JPH11186329A - Manufacture of semiconductor device, semiconductor device, and manufacture of solder ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make uniform the heat applied to a solder ball, prevent warpage of a semiconductor device, and improve reliability by almost horizontally arranging semicircular holes to arrange solder balls for terminals which are supplied from above in an array type, and heating the solder balls by a heating plate. SOLUTION: A heating plate 20 having semicircular holes 21, a runner 22 built in the heating plate 20, and gathering vessel 23 gathering solder balls 10 through the runner 22 are installed. Solder balls 10 which drop by the effect of self-weight enter the semicircular holes 21 on the heating plate 20. Excess solder balls which have not entered the semicircular holes 21 drop in the runner 22 by the X-Y sliding operation of the heating plate 20, and roll into the gathering vessel 23. When all the semicircular holes are filled with solder holes 10, heating is performed by using the heating plat 20. The heating temperature is controlled so as to be 1-5 deg.C/sec at the solder ball 10 surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a BGA, a CSP,
The present invention relates to a semiconductor device for forming bumps using solder balls as terminals, such as mounting of a bare chip, a method for manufacturing a semiconductor device, and a method for manufacturing a solder ball itself.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing a BGA, for example, an IC chip 11 is die-bonded to a substrate 13, connected by a gold wire 12 or the like, and then resin-sealed 14 by transfer molding or potting or the like, and then becomes a terminal on the substrate. The solder balls 10 are mounted.

[0003] As a method of mounting the solder ball 10, generally, the flux is transferred to the substrate 13 with a pin like a sword or a screen printing method using a mask made slightly smaller than a ball pad. Apply. The substrate 13 to which the flux has been applied is mounted on the substrate 13 by adsorbing the solder balls 10 floating in the stock container by an adsorbing jig or the like aligned in the next step. Thereafter halogen, melting the ball surface mounting the solder balls 10 by hot air or N ₂ reflow or the like.

[0004]

In such a method, first, it is difficult to control an appropriate amount of flux in flux application, and when the sealing surface and the solder ball mounting surface are on the same surface as in a face-down type, sealing is performed. There is a problem that the flux application position shifts due to the surface shift and the variation in height. In addition, when the ball is mounted, the ball must be always floated, so that the ball rubs and a zinc film is formed. Further, in the reflow, since heat is applied to the substrate at a temperature higher than the melting point of the solder ball, problems such as warpage of the substrate are likely to occur, and the reliability of the product is affected by thermal stress.

According to the present invention, the flux can be controlled to a uniform thickness by a roller, and the flux is transferred to a rubber plate again and then applied to a substrate, so that an appropriate amount of flux can be applied. In addition, as for mounting the balls, the balls can be aligned only by the production of the solder balls from the solder cream or by the natural fall of the solder balls, so that the rubbing of the balls is reduced.

Further, the heat applied to the solder ball is made uniform by heating the solder ball by the plate, and the heat of the semiconductor device itself is reduced by separating the heating of the semiconductor device and the solder ball. The purpose is to improve reliability.

[0007]

According to the present invention, there is provided a semicircle for arranging solder balls for terminals supplied from the upper side in an array in a substantially horizontal manner. A heating plate having a hole in the shape of a hole, which can be heated by a heating device, a runner serving as a passage for a ball overflowing from the plate incorporated in the heating plate, and an XY slide mechanism and a runner for dropping solder balls into the runner. The present invention is characterized in that a solder container is mounted by using a collection container for receiving solder balls discharged through the container.

In the first aspect, the method of supplying the solder ball to the semicircular hole is preferably a method of falling by its own weight. In this case, it is desirable that the heating plate is embedded with a thermocouple or the like so that the temperature can be controlled to a constant value. Further, it is preferable to take a countermeasure against static electricity on the entire surface of the plate and to perform a mirror finish and a surface treatment such as titanium coating on the plate surface in order to improve the surface condition of the solder ball and reduce the adhesion. It is desirable that the series of operations of claim 1 be performed in an N ₂ atmosphere in order to prevent deterioration of the solder balls.

According to a second aspect of the present invention, there is provided a semi-circular hole for arranging the solder balls for terminals supplied from the upper side in an array, and for adsorbing the solder balls. A heating plate having a vacuum path leading from the semicircular hole to the vacuum suction device and capable of being heated by the heating device, a reversing mechanism for reversing and dropping excess solder balls dropped on the heating plate, The method is characterized in that a solder container is mounted using a collection container for receiving the solder ball. According to this structure, in addition to the effect according to the first aspect, by further providing the vacuum suction method, the positional accuracy of the solder ball is further improved, and the surplus solder ball can be reliably removed. . In this case, it is desirable that the number of the vacuum paths is equal to the number of the solder balls so that the vacuum paths can function individually, and the presence or absence of the balls can be individually detected by a sensor.

As in the first aspect, the method of supplying the solder ball to the semicircular hole is preferably a method of falling by its own weight. In this case, it is desirable that the heating plate is embedded with a thermocouple or the like so that the temperature can be controlled to a constant value. In addition, it is preferable to take anti-static measures on the entire surface of the plate and to apply a mirror finish to the surface of the plate to improve the surface condition of the solder balls and to reduce adhesion, and to perform surface treatment such as titanium coating. Is preferably performed in an N ₂ atmosphere in order to prevent the deterioration of Nb. In addition, a slide plate is incorporated between the vacuum path and the semicircular hole in order to prevent the solder from flowing out into the vacuum path when the solder balls are melted. It is desirable to have a mechanism for shielding the semicircular hole.

According to a third aspect of the present invention, when the heating plate according to the first or second aspect is used, a counterbore is provided in a portion which should not be heated, and a heat insulating material is attached to the counterbore to block heat. Features. According to this structure, heat is applied only to the periphery of the solder ball, and heat is not applied to other portions, particularly, a portion that is vulnerable to thermal stress such as a semiconductor element, so that the reliability of the semiconductor device is improved. In this case, the heat insulating material may be any material as long as it has a low thermal conductivity,
A material that can be easily processed is preferable because it must be processed to conform to the shape. It is desirable that the heat insulating material has a minimum necessary size.

According to a fourth aspect of the present invention, the distance between the rotating shaft that rotates from the power source, the roller A that rotates by receiving the power of the rotating shaft, and the roller A to make the thickness of the flux uniform is variable. And a reservoir having a roller B for further transferring the flux whose thickness is controlled by the blade and the roller A, and a roller C that can contact the roller B and horizontally reciprocate to be transferred to the roller C. And a mechanism for applying the flux.

According to this structure, the flux can be constantly kneaded, so that the viscosity can be kept constant and the thickness of the flux can be easily controlled. Also, the scattering of the flux can be reduced, and the workability can be improved. In this case, it is desirable to use a metal material such as steel or super hard for the roller A and the blade in order to prevent abrasion. It is preferable that the surfaces of the rollers B and C are covered with conductive rubber or the like.

According to a fifth aspect of the present invention, there is provided a mechanism according to the fourth aspect, wherein the flux is transferred from the roller C to the protruding rubber plate and the flux is applied by moving the rubber plate up and down. According to this structure, since the coating is performed by the rubber plate, the friction with the material to be coated is reduced as compared with the fourth aspect, so that the accuracy of the application position of the flux is improved and the scattering of the flux can be prevented. In the method according to the fourth aspect, the entire surface is applied to the planar object.
The present invention can be applied to any point. Also, damage to the material to be coated is eliminated. In this case, the rubber plate is preferably made of a conductive material, and it is desirable that the projections be tapered in order to maintain strength and improve positional accuracy.

According to a sixth aspect of the present invention, there is provided a guide plate for positioning and guiding a semiconductor device, a heating device for heating the guide plate, and a semiconductor device positioned and heated by the guide plate being moved up and down by the guide plate. The method is characterized in that the solder ball is mounted by making contact with the solder ball. According to this structure, compared to solder ball mounting by normal reflow,
The semiconductor device does not need to be heated to the solder melting point, and the thermal stress on the semiconductor device is significantly reduced. Claim 6
Is desirably performed in an N ₂ atmosphere.

According to a seventh aspect of the present invention, in the sixth aspect, a cushioning material is incorporated in the guide plate to make the contact pressure uniform at the time of solder ball contact. According to this structure, there is no damage to the solder balls at the time of contact, so that stable ball mounting is possible. The cushioning material in this case may be any material as long as it can absorb the stress between the semiconductor device and the solder ball, and includes, for example, a spring. It is desirable that the series of operations in claim 7 be performed in an N ₂ atmosphere as in claim 6.

According to an eighth aspect of the present invention, it is preferable that the semiconductor device according to the first to seventh aspects is manufactured by performing a series of operations.

The present invention according to claim 9 is arranged substantially horizontally,
A heating plate that has a semicircular hole for aligning in an array, and can be heated by a heating device, and a supply device having a dispenser that flows an appropriate amount of molten solder or solder cream into individual semicircles, A heating mechanism that keeps the molten solder or solder cream in the supply device at a constant temperature, a drive device that moves the supply device up, down, left, and right, a storage container that stores the solder balls manufactured on the heating plate, and a solder ball storage The method is characterized in that a solder ball is manufactured using a cleaning device for cleaning the plate later.

According to this structure, since the solder is heated by the plate, the temperature is stabilized as compared with the heating in the atmosphere. Further, since the hole serves as a solder ball-shaped guide, the ball shape is stabilized. In this case, it is desirable that the heating plate is embedded with a thermocouple or the like so that the temperature can be controlled to a constant value. As a storing method, a fall by an inversion mechanism may be used, but a method of storing the solder balls in the storage container by suction to reduce damage to the solder balls is desirable.

It is preferable that the cleaning apparatus performs plasma cleaning or UV cleaning to prevent contamination of the plate surface. It is preferable that the series of operations described in claim 9 be performed in an N ₂ atmosphere in order to prevent the deterioration of the solder balls.

According to a tenth aspect of the present invention, there is provided a general semiconductor device using the solder ball manufactured in the ninth aspect. In this case, it is desirable to mount the solder ball immediately after the manufacture to prevent the deterioration of the solder ball.

According to an eleventh aspect of the present invention, when the solder is formed into a spherical shape in the ninth aspect, a ball is mounted on the substrate. According to this method, the solder balls can be mounted simultaneously with the production of the solder balls, and the efficiency can be improved.

[0023]

Embodiments of the present invention will be described below with reference to the accompanying drawings. An example of a semiconductor device manufactured according to the present invention will be described first for easy understanding.

FIG. 1 is a sectional view of a face-down type BGA, and FIG. 2 is a rear view. The IC chip 11 die-bonded on the substrate 13 is
It is connected to the upper wiring 15 and is sealed 14 with resin.

The wiring 15 on the substrate 13 is connected to the pad portion 16 and is connected to the terminal and the solder ball 10.

In the case of the face-down type, the solder balls 10 are arranged in a grid pattern except for the sealing portion 14. Here, a face-down type BGA is described as an example, but it goes without saying that there are various types of BGAs and CSPs having other structures.

The first aspect of the present invention is a manufacturing method for mounting a solder ball 10 on the substrate.

FIG. 3 is a plan view showing the structure of the manufacturing method according to claim 1 of the present invention, and FIG. 4 is a side view. As shown in both figures, the present invention includes a heating plate 20 having a semicircular hole 21, a runner 22 incorporated in the heating plate 20, and a collecting container 23 for collecting the solder balls 10 through the runner. The solder ball 10 dropped by its own weight enters the semicircular hole 21 on the heating plate 20. The solder balls 10 that have become excessive and have not entered the semicircular holes 21 fall into the runners 22 by the XY sliding operation of the heating plate 20 and roll into the collection containers 23.
When the solder balls 20 are accommodated in all the semicircular holes 21, the heating plate 20 is heated by the heating device.
The heating temperature is controlled by a thermocouple incorporated in the heating plate 20. In this case, the temperature gradient is controlled so as to be 1 to 5 ° C./sec on the surface of the solder ball 10, and the plate temperature depends on the solder ball diameter and the like.
The target value is 50 ° C to 250 ° C.

Here, the manufacturing method according to claim 2 will be described first. The second aspect of the present invention is a manufacturing method which is advantageous for a solder ball having a narrow pitch or a solder ball having a small diameter. FIG. 5 is a plan view showing the structure of the manufacturing method according to claim 2 of the present invention, and FIG. 6 is a side view.

Here, parts different from the above-described manufacturing method will be described. As shown in both figures, the present invention provides the semicircular hole 21 and the semicircular hole 21 for adsorbing the solder ball 10.
It comprises a heating plate 20 having a vacuum path 24 connected to a vacuum suction device, a reversing mechanism 25 for reversing the heating plate, and a collecting container 23 for receiving the dropped solder balls 10. The solder ball 10 dropped by its own weight enters the semicircular hole 21 on the heating plate 20. The solder ball 10 entering the semicircular hole 21 is sucked by a vacuum path 24 connected to a vacuum suction device. All semicircular holes 21
When the solder balls 10 enter and are adsorbed, the heating plate 20 is inverted by the inversion mechanism 25 to remove the excess solder balls 10 on the heating plate 20, and the excess solder balls 10 fall into the collection container 23. After removing the surplus solder balls 10, the heating plate 20 is again inverted and returns to the original state.

Thereafter, the heating plate 20 is heated by the heating device. The heating conditions are the same as described above, and thus are omitted.

Next, the flux application will be described. FIG. 7 is a diagram showing the configuration of the manufacturing method according to claim 4 of the present invention.

A reservoir 30 comprising a rotating shaft 31 rotated by a power source, a roller A 32 on the rotating shaft 31, a blade 33 for controlling the amount of flux, and a roller B 34 in contact with the roller A, and a roller of the reservoir 30. It is constituted by a roller C35 which comes into contact with B34 and is driven to reciprocate horizontally. An appropriate amount of flux is applied to the reservoir 30, the gap between the roller A32 and the roller A32 is adjusted by the blade 33, and the thickness is controlled and well stirred. Flux by roller C3
5 is transferred. The transferred flux is a roller C3
The reciprocating drive 5 is applied to the object.

FIG. 8 shows a manufacturing method according to a fifth embodiment of the present invention. The roller C35 is reciprocally driven and further transferred onto the rubber plate 36, and then the rubber plate 36 is moved up and down. Here's how to do it. The flux is applied to the solder ball 10 or the substrate pad portion. The former roller C35 is suitable for application to the solder ball 10, and the latter rubber plate 36 is preferably applied to the pad portion. In the case of directly applying to the solder balls 10 on the heating plate 20, it is performed before heating.

FIG. 9 is a view showing a structure of a manufacturing method according to claim 6 of the present invention. The semiconductor device is sealed, chucked by the guide plate 40, positioned, and heated by a heating device. Although the heating temperature varies depending on the material of the semiconductor device at a temperature gradient of 1 to 5 ° C./sec, the target value is 50 ° C. to 180 ° C. Solder ball 1
If there is a concern about the stress at the time of mounting, as shown in FIG. 10, a structure is adopted in which a spring 41 is incorporated in the guide plate 40 to cushion it. In this case, when applying flux to the pad portion of the substrate, it is preferable to chuck the semiconductor device to which the flux has been applied in advance.

When all of the above is completed, as shown in FIG. 11, a guide plate 40 for guiding the semiconductor device is provided.
And lower the solder balls 10 on the heating plate 20 described above.
Contact. In this case, when a high temperature is directly applied to an IC chip or the like, such as a face-down type, a counterbore is provided on the heating plate 20 in advance as shown in FIG. A method of shutting off heat is effective. At the contact, the heating devices of the heating plate 20 and the guide plate 40 are turned off and cooled. When the solder ball 10 is cooled and hardened, the guide plate 40 is raised to complete the solder ball mounting.

FIG. 13 shows a method of manufacturing a solder ball according to the ninth aspect. A supply device 51 for flowing molten solder or solder cream is provided on the upper portion of the above-described heating plate 20.
Pour into 1. When the solder has entered the semicircular holes 21, heating is performed under the above-described conditions. The heated solder becomes spherical due to surface tension. The heating device is turned off and cooled when the sphere is formed, so that a solder ball is formed.

The semiconductor device can be mounted on a solder ball from molten solder or solder cream by cutting the heating device after lowering the guide plate 40 to contact the semiconductor device without turning off the heating device. Can be.

As described above, according to the present invention, the solder ball 1
Since the melting of 0 is performed by the plate, the temperature is stabilized, and the high quality solder ball 10 is obtained. The flux can be applied by a very simple method. The main advantage of the present invention is that in the conventional reflow, the semiconductor device itself enters the reflow due to the solder ball mounting, so that thermal stress was unavoidable, but the present invention divides the heating of the semiconductor device and the solder ball. As a result, thermal stress applied to the semiconductor device is significantly reduced, and a highly reliable semiconductor device can be obtained.
Although the above description has been made with reference to a BGA as an example, it goes without saying that the present invention can also be applied to the formation of solder bumps on CSPs and bare chips. Also, this description is intended to be illustrative and not limiting.

[0040]

According to the semiconductor device manufacturing method of the present invention, the solder balls are melted by uniform heat, and a high-quality and stable ball-shaped semiconductor device can be manufactured.

According to the method of manufacturing a semiconductor device of the second aspect, the manufacturing method is further simplified as compared with the first aspect, and a high-quality and stable ball-shaped semiconductor device can be manufactured very easily. .

According to the manufacturing method of the third aspect, even a face-down type semiconductor device can reduce a thermal stress on a chip or the like and manufacture a high-quality semiconductor device.

According to the manufacturing method of the fourth aspect, it is possible to apply an appropriate amount of the flux uniformly.

According to the manufacturing method described in claim 5, claim 4
It is possible to apply an appropriate amount of flux to a more precise and fine portion as compared with the method described above.

According to the manufacturing method of the sixth aspect, since the positional accuracy between the semiconductor device and the solder ball is improved, and the heating of the solder ball and the heating of the semiconductor device can be divided by the present method, the thermal stress applied to the semiconductor device is reduced. It is possible to manufacture a high quality and highly reliable semiconductor device.

According to the manufacturing method of claim 7, the method of claim 6
Since the pressure applied to the ball is more uniform than in the case of the first embodiment, it is possible to form a solder ball having higher quality and higher precision.

According to the semiconductor device of the eighth aspect, the thermal stress applied to the semiconductor device can be remarkably reduced, and the semiconductor device has high reliability and high quality.

According to the manufacturing method of the ninth aspect, the manufacturing of the solder ball can be made very easily.

According to the semiconductor device of the tenth aspect, since the semiconductor device can be manufactured rationally and easily, a low-cost semiconductor device can be obtained.

According to the manufacturing method of the eleventh aspect, it is possible to manufacture a semiconductor device with a very reasonable and easy configuration at a low cost.

[Brief description of the drawings]

FIG. 1 is a BGA sectional view of a face-down type.

FIG. 2 is a back view of a face-down type BGA.

FIG. 3 is a plan view of an embodiment of the semiconductor device manufacturing method according to claim 1 of the present invention.

FIG. 4 is a side view of the embodiment of the semiconductor device manufacturing method according to claim 1 of the present invention.

FIG. 5 is a plan view of an embodiment of a semiconductor device manufacturing method according to claim 2 of the present invention.

FIG. 6 is a side view of an embodiment of a semiconductor device manufacturing method according to claim 2 of the present invention.

FIG. 7 is a side view of an embodiment of a semiconductor device manufacturing method according to claim 4 of the present invention.

FIG. 8 is a side view of an embodiment of a semiconductor device manufacturing method according to claim 5 of the present invention.

FIG. 9 is a side view of an embodiment of a semiconductor device manufacturing method according to claim 6 of the present invention.

FIG. 10 is a side view of an embodiment of a semiconductor device manufacturing method according to claim 7 of the present invention.

FIG. 11 is a side view in which the first and second aspects of the present invention and the sixth and seventh aspects are combined.

FIG. 12 is a sectional view of an embodiment of a semiconductor device manufacturing method according to claim 3 of the present invention.

FIG. 13 is a side view of an embodiment of the method for manufacturing a solder ball according to claim 9 of the present invention.

[Explanation of symbols]

 Reference Signs List 10 solder ball 11 IC chip 12 gold wire 13 substrate 14 sealing 15 wiring 16 pad section 20 heating plate 21 semicircular hole 22 runner 23 collection container 24 vacuum path 25 inversion mechanism 30 reservoir 31 rotation axis 32 roller A 33 blade 34 roller B 35 roller C 36 rubber plate 40 guide plate 41 spring 51 supply device 52 heating mechanism 53 heat insulating material

Claims (11)

[Claims] 1. A heating plate which is disposed substantially horizontally, has a semicircular hole for aligning solder balls for terminals supplied from above in an array, and can be heated by a heating device. The mounting of the solder balls is performed by using a runner which becomes a passage of the balls overflowing from the plate incorporated in the heating plate, an XY slide mechanism for dropping the solder balls to the runner, and a collecting container for receiving the solder balls discharged through the runner. A method of manufacturing a semiconductor device. 2. A semi-circular hole for arranging the solder balls for terminals supplied from the upper side in an array in a substantially horizontal manner, and a vacuum from the semi-circular hole for adsorbing the solder balls. A heating plate having a vacuum path connected to the suction device and capable of being heated by the heating device, a reversing mechanism for reversing the heating plate by turning over the surplus solder balls that have fallen on the heating plate, and a falling solder ball. A method for manufacturing a semiconductor device, comprising: mounting a solder ball using a receiving container. 3. The semiconductor device according to claim 1, wherein a counterbore is provided in a portion not to be heated, and a heat insulating material is attached to the counterbore portion to block heat. Manufacturing method. 4. A rotating shaft rotating from a power source, a roller A rotating by receiving the power of the rotating shaft, and a blade capable of changing a distance between the roller A to make the thickness of the flux uniform, A roller C having a reservoir having a roller B for further transferring the flux whose thickness is controlled by the blade A and the roller A, and a roller C which can contact the roller B and reciprocate horizontally.
A method for manufacturing a semiconductor device, characterized by a mechanism for applying a flux transferred to a substrate. 5. A method of manufacturing a semiconductor device, comprising: a mechanism for transferring a flux from a roller C to a protruding rubber plate by the roller C and applying the flux by vertically moving the rubber plate. 6. A guide plate for positioning and guiding the semiconductor device, a heating device for heating the guide plate, and bringing the semiconductor device positioned and heated by the guide plate into contact with the solder balls by vertically moving the guide plate. A method for manufacturing a semiconductor device, comprising: mounting a solder ball by using the method. 7. A method for manufacturing a semiconductor device, wherein a buffer material is incorporated into the guide plate according to claim 6, and a contact pressure is made uniform when a solder ball contacts. 8. A semiconductor device using any one of claims 1 to 7. 9. A heating plate which is arranged substantially horizontally, has a semicircular hole for aligning in an array, and can be heated by a heating device, and melts solder or solder cream in individual semicircles. A supply device equipped with a dispenser that flows an appropriate amount in a shape, a heating mechanism that maintains the molten solder or solder cream in the supply device at a fixed temperature, a driving device that operates the supply device up, down, left and right, and a heating plate A method for manufacturing solder balls, comprising using a storage container for storing the solder balls and a cleaning device for cleaning the plate after storing the solder balls. 10. A semiconductor device using a solder ball manufactured by the method for manufacturing a solder ball according to claim 9. 11. A method of manufacturing a semiconductor device, comprising: mounting a ball on a substrate at the time when the solder is formed into a spherical shape by the method of manufacturing a solder ball according to claim 9.