KR101062082B1 - Method and apparatus for bumping solders - Google Patents

Abstract

The solder bumping method involves partially applying a flux through a mask to a plurality of solder sites injected into each of the cavities of the template, placing the flux-coated template at the bottom of the wafer with multiple bump pads. Aligning the template and the wafer so that each of the solders and the bump pads face each other, lowering the wafer while heating the template so that the flux vaporizes, removing the oxide film formed on the solder and bumping each of the solders of the aligned template Bumping each of the pads and raising the wafer to separate the wafer with the solder bumped from the template.

Description

Solder Bumping Method and Apparatus {METHOD AND APPARATUS FOR BUMPING SOLDERS}

The present invention relates to a solder bumping method and apparatus, and more particularly, to a method of bumping solders injected into a template on a wafer and an apparatus using the same.

In recent years, microelectronic packaging technology has shifted from wire bonding to solder bumps in which solders are directly bumped onto bump pads of a wafer. Here, a variety of techniques using the solder bump method are known, and for example, electroplating, solder paste printing, evaporation dehydration, and direct attachment of solder balls are widely known.

In particular, C4NP (controlled collapse chip connection new process) technology has attracted much attention due to the advantages that can realize a fine pitch at a low cost and improve the reliability of semiconductor devices manufactured from wafers. Examples of the C4NP technology are disclosed in US Pat. Nos. 5,607,099, 5,775,569, 6,025,258, and the like.

Thus, referring briefly to the C4NP technology, solders are injected into each of the cavities of the template supported and fixed to the first chuck plate, and the wafer is second chucked so that each of the bump pads faces each of the solders. After supporting and fixing to the plate, each of the solders are thermocompression-bonded to each of the bump pads to bump each other while narrowing the gap between the first and second chuck plates.

In this case, an oxide layer may be formed on the surfaces of the solders injected into the cavities of the template due to air containing oxygen, and thus the solders may not be stably bumped into the bump pads.

It is an object of the present invention to provide a method for stably bumping each of the solders to each of the bump pads of a wafer by preventing the formation of an oxide film on the surfaces of the solders.

Another object of the present invention is to provide a solder bumping device to which the above-described method is applied.

In order to achieve the above object of the present invention, a solder bumping method according to one aspect of the present invention comprises the steps of partially applying flux through a mask to a plurality of solders injected into each of the cavities of the template, the flux is Positioning an applied template under the wafer having a plurality of bump pads, aligning the template with the wafer such that each of the solders and each of the bump pads faces, an oxide film in which the flux is formed in the solders Lowering the wafer while heating the template to vaporize while removing the bumps so as to bump each of the solders of the aligned template to each of the bump pads and to raise the wafer to separate the wafers where the solders are bumped from the template. It comprises the step of.

At this time, the step of separating the wafer from the template may be separated from one side of the wafer and the template bumped each other. In addition, in the step of bumping each of the solders to each of the bump pads, the wafer and the template may maintain a floating state.

In order to achieve the above object of the present invention, a solder bumping device according to one aspect includes an application mechanism, a transfer mechanism, an alignment mechanism, a heater, and a lift mechanism. The applicator partially applies flux through a mask to a plurality of solder sites injected into each of the cavities of the template. The transfer mechanism moves the template to the bottom of the wafer with a plurality of bump pads with the flux applied. The alignment mechanism aligns the template with the wafer such that each of the solders and each of the bump pads faces. The heater is disposed under the template moved to the bottom of the wafer, and heats the template so that the flux is vaporized while removing the oxide film formed on the solders. The elevating mechanism lowers the wafer such that each of the solders bumps to each of the bump pads when the flux is vaporized or raises the wafer so that the wafer and the template are separated.

Accordingly, the solder bumping device may support the first chuck plate connected to the alignment mechanism while supporting and fixing the lower portion of the template, the second chuck plate connected to the lifting mechanism while supporting and fixing the upper portion of the wafer, and the lower portion of the first chuck plate. The first chuck plate is supported between the first elastic body to maintain the first chuck plate and the template in a floating state, and the first support plate having the heater embedded therein and the second elastic body on the second chuck plate. The apparatus may further include a second support plate supporting the second chuck plate to maintain the second chuck plate and the wafer in a floating state.

The solder bumping device may further include a lift pin penetrating the first chuck plate and the first support plate in a vertical direction, and a lift pin connected to the lift pin to separate the template from the first chuck plate. It may further include a second lifting mechanism for lifting.

In this case, the transfer mechanism may include a transfer fork for entering the space formed between the template and the first chuck plate by the lift pin to support the template for transfer.

Meanwhile, the solder bumping device is lower than each of the first and second elastic bodies so as to maintain a constant gap between the first chuck plate and the first support plate and between the second chuck plate and the second support plate. It may further comprise first and second spacers disposed at a height.

In addition, the alignment mechanism includes a horizontal alignment unit for aligning the template in a horizontal direction such that the position of the template and the wafer coincide with each other in a vertical direction and at least three points of the template such that the template and the wafer are parallel to each other. And a plurality of vertical alignment portions which adjust a height of the template and which are partially lowered to be separated from one side when the wafer and the plate are separated.

According to such a solder bumping method and apparatus, a flux is applied to a surface of each of the solders injected into the cavities of the template, thereby removing each of the solders from the wafer while removing the oxide film formed on the surfaces of the solders. It is possible to stably bump each of the pads. Thereby, the quality of the semiconductor element manufactured from the said wafer can be improved.

1 is a configuration diagram schematically showing a solder bumping device according to an embodiment of the present invention.
FIG. 2 is an enlarged view of solders into which cavities of a template are injected in the solder bumping apparatus of FIG. 1.
3 is a view from above of the alignment mechanism of the solder bumping device shown in FIG.
4 is a view illustrating in detail the first chuck plate and the first support plate portion of the solder bumping device shown in FIG.
FIG. 5 is a flowchart illustrating a process of bumping solders to bump pads of a wafer by using the solder bumping apparatus of FIG. 1.

Hereinafter, a solder bumping method and apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing. In the accompanying drawings, the dimensions of the structures are shown in an enlarged scale than actual for clarity of the invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a part or a combination thereof is described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

On the other hand, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

FIG. 1 is a schematic view illustrating a solder bumping device according to an exemplary embodiment of the present invention, and FIG. 2 is an enlarged view of solders into which cavities of a template are injected in the solder bumping device shown in FIG. 1.

Referring to FIG. 1, the solder bumping apparatus 1000 according to an embodiment of the present invention may include an application mechanism 100, a transfer mechanism 200, an alignment mechanism 300, a heater 400, and a lifting mechanism 500. Include.

The applicator 100 applies flux F to the surface of the template 10. The applicator 100 partially applies the flux F to portions of solder 14 injected into each of the plurality of cavities 12 of the template 10. To this end, the applicator 100 may partially apply the flux F by placing a mask 20 having holes 22 corresponding to the cavities 12 between the template 10 and the template 10. Can be.

In this case, even though the holes 22 of the mask 20 do not correspond exactly to the cavities 12, the flux F may be naturally applied to adjacent solders 14 due to its fluidity. Here, the flux (F) is made of a liquid form, may be included in a predetermined amount of resin material to provide adhesion.

The transfer mechanism 200 is connected to the template 10. The transfer mechanism 200 moves the template 10 to the bottom of the wafer 30 having a plurality of bump pads 32 corresponding to each of the solders 14 with the flux F applied thereto. Let's do it.

In this case, the template 10 may be supported and fixed by the first chuck plate 600 disposed below the wafer 10, and the wafer 30 may be supported and fixed by the second chuck plate 650 disposed above the template 10. have. Here, each of the first and second chuck plates 600 and 650 may support and fix each of the template 10 and the wafer 30 through vacuum pressure.

Thus, the applicator 100 is installed at an adjacent place different from the first and second chuck plates 600 and 650 to apply the flux F to the template 10, and the transfer mechanism 200. The template 10 to which the flux F is applied may be moved to the first chuck plate 600 from a position where the application device 100 is installed.

The alignment mechanism 300 is installed below the first chuck plate 600. The alignment mechanism 300 aligns the template 10 with the wafer 30 so that each of the solders 14 and each of the bump pads 32 face each other.

Hereinafter, the alignment mechanism 300 will be described in more detail with reference to FIG. 3.

3 is a view from above of the alignment mechanism of the solder bumping device shown in FIG.

Referring further to FIG. 3, the alignment mechanism 300 may include a horizontal alignment unit 310 and a plurality of vertical alignment units 320.

The horizontal alignment unit 310 is disposed below the first chuck plate 600. Positioning the template 10 fixed to the first chuck plate 600 by moving the first chuck plate 600 in a plane direction defined by the x-axis or the y-axis, along the wafer 30 and the z-axis. To match.

In this case, the alignment state by the horizontal alignment unit 310 may be confirmed through the vision mechanism 700 that enters between the template 10 and the wafer 30 and captures respective images.

Specifically, the horizontal alignment unit 310 is formed by the vision mechanism 700 such that the alignment marks (not shown) of each of the template 10 and the wafer 30 are coincident with each other along the z axis. The template 10 may be aligned with the wafer 30 through the one chuck plate 600.

The vertical alignment units 320 are disposed at at least three points P1, P2, and P3 having a polygonal composition between the first chuck plate 600 and the horizontal alignment unit 310. For example, the vertical alignment units 320 may be arranged to have a triangular composition as shown in FIG. 3.

The vertical alignment units 320 adjust the height of the first chuck plate 600 at the points P1, P2, and P3 to align the template 10 in parallel with the wafer 30.

In the present exemplary embodiment, the vertical alignment units 320 are described as being disposed between the first chuck plate 600 and the horizontal alignment unit 310, but the vertical alignment units 320 are the first chuck plate. The horizontal alignment unit 310 may be disposed below the horizontal alignment unit 310 such that the horizontal alignment unit 310 is disposed therebetween.

In addition, the alignment state by the vertical alignment units 320 may be confirmed through the vision mechanism 700, similarly to the horizontal alignment unit 310. Specifically, the template 10 and the image calculated at each position by focusing the images of the template 10 and the wafer 30 at at least three positions having a polygonal composition by the vision mechanism 700. The vertical alignment units 320 may be aligned by adjusting the height of the template 10 through the first chuck plate 600 so that the distances between the wafers 30 are all coincident with each other.

Each of the vertical alignment units 320 is, for example, a reference block 322 having an inclined surface 323 thereon, and is disposed to slide along the inclined surface 323 to support the first chuck plate 600. The sliding block 324 having the sliding block 324 along the z axis by moving the reference block 322 toward or away from the center C of the template 10. The driving unit 325 may be adjusted.

In addition, each of the vertical alignment units 320 includes a guide block 326 for guiding the movement of the reference block 322 and a sliding block 324 sliding along the inclined surface 323 of the reference block 322. The cover block 327 may further include covering both side portions or the rear portion to prevent the deviation from each other.

On the other hand, the vision mechanism 700 may be of a dual lens type equipped with two lenses up and down so that the image of the wafer 30 and the template 10 can be taken at the same time, in this case the alignment mechanism ( The alignment operation by 300 may be performed more quickly.

The heater 400 is disposed under the first chuck plate 600 to heat the template 10 supported by the first chuck plate 600. In this case, the flux F partially applied to the template 10 may be vaporized while removing the oxide films formed on the surfaces of the solders 14 by heating of the heater 400.

The elevating mechanism 500 is connected to an upper portion of the wafer 30 to raise and lower the wafer 30. Accordingly, the elevating mechanism 500 descends the wafer 30 while the template 10 is heated by the heater 400, thereby allowing each of the solders 14 to be vaporized by the flux F. In the state where the oxide film is removed, the bump pads 32 of the wafer 30 may be thermally compressed to stably bump. As a result, the quality of the semiconductor device manufactured from the wafer 30 can be improved.

In addition, the template 10 and the wafer 30 are partially adhered through a resin material partially included in the flux F while the solders 14 are bumped to the bump pads 32. The bumped position can be prevented from changing. In this case, some of the resin material remaining from the flux F may be separated from the template 10 and then removed through a separate cleaning process.

In addition, when the solders 14 are stably bumped to the bump pads 32 of the wafer 30, the lifting mechanism 500 may separate the template 10 from the wafer 30 so as to separate the wafer 30. Raise 30).

At this time, in order to stably separate the template 10 and the wafer 30, the lifting mechanism 500 is disposed at the points P1, P2, and P3 before the lifting mechanism 500 raises the wafer 30. By lowering some of the vertical alignment portions 320, the bumped template 10 and the wafer 30 may be separated from one side.

In addition, as the flux F is partially applied to the solder portions 14 of the template 10, the flux F when the solders 14 are bumped to the bump pads 32. The air layer may be formed at the portion where the is not applied. Accordingly, the template 10 and the wafer 30 may be separated more stably by the air layer.

Meanwhile, the template 10, the first chuck plate 600, the wafer 30, and the first material are formed by the heat of the heater 400 while the solders 14 are bumped to the bump pads 32. In order to naturally expand the two chuck plates 650, the first and second chuck plates 600 and 650 supporting each of the template 10 and the wafer 30 may maintain a floating state. Hereinafter, the floating structures of the first and second chuck plates 600 and 650 will be described in more detail with reference to FIG. 4.

4 is a view illustrating in detail the first chuck plate and the first support plate portion of the solder bumping device shown in FIG.

Referring to FIG. 4, the solder bumping device 1000 may include a first support plate 800 supporting a lower portion of the first chuck plate 600 and an upper portion of the second chuck plate 650. 2 may further include a support plate (850).

Thus, the heater 400 may be embedded in the first support plate 800 to heat the first chuck plate 600, and the first support plate 800 may have heat from the heater 400. Cooling passage (not shown) for controlling the may be configured.

A first elastic body 810 is inserted between the first support plate 800 and the first chuck plate 600. For example, the first elastic body 810 may be formed of a spring.

Accordingly, the template 10 and the first generated by the heat of the heater 400 through the property that the first elastic body 810 can be twisted while the solders 14 are bumped to the bump pads 32. Thermal expansion of the chuck plate 600 can be induced naturally. In this case, the first elastic body 810 may be disposed at a position adjacent to the center of the first chuck plate 600 for more natural thermal expansion of the template 10 and the first chuck plate 600. .

In addition, a second elastic body 860 similar to the first elastic body 810 is inserted between the second supporting plate 850 and the first chuck plate 600. Thus, the wafer 30 and the second chuck plate 650 may also induce natural thermal expansion by the second elastic body 860 for the same reason as the description of the first elastic body 810.

Accordingly, even when the template 10 and the wafer 30 are thermally compressed to each other, the thermal expansion is naturally induced while preventing the template 10 or the wafer 30 from being damaged by the thermal expansion. can do.

Meanwhile, the first and second elastic bodies 810 between the first chuck plate 600 and the first support plate 800 and between the second chuck plate 650 and the second support plate 850. The first and second spacers 820 and 870 disposed at a lower height than each of the first and second spacers 860 may be further disposed.

The first and second spacers 820 and 870 are first and second chuck plates when the wafer 30 is thermocompressed with the template 10 by the lifting mechanism 500. Each of the 600 and 650 maintains a constant distance so as not to hit each of the first and second support plates 800 and 850.

In this case, thermal expansion of the template 10, the first chuck plate 600, the wafer 30, and the second chuck plate 650 may be applied to the first and second support plates 800 and 850, respectively. Interference can be prevented.

Meanwhile, the solder bumping apparatus 1000 may include a first through hole 610 of the first chuck plate 600 and a second through hole of the first support plate 800 connected to the first through hole 610. At least one lift pin 900 penetrating through 660 and a second lifting mechanism 550 connected to the lift pin 900 to lift and lower the lift pin 900 may be further included.

The lift pin 900 may be lifted by the second elevating mechanism 550 to separate the template 10 from the first chuck plate 600. In this case, a space may be formed between the template 10 and the first chuck plate 600.

Thus, the transport mechanism 200 for transporting the template 10 may include a transport fork 210 that can enter the space to support the template at a lower level and stably transport it.

Hereinafter, a process of bumping each of the solders 14 to each of the bump pads 32 of the wafer 30 through the solder bumping device 1000 will be described in more detail with reference to FIG. 5. I would like to.

FIG. 5 is a flowchart illustrating a process of bumping solders to bump pads of a wafer by using the solder bumping apparatus of FIG. 1.

Referring further to FIG. 5, in order to bump each of the solders 14 to each of the bump pads 32, first of all solders 14 injected into the cavities 12 of the template 10, respectively. The flux (F) to the site is partially applied through the applicator 100 (S100).

Subsequently, the template 10 to which the flux F is applied is positioned below the wafer 30 (S200). Specifically, as the upper portion of the wafer 30 is supported and fixed to the second chuck plate 650, the transfer mechanism 200 arranges the template 10 under the wafer 30. It is moved to the first chuck plate 600 is fixed to the first chuck plate 600.

More specifically, the transfer mechanism 200 places the template 10 supporting the lower portion through the transfer fork 210 on the lift pin 900 lifted from the first chuck plate 600, and then the lift The pin 900 may be lowered through the second elevating mechanism 550 to support and fix the template 10 to the first chuck plate 600.

Subsequently, the template 10 and the wafer 30 are aligned with each other through the alignment mechanism 300 such that each of the solders 14 and the bump pads 32 face each other (S300). At this time, the alignment mechanism 300 is the x-axis or y to the template 10 so that the position of each other along the z-axis of the template 10 and the wafer 30 through the horizontal alignment unit 310 to match. Move at an axis and at at least three points P1, P2, P3 of the template 10 such that the template 10 and the wafer 30 are parallel to each other through the vertical alignment unit 320. The template 10 may be aligned by adjusting its height along the z axis.

Subsequently, the lifting mechanism 500 moves the wafer 30 while heating the template 10 through the heater 400 so that the flux F is vaporized while removing the oxide film formed on each of the solders 14. The solder 14 is bumped to each of the bump pads 32 by lowering through S400. In this case, each of the solders 14 may be bumped while being more stably thermocompressed to each of the bump pads 32 while the oxide film is removed by the flux F. FIG.

Subsequently, in the state where the solders 14 are bumped to the bump pads 32, the wafer 30 is lifted through the lifting mechanism 500 to separate the template 10 and the wafer 30. (S500). At this time, the bumped template 10 and the wafer 30 are separated from one side. In order to implement this, some of the vertical alignment units 320 for adjusting the height of the template 10 along the z axis may be lowered at the points P1, P2, and P3.

Thereafter, the lift pin 900 is raised again through the second elevating mechanism 550 to separate the template 10 from the first chuck plate 600, and then the transfer mechanism 200 therebetween. The transfer fork 210 may enter to transfer the template 10 to a place for injecting the solders 14. Thereafter, the steps S100 to S500 may be repeatedly performed on the template 10 into which the solders 14 are re-injected.

While the present invention has been described in connection with what is presently considered to be practical and exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

F: Flux 10: Template
14 solder 20 mask
30 wafer 100 application mechanism
200: transfer mechanism 210: transfer fork
300: alignment mechanism 310: horizontal alignment
320: vertical alignment unit 400: heater
500: lifting mechanism 600: first chuck plate
650: second chuck plate 700: vision mechanism
800: first support plate 810: first elastic body
820: first spacer 850: second support plate
860: second elastic body 870: second spacer
900: lift pin 1000: solder bumping device

Claims (8)

Partially applying a flux through a mask to the plurality of solder sites injected into each of the cavities of the template;
Placing the flux-applied template at the bottom of the wafer with a plurality of bump pads;
Aligning the template and the wafer such that each of the solders and each of the bump pads faces each other;
Lowering the wafer while heating the template so that the flux is vaporized while removing the oxide film formed on the solders, thereby bumping each of the solders of the aligned template to each of the bump pads; And
Raising the wafer to separate the wafer with the solder bumps from the template,
Separating the wafer from the template, wherein the wafer is separated from one side of the wafer and the template bumped with each other. delete The solder bumping method of claim 1, wherein the wafer and the template remain in a floating state in bumping each of the solders to each of the bump pads. An applicator for partially applying a flux through a mask to a plurality of solder portions injected into each of the cavities of the template;
A transfer mechanism for moving the template to the bottom of the wafer with a plurality of bump pads with the flux applied thereon;
An alignment mechanism for aligning the template with the wafer such that each of the solders and each of the bump pads faces each other;
A heater disposed below the template moved to the bottom of the wafer, the heater heating the template such that the flux is vaporized while removing the oxide film formed on the solders; And
A lift mechanism for lowering the wafer such that each of the solders bumps to each of the bump pads when the flux is vaporized or raising the wafer to separate the wafer and the template,
The alignment mechanism adjusts the height of the template at at least three points of the template such that the template and the wafer are parallel to each other, and the plurality of portions descending so that the wafer and the template are separated from one side when the template is separated. Solder bumping device comprising a vertical alignment. The method of claim 4, wherein
A first chuck plate connected to the alignment mechanism while supporting and fixing a lower portion of the template;
A second chuck plate connected to the lifting mechanism while supporting and fixing an upper portion of the wafer;
A first support plate on which the first chuck plate and the template are held in a floating state by supporting the first chuck plate under the first chuck plate with a first elastic body interposed therebetween; And
And a second support plate supporting the second chuck plate through the second elastic body on the second chuck plate to hold the second chuck plate and the wafer in a floating state. The method of claim 5,
A lift pin penetrating the first chuck plate and the first support plate in a vertical direction; And
A second lifting mechanism coupled with the lift pin, the second lifting mechanism for lifting the lift pin to separate the template from the first chuck plate;
And the transfer mechanism includes a transfer fork which enters a space formed between the template and the first chuck plate by the lift pin and supports the template for transfer. The device of claim 5, wherein the height is lower than each of the first and second elastic bodies so as to maintain a constant distance between the first chuck plate and the first support plate and between the second chuck plate and the second support plate. And the first and second spacers disposed by the solder bumping device. 5. The solder bumping device of claim 4, wherein the alignment mechanism further comprises a horizontal alignment unit for aligning the template in a horizontal direction such that the template and the wafer coincide with each other in a vertical direction.

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