JPH0412637Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is applicable to the handling of semiconductor devices, etc.
This relates to a disposable wrist strap that is worn around the wrist to release static electricity accumulated in the human body.

BACKGROUND OF THE INVENTION When handling semiconductor devices, if the static electricity accumulated in the worker's body is not immediately released, the semiconductor device may be damaged. Therefore, in rooms where semiconductor devices are handled, it is common practice to use conductive materials for work tables, chairs, floors, containers, etc., or to cover them with conductive sheets or covers, and to ground them. It is being done. In addition, workers are required to wear conductive aprons, conductive arm covers, and conductive gloves, and are also required to wear conductive wrist straps on their wrists and ground them with a ground wire.

By the way, the following wrist straps have been used or proposed in the past.

A sheet made of plastic or rubber into which a large amount of carbon black is kneaded.

A cloth-like fastener is attached to opposing surfaces at both ends of a cloth band made of conductive fiber (Japanese Utility Model Publication No. 55-52833).

An antistatic woven or knitted fabric or film is laminated on the back side of a woven or knitted fabric, and can be worn on the wrist with a hook, lock, hook-and-loop fastener, etc. (Japanese Utility Model Publication No. 58-60899).

Made of woven or knitted fabric mixed with conductive fibers, it can be worn on the wrist with hooks, locks, hook-and-loop fasteners, etc.
Publication No.).

It has a structure in which conductive fibers are integrated into a belt-like material made of lightweight, flexible, and breathable material, and is used for hook-and-loop fasteners, hooks,
Other fasteners to be worn on the wrist (Japanese Utility Model Publication No. 173200/1983) All of these wrist straps are intended for repeated use over a long period of time.

Problems that the invention aims to solve The wrist straps mentioned above are currently widely used, but they are heavy and feel cold, and because they are not breathable, you get sweaty while wearing them.
It causes great discomfort, and because it contains carbon black, only a black wrist strap can be obtained, visually lacking in fashionability.The wrist strap that is worn gives the worker a feeling of restraint.
There are problems such as the wrist strap being worn becomes a concern and the work efficiency decreases.

The above wrist straps, , and above are intended to solve the problems of the above wrist straps, but due to their simplicity and manufacturing cost, they are practically difficult to use for disposable purposes.

In view of the above-mentioned circumstances, the present invention has been made with the purpose of providing a wrist strap that is disposable in terms of both performance and cost.

Means for Solving the Problems The disposable wrist strap of the present invention has a strip 1 made of a non-woven fabric mixed with conductive fibers, one side of which is a flocked surface, and one end of the other side has a strip. A pressure-sensitive adhesive layer 2 is provided up to 5 to 20% of the total length of the strip 1, a release sheet piece 3 is placed over the pressure-sensitive adhesive layer 2, and a ground wire is connected to an appropriate location of the strip 1. It is made by installing a hook 4 for use.

The present invention will be explained in detail below.

In the present invention, a strip 1 made of a nonwoven fabric mixed with conductive fibers is used. Here, the term "nonwoven fabric" is a concept that includes paper. Woven or knitted fabrics are costly and unsuitable for the disposable purpose of the present invention.

Examples of the conductive fibers include copper adsorption fibers, electroless plating fibers, carbon composite fibers, metal-deposited fibers, and thin metal wires.

Here, the copper-adsorbing fiber refers to a fiber obtained by adsorbing copper ions to a fiber having a cyano group and then reducing the adsorbed copper ion. Electroless plated fibers refer to fibers obtained by immersing synthetic fibers in a metal salt solution containing a reducing agent, and are usually simply referred to as metal plated fibers.

Among the above-mentioned conductive fibers, copper adsorption fibers or/
It is particularly preferable to use electroless plating fibers. This is because copper adsorption fibers and electroless plating fibers have appropriate surface resistance values, so there is no risk of overcurrent flowing. Carbon composite fibers are also suitable, but
Colors may be limited. metallized fiber,
A thin metal wire can also be used, but in this case it may be necessary to take measures such as providing a resistance in the ground wire.

The proportion of conductive fibers in the nonwoven fabric is 0.1~
40% by weight, preferably from 0.5 to 30% by weight. If the proportion of conductive fibers is too low, the effect of removing static electricity accumulated in the human body will be insufficient, while if the proportion of conductive fibers is too high, the manufacturing cost will increase rapidly, making it unsuitable for disposable use.

One side of the strip 1 is a flocked surface to limit the number of times that the pressure-sensitive adhesive layer 2 can be bonded repeatedly. The flocked surface is advantageous in that it not only improves the feel and appearance but also allows for color coding.

Dimensions of strip 1 are length 17~30mm, width 10~
It is desirable to set the length to 40 mm, preferably within the range of 18 to 25 mm in length and 15 to 30 mm in width. If the length is too short, it will be difficult to wear on the wrist, while if it is too long, it will be disadvantageous in terms of cost. If the width is too narrow, the contact area with the skin will be small, reducing reliability and making it difficult to install the hook 4 for connecting the ground wire.On the other hand, if it is too wide, the feeling of wearing will be poor and it will be disadvantageous in terms of cost. Become.

A pressure-sensitive adhesive layer 2 is provided on one end of one side of the strip 1, and a release sheet piece 3 is placed thereon.

As the pressure-sensitive adhesive forming layer 2, any known pressure-sensitive adhesive such as a rubber-based pressure-sensitive adhesive or an acrylic-based pressure-sensitive adhesive can be used.

As is well known, rubber-based pressure-sensitive adhesives include elastomers (natural rubber, isoprene rubber, styrene-butadiene rubber, styrene-isoprene rubber, butyl rubber, polyisobutylene, polyvinyl isobutyl ether, chloroprene rubber, nitrile rubber, etc.), tackifiers, etc. agent resin (rosin, ester gum,
Polyterpene resin, petroleum resin, styrene resin,
alkylphenol resin, terpene-phenol resin, etc.), softeners (plasticizers, polybutene, liquid tackifying resin, polyisobutylene low polymer, polyvinyl isobutyl ether low polymer, lanolin,
depolymerized rubber, process oil, vulcanized oil, etc.),
Its constituent ingredients include anti-aging agents and fillers.

Acrylic pressure-sensitive adhesives typically consist of a soft component (acrylic acid alkyl ester or methacrylic acid alkyl ester having a long-chain alkyl group with 4 to 12 carbon atoms) and a hard component (vinyl acetate, short-chain alkyl group). acrylic acid alkyl ester or methacrylic acid alkyl ester, acrylonitrile, styrene, etc.) and ethylenically unsaturated carboxylic acids (maleic acid or its anhydride, itaconic acid or its anhydride, fumaric acid, acrylic acid, methacrylic acid, etc.) After copolymerizing, polyols, polyamines, polyisocyanates, etc. are blended as necessary.

The pressure sensitive adhesive may also contain carbon black or other conductive fillers.

The pressure sensitive adhesive layer 2 is provided from one end of the strip 1 to 5 to 20% of the total length of the strip 1. For example, the total length of strip 1 is 200 mm.
mm, the pressure sensitive adhesive layer 2 is strip 1
It is sufficient to provide it 10 to 40 mm from one end of the .

The release sheet piece 3 covered on the pressure-sensitive adhesive layer 2 may be, for example, a plastic film,
A sheet such as paper or metal foil treated with silicone, fluororesin, fluorosurfactant, long-chain alkyl group-containing copolymer, etc. is preferably used. The release sheet piece 3 is usually provided so as to cover the entire surface of the pressure-sensitive adhesive layer 2, but it can also be provided over a slightly wider area. The protruding portion of the release sheet piece 3 can be caught with a fingertip or nail, making the peeling operation easier.

Then, hooks 4 for connecting the ground wire are installed at appropriate locations on the strip 1. However, avoid the area where the pressure sensitive adhesive layer 2 is installed.

As the ground wire connected to this hook 4, any conventionally used ground wire can be used. A typical wire is a resin-coated copper wire, and there are straight and curled types.

In addition, (a) conductive fiber threads are attached to tape-like or string-like materials made of lightweight, flexible materials (woven fabrics, non-woven fabrics, felt, knitted fabrics, natural leather, synthetic leather, twisted strings, etc.). (b) Threads made of conductive fibers twisted together or other ordinary threads (synthetic fibers, semi-synthetic fibers,
Regenerated fibers, natural fibers, etc.) may also be used. Here, examples of the conductive fibers include the conductive fibers mentioned above in the description of strip 1.

One end of the ground wire is provided with a corresponding hook for connection to the aforementioned hook 4, and the other end is provided with a clip or the like as necessary to facilitate grounding by contact with a conductive workbench or the like.

The conductivity between both ends of the wrist strap of this invention and the ground wire is determined by the surface resistance value, for example.
It is desirable to set it to about 10 ⁴ to ^{10 8} Ω. Note that, if necessary, a resistor can be provided at any location on the ground wire.

Function When using the wrist strap of the present invention, first peel off the release sheet piece 3 covered on the pressure-sensitive adhesive layer 2, wrap the wrist strap around the wrist, and then press the overlapping part. , pressure sensitive adhesive layer 2
Adhere and secure both ends of the wrist strap.

Then, engage the hook at one end of the ground wire with the hook 4.

If you work on semiconductor devices in this state, the static electricity accumulated in your body will be removed from the strip 1.
The conductive fibers mixed in the conductive fibers, the hook 4, and the ground wire are immediately released, and there is no risk of damaging the semiconductor device.

When work is interrupted, the ground wire can be removed from the hook 4 and the wrist strap can be left on the wrist.

During a lunch break or the like, the wrist strap worn on the wrist can be removed by opening the overlapping parts (the parts adhered by the pressure-sensitive adhesive layer 2) at both ends. When you start working, you can wear it on your wrist again as described above.

After one day of use, it can be thrown away. If the pressure-sensitive adhesive layer 2 still has sufficient adhesive strength, it can be used the next day.

Example Next, the present invention will be further explained with reference to Examples.

Example 1 Figures 1 to 6 are explanatory diagrams showing an example of the wrist strap of the present invention. Figure 1 is a front view, Figure 2 is a top view, Figure 3 is a bottom view, and Figure 4 is a right side view. side view,
FIG. 5 is a left side view, and FIG. 6 is a sectional view taken along line A-A. However, in FIGS. 1 to 6, the hair transplantation is omitted.

FIG. 7 is a front view of the wrist strap of the present invention, and the hair implants are shown in FIG.

Acrylic fiber, rayon and acrylic copper adsorption fiber (Thunderon manufactured by Nippon Kasuke Dyeing Co., Ltd.)
A length of 0.6 on one side of a nonwoven fabric with a basis weight of 30 g/ ^m2
After transplanting mm dyed flock (pile),
Cut it to a length of 200mm and attach it to one end of the non-flocked side.
An acrylic pressure-sensitive adhesive is applied to a width of 20 mm and dried to form a pressure-sensitive adhesive layer 2, and then a peeling film consisting of a silicone-treated plastic sheet with a slightly wider area is placed on the pressure-sensitive adhesive layer 2. Covered with sheet piece 3.

Next, the nonwoven fabric sheet thus obtained was cut to a width of 25 mm to obtain a strip 1 having a pressure-sensitive adhesive layer 2 and a release sheet piece 3 covering it on one side and one end.

A hook 4 is attached to the center of the strip 1 at a distance of 80 mm from the other end so that the side opposite to the pressure-sensitive adhesive layer 2 installation side (i.e., the flocked side) can be engaged, and is used as a disposable wrist strap. did.

The weight of the wrist strap thus obtained was only 1.6 g per piece, making it extremely lightweight.

When I repeated the operation of peeling off the release sheet piece 3 from this wrist strap and adhering the pressure-sensitive adhesive layer 2 to the other end of the strip 1, I was able to attach and detach it several times, but I was unable to attach and detach it any further. It was impossible.

A hook provided at one end of a 1 m long ground wire made of a resin-coated copper wire was engaged with the hook 4 of the wrist strap, and the semiconductor device was handled. Workability was good.

In addition, in place of the ground wire made of the above-mentioned resin-coated copper wire, the same acrylic wire as above was used along both ends of a flat tape made of colored nylon monofilament yarn with a length of 1 m, a width of 5 mm, and a thickness of 0.5 mm. A ground wire with a structure made of machine-sewn copper-adsorbing fiber thread, a string approximately 1.2 mm thick and 1.5 m long, made by twisting together 10 colored nylon monofilament threads and 2 threads made of acrylic copper-adsorbing fiber. By using a shaped ground wire, the work efficiency was further improved because the ground wire was lightweight. The conductivity between both ends of the human body grounding device consisting of the wrist strap and the ground wire was 10 ⁶ Ω in terms of surface resistance, indicating the optimum conductivity for a human body grounding device.

Example 2 A wrist strap was made in the same manner as in Example 1, except that a nonwoven fabric made of electroless nickel plating fiber was used instead of the acrylic copper adsorption fiber as the conductive fiber. Similar good results were obtained.

Effects of the invention The wrist strap of this invention is extremely lightweight, feels good on the skin because it is made of non-woven fabric, absorbs sweat, has a simple structure, and the material is inexpensive, so manufacturing costs are low. It is inexpensive, can be dyed in any color to make it colorful, is flexible, comfortable to wear, does not cause any discomfort or discomfort, can be worn on the wrist with one touch, and is safe for the human body. It has various excellent effects such as being able to reliably remove accumulated static electricity and being able to wear a wristwatch over this wrist strap.

Therefore, the wrist strap of the present invention is highly practical as a disposable wrist strap.

Moreover, by making it disposable like this,
Since a new wrist strap is used every 1 to 2 days, there is a risk of damage to semiconductor devices by wearing the wrist strap without realizing that it can break due to repeated use over a long period of time, unlike conventional non-disposable wrist straps. This eliminates the risk (that is, eliminates unexpected troubles such as the wrist strap not having the desired static electricity removal effect despite being worn), and reliability can be ensured.

Even if you try to use this wrist strap after the expiration date for disposal, after you put it on and take it off several times, the pressure-sensitive adhesive layer 2 will lose its adhesion to the flocked surface, making it impossible to wear it on your wrist. This prevents workers from accidentally using old wrist straps. In other words, the pressure-sensitive adhesive layer 2 not only plays a role in simply fixing the wrist strap to the wrist;
It definitely serves as an indicator of usable life. Such a role cannot be expected from hooks, surface fasteners, etc.

[Brief explanation of the drawing]

1 to 6 are explanatory diagrams showing an example of the wrist strap of the present invention, in which FIG. 1 is a front view, FIG. 2 is a top view, FIG. 3 is a bottom view, and FIG. 4 is a right side view.
FIG. 5 is a left side view, and FIG. 6 is a sectional view taken along line A-A. However, in FIGS. 1 to 6, the hair transplantation is omitted. FIG. 7 is a front view of the wrist strap of the present invention, and the hair implants are shown in FIG. 1... Strip, 2... Pressure sensitive adhesive layer, 3...
... Peeling sheet piece, 4... Hook for connecting ground wire.

Claims (1)

[Scope of utility model registration request] One side of the strip 1 made of a nonwoven fabric mixed with conductive fibers is a flocked surface, and one end of the other side is coated with 5 to 20% of the total length of the strip 1.
A pressure-sensitive adhesive layer 2 is provided up to the point, a release sheet piece 3 is placed over the pressure-sensitive adhesive layer 2, and a hook 4 for connecting the ground wire is installed at an appropriate location on the strip 1. A disposable wrist strap.