JP2000335633A - Container for solder ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent solder balls from blacking and being charged with electricity during transportation period by providing a projected body with a shape which does not deform the solder balls when it protrudes into a number of solder balls filled in a container on the opening part of the container. SOLUTION: When an inner lid 3 is inserted into the opening of a main body 1 wherein balls B are stored in the main body 1 and there exists a gap on the top part until the flange 7 is brought into intimate contact with the top part of the opening 4, the projected body 8 is forwarded into the balls B filled in the main body 1. The balls pushed aside by forwarding of the projected body 8 are elevated to decrease the gap K. Thereafter, an outer lid 2 is screwed into the female screw of the opening and is sealed. Therefore, by inserting the inner lid into the opening 4 and forwarding furthermore the projected body 8 inside, it becomes possible to decrease the size of the gap K at that time as much as possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container for accommodating a large number of minute solder balls.

[0002]

2. Description of the Related Art Multifunctional electronic components such as BGA and CSP are:
When mounting on a printed circuit board, the lead and the land of the printed circuit board are joined by soldering. However, multi-function electronic components have a large number of leads, and the leads are very small, so if solder was separately supplied when soldering, not only would it take a lot of time and effort, Solder cannot be supplied accurately to a small soldered portion. Therefore, in a multifunctional electronic component, solder is previously attached to a lead to form a solder bump, and the solder bump is melted at the time of soldering to perform solder joining. A solder ball is used for forming a solder bump of such a multifunctional electronic component.

[0003] In general, solder balls used for BGA have a diameter of 0.76 mm.
Very small things such as 0.15mm and 0.1mm are used,
These solder balls are placed in a container made of glass or plastic and transported from the manufacturer to the customer.

A method of forming a solder bump on a multifunctional electronic component is to apply an adhesive flux to a lead of a portion to be soldered, mount a solder ball on the portion where the flux is applied by a mounting device, and then apply a reflow furnace. A solder bump is formed by heating with a heating device such as described above to melt the solder balls.

[0005] When a solder bump is formed on a multifunctional electronic component, there has been a problem that the solder ball does not completely adhere to the lead, resulting in insufficient bonding strength, or that the vicinity of the solder bump forming portion becomes dirty. Further, as a further problem, the solder ball is not mounted at all at the solder bump forming portion of the multifunctional electronic component, or the solder bump is not mounted at all, or the solder ball is excessively mounted such that a plurality of solder balls are mounted.

As a result of the present inventors' intensive studies on the above-mentioned problems, it has been found that insufficient bonding strength or contamination near the solder bump formation portion is caused by the fact that the surface of the solder ball is covered with black powder and becomes black. It was found that the solder balls were not mounted or excessively mounted at the solder bump formation locations because the solder balls were charged with static electricity.

That is, if the surface of the solder ball is blackened, the black powder hinders the soldering at the time of soldering, so that the solder ball does not completely adhere to the lead. Even if it adheres, the black powder that has fallen off the solder balls remains in the vicinity of the solder bump formation location and becomes dirty. In addition, if the black powder adheres between the leads having a narrow pitch, insulation failure may occur.

When the solder balls are charged, static electricity may adhere to unnecessary places and may not be mounted at predetermined places of the solder ball mounting apparatus. Further, if a plurality of solder balls are attached to predetermined portions of the mounting jig by static electricity, they are excessively mounted and become large bumps when forming solder bumps.

A conventional solder ball container (hereinafter, referred to as a container) includes a main body 1, an outer lid 2, and an inner lid 3, as shown in FIG. The main body 1 is a bottomed cylindrical body made of a transparent material such as glass or plastic, and has an opening 4 formed at an upper portion, and a male screw 5 is screwed outside the upper portion.

The outer lid 2 has a cap shape, and a female screw 6 screwed with the male screw 5 of the main body 1 is screwed inside the outer lid 2. The inner lid 3 has a shallow bottomed cylindrical shape, an outer diameter substantially equal to the diameter of the opening 4 of the main body 1, and a flange 7 formed at an upper portion. The inner lid 3 seals the opening 4 by fitting the flange 7 into the opening 4 of the main body 1.

Here, a state in which solder balls are put in a conventional container will be briefly described. As shown in FIG. 2, a predetermined amount of solder balls (hereinafter, simply referred to as “balls”) B is put into the main body 1 of the container, the opening 4 is sealed with the inner lid 3, and the opening 4 is further sealed with the outer lid 2. At this time, a large gap K is formed between the ball B and the lower surface of the inner lid 3. The reason why such a large container having a large void is used is to make it possible to cope with an increase or decrease in the volume of the ball. In other words, if the container is made large, the ball can be accommodated with a sufficient margin even if the volume of the whole ball becomes slightly large. For example, a 0.76 mm diameter ball generally has a tolerance of ± 0.
Although it is 02 mm, if a large-diameter ball having a large diameter on the positive side is put in a container in a large amount within the allowable range, the volume of the whole ball increases. This is because the volume of the ball itself increases by a factor of 3 with the increase in the diameter of the ball. This is because a predetermined number of balls cannot enter.

However, if a large amount of balls having a predetermined size or smaller than the predetermined size are put in such a large container, a large gap K is formed as shown in FIG.

[0013]

When a ball manufacturer puts a solder ball in a container in which a large gap is formed after putting the ball in this way and transports the solder ball to a customer, the solder ball is placed in the container during transportation. And rubbed against the wall of the container. As a result, the surface of the ball is blackened, or the ball is charged with static electricity. As described above, the blackening or electrification of the balls results in defective soldering, contamination near the solder bumps, and defects such as unmounted or overloaded balls.

[0014] The cause of blackening and charging of the ball is caused by a large void in the container. Therefore, means for eliminating the void have been considered. The means is to fill the gap formed in the container with packing. As a packing to prevent the movement of the ball, it is conceivable that the sheet-shaped paper or polyethylene is rolled and packed.However, when the packing is made by rolling a sheet-shaped thing, the ball enters the rounded gap and the packing is removed. The ball jumps out and scatters around.

Therefore, it is conceivable to pack the packing P of the sponge as shown in FIG. However, if the sponge packing keeps the ball pressed until the void is eliminated, the solder ball will always receive the elastic stress from the packing, and the soft ball made of tin and lead will be deformed over a long time. In addition, the ball cannot be mounted accurately by the ball mounting device at the time of forming the solder bumps, which also causes the non-mounting.

An object of the present invention is to provide a solder ball container which prevents blackening and electrification of the solder ball during the period of transport of the solder ball filled in the container and does not cause deformation.

[0017]

The blackening of the ball and the electrification of static electricity are due to the ball being shaken or rolled during transportation and rubbing against the wall surface of the container as described above. That is, when the ball is rubbed against the wall surface of the container, the surface of the ball is shaved and fine solder powder spills from the ball surface. Since the solder powder has a large surface area, it easily oxidizes and blackens, and it adheres to the ball or adheres to the vicinity of the solder bump after soldering, resulting in ugly stains. The reason why the ball is charged with static electricity is that the ball rolled in the container during transportation rubs against the wall surface of the container to generate static electricity, which is charged on the ball.

The inventors of the present invention have completed the present invention by noting that the ball placed in the container does not shake or roll during transportation without blackening or charging of the ball.

According to the present invention, there is provided a solder ball container for sealing an opening of a bottomed cylindrical main body with an outer lid, wherein the opening of the container is filled with a large number of solder balls filled in the container. A container for a solder ball, wherein a protrusion having a shape that does not deform the solder ball is provided.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in an exploded perspective view of FIG. 4, a solder ball container according to the present invention has a main body 1 having a bottomed cylindrical body made of a transparent material such as glass or plastic, and an outer lid 2. , And an inner lid 3, and an opening 4
Are formed, and a male screw 5 is screwed on the upper outer side. The outer lid 2 has a cap shape, and a female screw 6 screwed with the male screw 5 of the main body 1 is screwed inside the outer lid 2.

According to the present invention, the inner lid 3 is a bottomed cylindrical body having a shallow bottom, a projection 8 is provided on the bottom, and the outer diameter is substantially the same as the opening 4 of the main body 1. , A flange 7 is formed on the upper part. The inner lid 3 is the main body 1 up to the flange 7
The opening 4 is sealed by fitting into the opening 4.

The protruding body 8 used in the solder ball container of the present invention has a shape such that the ball is not pressed and deformed even when its tip is inserted into the filling layer of the ball placed in the container, for example, as shown in FIG. The cross section of the protruding body 8 has a streamline shape as shown in FIG. 5A, an inverted conical cross section as shown in FIG. 5B, and a hemispherical tip as shown in FIG. 5C. Alternatively, it is an inverted conical cylindrical body (not shown).

When the projecting body is immersed in the ball-filled layer in the container filled with the ball in a state where a gap is formed, the projecting body pushes the ball up and raises the ball to reduce the gap. As a result, the balls in the container move less and do not blacken or charge. Further, when the protruding body is immersed in the ball filling layer in the container, some space remains, and even if the ball attempts to move during transportation, the protruding body impedes the movement of the ball.

That is, in the container of the present invention, the protrusion 8 reduces the gap K and simultaneously prevents the ball from moving, thereby preventing the ball from being blackened or charged. As shown in FIG. 5 (3), when the projecting length of the projecting body used in the present invention can be adjusted (arrow A), the projecting body 8 is moved according to a change in the volume of the ball in the container. The gap K can be made as small as possible.

In the illustrated example, the protruding body is attached to the inner lid, but may be attached directly to the upper lid. In that case, the inner lid can be omitted. That is, the container of the present invention may be one in which the projection is formed on the inner lid and the outer lid and the projection are separate, or the outer lid and the projection are completely integrated, or the outer lid and the projection are May be fitted and integrated.

FIG. 6 is an exploded perspective view showing still another embodiment of the solder ball container according to the present invention shown in FIG. 5 (3). In the drawing, the same members as those in FIG. 4 are denoted by the same reference numerals. In the illustrated example, the inner lid 10 includes a cylindrical body 12 with a flange, and a cylindrical sliding body 14 fitted with the flanged body and provided with a protruding body 8 at the bottom. The sliding surfaces of the cylindrical body 12 and the sliding body 14 are provided with shallow annular grooves 16, respectively, so that they can slide with each other and be held at arbitrary positions. Annular groove 16
Instead, the sliding surface may be simply roughened so long as sliding and holding are possible.

[0027]

Next, based on the container of the present invention shown in FIG.
The operation and effect will be described more specifically.

In the embodiment shown in FIG. 4, a protruding body is formed on the inner lid, and a protruding body 8 is formed on the bottom 9 of the inner lid 3 so as to protrude downward. The protrusion is streamlined and the tip is rounded. The size of the protrusion is suitably such that a gap of about 3 to 8% of the volume of the main body is formed at the top of the main body when immersed in the ball of the container.
That is, the size of the protruding body is such that when the protruding body is immersed in the ball of the container, a small gap remains at the top.

Next, a description will be given of a state where the container of the present invention is filled with a ball and the protruding body is immersed in the ball. First, a predetermined amount of balls B is put into the main body 1. At this time, the main body has a slightly larger volume so that a gap is formed in the upper portion even if a predetermined amount of balls of a predetermined size are put. When the inner lid 3 is fitted into the opening 4 of the main body 1 in which the ball B is inserted and a gap is formed at the upper part until the flange 7 is in close contact with the upper part of the opening 4, the protruding body 8 is filled in the main body 1 as shown in FIG. Into the hit ball B. The ball displaced by the entry of the protrusion 8 rises, and the gap K becomes smaller. Thereafter, the outer lid 2 is screwed into the male screw 5 of the opening 4 and sealed.

As shown in FIGS. 5 (3) and 6, after the inner lid is fitted into the opening 4, the size of the gap K at that time is increased by further moving the protruding body 8 into the inside. It is possible to make it as small as possible.

A blackening test was performed on the balls of the container of the present invention and the conventional container. The volume of the container was 100 cc, and 250,000 balls having a size of 0.76 mm ± 0.01 mm were placed. The projecting body used in the container of the present invention has a streamlined type as shown in FIG.
cc.

As shown in FIG. 1, a conventional container has a bottomed cylindrical shape with a shallow bottom. The container filled with the balls was placed on a rotating machine and rotated 150 times / minute. As a result, the ball put in the conventional container turned black in 20 minutes and completely turned black in 30 minutes. Thereafter, when the blackened ball was taken out of the container, it was found that the balls adhered to each other.

On the other hand, the ball put in the container of the present invention has 30 balls.
Even after a lapse of minutes, there was no blackening, and none of the balls adhered to each other even after being taken out of the container.

[0034]

As described above, the container of the present invention is
Since the protruding body that does not deform the ball when immersed in a large number of balls is installed in the opening of the main body, raise the ball without giving any deformation to the ball filled in the main body and reduce the gap In addition to reducing the movement of the ball, the protruding body inserted into the ball further hinders the movement of the ball, so that even if the container filled with the ball is subjected to vibration or shaking during transportation, the ball is blackened or charged. This has an unprecedented excellent effect of preventing the occurrence of the above.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a conventional solder ball container.

FIG. 2 is a cross-sectional view of a conventional solder ball container filled with solder balls.

FIG. 3 is a cross-sectional view showing a state where another conventional solder ball container is filled with solder balls.

FIG. 4 is an exploded perspective view of the solder ball container of the present invention.

FIGS. 5 (1), 5 (2), and 5 (3) are cross-sectional views of various protrusions used in the solder ball container of the present invention.

FIG. 6 is an exploded perspective view of another embodiment of the solder ball container of the present invention.

FIG. 7 is a cross-sectional view showing a state in which a solder ball is filled in the solder ball container of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 7 Flange 2 Outer lid 8 Projecting body 3 Inner lid 9 Bottom 4 Opening B Solder ball 5 Male screw K Void 6 Female screw

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Michio Iguchi 23 Sensenhashido-cho, Adachi-ku, Tokyo Inside Senju Metal Industry Co., Ltd. (72) Inventor Hiroshi Akutsu 23 Senju-Hashito-cho, Adachi-ku, Tokyo Senju Metal Industry Co., Ltd. (72) Inventor: Hisashi Narita, 23, Senjuhashido-cho, Adachi-ku, Tokyo, Japan Inside (72) Inventor, Takeshi 23, Senju-Hashido-cho, Adachi-ku, Tokyo, Senju Metal Industry Co., Ltd.

Claims (9)

[Claims] 1. A solder ball container in which an opening of a bottomed cylindrical main body is sealed with an outer lid, wherein the opening of the container is immersed in a filling layer of a large number of solder balls in the container. A container for a solder ball, wherein a protrusion having a shape that does not deform the solder ball is provided. 2. The solder ball container according to claim 1, wherein a length of the projecting body projecting into the filling layer of the solder ball is adjustable. 3. The solder ball container according to claim 1, wherein the projecting body is integrated with an outer lid. 4. A solder ball container for sealing an opening of a bottomed cylindrical main body with an inner lid and an outer lid, wherein the inner lid is immersed in a filling layer of a large number of solder balls in the container. A solder ball container, wherein a projection having a shape that does not sometimes deform the solder ball is provided. 5. The solder ball container according to claim 4, wherein the protruding body is separated from the inner lid so that a protruding length of the solder ball into the filling layer can be adjusted. 6. The solder ball container according to claim 4, wherein said projecting body is integrated with an inner lid. 7. The solder ball container according to claim 1, wherein said projecting body has a streamlined cross section. 8. The solder ball container according to claim 1, wherein the projecting body has an inverted conical cross section. 9. The projection according to claim 1, wherein the tip is a cylinder having a hemispherical or inverted conical tip.
7. The container for solder balls according to any one of 6.