JP2953391B2 - Chip-type electronic component storage board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip-type electronic component storage board (also referred to as a paper carrier tape) used for a carrier of a chip-type electronic component (hereinafter referred to as a chip component) used for a printed circuit board of electronic equipment.

[0002]

2. Description of the Related Art A chip-type electronic component storage board (hereinafter referred to as a storage board unless otherwise specified) is usually processed as described below and plays a role as a carrier.

[0003] A slit is formed to a width of 8 mm. Approximately 1-3 mm square holes (holes for accommodating chip parts, hereinafter referred to as cavities), and round holes having a diameter of about 1.5 mm (holes for feeding a carrier tape in a filling machine, hereinafter referred to as feed holes).
Open. Hereinafter, this drilling operation is referred to as punching. Adhere the cover tape to the back (bottom side) of the paper. Fill chip components. A cover tape is adhered to the paper surface (front side = top side). It is wound around a cassette reel having a diameter of about 5 cm and shipped together with chip components (see FIG. 1). At the end user, peel off the top side cover tape and take out the chip parts.

[0004] Because of its use as described above, the quality required of the storage board is to have smoothness on the surface of the paper so that the cover tape can be adhered well and to have strength enough to withstand various kinds of processing on the paper. And that the filled chip components are not adversely affected.

[0005] Among them, one of the points that is easily pointed out as a quality defect of the storage board is insufficient strength. It is necessary to perform slit processing and thereafter, the storage board must have a width of 8 mm to cope with various loads. However, since the storage board has a maximum thickness of about 1 mm, there are cases where the storage board peels off in the thickness direction. When peeling occurs, it leads to a serious disadvantage that chip components spill. Therefore, quality control for peeling is an important management item for storage mount manufacturers, slit manufacturers, and chip component manufacturers. The reason for the occurrence of the peeling is not limited to the strength of the storage board itself, but also involves the complexity of the above-described processing and its steps.

Here, in order to deepen the understanding of the present invention, the processing for processing the storage board will be described in detail. Processing is mainly performed by slit manufacturers and chip component manufacturers. Among them, the processes after the chip component filling step (described above) are performed by the chip component manufacturer, but there is no clear category among the manufacturers regarding the pre-process. Therefore, there are various cases, such as a case where a slit maker slits to 8 mm and then delivered to a chip component maker, or a case where it is delivered after performing processes up to punching and bonding a cover tape on the back surface. Further, the size of the cavity for performing the punching process also differs depending on the size of the chip to be filled. From this, the quality required of the storage board may differ depending on the maker or the processing conditions, and at present, the storage board supplier maintains the strength quality at a high level.

Another important point in the processing of the backing paper is that the paper transport form delivered from the slit maker to the chip component maker is a record winding (8 mm slit paper in a paper tube having a diameter of about 10 cm on the same surface). Winding method and traverse winding (diameter less than 20cm, width about 10cm)
(A system in which an 8 mm slit paper is spirally wound around a paper tube). In particular, in recent years, traverse winding has been frequently used. Due to the winding shape of the record winding, the winding length per one 8 mm slit product is several hundred m, whereas the traverse winding can obtain several thousand m, and depending on the thickness of the storage board, a winding length of 4000 m or more. In the filling process of the chip component manufacturer, the joint work between the used winding and the newly used winding is performed by the operator, and the introduction of traverse winding is indispensable for speeding up the filling process and improving operation efficiency. Things.

However, when considering the load on the storage board, the traverse winding process applies a greater load than the record winding process. Because it is wound on the same surface in the case of record winding, a load is mainly applied to the paper in the traveling direction (one-dimensional direction). However, in the case of traverse winding (a), the paper is wound in a spiral shape. Vertical direction) and width direction (horizontal direction of paper)
Such a load is applied two-dimensionally. (B) Since the paper tube turns and winds at both ends in the width direction, a three-dimensional load is applied. In particular, in order to wind the paper in a spiral shape, the paper tube is slid in the width direction while winding the paper (bobbin traverse method, see FIG. 2), or the paper is wound while being moved in the width direction of the paper tube by a guide ( The load on the paper, such as the guide traverse method (see FIG. 3), appears as a so-called “ironing load”. Also, applying an ironing load to thick paper leads to the application of a "shear load" inside the paper. Therefore, it is a fact that, with the frequent use of the traverse winding, the occurrence of peeling of the 8 mm slit paper is often recognized. The large load caused by the ironing (shear) load not only causes peeling in the traverse process, but also in the punching process in the subsequent process, the occurrence of peeling and breakage, and the occurrence of roughness in the punched cross section, causing a large amount of paper dust. Is also connected. If paper dust adheres to the miniaturized chip component, it leads to poor adhesion to the printed wiring board, which is a fatal defect. In particular, when the thickness of the backing paper was 0.75 mm or more, the occurrence of these defects was remarkable.

On the other hand, thick paper such as a backing paper
It consists of a so-called paperboard manufacturing method by laminating multiple layers.
It is a well-known fact that in the case of paperboard, peeling is likely to occur due to its structural reasons. Therefore, it is necessary to have a very high level of quality design and manufacturing technology to have a thickness of about 1 mm at the maximum and a shape capable of withstanding an ironing (shear) load with a width of 8 mm like a storage board. In the general paperboard manufacturing method, pulp used is beaten, and chemicals that have paper-strengthening effects such as starch and polyacrylamide are internally added to each layer to increase the strength in the layers, and to increase the paper strength between layers. It is customary to spray a chemical to increase the interlayer strength and take measures against peeling. Each of the above-mentioned strength improving methods is a strength developing method corresponding to an increase or compensation of so-called inter-fiber bonds (hydrogen bonds). Heretofore, when the storage board was used in a record winding, a sufficient method of improving the strength in accordance with the above-mentioned fiber-to-fiber bonding could sufficiently cope.

[0010] However, it has been difficult to use a traverse winding, which is a severer operating condition, by a method of developing strength in accordance with inter-fiber bonding. This is because not only the strength factor, but too much beating treatment causes operational problems (such as a decrease in paper machine speed) due to a decrease in drainage of the pulp. If a large amount of chemicals is used, stains occur in the papermaking process,
Various problems occur, such as the occurrence of defects in products, a decrease in production efficiency, and an increase in organic pollutants in papermaking wastewater. Therefore, a method of developing strength suitable for use conditions and a method of manufacturing a storage board according to the method were required.

[0011]

DISCLOSURE OF THE INVENTION The present inventors have found that a product having a sufficient function as a carrier (particularly maintaining strength) even if the treatment is performed under severe use conditions called traverse winding in the production of a storage board. To provide In particular, since the manufacture of a backing sheet that can withstand the ironing (shear) load also prevents the induction of other quality defects (paper breakage, generation of paper dust, etc.), we propose a new paper strength expression method and a production method equivalent thereto. Is what you do.

[0012]

In order to solve the above problems, the present invention employs the following constitution. That is, the present invention
"A chip-type electronic component housing characterized in that it is a multilayer paperboard having a thickness of 0.75 mm or more, has a smoother surface smoothness of 70 cm or less, and has a coefficient of weight variation of 1.250% or more. Mount ". Here, the paper weight variation coefficient is a value measured according to the method described below in <Evaluation Method of Each Test> and calculated by the equation (1). The smoother smoothness is defined as JAPA
N TAPPI No. 5A.

To increase the weight variation coefficient is to break the so-called formation. Although it was mentioned earlier that a large amount of squeezing load is applied during the use of the storage board, the present inventors have conducted intensive research on a method of developing strength capable of withstanding squeezing (shear) load. It has been found that breaking the formation, that is, increasing the weight variation coefficient, is extremely effective for developing the strength. In particular, non-uniform sheet formation called crushing formation is most effective. Performing non-uniform sheet formation in the production of paper and paperboard is different from ordinary common sense. This is because it is an essential condition to maintain a constant weight (USP) in order to maintain a high level of processing suitability, including printability of paper and paperboard. In other words, it is a known fact that the weight variation coefficient of paper is reduced.
There is no case in which the quality is secured by making the paper texture uneven as in the present invention.

The reason why the strength against ironing load (hereinafter referred to as ironing strength) is developed in the formation of paper will be described below. In the proposal of the present invention, a method for evaluating the ironing strength (hereinafter referred to as ironing test) is greatly proposed. Had an effect. Although the ironing test shown in the present invention is based on an original idea, it has an extremely high correlation with the occurrence of peeling of a paper carrier having a width of 8 mm actually subjected to traverse winding. Further, by performing a test before processing the storage board, the occurrence of peeling was prevented beforehand. Here, in order to deepen the understanding of the ironing test of the present invention, a conventional test method for peeling will be described.

Until now, measurement of the peel strength of paper and paperboard has been conducted by Japan
AN TAPPI No. 18 (so-called Z-axis strength) and JAPAN TAPPI
No. A tensile load is applied in the Z-axis direction of the paper as in a method for testing the peel strength (so-called peel strength) shown in FIG.
A static strength measurement method for reading a strength value at the time of breaking is performed. However, in these test methods, the load direction applied to the test piece is different from the ironing (shear) load applied in practical use of the storage board, so that it is difficult to predict the occurrence of peeling particularly by measurement before processing. . Recently, a sample with an adhesive tape attached to both sides of the paper, like an internal bond tester (Kumaya Riki Kogyo Co., Ltd.), is adhered to a holder and an aluminum angle, and an impact is applied with a hammer that is swung down from a certain angle. Dynamic tester and delamination tester (SMT JTC 9000ST) for measuring the strength of the part that peels off together with the aluminum angle
As described above, there is a commercially available apparatus for measuring and analyzing a peel resistance generated when a paper layer is divided by passing a sample partially adhered with an adhesive tape between two rollers rotating at a constant speed. However, even these strength measurement methods are not test methods in which a two-dimensional or three-dimensional ironing load is applied as a shear load inside the paper.

The ironing test method used in the present invention will be described below. FIG. 4 shows a schematic diagram of the ironing test apparatus invented. A piece of paper taken 8 mm in the horizontal direction and 54.5 cm in the vertical direction was joined at both ends in the vertical direction to form a circle, and fitted between the rolls (each 13.5 cm in width) as shown by the broken line in FIG. Thereafter, the drive roll is operated while applying a load to the rubber roll. The other rolls rotate in conjunction with each other, and the test sample also goes around between the rolls. In addition, a metal roll (diameter 116
mm) slides 35 mm at a time in the width direction of the paper, so that a strong ironing stress is applied to the test sample two-dimensionally and three-dimensionally between A → B and B → C in FIG. In addition, A → B in FIG.
As shown between the points, at point A, compressive stress is applied to the metal roll side (inside of the test sample), and tensile stress is applied to the opposite side of the metal roll (outside of the test sample). However, at point B, opposite stresses are applied. Therefore, as a result of being squeezed by the metal roll and the rubber roll at the intermediate point between AB, a shear stress is applied to the test sample. It has been found that the above stress is applied to the paper, and finally peeling occurs between the paper layers or within the layers. The evaluation of the test sample was performed by the number of rounds until peeling occurred. For example, even in the test piece having the same Z-axis strength, different strengths were shown in the present ironing test. The relationship between the ironing strength, the Z-axis strength and the occurrence of peeling in practical use in the present invention will be described in detail in Examples.

An important factor in the ironing test shown in the present invention is the location of the rubber roll disposed on the two types of metal rolls, as well as the sliding of the metal roll. For example, even if a rubber roll is placed on one of the metal rolls and a "ironing load" is applied to the test sample, it is difficult to apply as a shear load and no peeling occurs. In order to cause peeling, another (third) roll arrangement is required between two adjacent rolls. In the case of the present invention, a rubber roll was selected in consideration of adhesion to a metal roll or a test sample.

It is also important to specify where the peeling occurs in the thickness direction of the test sample, but various portions occur. However, it is extremely rare that peeling occurs between the surface layer and the back layer of the test sample and between the layers, and even if peeling occurs, the number of laps required before that is large, and furthermore, peeling in actual use It is considered that it is easy to concentrate near the middle side in the thickness direction, taking into account the situation of occurrence of cracks. When a test sample is formed in a circular shape, it is also an important factor whether the front surface or the back surface of the sample is outside. This is because the location where peeling occurs differs due to the difference. In this case, it is necessary to match with the peeled portion generated in the actual traverse winding process. However, since the technical factors of the respective slitter makers are also greatly related, they are not particularly limited here.

As described above, a unique ironing test in which shear stress is applied was devised, and as a result of evaluating each of the mounting sheets having different manufacturing methods, the ironing strength was strong, that is, a method of developing strength that does not cause peeling in practical use, and a method of manufacturing the same. Found that a method completely different from the conventional method of reinforcing the in-layer and inter-layer strength in which peeling was prevented by a record winding was effective. That is, the formation of the paper is broken, and in particular, the formation of the crushed paper is formed to increase the weight variation coefficient. This method is particularly effective in the production of a multilayer paperboard such as a backing paper. Performing lamination as described above merely bonds the formed fiber sheets with a chemical that supplements the interfiber bonds. Therefore, it is impossible to maintain a sufficient strength under an ironing (shear) load by a conventional method which aims at uniformly producing each fiber sheet. In general, when a two-dimensional or three-dimensional load is applied to a paper, compared to when a one-dimensional load is applied to the paper (for example, Z-axis strength), the paper is extremely brittle in the sense that it undergoes irreversible shape change or breakage. Have. This can be explained, for example, by the phenomenon that the paper is bent when the paper is bent, and the fact that the thick paper such as the backing paper easily breaks and peels inside the paper. Therefore, with respect to an ironing (shear) load applied two-dimensionally and three-dimensionally, it is necessary to form the inside of the paper, that is, each layer alone and its bonding surface three-dimensionally, to generate structural strength. .

[0020]

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a paperboard having a thickness of 0.75 mm or more. According to the research results of the present inventors, when the thickness of the paper is less than 0.75 mm, the possibility of occurrence of peeling due to an ironing (shear) load is extremely low, and it is determined that the strength developing method described here is not necessary.

The paperboard of the present invention has a paper weight variation coefficient of 1.
It is required to be 250% or more. The weight variation coefficient referred to in the present invention means a paper weight variation coefficient measured by the measuring method described in <Evaluation Method of Each Test> in the section of “Examples” described later. Next, a formation forming method suitable for manufacturing the storage board of the present invention will be described. As described above, in the production of a multi-layered paperboard, the principle is that the wet sheet of each layer formed on a wire is sequentially transferred to a felt and laminated, although there is a difference in a paper machine. It is preferable that the formation method in the present invention is formed by a wire part of a paper machine. In particular, it is important to form each layer at the joining portion. The formation principle of the wire part is as follows.

A wet sheet formed on a wire of a circular or fourdrinier paper machine is transferred onto a felt by a coach roll or a forming roll. The formation of the formation is influenced by the uniform fiber distribution on the wire and the degree of dewatering.
In particular, dewatering has a strong relationship with the formation of the formation desired in the present invention, and when the wet sheet contains a large amount of water and passes through a couch roll or a forming roll, a crushed formation is likely to occur. Therefore, the operation of adjusting the water content of the wet sheet formed on the wire is particularly important. It has some influence on the type of pulp, drainage, the amount of internal chemicals, and the amount of chemicals sprayed between layers, but the most influential is the papermaking conditions in the paper machine. For example, the water level of the vat in a round paper machine, the degree of dehydration in a foil or a vacuum in a fourdrinier machine, and the like. In addition, common items include increasing the speed of the paper machine and decreasing the drainage improver. However, there are conditions corresponding to the characteristics of the paper machine, and the present invention is not particularly limited.

As described above, in the present invention, the formation of strength against an ironing (shear) load is performed by making the formation non-uniform, but this operation is performed on the surface layer and the back layer of the storage board which is a multilayer paperboard. Absent. As mentioned earlier, the reason for this is that chip component storage mounts require a smoothness to adhere the cover tape to the mount, and that peeling is unlikely to occur in the surface layer, the back layer, and between those layers. Did
There is nothing particularly necessary. Therefore, in the storage board of the present invention, the formation of a uniform formation is intended for the surface layer and the back layer. Particularly on a surface where smoothness is important, it is assumed that a smoother smoothness of 70 cm or less is satisfied. The surface layer (front layer) referred to herein is a layer that forms the outermost layer on the surface (front side) of the paper among the layers of the multilayer paperboard. The back layer is a layer that forms the outermost layer on the back side.

In the present invention, the smoother smoothness of the paper surface needs to be 70 cm or less. The smoother smoothness was set to JAPAN TAPPI No. Measured by 5A. The reason for setting the smoothness standard only on the surface of the paper is a method of using the storage board. As described above, the cover tape is adhered to the backing paper on the front surface (top tape) and the back surface (bottom tape) of the paper, but only the top tape is peeled off by the end user to take out the chip components. Therefore, the top surface of the storage board is required to have good adhesiveness of the top tape, but in addition, the top tape is also required to be peelable. It is also an important factor that when the top tape is peeled off from the backing paper, that the paper itself does not peel off and that the fibers do not fluff.
The suitability of the top tape for adhesion and peeling depends on the surface treatment of the backing sheet and the quality design of the top tape in consideration of the above, but the first condition is that the backing sheet has a smooth surface. Becomes However, the bottom tape is required only to maintain good adhesiveness, and the quality design of the bottom tape and the bonding conditions of the bottom tape are applied so as to have sufficient adhesiveness. For this reason, although a certain degree of smoothness is required for the back surface of the storage board, at present it is not necessary to have a fine smoothness like the front surface. (However, this is not the case under the circumstances where the back surface of the storage board also needs to be minutely smooth for the purpose of recycling used paper.)

[0025]

Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited by these examples. Unless otherwise specified, the blending percentages, addition percentages and weights in the examples are weight percentages in terms of solid content. The paper made for all the examples is JIS P 8111
After performing the pretreatment according to the above, the ironing strength, the Z-axis strength, the smoother smoothness, and the coefficient of variation of the weight by the ironing test were measured. Further, an 8 mm slit with a slitter, a punching process, and a cover tape were actually bonded, and after the punching process, the presence or absence of peeling and the adhesion of the top cover tape were confirmed. The method of performing each test will be described later.

<Example 1> Pulp is selectively used for the surface layer, the middle layer and the back layer, and the surface layer is made of 100% virgin pulp and CSF.
(Canadian Standard Freeness) 400ml, CSF 350ml for the middle layer containing 40% virgin pulp, 20% high quality waste paper pulp, and 40% newspaper waste pulp, and 400ml CSF for the back layer containing 50% virgin pulp and 50% newspaper waste pulp. Prepared. In addition, P
After adjusting to H 6.0, 0.3% of polyacrylamide was added as an internal paper strength enhancer. Using the pulp treated under the above conditions, a multilayer paperboard having a thickness of 0.95 mm was formed. At this time, the paper weight variation coefficient was adjusted to 1.252% in the wet part of the paper machine. The smoother smoothness of the surface was 55 cm. In addition, a starch aqueous solution is sprayed between the layers in the wet part of the paper machine, and a total of 9 g / m
I tried to be ² . The results are shown in Tables 1 and 2. (All the following Examples and Comparative Examples are collectively described in Tables 1 and 2.

<Example 2> Paper was produced under the same conditions as in Example 1 except that the paper weight variation coefficient was 1.549% in the wet part of the paper machine. At this time, the smoother smoothness of the surface was 56 cm.

<Example 3> The paper was manufactured under the same conditions as in Example 1 except that the weight variation coefficient of the paper was 1.730% and the smoother smoothness of the surface was 67 cm in the wet part of the paper machine. Was prepared.

Example 4 A multilayer paperboard having a thickness of 0.75 mm was formed, and the weight variation coefficient of the paper was 1.310% in the wet part of the paper machine, and the smoother smoothness of the surface was 58c.
All conditions were the same as in Example 1 except that m was used.

Example 5 The same conditions as in Example 4 were used except that the paper weight variation coefficient was 1.635% in the wet part of the paper machine.

<Example 6> The paper was manufactured under the same conditions as in Example 4 except that the weight variation coefficient of the paper was 1.965% and the smoother smoothness of the surface was 69 cm in the wet part of the paper machine. Was prepared.

Comparative Example 1 The pulp of the surface layer, the middle layer and the back layer was 100% virgin pulp, and the weight variation coefficient of the paper was 1.195% in the wet part of the paper machine. Paper was made under the same conditions as described above. At this time, the smoother smoothness of the surface was 56 cm.

Comparative Example 2 Paper was produced under the same conditions as in Example 1 except that the CSF of the middle layer was set to 320 ml and the coefficient of variation in paper weight was set to 1.211% in the wet part of the paper machine. did. At this time, the smoother smoothness of the surface was 55 cm.

Comparative Example 3 The addition percentage of the internal paper strength agent was 0.5
%, And the paper was made under the same conditions as in Example 1 except that the weight variation coefficient of the paper in the wet part of the paper machine was 1.220%. At this time, the smoother smoothness of the surface was 56 cm.

<Comparative Example 4> A starch aqueous solution was sprayed between the layers in the wet part of a paper machine, and a total of 12 g between the layers was used.
/ M ² , and paper was made under the same conditions as in Example 1 except that the weight variation coefficient of the paper was 1.200%. The smoother smoothness of the surface at this time was 57 cm.

<Comparative Example 5> The middle layer CSF was 300 ml,
The amount of the aqueous starch solution sprayed in the wet part of the paper machine was 15 g / m ^{2 in} total between the layers, and the coefficient of variation in paper weight was 2.
Paper was made under the same conditions as in Example 1 except that the paper was 309. At this time, the dewatering property of the middle layer wire part was significantly reduced, the influence was exerted on the paper surface, and the smoother smoothness was reduced to 76 cm or more.

Comparative Example 6 Example 4 was repeated except that the pulp of the surface layer, the middle layer, and the back layer was all 100% virgin pulp, and the coefficient of variation in paper weight was 1.203% in the wet part of the paper machine. Paper was made under the same conditions as described above. The smoother smoothness of the surface at this time was 58 cm.

<Comparative Example 7> Paper was produced under the same conditions as in Example 4 except that the CSF of the middle layer was 320 ml and the coefficient of variation in paper weight was 1.200% in the wet part of the paper machine. did. At this time, the smoother smoothness of the surface was 59 cm.

<Comparative Example 8> The addition% of the internal paper strength agent was set to 0.5
%, And the paper was made under the same conditions as in Example 4 except that the weight variation coefficient of the paper was 1.204% in the wet part of the paper machine. The smoother smoothness of the surface at this time was 58 cm.

<Comparative Example 9> A starch aqueous solution was sprayed between the respective layers in the wet part of a paper machine, and a total of 12 g was measured between the respective layers.
/ M ² , and paper was made under the same conditions as in Example 4 except that the weight variation coefficient of the paper was 1.213%. At this time, the smoother smoothness of the surface was 59 cm.

Comparative Example 10 The CSF of the middle layer was 300 m
1, all the same as in Example 4 except that the amount of the aqueous starch solution sprayed in the wet part of the paper machine was 15 g / m ^{2 in} total between the layers and the weight variation coefficient of the paper was 2.415%. Paper was made under the conditions. At this time, the dewatering property of the middle layer wire part was significantly reduced, the influence was exerted on the paper surface, and the smoother smoothness was reduced to 76 cm or more.

<Comparative Example 11> A paperboard having a thickness of 0.60 mm was formed into a paperboard, and the weight variation coefficient of the paper was 1.200% and the smoother smoothness of the surface was 58 in the wet part of the papermaking machine.
All conditions were the same as in Example 1, except for the cm.

<Evaluation method for each test> Ironing strength Cutting was performed with a hand-held cutter (DAHLE 567 type paper cutter) to a width (horizontal direction of paper) of 8 mm × length (vertical direction of paper) of 54.5 cm. The ironing test shown in the present invention was performed. In the test using the same testing machine, a load of 1.8 kg was applied to the rubber roll. The test sample was 1.6 sec. / 1 orbit. The ironing strength was indicated by the number of times the test sample circulated between the rolls.

Z-axis strength JAPAN TAPPI No. Performed according to 18.

Smoother smoothness JAPAN TAPPI No. 5A.

Paper Weight Variation Coefficient The paper thus formed was taken 8 mm wide (horizontal direction of paper) × 120 cm long (longitudinal direction of paper) and punched out sequentially with a punch having a diameter of 6 mm inside. The punched small piece sample was set so that the center point between adjacent circles was 11 mm apart. 100 samples punched out by the above method were measured with an electronic balance capable of measuring up to four digits after the decimal point, and the variation in weight was represented by a coefficient of variation (CV) according to the following equation (1). This is referred to as “weight variation coefficient”. Equation (1): Coefficient of variation CV (%) = (S / X) × 100 However, in equation (1), S represents a standard deviation and X represents an average value.

Confirmation of Peeling and Adhesion of Top Cover Tape From base paper made under each papermaking condition, width 167 mm, length 20
Twenty-five traverse windings having a length of 2000 m were produced by taking up a winding of 00 m and slitting it to 8 mm with an actual machine slitter. One of the rolls was subjected to a punching treatment and a cover tape bonding by a punching machine, and actual peeling and adhesion of the cover tape were confirmed. Nitto Kogyo Co., Ltd.
PM-1200 type (punching and bottom tape bonding) and TST-1200 type (top tape bonding)
Used in the unit. The punching process uses a mold that can open two pockets with a single punch in a square hole (cavity) of 2.30 mm in the width direction of the paper and 1.60 mm in the length direction and a round hole (feed hole) of 1.55 mm in diameter. And 1600 /
min. I went in. The bottom cover tape is adhered to the tape by No. Nitto Denko Corporation. 318H-6P, bonding temperature 190 ° C., speed 6.4 m / min. The top cover tape was adhered to the tape by No. Nitto Denko Corporation.
318H-14A at a bonding temperature of 160 ° C. and a speed of 4.3 m /
min. I went in. In addition, NPM-
Model 1200 was operated by intermittent operation as appropriate. The peeling and the adhesion of the top cover tape were all performed visually, and the peeling was confirmed by observing the peeled portion in the thickness direction of the paper and determining the following mode. A: No peeling occurred. B: Peeling with a length of 2 cm or less occurred in three places or less. C: Peeling with a length of 2 cm or less occurred at four or more locations. D: Peeling of 2 cm or more in length occurred. The adhesiveness of the top cover tape is measured by observing the part that does not adhere to the paper (the part where the top tape floats) in a state where the light is applied perpendicularly to the thickness direction of the paper. went. a: No top tape floating. b: Top tape floating occurred at 5 places or less. c: Top tape floating occurred at 6 to 10 places. d: Top tape floating occurred at 11 or more locations.

[0048]

[Table 1]

[0049]

[Table 2]

[0050]

According to the method for developing ironing strength of paper shown in the present invention, when the weight variation coefficient is 1.25% or more, the thickness is 0.7.
It is possible to supply a product that has sufficient strength with a multi-layered storage board with a thickness of 5 mm or more and that can respond to traverse processing in the processing stage of the storage board and does not cause problems such as peeling. did it. In addition, by setting the smoother smoothness of the surface to 70 cm or less, it was possible to maintain good adhesion of the cover tape. The use of the paperboard having the suitability as the storage board described above for storing, storing, and transporting chip components makes it possible to cope with an increase in the speed of operation and an improvement in operation efficiency at chip component manufacturing and use manufacturers. Also, as shown in the examples, the proposal of a new strength expression method enables the use of wastepaper pulp, which is generally considered to have low strength, to be possible at a high level, and is expected to play a social role such as global environmental problems.

[Brief description of the drawings]

FIG. 1 is a diagram of winding a cassette reel in a method of using a chip component storage board.

FIG. 2 is a conceptual diagram of a bobbin traverse method.

FIG. 3 is a conceptual diagram of a guide traverse method.

FIG. 4 is a schematic diagram of an ironing tester.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-249300 (JP, A) JP-A-5-81065 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B65D 85/86 D21H 27/00

Claims (1)

(57) [Claims] 1. A multi-layer paperboard having a thickness of 0.75 mm or more, which is made of JAPAN TAPPI No. 5A, the smoother smoothness of the surface is 70 cm or less, and the weight variation coefficient of paper defined by the following (A) is 1.2.
A chip-type electronic component storage board characterized by being 50% or more. (A) Coefficient of paper weight variation: The paper is 8 mm in width (horizontal direction of paper) × 12 in length (vertical direction of paper).
Take 0 cm and punch out sequentially with a 6 mm diameter punch inside. In the punched sample, the distance between the center points of adjacent circles is 1
The spacing is 1 mm. 100 samples punched out by the above method are measured by an electronic balance that can measure up to four digits after the decimal point, and the variation in weight is represented by a coefficient of variation (CV) according to the following equation (1). This is referred to as “weight variation coefficient”. Equation (1): Coefficient of variation CV (%) = (S / X) × 100 However, in equation (1), S represents a standard deviation, and X represents an average value.