JPH11260859A - Method for mounting semiconductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain accurate mounting of a semiconductor element even with respect to minute bumps. SOLUTION: This method is for mounting a semiconductor element for soldering a semiconductor element 1 on a substrate 2, by reflowing a solder bump 10 of the semiconductor element 1 under pressurizing and heating conditions. In this case, the solder bump 10 is reflowed under the pressurizing condition, only by a heavy bob 3 placed on the semiconductor element 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a semiconductor device, and more particularly, to a method for mounting a semiconductor device for performing solder bump bonding by local heating, such as replacing a single semiconductor device on a high-density mounting substrate. It is about the method.

At present, a solder bump method is often used for mounting a semiconductor element on a substrate. However, in a repairing process (EC), there are irregularities of remaining solder on the substrate after the element is removed, and unevenness of bumps of the element itself. Therefore, there is a need for a method of mounting a semiconductor element that can be reliably mounted under these conditions.

[0003]

2. Description of the Related Art As a conventional method for mounting a semiconductor element in a repair process, the method shown in FIG. 8 is employed. In this conventional example, a tool 7 is mounted on a semiconductor element 1 mounted on a substrate 2, and a pressing body 70 is
Is arranged. The pressurizing member 70 has a heat generating portion 70a that generates heat by receiving a current from a welding power supply (not shown), and reflows the solder bump 10 while pressing the semiconductor element 1 against the substrate 2 with a predetermined load by controlling the height. .

[0004]

However, the above-mentioned prior art has the following disadvantages. That is, the semiconductor element 1 is pressed with a predetermined load by the pressurizing body 70 during the solder reflow. Mounting on the board 2 makes mounting positioning difficult.

An object of the present invention is to solve the above-mentioned drawbacks, and an object of the present invention is to provide a method of mounting a semiconductor element capable of accurately mounting even a minute bump.

[0006]

According to the present invention, the object is to provide a semiconductor device having a solder bump under pressure and heating conditions.
This is a method of mounting a semiconductor element in which the semiconductor element 1 is soldered on the substrate 2 by reflowing the solder bumps 10, wherein the solder bumps 10 are reflowed under the pressurized condition only by the weight 3 placed on the semiconductor element 1. This is achieved by providing a method for mounting a semiconductor device.

[0007] Solder bumps 10 are formed on the substrate facing surface of the semiconductor element 1, and the semiconductor element 1 is held on the substrate 2 with the solder bumps 10 corresponding to predetermined pads. When mounting the semiconductor element 1, first, the weight 3 is placed on the semiconductor element 1 by using an appropriate transport means such as the suction head 5. After the weight 3 has been placed, the transfer means presses the semiconductor element 1 with a predetermined load as necessary to apply a predetermined crushing deformation to the solder bump 10 and then retreats to the retreat position.

[0008] The reflow of the solder bumps 10
While being held down by the weight of
Since it is performed under the pressurizing condition only by the pressure, there is no displacement or the like due to the minute vibration unlike the conventional example.

Various means can be used to supply the heat for reflowing the solder bumps 10. For example, near-infrared irradiation or indirect heating by an indirect heating means 6 such as an inert hot gas can be used. When the weight 3 has been heated in advance, the solder bumps 10 can be reflowed by the radiant heat of the weight 3 without using the indirect heating means 6. The heating of the weight 3 can be carried out by a conveying means having the weight heating means 4 in addition to the heating by the weight heating means 4 provided at an appropriate position in the apparatus.

According to a second aspect of the present invention, there is provided a method of mounting a semiconductor device, comprising reflowing solder bumps 10 of a semiconductor device 1 under conditions of pressure and heating to solder the semiconductor device 1 onto a substrate 2. A semiconductor element 1 on which a weight 3 having a predetermined weight is mounted is placed at a predetermined position on a substrate 2 and a solder bump 10 is reflowed under a pressurized condition using only the weight 3. .

The present invention provides an effective mounting method when the semiconductor element 1 is not positioned on the substrate 2 in advance. The weight 3 is mounted on the semiconductor element 1 which stands by at a predetermined position. In this state, it is transported to a predetermined position on the substrate 2. Since it is necessary to perform positioning on the substrate 2, it is desirable to use the suction head 5 as the transporting means. A plurality of through holes are drilled in the weight 3 so that the weight 3 in the stacked state and the suction head 5 of the semiconductor element 1 can be suctioned.
If necessary, the transfer means positions the semiconductor element 1 at a predetermined position on the substrate 2 and then presses the semiconductor element 1 with a predetermined load to apply a predetermined crushing deformation to the solder bump 10. 2. The heat source for reflowing the solder bumps 10 according to claim 1.
The means described in the invention according to (1) can be used as it is.

According to a third aspect of the present invention, there is provided a weight 3 having a predetermined weight.
And a suction head 5 that conveys the weight 3 heated by the weight heating means 4 to the upper surface of the semiconductor element 1 held on the substrate 2 and retracts from the conveyance position after the conveyance. This is a semiconductor device mounting apparatus that reflows the solder bumps 10 of the semiconductor device 1 by radiant heat of the weight 3 while pressing the semiconductor device 1.

In the present invention, the weight 3 having a predetermined weight is heated to a predetermined temperature by the weight heating means 4 and is conveyed by the suction head 5 onto the semiconductor element 1 on the substrate 2. The weight heating means 4 can be provided at an appropriate place in the apparatus, or can be provided on the suction head 5 itself. After placing the weight 3 on the semiconductor element 1, the suction head 5 presses the semiconductor element 1 with a predetermined load as necessary to give a predetermined crushing deformation to the solder bump 10, and then retracts to the retracted position.

The reflow of the solder bump 10 depends on the weight 3
While being held down by the weight of
Since it is performed under the pressurizing condition only by the pressure, there is no displacement or the like due to the minute vibration unlike the conventional example.

In the case where the semiconductor element 1 is not positioned on the substrate 2 in advance, the weight 3 having a predetermined weight and the weight 3 are stacked on the upper surface as in the invention according to claim 4. Is transported to a predetermined position on the substrate 2, the suction head 5 that retreats from the transport position after the transport, the weight 3, and the semiconductor element 1 are heated, and the solder bumps 10 are reflowed under the pressure of the weight 3. A semiconductor device mounting apparatus having the indirect heating means 6 can be configured.

The heat source for reflowing the solder bumps 10 includes a near-infrared irradiating device as in the invention according to claim 4,
Alternatively, in addition to using the indirect heating means 6 such as an inert hot gas device, the radiant heat of the weight 3 can be used,
In this case, as in the invention according to claim 5, the weight 3 having the predetermined weight and the semiconductor element 1 having the weight 3 laminated on the upper surface are transported to a predetermined position on the substrate 2, and after the transport, are retracted from the transport position. And a weight 3 heated while being pressed by the weight 3 heated by the suction head 5.
The semiconductor device mounting apparatus that reflows the solder bumps 10 of the semiconductor device 1 with the radiant heat of the semiconductor device 1 can be configured.

[0017]

FIG. 2 shows a semiconductor mounting apparatus according to an embodiment of the present invention. The semiconductor mounting device includes an XY table 81 housed in the device housing 8 in an inert gas atmosphere by an inert gas supply device 80.
A hot plate 82 is held on the table 81. The hot plate 82 has a heat source (not shown) inside, and keeps the surface at a preheating temperature and the weight storage section (weight heating means 4) at a predetermined heating temperature.

The weight 3 has a predetermined weight, and the weight accommodation portion 4
To be housed. For example, the weight of the weight 3 can prevent the semiconductor element 1 from rising due to surface tension when a solder bump 10 of the semiconductor element 1 described later is melted, and can maintain the semiconductor element 1 at an appropriate height. The weight is set so that the molten solder is not crushed too much to cause pattern contact or the like.
The heating temperature of the hot plate 82 is set to a temperature at which the weight 3 can supply radiant heat sufficient to melt the solder bumps 10 as described later.

The substrate 2 on which the semiconductor element 1 to be mounted is mounted is mounted on the surface of the hot plate and preheated to a predetermined temperature. The semiconductor element 1 is previously positioned at a predetermined position on the substrate 2 and is temporarily fixed by means such as thermocompression bonding. 5
Denotes a suction head, which can be displaced in a height direction and a rotation direction.

A mounting method using the semiconductor mounting apparatus according to the present embodiment will be described. First, after the suction head 5 is driven in the height direction to suck and lift the upper surface of the heated weight 3 in the weight storage unit 4, the XY table 81 is driven to move the target semiconductor element 1. It is located directly below the suction head 5 (see FIG. 2B). Then, while rotating the shaft, the weight 3
Is placed on the upper surface of the semiconductor element 1, and the semiconductor element 1 is further pressed with a predetermined load. The solder bump 10 fixed to the back surface of the semiconductor element 1 is crushed and deformed by a predetermined amount due to the pressing by the suction head 5 (see FIGS. 1A and 1B).

After a predetermined crushing deformation is applied to the solder bumps 10, the suction head 5 is pulled up again as shown in FIG. 1C, and retreats from the pressing position of the semiconductor element 1. If left in this state, the solder bumps 10 are melted by the radiant heat of the weight 3, and thereafter, the suction head 5
Is driven to suck the weight 3 placed on the semiconductor element 1 and transported to the weight receiving section 4 to complete the mounting operation.

In the above description, the weight housing portion serving as the weight heating means 4 is disposed in the apparatus housing 8, and the weight 3 is configured to be heated to a predetermined temperature by the weight heating means 4. However, the weight 3 can also be heated by providing the suction head 5 with a heating means.

FIG. 4 shows a modification of this embodiment. In the following description, components that are essentially the same as those in the above-described embodiment will be denoted by the same reference numerals in the drawings, and description thereof will be omitted. In this modification, a near-infrared irradiating device (indirect heating means 6) is arranged in the device housing 8. As shown in FIG. 4B, after the weight 3 preheated by the hot plate 82 is placed on the upper surface of the semiconductor element 1, the XY table 81 is driven to convey the substrate 2 to the vicinity of the near-infrared irradiation device. I do. As shown in FIG. 3, the suction head 5 connects the weight 3 to the semiconductor element 1.
The weight 3 is pressed against the solder bump 10 of the semiconductor device 1 by a predetermined load when the semiconductor device 1 is placed on the semiconductor device 1 to apply a predetermined amount of crushing deformation. The residual heat temperature of the weight 3 is set lower than the heating temperature of the weight heating means 4 described above, and the near infrared irradiation device 6 irradiates infrared rays to heat the weight 3 and the semiconductor element 1, and Is melted. Thereafter, the XY table 81 is driven to convey the substrate 2 directly below the suction head 5, and the suction head 5 removes the weight 3 to complete the mounting operation.

In the above description, the case where a near-infrared irradiation device is used as the indirect heating means 6 has been described. However, a high-temperature inert gas is supplied from an inert gas supply device to be used as a heat source for reflow. Can also.

FIG. 5 shows a second embodiment of the present invention.
In this embodiment, the substrate 2 is preheated on the hot plate 82 without mounting the semiconductor element 1,
A supply section for the target semiconductor element 1 is provided at an appropriate position in the device housing 8. The weight 3 is preliminarily laminated on the semiconductor element 1, and as shown in FIG. 5A, the suction head 5 that can be driven in the X-Y direction sucks the weight 3 and the semiconductor element 1,
It is transported to a predetermined position on the substrate 2. Weight 3 and semiconductor element 1
In order to adsorb both of them in a laminated state, through holes are formed in the weight 3 so as to penetrate both sides.

The suction head 5 has a heating means, and heats the weight 3 while the weight 3 and the semiconductor element 1 are suctioned. Thereafter, the semiconductor element 1 is positioned by operating the XY table 81 or the suction head 5, and the semiconductor element 1 is pressed against the substrate 2 by the suction head 5.
A predetermined amount of crush deformation is applied to the solder bumps 10 of the semiconductor element 1 (see FIG. 5B). After the step of crushing the solder bumps 10, the suction head 5 releases the suction operation and is lifted upward as shown in FIG. 5C. I do. Finally, the weight 3 is removed, and the mounting operation is completed. The weight 3 can be removed by, for example, handling means (not shown) arranged in the apparatus.

In the above description, the case where the radiant heat of the weight 3 is used as a heat source for reflowing the solder bumps 10 has been described. In addition to this, the modification is shown in the first embodiment described above. As described above, a near-infrared irradiation device or an indirect heating means 6 such as an inert hot gas can be used (see FIG. 6).

Further, in the above, the weight 3 has a rectangular parallelepiped shape. However, as shown in FIG.
If the distribution of the solder bumps 10 is not uniform, FIG.
As shown in FIG. 7 (b), a protrusion 30 is provided on the upper surface, or as shown in FIG. Bump shorts can be prevented. The arrangement or cross-sectional shape of the projection 30 is determined so that the centroid of the group of the solder bumps 10 and the position of the center of gravity of the weight 3 coincide.

[0029]

As is apparent from the above description, according to the present invention, since only the weight is used as the pressing means,
It is possible to reliably prevent displacement or the like due to minute vibration during heating.

[Brief description of the drawings]

1A and 1B are diagrams showing the present invention, wherein FIG. 1A is a diagram showing a weight placing process, FIG. 1B is a diagram showing a solder bump crushing process,
(C) It is a figure which shows a solder bump reflow process.

FIGS. 2A and 2B are diagrams showing a semiconductor mounting device, wherein FIG. 2A is a diagram showing an initial state, and FIG. 2B is a diagram showing a mounting process of a weight.

3A and 3B are views showing a modification of FIG. 1, wherein FIG. 3A shows a step of placing a weight, FIG. 3B shows a step of crushing solder bumps, and FIG. 3C shows a step of solder bump reflow. FIG.

4A and 4B are diagrams showing a semiconductor mounting device, wherein FIG. 4A is a diagram showing an initial state, and FIG. 4B is a diagram showing a solder bump reflow process.

FIG. 5 is a diagram showing a second embodiment of the present invention;
FIG. 7 is a view showing a mounting step on a substrate, FIG. 7B is a view showing a solder bump crushing step, and FIG. 7C is a view showing a solder bump reflow step.

6A and 6B are diagrams showing a modification of FIG. 5, wherein FIG. 6A shows a weight placing process, FIG. 6B shows a solder bump crushing process, and FIG. 6C shows a solder bump reflow process. FIG.

7A and 7B are diagrams showing a modification of the weight, wherein FIG. 7A is a diagram showing a semiconductor element, FIG. 7A is a plan view of the mass, and FIG. 7B is a sectional view of a mass according to another modification. is there.

FIG. 8 is a diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor element 10 Solder bump 2 Substrate 3 Weight 4 Weight heating means 5 Suction head 6 Indirect heating means

Claims (5)

[Claims] 1. A method for mounting a semiconductor element, comprising reflowing solder bumps of the semiconductor element under pressure and heating conditions and soldering the semiconductor element on a substrate, wherein only a weight placed on the semiconductor element is provided. A method of mounting a semiconductor device in which solder bumps are reflowed under pressurized conditions according to the present invention. 2. A method of mounting a semiconductor device, comprising reflowing solder bumps of the semiconductor device under pressure and heating conditions and soldering the semiconductor device on a substrate, wherein a weight having a predetermined weight is placed on the upper surface. A method of mounting a semiconductor element, comprising mounting a semiconductor element at a predetermined position on a substrate and reflowing a solder bump under a pressurized condition using only the weight. 3. A weight having a predetermined weight, and a suction head for transferring the weight heated by the weight heating means to an upper surface of the semiconductor element held on the substrate, and retreating from the transfer position after the transfer. A semiconductor element mounting apparatus that reflows solder bumps of a semiconductor element by radiant heat of the weight while the semiconductor element is pressed by the weight. 4. A weight having a predetermined weight, a suction head for transferring a semiconductor element having a weight stacked on an upper surface thereof to a predetermined position on a substrate, and retreating from the transfer position after the transfer, a weight and the semiconductor element. An indirect heating means for heating and reflowing the solder bumps under a pressure condition by a weight. 5. A weight having a predetermined weight, and a suction head for transferring a semiconductor element having a weight stacked on an upper surface thereof to a predetermined position on a substrate and retracting from the transfer position after the transfer, and A semiconductor element mounting apparatus that reflows solder bumps of a semiconductor element by radiant heat of the weight while the semiconductor element is pressed by the heated weight.