JPH0632385A - Sheet for packing electronic parts and packing method using thereof - Google Patents

Abstract

PURPOSE:To provide a packing sheet which holds electronic parts in a suitable dried state and guides well the generated static electricity to the outside and further, shields well the external electromagnetic waves. CONSTITUTION:A packing sheet 2 enveloping electronic parts is constituted of an air-permeable sheet 6 at one side thereof and an air-impermeable sheet 7 having an electro-conductive layer and an insulating layer at the other side. A number of partitioned packs 3 are formed between both sheets 6, 7. Respective packs 3 are charged with silica get 15 and electro-conductive foaming beads 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to liquid crystal parts, IC, L
The present invention relates to a packaging sheet for packaging electronic components such as SI and VLSI and other precision components, and a packaging method using the packaging sheet.

[0002]

2. Description of the Related Art Conventionally, when electronic parts such as ICs and LSIs are stored or transported, when water adheres to the electronic parts, or when moisture adheres due to generation of dew point,
Since electronic components are leaked, and corrosion causes improper energization, other malfunctions, disconnections, etc., it is necessary to store and transport electronic components in a dry state. Therefore, in the past, electronic components were dried with a desiccant. It is stored as it is, and silica gel or the like is used as a desiccant. However, during transportation, etc., between desiccants, or
If rubbing occurs on the plastic material that wraps the desiccant,
Static electricity is generated by this rubbing, and since the humidity is low due to the desiccant, the degree of static electricity generation is further increased,
Due to the generated static electricity, the oxide film that insulates the gate electrode is extremely thin and has a low withstand voltage, particularly in a MOS type IC, so that the insulation is destroyed by the discharge of the generated static electricity, which adversely affects the semiconductor. There was a problem. In addition, conventionally, the desiccant is destroyed by rubbing etc. to become fine powder, dust is generated and spills to the outside,
There is a problem that it adversely affects electronic parts such as ICs.

[0003]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned problems of the prior art, and keeps electronic components in a good dry state to effectively block the influence of moisture.
The purpose of the present invention is not to provide a wrapping sheet for electronic parts that can satisfactorily eliminate the adverse effects of static electricity generated.
The first point is that one side is made of a breathable sheet,
The other surface side is composed of a non-breathable sheet having a conductive layer and an insulating layer, and a large number of divided packaging parts are formed between both sheets, and silica gel and conductive foam beads are provided in each packaging part. Is enclosed. The second gist is to form a transparent portion on the non-breathable sheet side so that the inside of the packaging portion can be visually recognized. The packaging method for electronic components is to wrap the electronic components with the packaging sheet and then seal the outside with a non-air-permeable bag or the like formed with a static electricity and electromagnetic wave shield layer.

[0004]

Since the packaging sheet for electronic parts has a large number of divided packaging parts, the packaging parts are evenly arranged on the outer periphery of the electronic component, and the packing sheet is filled with silica gel. It can remove moisture well. In addition, the foam beads prevent the silica gel from being crushed well and provide cushioning properties, and the foam beads are electrically conductive, allowing the static electricity generated from the silica gel to escape to the non-air permeable sheet on the outside, which is non-air permeable. Since the sheet further has a conductive layer that releases static electricity to the outside and an insulating layer that blocks electromagnetic waves from the outside, it is possible to enhance the electrostatic shield effect and the electromagnetic wave shield effect, and protect electronic components satisfactorily. Further, since the transparent portion is formed on the side of the non-breathable sheet, the water absorption capacity of the silica gel inside can be confirmed through the transparent portion. Also, after wrapping the electronic parts with such a packaging sheet, by sealing the outside with a non-air-permeable bag, it is possible to secure a better dry state. Also, since the electromagnetic wave shield layer is formed, static electricity can be satisfactorily released to the outside and electromagnetic waves from the outside can be blocked well.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective perspective view of a state in which electronic components are packaged and is an electronic component 1 that is a substrate on which IC, LSI, etc. are mounted.
The wrapping sheet 2 is wrapped around the outer periphery of the sheet, and the sheet is wrapped in the wrapping sheet 2 and sealed in the airtight bag 18, and then stored in the outer box 26 for storage and transportation.

First, the packaging sheet 2 will be described.
As shown in FIG. 2, the packaging sheet 2 is composed of a sheet in which the packaging portions 3, 3, 3 are formed at predetermined intervals, and the silica gel 15 and the foam beads 16 described later are enclosed in the packaging portion 3. ing. Further, a cross-sectional view of a main part of the packaging sheet 2 is shown in FIG. 3 and explained. The packaging section 3 is formed by being divided into a bag shape, and the inner sheet 6 and the outer sheet 7 are heat-sealed and welded. The packaging unit 3 is formed by the sealing unit 5, and each packaging unit 3 is formed before the sealing unit 5 is formed.
The silica gel 15 and the foam beads 16 are enclosed inside.

The expanded beads 16 may be encapsulated and then heat-expanded in the packaging part 3, or pre-expanded beads may be encapsulated in the packaging part 3. good. The inner sheet 6 is breathable, and the outer sheet 7 is made of a non-breathable film. When the details of each part are described in detail in the enlarged schematic configuration diagram of FIG. 4, the inner sheet 6 is composed of an inner film 8 and an inner non-woven fabric 9, while the outer sheet 7 is composed of an antistatic protective layer 11 and The metal vapor deposition layer 12, the insulating layer 13, and the adhesive layer 32 are formed in four layers.

First, the inner film 8 will be described. The inner film 8 has a large number of through holes 8 of about 0.1 to 2 microns.
a and 8a are formed by perforation, and have a structure that allows gas and water vapor to pass through but does not allow liquid such as water to pass through, and is composed of a microporous film containing an antistatic agent. As an antistatic agent, polyamide or Polyimide or the like is kneaded or coated. Next, the inner non-woven fabric 9 is composed of fibers having a long / short core-sheath structure, each fiber has a three-layer structure, and an insulating core 9a is arranged at the center thereof. Conductive coating 9 on the periphery
b is coated, and the outside is further coated with an antistatic coating 9c. The insulating core 9a is made of polyester resin with synthetic mica or mica powder mixed therein, and the conductive coating 9b has metal powder of Ketjen carbon black, Cu, Ni, Ag, AL mixed therein. It is made of resin. Further, the antistatic coating 9c is formed of polyethylene in which polyamide or polyimide is kneaded.

Next, each layer of the outer sheet 7 will be described. First, the outermost antistatic protective layer 11 is kneaded or coated with polyamide or polyimide, and the metal vapor deposition layer on the inner side thereof. Metal powder such as Ketjen carbon black, Cu, Ni, Ag, and AL is mixed in the inside 12. Furthermore, the insulating layer 13 inside thereof
Is composed of a polyester film mixed with mica or mica powder. Further, the adhesive layer 32 inside thereof
Is made of polyethylene or polyethylene kneaded with polyimide. In addition, a transparent portion 4 is formed on a part of the outer sheet 7 so that the inside of the packaging portion 3 can be visually recognized, and the transparent portion 4 is formed by internal perforation processing. The product name and other characters are written in the conductive ink 14, and powder such as Ketjen black or silver is mixed in the conductive ink 14.

Next, the silica gel 1 is placed in the packaging part 3.
In addition to 5, quick lime, alumina, zeolite, etc. may be mixed and sealed. Further, particles of the water-absorbing polymer 17 may be enclosed in the packaging part 3 together with the silica gel 15, and the water-absorbing polymer 17 is used when the ambient humidity becomes extremely high due to the generation of a dew point or the like. 1
7 absorbs a large amount of water and mixes in order to assist the water absorbing ability of the silica gel 15. The water-absorbing polymer 17 is, for example, a copolymer of a monomer such as a starch-acrylonitrile graft polymer hydrolyzate or a cellulose-acrylonitrile graft polymer hydrolyzate and a crosslinking agent, for example, crosslinked polyacrylamide and its hydrolysis. Products, crosslinked sulfonated polyethylene, crosslinked poplar, JP-A-52-14689 and JP-A-52-274.
55, crosslinked vinyl ester-unsaturated carboxylic acid copolymer saponified product, crosslinked polyacrylic acid salt and acrylic acid-acrylic acid ester copolymer, crosslinked isobutylene-maleic anhydride copolymer, And cross-linked polyethylene oxide. Further, a polymer having self-crosslinking property, for example, self-crosslinking polyacrylic acid, a resin described in JP-B-54-30710, or a polymer having at least a hydroxyl group and a carboxylate group in the molecule, for example, JP-B-54- The resin described in 37994 may be used. A water-absorbent resin obtained by polymerizing starch or cellulose with a water-soluble monomer and / or a monomer which becomes water-soluble by hydrolysis and a cross-linking agent as essential components, and optionally performing hydrolysis. Is also good.

The foam beads 16 enclosed with the silica gel 15 in the packaging portion 3 are made of polystyrene, polyethylene or the like having Ketjen black carbon mixed therein, and are provided with cushioning properties by foaming. Therefore, the silica gel 15 is prevented from rubbing against each other, and the silica gel 15 is effectively prevented from being broken by its cushioning property. Further, when static electricity is generated due to the rubbing of the silica gel 15 at the time of sealing in the packaging portion 3, static electricity can be released to the outside through the Ketjen black carbon inside. Moreover, the electronic component 1 can be protected by exerting a buffering ability against external pressure from the outside.

In FIG. 4, reference numeral 10 is an adhesive, which is used to adhere the nonwoven fabric 9 to the inner film 8. In this example, the inner sheet 6 on the inner side is made breathable, and the outer sheet 7 is made non-breathable.
It may be a breathable one. By wrapping the electronic component 1 with the packaging sheet 2 as described above, due to the water-absorbing ability of the silica gel 15 and the water-absorbing polymer 17, moisture around the electronic component 1 can be satisfactorily absorbed and stored in a dry state. The generated static electricity can be satisfactorily released to the outside through the non-woven fabric 9, the foam beads 16, the adhesive layer 32, the conductive ink 14, the metal deposition layer 12, and the antistatic protective layer 11, and the electronic component 1 is adversely affected by static electricity. Never. Also, electromagnetic waves from the outside are well prevented from entering the inside of the insulating layer 13, and the insulating layer 13, the metal vapor deposition layer 12, the antistatic protection layer 11
The electromagnetic waves are not reflected, agitated, absorbed, or the like in the interior, and the electromagnetic waves do not affect the electronic component 1.

Next, the structure of the sealing bag 18 for sealing the outside is enlarged and shown in a sectional view in FIG. That is, the sealed bag 1
No. 8 is formed of a film having no breathability composed of seven layers from the first layer to the seventh layer. Outer first layer 1
9 is an antistatic coating layer,
Siloxane / surfactant is mixed. The inner second layer 20 is a metal vapor deposition layer in which metal powder such as Cu, Ag, Ni and AL is mixed. Further, the inner third layer 21 forms an insulating layer in which a synthetic mica or mica powder is mixed in polyethylene terephthalate. The inner fourth layer 22 is a polyvinylidene chloride coating layer, and the inner fifth layer 2 is
3 is a layer made of biaxially oriented polypropylene, and the sixth layer 24 inside thereof is an adhesive layer made of linear low-density polyethylene. Further, the seventh layer 25 on the inner side is an antistatic coating layer having a siloxane-based / surfactant mixed therein. The thickness of the first layer 19 to the seventh layer 25 is, for example, about 40 μm.

The first layer 19, the second layer 20, and the third layer 21
Form a shield layer for static electricity and electromagnetic waves,
The fourth layer 22 and the fifth layer 23 form a moisture-proof barrier layer that blocks moisture. Sealing bag 1 having such a structure
According to 8, the static electricity generated from the packaging sheet 2 side is favorably directed from the inner side to the outer side, that is, because the outer side has high humidity, the static electricity is flown toward the outer side and is discharged to the outside. In addition, the electromagnetic waves from the outside are the first to third layers 19,
It is blocked from being diffused and reflected in the inside of 20, 21 and reaching the inside. Further, by the fourth and fifth layers 22 and 23,
The moisture can be blocked and the inside can be well sealed. The closed bag 18 can be sealed by sealing the upper end with a heat seal.

Next, the outer box 26 for accommodating the hermetically sealed bag 18 is formed of the constituent members shown in FIG. 6 or 7. That is, in the case of FIG. 6, an inner liner 27 made of carbon paper is provided on the inner side, a core liner 28 made of a metal plate is arranged on the outer side thereof, and further, an outer surface of the core liner 28 made of a corona discharge treatment is charged with metal fibers to prevent static electricity A paper 29 is arranged, and an outer liner 30 made of corrugated cardboard is arranged on the outer side of the paper 29. In such a structure, the static electricity from the inside can be favorably discharged to the outside with high humidity. Further, even if the outer box 26 is formed from the plastic cardboard 31 mixed with carbon black as shown in FIG. 7, static electricity can be similarly satisfactorily discharged to the outside.

[0016]

The electronic component packaging sheet of the present invention has a breathable sheet on one side and a non-breathable sheet having a conductive layer and an insulating layer on the other side, and is divided into a large number of sheets. The sachets are formed, and in each sachet,
When the electronic parts are wrapped with this packing sheet because silica gel and conductive foam beads are enclosed, moisture is sucked into the silica gel inside through the breathable sheet to keep the electronic parts in a good dry state. In addition, static electricity caused by rubbing of silica gel, etc. can be satisfactorily discharged to the outside through electrically conductive foam beads and a non-breathable sheet, and the adverse effect of static electricity on electronic parts is good. Can be resolved. Furthermore, it is possible to protect the electronic components by satisfactorily blocking electromagnetic waves and the like from the outside. Further, the cushioning properties of the foam beads can favorably protect the electronic component against external pressure. Also,
By forming the transparent portion in the packaging portion of the sheet, the water absorption capacity of the silica gel inside can be confirmed from the outside. In addition, after wrapping the electronic parts in the packaging sheet and then sealing the outside with a non-air-permeable bag, etc., it is possible to ensure a better dry state, and also to eliminate static electricity generated inside from the outside. In addition, the electromagnetic waves from the outside can be satisfactorily shielded, and the electronic component can be stored in a perfect state.

[Brief description of drawings]

FIG. 1 is a perspective perspective view showing a state in which electronic components are packaged.

FIG. 2 is a development view of a packaging sheet.

FIG. 3 is an enlarged cross-sectional view of the packaging sheet of FIG.

FIG. 4 is an enlarged configuration diagram of a main part of a packaging sheet.

FIG. 5 is an enlarged cross-sectional configuration diagram of a sealed bag.

FIG. 6 is a perspective view of a main part showing a sectional structure of an outer box.

FIG. 7 is a perspective view of a main part showing a modified example of the cross-sectional structure of the outer box.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electronic component 2 Packaging sheet 3 Packaging part 4 Transparent part 6 Inner sheet 7 Outer sheet 8 Inner film 9 Inner nonwoven fabric 11 Antistatic protective layer 12 Metal deposition layer 13 Insulating layer 14 Conductive ink 15 Silica gel 16 Foamed beads 17 Water absorbing polymer 18 Sealing bag 26 outer box

Claims (3)

[Claims] 1. One side is made of a breathable sheet, the other side is made of a non-breathable sheet having a conductive layer and an insulating layer, and a large number of divided packaging portions are formed between both sheets. A sheet for packaging electronic parts, characterized in that silica gel and conductive foam beads are enclosed in each of the packaging parts. 2. The sheet for packaging electronic parts according to claim 1, wherein a transparent portion is formed on the side of the non-breathable sheet so that the inside of the packaging portion can be seen. 3. After wrapping an electronic component with the packaging sheet according to claim 1, the outside is sealed with a non-air-permeable bag or the like formed with an electrostatic shield layer and an electromagnetic wave shield layer. Electronic component packaging method.