JPS6160443A - Vessel protecting article from static electricity - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a container for protecting articles that can be destroyed by electrostatic discharge.

Silence has become a major problem in the electronics industry.

With the advent of microcircuits and the use of proven circuits incorporating metal oxide semiconductors, supplementary metal oxide semiconductors and silicon chips for field effect transistors, printed circuit (PC) sheets within production and repair lines for transportation, storage and movement. The packaging must provide protection against static electricity. Static electricity can be generated in a variety of ways, but most commonly when people move around the floor, the charge can be transferred from the person's hands to the circuitry and permanently damage one or more chips. This fact is often unknown.

Today, carbon-impregnated plastic bags are used to protect printed circuit boards from damage caused by large static charges. Translucent polyethylene (bag or wrapping material) and “
There are various materials for wrapping the pink foam pad, and each of these materials is 6.45c1rL2 (1 square inch), 92500
Although only sheet resistance up to volts is guaranteed, static charges can be much higher.

The use of weak plastic bags containing conductive carbon is expensive and hinders the handling, storage, and inventory of printed circuit boards14.
It has been established that the material is unsuitable for transportation. During assembly in the splint circuit board f'i fabrication shop, it is removed from the bag, some chips are added at some point, reinserted into the bag, and the bag is sent to the next work station where it is further processed. Chips are added, and so on. A similar procedure inevitably occurs when a repair person repairs a customer's equipment.
A repair tool box may contain as much as $1,000 worth of printed circuit boards. The repair person assembles the defective printed circuit board, takes out a new printed circuit board (one in bag 1) from the box, replaces it with the defective printed circuit board, places the defective board in the bag, returns to the repair shop, and replaces the defective board (i- Transport capacity - packed in tons,
Manufacturer K did not change this.

A transport cart/cart is usually dumped and is also used to return the replaced board to the manufacturer. During this procedure, as well as the assembly process, electrostatic charges are inadvertently transferred to the board, further damaging the circuit, and therefore no one knows for certain the source of the failure in the first place. The repairer blames the manufacturer, the manufacturer blames the repairer, and the consumer does not know who is to blame.

There is no limit to the size of the problem. Manufacturers in the region assemble and ship more than 20,1100 printed circuit boards each week, with the majority of these boards sent to repairers for on-site replacement purposes or sent to other assembly plants. ,
Each printed circuit board is usually placed in a side bag or box.

Some go from one place to another as inventory.

Impregnated plastic bags protect printed circuit boards against high voltage electrostatic charges, but they are expensive, have a useful handling life of only about 6 cycles, and the bags do not protect printed circuit boards against physical damage. .

It is therefore a principal object of the present invention to provide a container for enclosing carbon black to protect printed circuit boards and other articles against electrostatic discharge damage.

Although the invention has been described so far from the perspective of a printed circuit board, the invention is equally applicable to protecting expensive lenses, since static charges on the lenses can scratch the lenses when they are being polished. This is because it attracts and retains the abrasive grains that would otherwise be damaged.

Currently, replacement printed circuit boards are shipped to repair locations around the world. Each is placed in a carbon black impregnated polyethylene bag, the bag is wrapped with packaging material and placed in a box. Upon arrival at the destination, the outer packaging containing the box and packaging material is discarded until used, and the black bag containing the printed circuit board is stored on a shelf or in the utensils until assembled to replace the equipment. Placed in a box or rotated around.

Defective printed circuit boards are placed in polyethylene (black) bags and returned to the laboratory, where they are repackaged and sent back to the manufacturer.

In the present invention, an inexpensive but generally effective carbon black enclosure on a durable support is constructed to create a cavity within which a printed circuit board or other material sensitive to electrostatic discharge may be placed. The article is inserted. If the discharge is high enough to penetrate the support from outside the cavity, it will encounter the carbon black encapsulant trap and e-circulate around it until it disappears, never reaching the article. In particular, the carbon black capture body is a coating of carbon black applied to a web of paperboard laminates at least as thick as the other paperboard, and the support is separated from the FAR body and raised from the carton stock. ing.

In one type of practice, the printed circuit board, prior to insertion, is wrapped in a sheet of antistatic plastic, such as "polyethylene 6 foam wrapper". The box or carton has a label on its edge identifying the particular printed circuit board. The repairer may have a work order sheet, which he or she may have on hand, and which may include a work order sheet, which must be filled out by the repairer to indicate the problems with the defective printed circuit board he replaced, and which he will also include on the return label. The box is usually not opened until the printed circuit board inside has been installed as a replacement for a defective printed circuit board.

When a new printed circuit board is installed, the old one is wrapped inside and placed in the same box with a work order sheet filled out by the repair person. The inner mailing label is applied over the old label and the n1 box is prepared for return to the manufacturer.

In another conventional method, cartons are trays that are stacked on top of each other so that printed circuit boards can be assembled without fear of being destroyed by electrostatic discharge.

In another customary version, the carton partitions are cut from a paperboard web coated on both sides with carbon black, so that the partitions create a number of enclosing compartments within said carton or box for the items inside one box. so inserted, the boxes are stacked on top of each other.

This device reduces material costs, provides stronger support than just bags, is easily stocked, eliminates handling and packaging effort, and
More carbon black can be used compared to bags. These advantages constitute another object of the invention.

The coating medium mixed with carbon black weighed 31.7 kg (
13.70 lbs. of water and 12.5 lbs. of dispersed conductive carbon black particles.
Consist of 6 Kp (30 Bond) of any suitable printing infusion. cn, is calculated to be 3.785 J (1 gallon) per J0.566 to 9 (1,25 bond) of tetraelectric carbon black. The coating may be roller coated or by any other convenient method. 0.453 K1
1 (1 pound) 9.3 m" (100 feet) 0.453 to 7 (1 bond) (formula above) has a covering weight of 6.45 cm2 (square inch) approximately 50
It can withstand a charge of 000 volts.

Printed inflatables are preferred as the main medium for carbon black particles because they are inexpensive, have good adhesion to paper, easily dry and become sticky (adhesive) to effectively hold carbon black particles in dispersed form. This is because it means a material.It can also contain other equivalent viscous media.
That is, the fest may be replaced by an acrylic or other liquid medium used in paperboard printing inks in which the carbon black particles can be fully dispersed.

The coating consisting of water and ink medium is of course an emulsion and 1. The conductive particles are preferably Palcuff XC-72LR 4% carbon black particles supplied by Cabot, i.e. 98.5% solid carbon (1,
5% volatiles), the average diameter is 19 millimicrons, and the measured volume resistance (ohms/cm) is in the range of approximately 2.3 to 6.

The assembly of the carbon black enclosure on the paperboard support is carried out in a variety of ways starting with the application of a conductive coating fc to the flat surface of the paperboard in a variety of ways. In this regard, in order to achieve the desired strength for protecting the box, often against a minimum strength, E-groove corrugation is a class known in the paper industry as board (both sides), or folded carton. It is considered to be a class of boards known as boards. In this specification, the term paperboard applies to any of the suitable classes.

Referring to FIG. 1, the already laminated E-groove waves allow the paperboard 10 to be advanced as a continuous web or band between a pair of opposed rollers 12,140. The above-mentioned conductive σ material (
The carbon black dispersion) is fed from trough 6 and is conveyed collectively to rollers 12 in a set of reservoir rollers designated 18, which rollers are of the type and characteristics used for applying printing inks. Roller 1 with suitable properties
2 applies a uniform continuous coating continuously across a predetermined width to the top paperboard sheet or sheet. Alternatively, the lower sheet or web of paperboard n may be continuously and uniformly covered in the same manner. Of course, the two webs 20,n are separated by an intermediate groove or pleat.

In some cases, it may be desirable to coat the paperboard webs separately and complete the lamination later. This is illustrated in FIG. 2, where web 2OA has been previously provided with a conductive coating and is re-wound onto a feed roller, which then has all the same pleats with respect to the coated laminate LO shown in FIG. The corrugation will be sent to the person to complete the laminate 10 A'i.

As discussed later, if the carton is partitioned, the first
Both sides of the illustrated laminate 10 may be coated as in FIG.
It may also be constructed from a pre-coated web as shown. This is illustrated in FIG. 3, where two paperboard webs 32, 34, each previously coated with conductive carbon black, are laminated on either side of an intermediate paperboard pleat 36. As mentioned above, a folded carton of the same strength (two or more flat layers) can be used in place of sheet metal pleating.

As shown in Figure 4, the laminated paperboard storage material is coated with dry carbon black throughout (preferably except for the edges, which should be discarded).
and shows at least one outer flat surface uniformly coated to constitute the entire carbon black enclosure. The dry coating is likewise indicated by dots in FIGS. 4, 5, 6, and 7. After the coating has dried, the laminated raw material is scored with FrC along the fold line 38 and grooves 4
0 and cut along cutting line 42 as the desired shape of the carton blank is fully separated from the laminated web.

The carton material shown in Figure 4 is for illustrative purposes;
In addition, the carton material from which the carton is erected includes a pair of side panels 44, a pair of ends joined to the side panels at fold lines,
It is shown having an e-flank 46, a pair of end flaps 48 joined to each end panel by a fold line, and a pair of side flaps 50 joined to each side end panel by a fold line. All flaps are separated by grooves 40. The side flaps define the length L of the resulting carton, and the end flaps define the width W of the resulting carton. The adhesive tab 52 for the adhesive joint is at the end/ξ
It can be attached to the flannel with 9 folded wires.

The material shown in Figure 4 allows a six-sided carton to be erected and closed on all inner surfaces opposite the outer surface to provide the desired carbon black enclosure, with the printed circuit board being inserted before the lid enters the carbon black enclosure. is inserted into the carton cavity,
And if any electrostatic discharge on the outside of the container penetrates the thickness of the paperboard, it will be captured by the inner carbon black surrounding coating on one of the flannel or flaps and continue around indefinitely until it is finally released or dissipated. circulate.

The joining tab 52 need not always be used; in fact the f'i end closure flap may be attached with tape or with a bayonet flap. If a bayonet flap is used, the closed end wall of the lid also has ears that bend in cooperation with the bayonet flap to secure the contained article. Particularly in the case of printed circuit boards or lenses, it may be desirable to wrap either of these prior to insertion.

Literally hundreds of thousands, if not a million, printed circuit boards are sent to distribution centers by a particular manufacturer each year. Furthermore, the opportunity for destruction of microprocessing circuits is literally unique;
And this is especially so from the standpoint of repeated handling for inventory or transportation purposes. Both inventory and transportation are therefore facilitated by the present invention by creating a carton partition, which serves not only to isolate the articles within individual compartments inside the container, but also to separate the carbon black enclosure. building the body. and with reference to FIG. 6, a carton 60 made by Uninvented and as described above.
incorporates a partition 62 inside the carton that defines eight compartments, each of which isolates an individual printed circuit board. The partitions are cut and separated from the blank 64 of FIG. 5, and the blank is coated on both sides with the conductive carbon black dispersion described above. The partitions are of the usual type having a frame 66 and a corresponding number of stringers and '(i-).

The compartmentalized carton shown in Figure 6 is a six-sided container, ie it has a lid flap creating a closed top wall. However, especially in the case of bulky inventory or transportation, the carton
They can be stacked on top of each other as shown, in which case only the top container needs to be closed. In order to save total costs and to facilitate the handling of the carton itself when loading goods, it is advantageous to make the carton material free of ``L7;7''7;7;7; without necessarily having side flaps; As shown in FIG. 7, the items placed in the bottom carton are covered with carbon gua, which is made on the inner surface of the bottom wall of the next upper container 72. 76
The inner surface of the lid is continuously coated with the carbon black dispersion described above. The lid 76 is made as a special item, the same as the partition is made separately from the laminate, but the lid 76 only needs to be coated on the surfaces that constitute the interior surface. A four-by-three stack of the type shown in Figure 7 is conveniently assembled on a pallet by closing the top of each of the four top cartons with a lid 76, the can lids being taped or individually battened. , and the entire assembly is tightly attached for transportation.

The exact amount of carbon black in the coating emulsion is not critical. A heavy key ratio of 5 is considered to be the minimum, and the density is 1.
A high concentration of 6.5% is used.

Another embodiment of the invention is shown in FIG. Instead of starting from raw material placed within a paperboard carton cavity, a conventional paperboard carton 80 is used, which is lined and partitioned with coated paperboard inserts to create a carbon black enclosure on its own.

8r! As shown in FIG.
The inner liner 82 is coated on its top surface with the carbon black specified above.
0 on the bottom wall with the carbon black side (indicated by the dots) facing up.

Once the bottom liner is in place, the partition 84 is then inserted into the container. The partition is typically characterized by a plurality of intersecting frames, and has horizontal beams 86 (
5 frames) and crossbeams 88 (4 crossbeams) are arranged to provide a short end distribution, 92, between which ends, 92 is the opposite side of the paperboard carton 80, as shown in FIG. Acts as a spacer when engaging the wall.

The outer surfaces 86A188A of the frame and stringer of the partition 84 need not be coated with carbon black, but the inner surfaces 86B
, 88B need to be so coated (indicated by dots) that each chamber 94 in FIG. 10 is defined by a five-sided carbon black enclosure containing a bottom lining 82 defining the bottom wall of the chamber. Ru.

The printed circuit board is easily damaged by static electricity.
4 (12 pieces), and the container TA section is then covered with the second lining, 81! It is flipped closed, the carbon black side facing downwards, completing twelve six-sided enclosures that encapsulate the printed circuit board completely inside the carton 8o. As shown in FIG. 11, the filled carts/carts are stacked on top for inventory or transportation. If desired, the top wall or lid may be in the form of a cap instead of a flat insert lining 82.

FIG. 12 shows another inexpensive embodiment in which the invention is practiced without the need to raise paperboard cartons from carbon black coated raw material. Also, the existing flat paperboard carton 100 is lined with the entire bottom wall lining 82 so that the carbon black coated side faces upward. Then, fold the cart so that there are two side walls of Y 100, and four sides corresponding to the end walls, and one inner lining of 10
2 is inserted vertically into the carton lOO. As shown in FIG. 12, the inside of the lining 102 is coated with carpump thick as indicated by the dots. A partition 104 having an internally fitted frame and stringers and coated with carbon black on all front faces is then placed inside the lining 102 and the first
In the example shown in Figure 2, there are 12 compartments in the carton.
Each of them exhibits a five-sided carbon black enclosure, which is finally closed on one lower side with a closure lid coated with carbon black as described above.

[Brief explanation of the drawing]

Figure 1 shows carbon black dispersed on the plane of laminated paperboard.
Fig. 2 is an illustration of the construction of a laminated paperboard using a web covered with paper, Fig. 3 is an illustration of the construction of a partition plate, and Fig. 4 is an illustration of preparation for separation from the laminate. Figure 5 is a fragmentary plan view of the carton material that has been cut and cut, Figure 5 is a fragmentary plan view of the carton partition assembly prepared for separation from the applicable & 8 is a perspective view of the top surface of the carton, FIG. 9 is a perspective view of another embodiment, FIG. 10 is a top view of the embodiment of FIG. 9, and FIG. 11 is a perspective view of the top surface of the carton. FIG. 12 is a perspective view of a stack of cartons in the illustrated embodiment; FIG. 12 is a perspective view of an alternative embodiment; 10... Laminate plate, 12.14... Roller, 16.
... Gutter, 18... Row y-, z... Web, 22
Paperboard, 24... pleats, ah... roll, 32.34
...web, 36...fold, 38...fold line 1.
40...groove, 42...cutting line, 44.46...panel, 48, sword...fushitsubu, 52...tab, ω・
・・Carton, 62・・Partition, control・・Material, secretion・
・Frame, 68...Stringer, 70...Cart 7, 7
2.74...container, 76...lid, (fund)...cart/, 82...liner, 84...partition, 86, wing...cross beam, 86A188A...outer surface, 86B, 88
B... Inner surface, 90.92... End, 94... Small chamber, 100... Carton, 102... Liner, 1o
4... Partition.

Claims (1)

[Claims] In containers for protecting articles that may be destroyed by electrostatic discharge, the surface of a paperboard consisting of corrugated pleats between two webs is applied to a surface of approximately 2.3 to 6 ohms/cm.
An emulsion of carbon black particles with a measured volumetric resistance of m is applied to form a five-sided enclosure with one side open, and the open side is also formed with corrugated pleats interposed between two webs, and the surface A container characterized by having a lid end made of paperboard coated with the same carbon black as above.