JP3460085B2 - Low humidity storage - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a low humidity storage box capable of managing storage time of stored items.

[0002]

2. Description of the Related Art Generally, when an IC package used in electronic equipment is placed on a printed wiring board and reflow soldering is performed, it is heated at about 250 ° C. for about 150 seconds by an infrared heater or the like.

At this time, if the mold resin of the IC package contains water, this water is instantly evaporated, and the water vapor pressure causes interface peeling between the die pad portion inside the IC package and the mold resin, and this water vapor escapes to the outside. At that time, the mold resin is cracked, which causes various complaints.

The moisture content of this IC package is by weight.
If it is contained in an amount of 0.15% or more, cracks occur in a state of almost 100%.

Therefore, on the shipping side of the IC package, the IC package is put into an aluminum pack which is baked so as not to adsorb moisture, and a humidity indicator card whose color changes when it absorbs moisture is sealed and shipped together with a desiccant. The guaranteed time for exposure to air after opening the aluminum pack varies depending on the IC package, but it is about 24 to 72 hours.
The user side opens the aluminum pack to mount this IC package and mounts it on the mounter, and stores the excess IC package in the low humidity storage box to prevent moisture absorption.

[0006] Conventionally, Japanese Patent No. 3060168 discloses a device provided with a means for displaying a dehumidifying time required for a stored article.

[0007]

However, in the above-mentioned low humidity storage, a constant value determined according to the type of the article is used as the necessary dehumidification time, which is not related to the atmospheric exposure time of the article. It was

However, as a result of various experiments and studies, the present inventor has found that the actually required dehumidification time is closely related to the type of article and the above-mentioned atmospheric exposure time, and that the humidity is 5% R.
If you use a low humidity storage that can be less than H
In the case of the package, it was found that there is a factor of about 5 between the atmospheric exposure time and the dehumidification time required to extract the moisture of the IC package to about 0%.

That is, FIG. 4 shows an IC package at 30 ° C. and 50% RH.
After being exposed to the atmosphere for 8 hours (see the broken line in FIG. 4), 4 hours (see the broken line in FIG. 4), and 2 hours (see the broken line in FIG. 4),
It is a figure showing the change of moisture content (weight%) of the IC package when the above IC package is stored in the low humidity storage box of 5% RH, and the IC package when the time of 5 times the atmospheric exposure time has elapsed. The water content of the product dropped to almost 0%.

The present invention is based on such findings.

[0011]

The present invention provides a low humidity storage
Display means for displaying the atmospheric exposure time of the stored article before storage and the dehumidification time required after storage in a position related to the storage position of the article, and a notification for notifying that the dehumidification time has elapsed And the dehumidifying time is a value obtained by multiplying the atmospheric exposure time by a predetermined magnification according to the type of the article.

The above-mentioned notification is characterized by blinking or color change.

Further, the notification is characterized by being made by light or voice.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, reference numeral 1 is a low humidity storage, 2
Is a shelf board, 3 is an article to be dehumidified placed on the shelf board 2, for example, an IC package, 3'is a tray for storing the IC package, and 4 is shown, for example, in Japanese Patent Laid-Open No. 6-304436. The dehumidifying device, 5 is a door provided corresponding to the shelf 2, and 6 is a glass window of the door 5.

In the present invention, as shown in FIG. 1, for each of the shelves 2, the shelves 2 and / or the outer surface of the door 5 corresponding to the shelves 2 or the inner surface of the low-humidity storage 1 is provided with the shelves. A setting display section 7 is provided for setting and displaying the atmospheric exposure time of the IC package 3 placed on 2 and the required dehumidification time.

FIG. 3 shows a setting display section 7 according to the present invention, 8 is a shelf 2 and a number display showing each position on the shelf 2,
9 is an article name display, 10 is an atmospheric exposure time display, 11 is a reset button of the atmospheric exposure time display 10, 12 is a dehumidification time obtained by multiplying the atmospheric exposure time by a multiplication factor determined according to the article, Reference numeral 13 is a reset button for the dehumidification time display 12, 14 is a dehumidification elapsed time display, 15 is a display section for the date when the IC package is stored, and 16 is a reset button for the display section 15.

The above magnification is set in advance according to the type of article and the type of low humidity storage.

It is also preferable that the dehumidifying time display 12 displays two kinds of values. For example, the time to be in the crack occurrence caution area is set to 4 times the atmospheric exposure time, the time to be in the safety area is set to 5 times the atmospheric exposure time, and each time is displayed on the dehumidification time display 12, and each specified time is set. It is preferable to generate a light signal or a voice signal when is passed.

Further, for example, the time of exposure to air after storing the articles
When it is less than 4 times, the amount of water near the crack occurrence caution area is displayed in red, and when it is 4 times or more and less than 5 times the atmospheric exposure time, it is displayed in yellow. It is displayed in green, etc., indicating that it is in the safe area. In this way, the article at the shelf position where the green lamp is lit can be taken out and used without anxiety.

[0021]

Since the low-humidity storage of the present invention has the above-mentioned structure, there is a great advantage that it can be easily and surely managed according to the required dehumidifying time for each article. .

[Brief description of drawings]

FIG. 1 is a front view of a low humidity storage of the present invention.

FIG. 2 is a side view of the low humidity storage of the present invention.

FIG. 3 is an explanatory diagram of a management meter in the low humidity storage of the present invention.

FIG. 4 is a diagram for explaining a dehumidifying state of an IC package in a low humidity storage.

[Explanation of symbols]

1 Low humidity storage 2 shelves 3 IC package 3'tray 4 Dehumidifier 5 doors 6 glass windows 7 Setting display section 8 number display 9 Item name display 10 Atmosphere exposure time display 11 Reset button 12 Dehumidification time display 13 Reset button 14 Dehumidification elapsed time display 15 Date display 16 Reset button

Claims (3)

(57) [Claims] 1. A display unit for displaying the atmospheric exposure time before the storage of the stored article and the dehumidification time required after the storage at a position related to the storage position of the article, and the dehumidification time has elapsed. A low-humidity storage having a notifying unit for notifying the fact that the dehumidifying time is a value obtained by multiplying the atmospheric exposure time by a predetermined scale factor according to the type of the article. 2. The low-humidity storage box according to claim 1, wherein the notification is made by blinking or color change. 3. The low humidity storage box according to claim 1, wherein the notification is made by light or voice.