JP2003298225A - Solder bump leveling device installed on the substrate - Google Patents

Abstract

(57) [Problem] To provide a leveling device capable of aligning solder bumps provided on a substrate to a uniform and stable height. A first contacting means for contacting one side surface of a substrate provided with solder bumps, a leveling means for equalizing the height of the solder pump, and a side edge of the other side surface of the substrate Second contact means for contacting the first contact means and the second contact means.
Driving means for relatively approaching and separating the contacting means, and the height of the solder bumps in a state where the substrate is held by the first contacting means and the second contacting means. Leveling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder bump leveling device provided on a substrate.

[0002]

2. Description of the Related Art Conventionally, a mounting technique called flip-chip connection in which a plurality of hemispherical solder bumps are formed on a circuit board on which a semiconductor chip is mounted and the semiconductor chips are collectively bonded to the circuit board via these solder bumps. It has been known.

Bump height and its uniformity are important factors in the load resistance level of the solder connection portion in such flip-chip connection, and if mounting is performed with the formed solder bumps having uneven heights, an open defect or short circuit of an electronic circuit will occur. Defects may occur.

Therefore, as shown in FIG. 5, usually, a leveling pressing plate 300 having a flat surface is pressed against a circuit board 200 on which the solder bumps 100 are formed with a predetermined load to collectively level the entire bumps. Was doing.

[0005]

However, the above-mentioned conventional leveling method still has the following problems.

That is, the circuit board 200 may be warped or twisted, and in particular, when the solder bump 100 is formed, heat is applied at that time, so that the warp or the like is likely to occur.

If the circuit board 200 is twisted or warped, the leveling pressure plate 300 and the solder bumps 100 do not come into contact with each other uniformly, as shown in FIG. As a result, when a semiconductor chip (not shown) is mounted on the circuit board 200, the mounting position, the inclination at the time of mounting, and the like change, and as described above, the semiconductor chip and the circuit board 2
The connection performance with 00 may be adversely affected.

For example, in order to maintain the adhesion between the semiconductor chip and the circuit board 200, the semiconductor chip and the circuit board 200
When the gap (gap) is filled with the underfill material by utilizing the capillary phenomenon to be sealed, there is a possibility that the underfill material cannot smoothly wrap around unless the gap is constant.

As described above, in the conventional leveling method in which the leveling pressing plate 300 is pressed against the solder bumps 100 with a predetermined load and the entire bumps are collectively leveled,
It was difficult to accurately align the bump heights for all the solder bumps 100.

The present invention solves the above-mentioned problems, and eliminates the influence of twisting and warping of the substrate, and can effectively and accurately arrange the height of each solder bump accurately and uniformly. The purpose is to provide a leveling device.

[0011]

In order to solve the above-mentioned problems, according to the present invention as set forth in claim 1, a first contact means for contacting one side surface of a substrate provided with a solder bump and the solder bump are provided. The leveling means for equalizing the height and the second contact means for pinching the side edge portion of the other side surface of the substrate between the first contact means and the second contact means are provided.

Further, according to the present invention as set forth in claim 2, there is provided drive means for relatively allowing the first contact means and the second contact means to approach and separate from each other.

According to a third aspect of the present invention, there is provided first contact means for contacting one side surface of the substrate provided with the solder bumps, and leveling means for making the height of the solder bump uniform. A second contact means for contacting a side edge portion of the other side surface of the substrate; and a drive means for relatively allowing the first contact means and the second contact means to approach and separate from each other. , The first
The height of the solder bumps is leveled while the substrate is held by the contact means and the second contact means.

According to the present invention, the first contact means for contacting and supporting the substrate provided with the solder bumps from below and the solder bumps for equalizing the height of the solder bumps above the first contact means. A belling means, a fixed second contact means for pinching both side edges of the substrate between the first contact means and the first contact means, and the first contact means separated from and contacted with the substrate. A driving means for freely moving the solder bump in a state where the substrate is held by the first contact means raised by the drive means and the second contact means fixed. I tried to level it.

Further, in the present invention according to claim 5, the leveling means is provided with a roller body that moves in parallel from one side direction to crush the tops of the solder bumps.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The leveling device according to the present invention is
First contact means for contacting one side surface of the board provided with solder bumps, leveling means for making the height of the solder bump uniform, and side edges of the other side surface of the board for the first side The second contact means for pinching with the contact means.

That is, in the case of flip-chip connection of semiconductor elements, as described in the description of the prior art, it is important to make the solder bumps on the circuit board on which the semiconductor elements are mounted uniform in height. With the above-described structure of the leveling device, the side edge portion of the other side surface of the substrate on which the solder bumps are formed is squeezed between the first abutting means and the second abutting means so that the same substrate is warped or twisted. Can be corrected, and each solder bump can be leveled using the corrected and horizontal substrate surface as a reference surface. Therefore, the height of each solder bump can be made uniform.

Further, since the first contact means and the second contact means clamp the substrate, the first contact means and the second contact means can be relatively approached and separated from each other. It is possible to adopt a configuration including a driving means for

That is, in this embodiment, the first contact means for contacting one side surface of the substrate provided with the solder bumps, the leveling means for equalizing the height of the solder bumps, A second contact means for contacting a side edge portion of the other side surface of the substrate, and a drive means for relatively allowing the first contact means and the second contact means to approach and separate from each other. As a configuration, the height of the solder bump is leveled while the substrate is held by the first abutting means and the second abutting means.

With this structure, the first contact means and the second contact means
Even if the positional relationship between the contact means and the contact means is relatively up or down, the drive means can easily bring them close to and away from each other to squeeze the substrate to correct the warp or the like.

Further, as a more specific configuration among the above configurations, the first contact means for contacting and supporting the substrate provided with the solder bump from below, and the height of the solder pump above the first contact means. The leveling means for equalizing, the fixed second abutting means for pinching the both side edges of the substrate between the first abutting means and the first abutting means. A driving means for moving the substrate so that it can be moved in and out of contact with the substrate, and the substrate is clamped by the first abutting means raised by the driving means and the second abutting means fixed by the driving means. It is preferable to level the height of the solder bumps.

The leveling means may be a roller body that moves in parallel from one side while pressing the solder bumps and crushes the tops of the solder bumps.

The roller body has a DLC (Diamond-Like
Carbon) is preferably applied, and the roller body is horizontally moved while maintaining the position set at a predetermined distance from the reference plane, and the top of each solder bump is formed on the surface of the roller body made of carbide. Crush and level to the set height. In this way, since the operation of the roller body with respect to the solder bumps only moves horizontally, there is no risk of applying unnecessary load to the circuit board on which the solder bumps are formed.

Further, as described above, the second contact means for pinching the both side edges of the substrate between the first contact means and the first contact means is fixed, and the supporting means is moved upward from below the substrate. It is preferable to be configured as possible.

That is, the second contact means has a structure in which reference surfaces are provided which can contact the vicinity of both side ends of the solder bump forming surface of the substrate, and are fixed.
On the other hand, the first contact means has a structure that can be raised by the drive means while mounting the substrate with the solder bump formation surface facing upward.

With this structure, the substrate is raised while being placed on the first abutting means, and both side edges of the substrate are pressed against the reference surface formed on the second abutting means. The warp of the substrate can be corrected by pressing the substrate with the first abutting unit and the second abutting unit.

By fixing the second abutting means in this way, the warp of the substrate can be corrected by a simple operation of raising the first abutting means, and the board is corrected and becomes horizontal. By using the upper surface of the substrate as a reference surface, the positioning of the leveling means composed of a roller body can be easily performed.

Then, by moving the positioned roller body in parallel from one side while contacting each solder bump, the top of each solder bump can be crushed and the bump height can be accurately leveled. .

It is to be noted that the above-mentioned leveling device is upside down, and both side surfaces of the substrate are placed in a locked state on the reference surface of the second abutting means, and the first abutting means is lowered and sandwiched. It is also possible to correct the warp of the substrate by pressing and raise the roller body to bring it into contact with the solder bumps and move in parallel from the position side direction to crush the bump tops and perform leveling.

The solder bump leveling device provided on the substrate will be described in more detail with reference to the accompanying drawings.

Is an explanatory view of the leveling device according to the present embodiment, FIGS. 2 and 3 are operation explanatory views of the leveling device,
FIG. 4 is an explanatory view showing a process until the warp is corrected by the leveling device and the solder bumps are leveled.

As shown in FIGS. 1 and 2, the leveling device A according to the present embodiment has a first contact means 3 for contacting and supporting the circuit board 2 provided with the solder bumps 1 from below.
And a second leveling means for pinching the side edge portions of the circuit board 2 between the leveling means 4 for equalizing the height of the solder pump 1 above the first contact means 3. The contact means 5 is provided. That is, the first contact means 3 and the second contact means 5 constitute a pinching mechanism.

The leveling means 4 is composed of a roller body 40 that can move up and down and move horizontally.
The top part of can be crushed. The surface of the roller body 40 is subjected to DLC (Diamond-Like Carbon) treatment. Reference numeral 41 denotes a roller shaft, and the roller 40 is connected to the elevator / horizontal moving device (not shown) via the roller shaft 41.

The first contact means 3 includes a stage 30 on which the circuit board 2 is placed with the solder bump forming surface facing upward, and a lifting device (not shown) as a driving means for moving the stage 30 up and down. It consists of. The first contact means 3 in the present embodiment is provided with a sensor that detects that the circuit board 2 is placed on the stage 30.

Further, the second abutting means 5 is capable of pinching both side edge portions 20, 20 of the circuit board 2 between the second abutting means 5 and the first abutting means 3, as shown in FIG. , A pair of left and right fixed columns 5 on both sides of the stage 30 forming the first contact means 3.
0 and 50 are erected, and a base end of a horizontal fixing plate 51, which is a smooth surface so that the lower surface thereof becomes the reference surface 5a, is connected to the upper ends of the respective fixed columns 50. Therefore,
In such a configuration, the reference surface 5a remains unchanged.

Further, in the present embodiment, the end of the board transfer device 6 is provided on the stage 30 of the leveling device A, and the circuit board 2 on which the solder bumps 1 are formed is transferred by the board transfer device 6. It is automatically placed on the stage 30. Therefore, the solder bumps can be automatically leveled on the manufacturing line, and work efficiency and manufacturing efficiency can be improved.

In this way, the second contact means 5 provided with the reference surface 5a is fixed, and the stage 30 forming the first contact means 3 can be moved upward from below the circuit board 2. As a result, the circuit board 2 is raised by the stage 30 so that both side edges 20, 20 of the circuit board 2 are moved to the reference plane 5.
The upper surface of the circuit board 2 can be set as a bump height reference surface for aligning the heights of the solder bumps 1 only by pressing it against a, and the circuit board 2 is pinched by the stage 30 and the horizontal fixing plate 51. The warp or twist of the circuit board 2 can be corrected.

Then, with the upper surface of the circuit board 2 which has been warped or the like corrected and becomes horizontal as a bump height reference surface of the solder bump 1, the roller body 40 is lowered from the reference surface to a predetermined height position. By horizontally moving, the solder bump 1 can be accurately and easily leveled.

At this time, the roller body 40 only moves horizontally while maintaining a predetermined distance from the reference plane, and does not apply an unnecessarily heavy load to the circuit board 2, so that the circuit board 2 is useless. There is no fear of doing any damage.

Then, the height of all the solder bumps 1 provided on the circuit board 2 is adjusted to a desired value, so that the strength of the connecting portion when the semiconductor chip (not shown) is flip-chip connected is sufficiently increased. It is possible to smoothly fill the underfill material for keeping the adhesiveness between the chip and the circuit board 2. Further, it becomes possible to control the gap between the chip and the circuit board 2 when the chip is mounted, and it is possible to secure the optimum gap according to the underfill material.

Here, a case where the solder bump 1 is actually leveled will be described. The leveling device A is provided with a control unit (not shown) and receives detection signals from various sensors including a sensor that detects that the circuit board 2 is placed on the stage 30 as described above. It is configured to be automatically controlled.

First, the circuit board 2 having a plurality of solder bumps 1 formed on the surface thereof is transferred via the board transfer device 6 and placed on the stage 30 of the first contact means 3 (see FIG. 2). .

When it is detected that the circuit board 2 is placed on the stage 30, the elevating device, which is a driving means, is driven to raise the stage 30, so that both end edges 20,
20 is pressed against the reference surface 5a formed on the horizontal fixing plate 51 of the second contact means 5, and a predetermined load is raised as it is so as to be applied to the circuit board 2.

At this time, if the circuit board 2 is warped as shown in FIG.
By being pinched between the reference surface 5a of No. 1 and the stage 30, it is corrected to a horizontal state as shown in FIG. 4 (b).

Then, the roller body 40 waiting at the initial position descends from the reference surface 5a to a position of a predetermined height.
This position is a predetermined height from the surface of the circuit board 2 that serves as a bump height reference surface, and the roller body 40 is in contact with the solder bumps 1 on the circuit board 2 while maintaining this constant height. The solder bumps 1 are moved (see FIGS. 1 and 3), and the tops of the solder bumps 1 are crushed and leveled to a set height.

Each solder bump 1 on the circuit board 2 is shown in FIG.
As shown in (c), the top portion is crushed to be slightly flat, and all the heights thereof are made uniform.

As described above, according to the leveling device A according to the present embodiment, the solder bumps 1 can be formed so as to have a uniform height, and the solder connecting portions, which are important for flip chip connection, can be formed. The strength and flexibility can be kept constant, and the quality of the product can be improved.

Although the roller body 40 is used as the leveling means 4 in the above example, the leveling means 4 is not limited to the roller body 40. It may have a flat plate shape or a spatula shape.

Further, the warp of the circuit board 2 in the illustrated example has been described as the case where the surface on which the solder bumps 1 are formed has a concave shape. However, even if the warp is in the opposite direction, the present leveling device A is used. It is possible to perform leveling with high accuracy.

[0050]

The present invention is carried out in the form as described above, and has the following effects.

(1) According to the present invention of claim 1, the first contact means for contacting one side surface of the substrate on which the solder bumps are provided and the solder bumps for equalizing the height of the solder bumps. Since the belling means and the second contact means for pinching the side edge portion of the other side surface of the substrate between the first contact means and the first contact means are provided, the first contact means and the first contact means It is possible to squeeze the board between the two abutting means and correct the warp and twist of the board, and the height of each solder bump is leveled with the corrected and horizontal board surface as a reference plane. It is possible to make them uniform by means. Further, since the bump heights are uniform, the strength and flexibility of the solder connection portion, which is important when performing flip-chip connection, can be kept constant, and the quality of the product can be improved.

Further, according to the present invention as set forth in claim 2, there is provided the driving means for relatively allowing the first contact means and the second contact means to approach and separate from each other. , Even if the positional relationship between the first abutting means and the second abutting means is relatively up or down, the driving means can easily bring them close to and away from each other to squeeze the substrate and correct the warp or the like. Becomes

Further, in the present invention according to claim 3, the first contact means for contacting one side surface of the substrate on which the solder bumps are provided, and the leveling means for making the height of the solder pump uniform. And a second contact means for contacting a side edge portion of the other side surface of the substrate, and a drive means for relatively allowing the first contact means and the second contact means to approach and separate from each other. Since the height of the solder bump is leveled while the substrate is sandwiched by the first contact means and the second contact means, the first contact means and the second contact means are provided. It is possible to squeeze the board between the contact means and to correct the warp and twist of the board, and the height of each solder bump is made uniform by the leveling means with the corrected and horizontal board surface as the reference plane. Can be converted. Further, since the bump heights are uniform, the strength and flexibility of the solder connection portion, which is important when performing flip-chip connection, can be kept constant, and the quality of the product can be improved.

According to the present invention, the first contact means for contacting and supporting the substrate provided with the solder bumps from below and the height of the solder bumps above the contact means are made uniform. The leveling means of the first and second side edges of the substrate.
A fixed second contact means for pinching between the contact means and the drive means, and a drive means for moving the first contact means so that the first contact means can be moved into and out of contact with the substrate. Since the height of the solder bump is leveled while the substrate is clamped by the raised first contact means and the fixed second contact means, only the support means is raised. The warp of the board can be corrected by only simple operation, and the corrected and horizontal board upper surface is used as a reference plane.
Positioning of the leveling means composed of a roller body can be easily performed. Further, for example, if the substrate can be automatically placed on the first abutting means from the substrate transfer line, the solder bumps can be automatically leveled on the manufacturing line. The efficiency in manufacturing can be improved.

Further, in the present invention as set forth in claim 5, the leveling means is a roller body that moves in parallel from one side while pressing the solder bumps and crushes the tops of the solder bumps. As a result, unnecessary load is not applied to the substrate, and there is no possibility of giving unnecessary damage to the substrate.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a leveling device according to the present embodiment.

FIG. 2 is an operation explanatory view of the leveling device.

FIG. 3 is an operation explanatory view of the leveling device.

FIG. 4 is an explanatory view showing a process until the warp is corrected by the leveling device and the solder bumps are leveled.

FIG. 5 is a schematic explanatory view of a conventional solder bump leveling device.

FIG. 6 is a schematic explanatory view of a conventional solder bump leveling device.

[Explanation of symbols]

A leveling device 1 Solder bump 2 substrates 3 First contact means 4 Leveling means 5 Second contact means 5a Reference plane 30 stages 40 roller body

Claims (5)

[Claims] 1. A first contact means for contacting one side surface of a substrate provided with a solder bump, a leveling means for equalizing the height of the solder bump, and a side edge of the other side surface of the substrate. A second contact means for pinching the portion between the first contact means and the first contact means, and a solder bump leveling device provided on a substrate. 2. The substrate according to claim 1, further comprising drive means for relatively allowing the first contact means and the second contact means to approach and separate from each other. Solder bump leveling device. 3. A first contact means for contacting one side surface of a substrate provided with a solder bump, a leveling means for equalizing the height of the solder bump, and a side edge of the other side surface of the substrate. A first contact means for contacting the first and second contact means, and a drive means for relatively allowing the first contact means and the second contact means to approach and separate from each other, the first contact means A solder bump leveling device, wherein the height of the solder bump is leveled while the substrate is held by the means and the second contact means. 4. A first contact means for contacting and supporting a board provided with solder bumps from below, leveling means for making the height of the solder bump uniform above the board, and the board. Fixed second abutting means for pinching both side edge portions between the first abutting means and the first abutting means; The height of the solder bumps is leveled while the substrate is held by the first contact means raised by the driving means and the second contact means fixed. Characteristic solder bump leveling device. 5. The leveling means comprises a roller body that moves in parallel from one side to crush the tops of the solder bumps, according to any one of claims 1 to 4. A solder bump leveling device provided on the substrate.