor package to reflow the solder balls. The semiconductor reflow apparatus of claim 1, wherein the cooling unit is installed to support the semiconductor package. The semiconductor package of claim 1, wherein the semiconductor package is a single package in which a single semiconductor chip is integrated. And a pusher for fixing the semiconductor package on the cooling unit above the semiconductor package. The semiconductor package of claim 1, wherein the semiconductor package is a stacked package in which at least one semiconductor package is stacked. And a cooling unit configured to fix the stacked semiconductor packages while cooling the semiconductor package positioned on the stacked semiconductor package. The semiconductor reflow apparatus according to claim 1, wherein the cooling unit is a water cooling plate or a TEC. The semiconductor reflow apparatus of claim 4, wherein the upper and lower cooling units are the same type. The semiconductor reflow apparatus of claim 4, wherein the vertical cooling units are different from each other. The semiconductor reflow apparatus of claim 1, wherein a thermal interface material (TIM) is interposed between the cooling unit and the semiconductor substrate. The semiconductor reflow apparatus of claim 1, wherein the heating unit is installed at one side of the semiconductor package. The semiconductor reflow apparatus of claim 1, wherein the heating unit is installed at both sides of the semiconductor package. The semiconductor reflow apparatus of claim 1, wherein the heating unit is an IR lamp or a laser gun. The semiconductor reflow apparatus according to claim 10, wherein the heating units are the same kind. The semiconductor reflow apparatus according to claim 10, wherein the heating units are of different kinds. The semiconductor reflow apparatus of claim 1, wherein the heating unit is surrounded by a peripheral support to thermally separate from the cooling unit.

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