JPH1051120A - Flux coater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coater wherein amount of coating can be controlled and irregurality can be reduced, when flux is previously spread on a position on a board wherein a solder bump electrode is to be formed. SOLUTION: A first jig 1 having a plurality of pins 2 which are arranged downward at the same pitch as the outside pads of a board is descended, and tips of the pins are made to abut against tips of pins 4 of a second jig 3 arranged in a tank 5 in which flux 6 is accommodated. Then the pins 2 receives flux from the pins 4. Since the contact area of the pins 4 and the pins 2 is smaller than the area of tip parts of the pins 2, transfer is performed without adhesion of the flux to the side surfaces of the pins 2. After that, the first jig is lifted by a driving mechanism, and the flux is spread on, e.g. pads of a BGA(ball grid array) package. Since the flux is transferred by using the pins 4, the flux is not stuck on the side surfaces of the pins 2, irregurality of the amount of coating of flux is reduced, and washing and drying of the tips of the pins 2 are unnecessary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for applying a flux to an electrode forming position in advance as a pretreatment for forming a solder bump electrode on a substrate such as a semiconductor package substrate or a semiconductor element.

[0002]

2. Description of the Related Art Conventionally, in this type of flux coating, a pin transfer method has been adopted. FIGS. 4A to 6F show a flux coating process by a pin transfer method. First, in FIG. 4A, reference numeral 21 denotes a transfer jig, for example, a BGA
It has pins 22 arranged at the same pitch as the external pads of (BALL GRID ARRAY). A high-viscosity flux 24 is placed on the stage 23 and is scraped with a squeegee 25 to have a uniform thickness. Next, as shown in FIG. 4B, the transfer jig 21 is lowered by a driving mechanism (not shown), and the tip of the pin 22 is put into the flux 24. Next, as shown in FIG. 5C, the transfer jig 21 is raised by the drive mechanism (not shown), and the flux 24 adheres to the tip of the pin 22 here. Then, as shown in FIGS. 5D and 6E, a flux 24 is applied to the solder electrode forming position of the BGA package 26, and as shown in FIG. By raising, the flux application is completed.

[0003] However, according to the above conventional method,
As shown in FIG. 7, there is a problem that the flux 24 is applied to the side surface of the pin 22 and the application amount is likely to vary. Also,
The flux 24 attached to the side surface of the pin 22 is dried and solidified to increase the substantial diameter of the pin 22 and the amount of application increases with time. Therefore, it is necessary to clean and dry the tip of the pin 22 each time the application is repeated. And the workability was reduced.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and provides a technique for controlling the amount of applied flux in a technique of applying a flux in advance to a position on a substrate where a solder bump electrode is to be formed. It is an object of the present invention to provide a flux coating device which can reduce the variation of the flux coating device.

[0005]

According to the present invention, there is provided an apparatus for applying a flux to a position on a substrate where a solder bump electrode is to be formed, the method comprising: A first jig having a plurality of pins arranged downward at the same pitch as the first jig, and is disposed in a tank containing the flux, and is arranged upward at the same pitch as the plurality of pins of the first jig. A second jig having a plurality of pins, the first jig and the second jig being separated from each other by a pin of the first jig and a pin of the second jig; The first position where the tip of the pin of the second jig is immersed in the flux in the tank, and the tip of the pin of the first jig and the tip of the pin of the second jig correspond to each other. A second position where the tip of the second pin contacts and projects above the liquid level of the flux in the tank. Fluxing apparatus is provided, characterized in that it comprises a drive mechanism in vertically moving.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments. FIG. 1A is a diagram schematically showing a main part of a flux coating apparatus according to one embodiment of the present invention. In the figure, reference numeral 1 denotes a first jig (transfer jig), which includes pins 2 arranged at the same pitch as, for example, external pads of a BGA, and the pins 2 extend downward. Pin 2
Suitable materials such as stainless steel, vinyl chloride, and the like can be used as the constituent materials. The tip surface of the pin 2 is formed flat. On the other hand, reference numeral 3 denotes a second jig, which includes pins 4 arranged at the same pitch as the pins 2 of the first jig 1, and the pins 4 extend upward.
In this example, the tip surface of the pin 4 is formed flat,
The diameter of the tip is set smaller than the diameter of the tip of the pin 2. As the constituent material of the pin 4, the same material as the constituent material of the pin 2 can be used, but may be different.

As shown in FIG. 1A, the second jig 3 is immersed in the flux 6 in the tank 5 by a known driving mechanism (not shown), and is moved to the position shown in FIG. FIG.
(C), the tip of the pin 2 moves up and down between the position where the tip of the pin 6 projects above the liquid level of the flux 6 stored in the tank 5. As the known driving mechanism, for example, a mechanism using a servomotor, a mechanism using a cam and a spring, and the like can be used. On the other hand, the first jig 1 is moved away from the tip of the second jig 4 by a similar driving mechanism (not shown) as shown in FIG. 1A, and shown in FIG. 2C. As described above, the tip of the pin 2 moves up and down between the position at which the tip of the pin 4 of the second jig 3 contacts the tip of the pin 4.

Next, the operation will be described. First, as shown in FIG. 1A, the second jig 3 is immersed in the flux 6 of the tank 5. Next, from this state, FIG.
As shown in FIG. 5, the second jig 3 is driven by a driving mechanism (not shown).
Is raised so that the tip of the pin 4 protrudes above the liquid level of the flux 6 to hold a required amount of the flux 6 at the tip of the pin 4. On the other hand, the first jig 1 is lowered by a driving mechanism (not shown), and the tip of the pin 2 is moved to the pin 4 of the second jig 3.
(FIG. 2C). Thus, the pin 2 receives the flux 6 from the pin 4. Here, since the contact area between the pin 4 and the pin 2 is smaller than the area of the tip of the pin 2, the flux 6 is transferred without adhering to the side surface of the pin 2 as shown in FIG. Thereafter, the first jig 1 is raised by a driving mechanism (not shown) (FIG. 2D),
The flux 6 is applied to, for example, pads of a BGA package in the same manner as in the related art.

In this embodiment, as described above, the second jig 3
Since the transfer of the flux 6 is performed by using the pin 4, the flux 6 does not adhere to the side surface of the pin 2, and the variation of the flux application amount can be reduced. Also,
Since the flux 6 does not adhere to the side surface of the pin 2, the tip of the pin 2 does not have to be washed and dried each time the coating is repeated, and the workability is improved.

Although the present invention has been described based on one embodiment, the present invention is not limited to this embodiment alone, and various modifications and changes are possible. For example, in the above embodiment, the diameter of the pin 4 is made smaller than the diameter of the pin 2 and the pins are brought into contact with each other on a plane, but if the tip of the pin 4 is made convex, the amount of flux transferred to the pin 2 is reduced. It is possible,
If the shape of the tip of the pin 4 is concave, the amount of flux transferred to the pin 2 can be increased. The flux amount can be controlled by changing the diameter ratio of the pin 4 to the pin 2 in addition to the shape of the pin 4.
Further, in the conventional pin transfer method, only a high-viscosity flux can be used. However, the above control enables the use of a low-viscosity flux.

[0011]

As described above in detail, according to the present invention, the following remarkable effects can be obtained by employing the above-described structure. (1) It is possible to reduce the variation in the amount of applied flux. (2) Each time coating is repeated, it is not necessary to clean and dry the tip of the pin, thereby improving workability. (3) Since the amount of flux can be controlled,
Conventionally, only high-viscosity fluxes could be used, but low-viscosity fluxes can now be used. (4) Since the amount of flux can be controlled,
It can be easily applied to small pads.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a flux application process by a flux application apparatus according to an embodiment of the present invention.

FIG. 2 is a view schematically showing a flux application process by a flux application apparatus according to an embodiment of the present invention.

FIG. 3 is a diagram showing a state of flux adhesion of a pin according to the present invention.

FIG. 4 is a view schematically showing a process of applying a flux to a BGA package by a conventional pin transfer method.

FIG. 5 is a view schematically showing a process of applying a flux to a BGA package by a conventional pin transfer method.

FIG. 6 is a view schematically showing a process of applying a flux to a BGA package by a conventional pin transfer method.

FIG. 7 is a diagram showing a state of flux adhesion of a pin in the case of a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st jig (transfer jig) 2 pin 3 2nd jig 4 pin 5 tank 6 flux

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[Procedure amendment]

[Submission date] October 1, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005]

According to the present invention, there is provided an apparatus for applying a flux in advance to a position on a substrate where a solder bump electrode is to be formed, comprising a tank for accommodating a flux. A first jig having a plurality of pins disposed above the substrate and arranged downward at the same pitch as the external pads of the substrate; and a plurality of the first jigs installed in a bath containing flux. A second jig having a plurality of pins arranged upward at the same pitch as the pins of the second jig, and a first position in which a tip of the pin of the second jig is immersed in the flux in the tank. The first end of the pin of the second jig is projected above the liquid level of the flux in the tank, and the first end is brought into contact with the second end of the pin of the first jig. Having a drive mechanism for vertically moving the jig and the second jig. Fluxing apparatus is provided to symptoms.

Claims (1)

[Claims] 1. An apparatus for applying a flux in advance to a position on a substrate at which a solder bump electrode is to be formed, comprising: a first pin having a plurality of pins arranged downward at the same pitch as an external pad of the substrate. A jig, a second jig having a plurality of pins disposed in a tank for accommodating the flux, and having a plurality of pins arranged upward at the same pitch as the plurality of pins of the first jig; The pin of the first jig and the pin of the second jig were separated from each other, and the tip of the pin of the second jig was immersed in the flux in the tank. A first position to be in a state, a tip of a pin of the first jig and a tip of a pin of the second jig are in contact with each other, and the tip of the second pin is higher than the liquid level of the flux in the tank. A flux having a drive mechanism for vertically moving between a second position protruding upward and the second position. Coating device.