JPH0330495A - Electronic component protective wrapping bag material and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent static electricity charged on the outside of a wrapping bag from reaching an electronic component in the wrapping bag, to enable static electricity charged on the inner face of the wrapping bag to disperse, and to restrain static electricity induced by the friction between the electronic component and the wrapping bag by a method wherein a sheet for a wrapping bag comprises a non-chargeable film as the inner surface the layer, a conductive layer including conductive fibers, an insulating film, the conductive layer and insulating film being as the intermediate layer, and a static charge dispersion layer as the outer surface layer, all films and layers having specific surface resistances, and the sheet has a specific total light transmissivity. CONSTITUTION:PE is laminated on an insulating PP film with a surface resistance of 10<9>-10<13>OMEGA/sq. to form a composite film, card web in which conductive fiber formed of nickel plated acrylic fiber and acrylic fiber are mixed is buried in the PE film and fixed to form a conductive layer whose surface resistance is 10<4>OMEGA/sq. or below, and PE mixed with destaticizing agent is laminated on the buried face concerned through a T-die to form antistatic film layer whose surface resistance is 10<14>OMEGA/sq. or above, moreover, a static charge dispersion agent is made to coat the insulating PP film to form a static charge dispersion thin film whose surface resistance is 10<6>-10<11>OMEGA/sq. for the formation of a wrapping material. The total light transmissivity of the material concerned is made 60% or above.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) (Prior Art) One method for protecting electronic components from static electricity is a method of wrapping electronic components in a protective envelope.

There are various types of conventional protective bags depending on the material they are made of. One type has a resistance value of approximately 106 to 10I4Ω/□
There are some that are made of only antistatic film material. This type is electrically charged to a certain extent (for example, about 5 KV) and has the effect of preventing the human body from frictionally charging the electronic components inside the packaging, and some of this type of hammers are transparent. Therefore, there is an advantage that the electronic components inside the packaging bag can be identified from the outside. However, with this type of product, if a highly charged object (for example, 15KV or more) comes into contact with the package. The limited diffusion capacity of the packaging bag can cause electrostatic discharge, or if a highly charged object approaches the packaging bag, electrostatic induction can damage electronic components.

The second type of protective packaging is made from a film or metal foil in which conductive carbon is kneaded. Bags made from these materials are opaque and therefore do not permit visual inspection or identification of electronic components within the bag. Furthermore, contact between the contained part and the inner surface of the packaging bag creates friction debris with metal or parts that contaminates the part. This type of material also conducts static electricity to the electronic components within the package.

A third type of protective envelope is made of a material with a structure that is a combination of the above two types. That is, as shown in Japanese Patent Publication No. 60-18294.
The outer surface layer of the wrapping bag is substantially a conductive layer and the inner surface layer is controlled.
, and the intermediate layer is an insulating layer. The substantially conductive layer referred to here refers to a layer that has the same surface resistance as the original conductive layer even if a thin film layer (for example, 0.15 μm or less) is provided on top of the original conductive layer. say.

This third type is. By making the outer surface 1 of the wrapping bag substantially a conductive Wt layer, even if a highly charged object approaches or comes into contact with it, it prevents the electronic components inside the wrapping bag from being affected based on the Faraday cage principle. The intermediate insulating layer prevents charge movement on the outer surface and further controls the inner surface layer! The layer protects the electronic components inside the package from frictional electrification. However, this type actually has a conductive layer on the outer surface of the bag.Although it protects the electronic components inside the bag, electrostatic discharge occurs between the bag and the highly charged object. It may cause malfunction or damage to external electronic parts and equipment.

The fourth type is made of a material in which a conductive layer is arranged in the middle.For example, as shown in JP-A-60-127143 and JP-A-58-165649, both sides of the conductive layer are insulated. There are layers. Since the inner surface of the envelope is also an insulating layer, it has no effect on frictional electrification of electronic components. Furthermore, as shown in Japanese Utility Model Application Publication No. 62-156325, there is a structure in which an antistatic layer is provided on the image side of a conductive layer, but this is not effective against charge transfer between layers.

It is also shown in Japanese Patent Application Laid-Open No. 62-182062 []
A completely opposite configuration of the third type, that is, a type in which the inner surface of the wrapping bag is a conductive layer, has also been proposed. This type has the same drawbacks as the second type mentioned above.

As mentioned above, various proposals have been made as packaging materials for protecting electronic components. The reality is that there is no material that is fully satisfactory as a wrapping material 1 for protecting electronic components inside and outside the packaging bag.

(Problem to be Solved by the Invention) The purpose of the present invention is to: 1) provide protection for electronic components from external electrostatic fields; and 2) prevent static electricity on the outside of the packaging from reaching electronic components inside the packaging. 3) Enables the diffusion of static "rtg!c" on the inner surface of the packaging bag and limits the generation of static electricity due to friction between electronic components and the inner surface of the packaging bag. 4) Prevents the surface from becoming a contaminant for electronic components. It is possible to form a packaging bag that does not cause particles to fall off, 5) allows the electronic components inside the bag to be visually recognized from the outside of the colored packaging, and 6) has electromagnetic shielding properties if necessary. , 7) The present invention provides a packaging material for protecting electronic components that can be easily manufactured industrially, and a method for manufacturing the same.

(Means for solving the problems) The present invention is as follows. The inner surface layer I, which is to become the inner surface of the packaging bag, is a non-static film layer with a surface resistance value of 109 to 1013 Ω/□, and the intermediate layer n is a conductive layer (1) containing conductive fibers and has a surface resistance value of 104 Ω/□ or less, and the surface The insulating film layer (2) has a resistance value of 1014Ω/□ or more, and the outer surface layer ■ has a surface resistance value of 10@~
A packaging material for protecting electronic parts, comprising a static electricity dissipating material of 1011 Ω/□, which is a sheet-like material in which each layer is sequentially laminated and integrated, and has a total light transmittance of 604 or more, and a melting point. Low melting point film NJVC of a composite film consisting of two different film layers, the high melting point film layer being an insulating film layer with a surface resistance value of 1014Ω/□ or more
A conductive fiber card web with a basis weight of 3 to 7 t/- is embedded by thermocompression bonding to form a conductive layer with a surface resistance value of 104Ω/□ or less, and the embedded surface of the card web is coated with an antistatic resin. Surface resistance value 109-101! A package for protecting electronic components, characterized in that a non-static film layer with a resistance of Ω/□ is formed, and a static electricity dissipative layer is formed with a surface resistance of 10 6 to 10 11 Ω/□ by coating a static electricity dissipating agent on the insulating film surface. It is in the manufacturing method of the bag material.

The wrapping bag as used in the present invention refers to an enclosing body made of a sheet-like material, with b permanently attached to the end of the sheet and b temporarily joined. This envelope may be of any shape as long as it can accommodate electronic components.

The material of the present invention has a cross-sectional structure as shown in FIG. 1, and the functions of each part of the material will be explained below.

The inner surface layer that should become the inner surface of the packaging bag when it is made using the material of the present invention! The non-static film layer is . Forms the surface that comes into contact with the electronic components stored in the packaging bag, and has a surface resistance value of 1.
09-101! Ω/□, preferably 10 to 101! Ω
/ There is Rochi. At a high resistance value exceeding 1oISnJ't3, the material becomes substantially insulative and does not have the effect of diffusing the charges generated by friction, and has no effect of protecting electronic components from frictional charging.

This non-static film layer is made by mixing an anti-static agent with a resin.
Although it is obtained by extruding it through a die or the like, the film thus obtained does not generate metal or wear debris that can cause contamination due to friction with electronic parts. Furthermore, if the resin is a heat-fusible resin such as low-density polyethylene. Heat sealing when making wrapping bags becomes easier. This non-chargeable film layer may be, for example, a four-hole composite film of low density polyethylene and polypropylene, and the low melting point resin side may be placed on the inner surface of the packaging bag. When used as a wrapping bag, this non-static film layer has the function of protecting not only electronic components but also the conductive fibers that form the next conductive layer. This non-chargeable film layer having a thickness of about 10 to 80 μm is sufficient to protect the conductive fibers.

The conductive layer ■ (
1). The conductive layer (1) connects the envelope to the electric field KWlt,
−, the electric field inside the envelope is extinguished based on the Faraday cage principle. However, the problem here is that the envelope is placed in an electric field. Electric lines of force are generated inside the bag during the transition period during which the electric field inside the bag disappears.
There is a risk that electronic components may be damaged during the transition period during which these lines of electric force are occurring. To solve this problem, it is necessary to shorten the time of the transition period, and for that purpose, it is necessary to lower the surface resistance value of the conductive layer n(1), which is 104Ω/□
Hereinafter, the resistance value should preferably be 10<9>Ω or less.

A conductive layer with such a surface resistance value! [(1) refers to a fibrous web containing thin wires of nickel, silver, gold, etc. or fibers plated with these metals on the surface, or fibers with metal compounds such as sulfide steel attached and adsorbed to the fiber surface as conductive fibers. can be formed by embedding it in the film Ji31. Furthermore, if we consider electrostatic discharge, conductivity ″Nt#■ (1)
An important point is the spacing between the conductive fibers within.

In the present invention, it is preferable that the spacing between the conductive fibers parallel to the layers in the conductive layer 11(1) satisfies the following formula. Total thickness is L
The distance d between the conductive fibers in the conductive layer (1) at the position where t is the thickness from the conductive NIu<1) to the outer surface is d (2% below; b-・...Formula 1 d 7...Formula 2 must be satisfied.

The outer surface layer m of the wrapping bag is a static electricity dissipative layer, but when a high voltage is applied directly to the inside of the wrapping bag from the outer surface of the wrapping bag.
When a part of the electronic component 50 inside the packaging bag, for example, the bottle 51, is located at the position closest to the high voltage applied from the outer surface of the packaging bag, a conduction 'K M II (1) is formed. The conductive fibers must exist within a circle with the high voltage application point P as the center and the radius B. Due to the lightning rod principle, the high voltage reaches the conductive fibers 21 in the conductive layer before reaching the bottle 51, which is a part of the electronic component. The distance d between the conductive fibers is the same as the above-mentioned t.
The larger the value, the smaller it becomes necessary. Therefore, equation 1,
Preferably, by satisfying Formula 2, shielding of static electricity becomes possible.

Conductive layer! If the surface resistance value of l(1) is less than lX10'Ω/□, it is effective for electrostatic shielding, and
If it is 2Ω/□ or less, it is effective for shielding electromagnetic waves in a frequency band of several GHz.

It is preferable that the conductive fibers 21 of the conductive layer (1) have contact points with each other and are electrically continuous.

The conductivity *, the thickness of m21 is not particularly limited, but the conductive layer I
In order to improve the density of the conductive fibers in I(1), the pongee fineness is more preferable, and in consideration of the card web forming property of the conductive FM, a, 5 to 2071 m is appropriate. When forming a web of conductive fibers, there is no limitation at all even if other fibers are mixed in addition to conductive fibers as long as Formula 1 is satisfied.

It is of course possible to further impart conductive properties by attaching metal to the conductive layer (1) by vacuum deposition using an electron beam method, sputtering, etc., but it is necessary to consider the reduction in transparency.

The other insulating film layer (2) of the intermediate layer n is located outside the conductive layer II (1) and has a surface resistance value of 1014 Ω/□ or more. The insulating film layer n(2) has a function of preventing the transfer of electric charge from the outside of the envelope into the inside. 1014Ω to prevent charge transfer into the bag.
A high surface resistance value of /□ or higher is required, but the insulating film layer (2) can be made by extruding the resin using a T-die, etc.
More can be obtained.

Also. If it is necessary to protect the electronic components inside the package against mechanical forces from inside and outside, such as puncture force,
This can be achieved by using polyester, polypropylene, etc. as the resin.

The outer surface layer m, which is to become the outer surface of the wrapping bag when it is made into a wrapping bag, needs to be a thin layer having a surface resistance value of 101 to 1011 Ω/□ and having static electricity dissipation performance.

The outer surface layer 1 is the wrapping bag. To prevent frictional electrification between the packaging bag and other substances, or to quickly dissipate the charge when an object from outside the packaging comes into contact with the packaging, and furthermore, when a charged object approaches the packaging, It performs functions such as preventing the generation of electromagnetic waves due to electrostatic discharge.

A surface resistance value of 1012 to 10'Ω/□ is effective in preventing frictional electrification, but static dissipation during contact between a charged object and the wrapping bag is insufficient, and a surface resistance value of 1011Ω or less is effective. In addition, if the surface resistance value is less than 10.07, when the charged object approaches the packaging bag, the discharge 1~
Because it easily discharges and generates electromagnetic waves, it causes troubles due to electromagnetic waves rather than problems caused by static electricity inside and outside the wrapping bag.

In order to set the surface resistance value of the outer surface layer (■) to 106 to 1011 Ω/□, mix a static electricity dissipating agent with a resin and extrude it using a T-die, etc., or coat the static electricity dissipating agent on the surface of the insulating film layer. Obtained by the method, thickness 11
The thickness is 0.01 to 0.5 μm.

As mentioned above, the packaging material for protecting electronic components of the present invention satisfies the functions of each layer and has a defined layer order, but in addition, the packaging material has a total light transmittance of 60 or more. It is necessary.

If the total light transmittance is less than 604, it will be difficult to visually recognize the condition of the components inside the wrapping bag. The total light transmittance of the material is 604 or more.

In order to obtain the packaging material for protecting electronic components of the present invention, the low melting point film is softened in the low melting point film layer of the composite film, which is composed of two types of films with different melting points, and the high melting point film layer has insulation performance. A card web of conductive fibers is embedded in a low melting point film layer by heat LF bonding at a temperature above the temperature and below the softening humidity of the high melting point film, and then an antistatic resin is coated on the side where the card web is embedded. Advantageously, a method is used in which a non-chargeable film layer is formed, and the surface of the insulating film is further coated with a static electricity dissipating agent. The melting point difference of a composite film containing an insulating film layer having a surface resistance value of 104 Ω/□ or more must be 10°C or more, preferably 30°C or more.

If the melting point difference is less than 10°C, the shape retention of the high melting point film layer will be impaired due to shrinkage during thermocompression bonding. Such a composite film containing an insulating film layer can be obtained, for example, by T-die lamination or dry lamination of a film made of a combination of polypropylene and polyethylene or polyester and polyethylene.

A card web is layered on the composite film at a temperature that is higher than the softening temperature of the low melting point film layer and lower than the softening temperature of the IEM point film layer and pressurized to embed the card web. If the temperature is below the melting temperature of the low melting point film layer, the embedding of the card web will be insufficient and peeling will easily occur on the web surface. The inclusion of air bubbles causes a decrease in light transmittance. - If the temperature is higher than the softening temperature of the blade high melting point film layer, the shape of the composite film cannot be maintained. Therefore, when embedding the card web into the low melting point film layer, it is necessary to set the temperature at a temperature higher than the softening temperature of the low melting point film layer and lower than the softening temperature of the storage melting point film layer. Even if the above requirements are met, if the low melting point film layer is heated to a temperature higher than the melting point of the low melting point film layer, the low melting point film layer will not adhere to the pressure roller when embedding the card web under pressure, for example, in the width direction of the film. There is some oozing etc., which is not desirable.Hot pressure WIK for embedding card web in composite film is
For example, a method using a heated belt nip method such as a knee-son press machine, or a method using a heated roll nip method such as a calender machine is preferably used.

A carded web of conductive fibers is obtained by carding conductive fibers or a mixture of conductive fibers and other fibers, but as described above, the distance between conductive fibers in the web state is 1.
must satisfy the expression d<2i. The allowable gaps between the conductive fibers vary depending on the total thickness of the packaging material and the position of the conductive layer in the packaging material, but basically the conductive fibers must be opened uniformly. There is. In order to improve the spreadability, it depends on the capacity of the carding machine, but the conductive fiber should have a thickness of 5 to 20 μm and a fiber length of 30 to 20 μm.
A value of 70■ gives better opening properties. Of course, when metal-plated conductive fibers are used, it is also possible to improve fiber opening by using a smoothing oil or by mixing other fibers into the conductive fibers. When using other fibers, it is preferable to use fibers having a refractive index close to that of the low melting point film of the composite film from the viewpoint of light transmittance.

After embedding a card web of conductive fibers in the low melting point film layer of the composite film containing an insulating film layer, the card web embedding surface of the conductive layer is coated with a charging resin to form an uncharged film layer. As the antistatic resin, there is, for example, a mixture of low-density polyethylene and polyethylene glycols. Here, "non-electrostatic" means that it does not cause frictional electrification, and only needs to have a surface resistance value of ions to 101sΩ/□, and is heat-sealable so that it can be industrially heat-sealed when the packaging material is used to make the packaging. Preferably one with good performance. Note that the method of laminating a previously prepared non-charged film does not give favorable results in terms of peel strength due to the inclusion of air bubbles at the interface between the web surface and the film surface. Also, from an industrial standpoint, coating in a molten state has great economic advantages.

Next, the insulating film layer of the high melting point film of the composite film containing the insulating film layer is coated with a static electricity dissipating agent. As a static electricity dissipator, @quaternary ammonium 4, Bo! These include J ethylene glycols, ethanolamines, amine salts, and prokenes. As the coating method, a gravure coater or the like is used. Although the coating is not particularly specified, it is important to form a thin electrostatic dissipative layer exhibiting a surface resistance value of 10 6 to 10 11 Ω/□ as described above.

The packaging material for protecting electronic components obtained by the method described above can be easily processed into bags by heat sealing with the inner surface layer facing inside.

(Effects of the Invention) The packaging material according to the present invention has a manufacturing cost of 0. It is used not only as a packaging material for the purpose of protecting semiconductor products such as LSIs and other electronic components from static electricity, but also as a packaging material for conductive layer materials and other electronic components.
It is also possible to provide electromagnetic wave shielding performance by selecting a low resistance value and setting the gap between 4" fibers, and the material of the present invention can also be applied to prevent noise that interferes with electrical equipment. It is possible.

Furthermore, the material of the present invention can be manufactured very rationally.

(Example) The present invention will be explained below with reference to Examples.

Example 1 Sample 1: On the PFe film surface of a composite film formed by laminating polyethylene (CPg) on an insulating polypropylene (PP) film with a surface resistance value of 5.4 x 1014Q/hole,
Acrylic fiber (2 denier x 51 m) is plated with nickel at a weight of 20%, making it a conductive vinyl fiber with a mix of 60fi grade bonding and acrylic fibers with a 40% weight resistance.Basic weight: 697m'' Conductivity 'fB, m average spacing 14 force At a temperature of 140° C., the conductive layer was formed by embedding and fixing the conductive layer in a 9/I7/l” plate. Next, Pffi containing an antistatic agent is laminated using a KT-die on the embedded surface to form an antistatic film layer, and a static electricity dissipating agent made of a quaternary ammonium salt is further coated on the insulating PP film surface to form a static electricity dissipating thin layer. form. A wrapping bag material was prepared and designated as Sample 1.

Sample 2; In the preparation of Sample 1, conductive fibers were made by adhering polyester fibers (1.4 denier x 5 1 wm) K sulfide steel with 2.8 layers of f-sulfur when forming the conductive layer! 100iit* fabric weight 5-5 t/gs” average fiber spacing 140μm
A packaging material was prepared as Sample 2 under the same conditions as Sample 1 except that the card web of 1 was used.

The compositions of Sample 1 and Sample 2 are shown in Table 1.

Sample 3 (comparison): A packaging bag made of a film with a thickness of 80 μm and a surface resistance value of 1×10 11 Ω/with an electric agent mixed therein.

Sample 4 (comparison) 1 The inner surface layer has a thickness of 38 μm and a surface resistance value of 1×1011Ω/
A packaging bag made of a laminated film consisting of an antistatic PG film (□), a 25 μm thick polyester film as the middle insulating layer, and a nickel sputtered thin layer (100A thick) as the outer surface layer.

Evaluation of Samples Samples 1 and 2 were heat-sealed with the pg film layer on the inside with a length of 5KL, and a packaging bag with a width of 105I was made. Table 2 shows the results of the electromagnetic waves generated outside the packaging. Destructive test experiment is 0-M084069 5
Each piece was stored in a wrapping bag, and an electrostatic discharge generator (BIT-30B manufactured by Sanki Denshi Kogyo Co., Ltd.) was used to generate a voltage of 10 KV.
This test was repeated 5 times by repeatedly applying the voltage from outside the bag.

After the experiment. The parts were removed from the packaging, and the state of damage to the XC was determined from the presence or absence of light-emitting diodes from the electrical circuit. Further, the electromagnetic wave generation status was determined by placing a KM locator (manufactured by Sanki Denshi Kogyo Co., Ltd.) outside the package during a destructive test based on the locator sound.

Table 2 Sample 1 Sample 2 Sample 3 Sample 4 [Destruction rate (fun)
0 0 36 0 electromagnetic wave induction
Weak Weak Weak Intense * Light transmittance <@ 75 73 89
38 lines Light transmittance: Compliant with J Engineering EI K-6714 Example 2 In the preparation of sample 1 in Example 1, 20 weights of silver was applied to acrylic fiber (2 denier x 51 mm) at the time of forming the conductive layer. A wrapping material was prepared in the same manner as Sample 1 except that a card web with a fiber average spacing of 140 μm was used. 1-1 Electromagnetic shielding property When measured, a value of 504B was obtained at a frequency of 500 MHz.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a model of the packaging material of the present invention, and Figure 2 is a model diagram showing the positional relationship between the thickness of the packaging material of the present invention and the spacing between conductive fibers in the conductive layer. ■(1)... Conductive layer ■(2)... Insulating film layer ■... Outer surface layer 21 consisting of a static electricity dissipative layer.
...Conductive fiber, 50...IQ.

Claims (2)

[Claims] 1. The inner surface layer I, which should become the inner surface of the wrapping bag, has a surface resistance value of 10.
Conductive layer (1) with a surface resistance of 10^4Ω/□ or less and a surface resistance of 10^1^4Ω, in which the intermediate layer II contains conductive fibers and a non-electrostatic film layer with a resistance of ^9 to 10^1^3Ω/□. /□ or more insulating film layer (2) and outer surface layer III consisting of a static electricity dissipative layer with a surface resistance value of 10^6 to 10^1^1 Ω/□, and each layer is sequentially laminated and integrated. A packaging material for protecting electronic components, which has a total light transmittance of 60% or more. 2. The composite film is composed of two types of film layers with different melting points, and the high melting point film layer is an insulating film layer with a surface resistance value of 10^1^4Ω/□ or more.The low melting point film layer has a basis weight of 3.
A conductive fiber card web of ~7 g/m^2 is embedded by thermocompression bonding to form a conductive layer with a surface resistance value of 10^4 Ω/□ or less, and the embedded surface of the card web is coated with antistatic resin. A non-static film layer with a surface resistance value of 10^9 to 10^1^3 Ω/□ is formed, and a static electricity dissipating agent is coated on the insulating film surface to give a surface resistance value of 10^6 to 10^1^1.
A method for producing a packaging material for protecting electronic components, characterized by forming a static electricity dissipative layer of Ω/□.