JPH11112132A - Container for molding solder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a solder ball against oxidation and charging by providing a container for molding solder comprising a bottomed tubular body made of an antistatic member internally threaded at the upper outer part, a filter stretched across a hole made in the shallow bottomed face having a flange at the upper part, an intermediate cover for containing a deoxidizer, and a cover member to be screwed into the internally threaded part of the body. SOLUTION: A bottomed tubular body 1 made of a transparent antistatic member is internally threaded at the upper outer part thereof. A flange 6 having outside diameter substantially identical to that of the body 1 is formed at the upper part of a shallow bottomed tubular intermediate cover 2 having outside diameter substantially identical to the inside diameter of the body 1 and being fitted tightly thereto. A filter 8 passing gas but blocking a solder being contained in the container is stretched across a plurality of holes 7,... made in the bottom face of the intermediate cover 2. Preferably, a deoxidizer for adsorbing oxygen in the air is contained in the flange 6 of the intermediate cover 2 which is then stretched with a sealing member 9, e.g. an aluminum fort or a synthetic resin film. Since the inside of the container is deoxidized, a molding solder is not oxidized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container for storing molded solder, such as solder balls, solder washers, and solder pellets, which have been molded into a predetermined shape in advance.

[0002]

2. Description of the Related Art In recent years, molding solder such as solder balls, solder washers, and solder pellets has been widely used for soldering electronic devices. In particular, the solder balls are BGA (Ball Grid Array),
It is used for so-called multi-function electronic components such as CSP (Chip Size Package).

[0003] Multifunctional electronic components are mounted on a printed circuit board by bonding leads and lands of the printed circuit board with solder. However, multifunctional electronic components are provided with a large number of leads. Small. Therefore, if solder is separately supplied at the time of soldering in a multifunctional electronic component, not only a great deal of labor is required but also solder cannot be accurately supplied to a minute soldered portion. Therefore, in a multifunctional electronic component, a solder is previously attached to a lead to form a solder bump, and soldering is performed with the solder bump at the time of soldering. Solder balls are used to form the solder bumps.

In general, the solder ball used for the BGA is mainly 0.76 mm, but the CSP is very small, such as 0.15 mm or 0.1 mm.

[0005] A method of forming solder bumps on a multifunctional electronic component is to apply an adhesive flux to the leads, place the solder balls on the applied portions with a solder ball mounting device, and then use a heating device such as a reflow furnace. The solder bumps are formed by heating and melting the solder balls.

When a solder bump is formed on a multifunctional electronic component, the solder ball may not completely adhere to the lead, resulting in insufficient bonding strength, or the vicinity of the solder bump forming portion may become dirty. . Further, as a further problem, there is a case where no solder ball is mounted on the solder bump forming portion of the multifunctional electronic component at all, or an excessive mounting where a plurality of solder balls are mounted.

[0007] As a result of the inventor's intensive studies on the above-mentioned problems, it is found that the insufficient bonding strength and the contamination around the solder bump forming portion are due to the oxidation of the solder ball or the solder bump forming portion. Unloaded or overloaded
It turned out that this was because the solder balls were charged.

That is, if the surface of the solder ball is oxidized, the oxide film hinders the soldering at the time of soldering, so that the solder ball does not completely adhere to the lead, and even if the oxidized solder ball adheres to the lead. In this case, the oxide film peeled off from the solder ball remains around the solder bump forming portion and becomes dirty. When the solder ball is charged, the solder ball does not adhere to a predetermined portion of the mounting jig of the solder ball mounting device, but adheres to an unnecessary portion due to static electricity. If the solder balls are not mounted, or if a plurality of solder balls adhere to predetermined portions of a mounting jig of the solder balls by static electricity, they are excessively mounted.

[0009] By the way, the conventional container for storing the molded solder simply uses a commercially available glass bottle or plastic bottle.

When a solder manufacturer puts solder balls in these containers and transports them to a user, the surface of the solder balls was oxidized by air contained in the containers during the transportation. . Also, during transportation, the solder balls in the container roll in the container due to the vibration of the vehicle or the shaking when carried by a person, and the surface of the container rubs and the static electricity is charged on the solder balls. Was. It is an object of the present invention to provide a container in which solder balls do not oxidize or become charged during transportation.

[0011]

SUMMARY OF THE INVENTION The present inventors have found that the oxidation of solder balls is due to the presence of oxygen in the air in the container, or that the solder balls are charged because the container is liable to generate static electricity. For this reason, the present invention has been completed by noting that there is no oxygen in the container and that the above-described problem does not occur unless the container generates static electricity.

The present invention relates to a bottomed cylindrical body, in which a male screw is screwed in an upper part on the outside, and furthermore, a main body made of an antistatic material; A body having a hole formed in the bottom surface and a filter stretched into the hole; an oxygen absorber capable of being stored inside the inner cover; A molded solder container characterized by comprising a lid member into which a possible female screw is screwed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the inner lid used in the present invention,
A filter installed in a hole is a filter that allows gas to pass through but does not allow the inside of the molded solder to pass.For example, when a small 0.1 mm solder ball is placed in a container, the solder ball does not pass through and air permeability does not pass. It is something with. A suitable filter for accommodating micro solder balls is a permeable film having air permeability.

The upper part of the inner lid may be open. However, if the upper part is sealed, the inner lid can be fitted to the main body even if the lid member is kept open during use. If not, the outside air will not enter the container, and the oxygen scavenger placed in the inner lid will not only absorb oxygen from the outside air and weaken the deoxygenation capacity, but also when opening and closing the lid member It is also possible to prevent the oxygen scavenger from jumping out. To seal the upper part of the inner lid, a simple and reliable sealed state can be obtained by using a means for thermally welding an aluminum wheel or a synthetic resin.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a combination diagram of the molded solder container of the present invention, and FIG. 2 is a half sectional view of the molded solder container of the present invention.

The molded solder container of the present invention comprises a main body 1, an inner lid 2, an oxygen absorber 3, and a lid member 4.

The main body 1 is a cylindrical body with a bottom and a male screw 5
Is screwed. The main body 1 is formed of an antistatic material, and the antistatic material is transparent so that the inside can be confirmed.

The inner lid 2 is a shallow bottomed cylindrical body, the outer diameter of which is substantially the same as the inner diameter of the main body, and has a size that allows close fitting. A flange 6 is formed on the upper part of the inner lid 2. The diameter of the flange is substantially the same as the outer diameter of the upper part of the main body. A plurality of holes 7 are formed in the bottom surface of the inner lid 2, and a filter 8 is stretched on the holes 7. The filter 8 allows gas to pass therethrough, but does not allow molding solder contained in the container to pass through. It is preferable that a sealing material 9 be stretched on the flange 6 of the inner lid 2 after a deoxidizer described below is housed inside. An aluminum wheel or a synthetic resin film is thermally welded as a sealant.

The oxygen absorber 3 is of a size that can be stored inside the inner lid 2 and has a function of adsorbing oxygen in the air.

On the inside of the cover member 4, a female screw 10 which can be screwed with the male screw 5 of the main body is screwed.

Next, an experiment was conducted on the change of the solder balls in the container of the present invention and a conventional plastic container. The size of the container of the present invention and that of the conventional container are substantially the same, and the outer diameter is 20 mm.
mm and the height is 40 mm. Each container contains 500,000 clean 0.15mm solder balls immediately after production,
After standing for 3 months in a constant temperature bath at 60 ° C., the container was taken out of the constant temperature bath and continuously rotated for 1 minute at a speed of once / second so that the vertical direction of the container was moved up and down. After that, the solder balls were taken out of the container, mounted on a CSP having an adhesive flux applied to a solder bump formation portion by a solder ball mounting machine, and then heated in a reflow furnace to form solder bumps.

Observation of the solder bump formation portion with a stereoscopic microscope revealed that the solder balls housed in the container of the present invention were:
One piece was completely adhered to all the solder bump formation locations, and the periphery of the solder bump formation location was also in a clean state.

On the other hand, the solder balls housed in the conventional container are excessively adhered to the solder bump forming portions to form excessive solder bumps, or no solder balls are adhered at all. In addition, the presence of an oxide was confirmed around the solder bump formation site.

[0024]

As described above, the molded solder container of the present invention can eliminate oxygen in the container.
The molded solder housed inside is not oxidized. Therefore, when soldering is performed using the molded solder contained in the molded solder container of the present invention, the solder is securely adhered to the soldered portion, and an oxide remains around the soldered portion and becomes dirty. Nor. Further, in the molded solder container of the present invention, since the main body is formed of an antistatic material, even if vibration or shaking is applied during transportation, static electricity is not charged to the molded solder stored therein. Therefore, the molded solder contained in the molded solder container of the present invention is always placed one by one at a predetermined position of the molded solder mounting machine, and as a result, unsolder is generated at the soldered portion. And a soldering portion excellent in reliability, in which no solder is attached or excessive solder is attached.

[Brief description of the drawings]

FIG. 1 is a combination diagram of a molded solder container of the present invention.

FIG. 2 is a half sectional view of a molded solder container of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Middle lid 3 Oxygen absorber 4 Lid member 5 Male screw 6 Flange 7 Hole 9 Sealing material 10 Female screw

Claims (2)

[Claims] 1. A bottomed cylindrical body having a male screw threaded at an upper part on the outside and formed of an antistatic material; a shallow bottomed cylindrical body having a flange formed at an upper part. There is a hole in the bottom surface, and a filter is stretched in the hole, an inner lid; an oxygen absorber that can be housed inside the inner lid; A molded solder container, comprising: a lid member into which a female screw is screwed. 2. The molded solder container according to claim 1, wherein a seal is stretched over the upper portion of the inner lid.