Carrier tape mount for chip-type electronic component and manufacturing method thereof

Abstract

To provide a carrier tape mount for chip-type electronic components that has high peel strength when a cover tape is peeled off and that suppresses fluffing from a mount surface and fluffing from a loading part, and a manufacturing method thereof; furthermore, to provide a carrier tape mount that has excellent processability and a manufacturing method thereof.SOLUTION: In a carrier tape mount for chip-type electronic components according to the present disclosure, which is a carrier tape mount for chip-type electronic components with base paper containing pulp as a main component, the pulp contained in the base paper contains at least LBKP, the mass blending ratio of LBKP to NBKP in the pulp satisfies (Equation 1), the surface of the base paper that contacts the cover tape contains polyvinyl alcohol, and the average penetration depth of the polyvinyl alcohol from the surface of the base paper that contacts the cover tape is 20 to 65 μm.(Equation 1) LBKP:NBKP=65-100:35-0.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a carrier tape base paper for chip-shaped electronic components and a method for manufacturing the same. More specifically, the present disclosure relates to a carrier tape base paper for chip-shaped electronic components having high peel strength when peeling the cover tape and suppressing kebabs from the base paper surface and kebabs from the loading part, and a method for manufacturing the same.

Background Art

[0002] Conventionally, in order to automate the production of various electronic devices, chip-shaped electronic components are automatically mounted on printed circuit boards. In the automatic mounting process of chip-shaped electronic components, chip component mounters and the like are used to supply chip-shaped electronic components one by one to a printed wiring board and automatically mount them on the printed wiring board. In this automatic mounting process, in order to easily handle chip-shaped electronic components, a taping package in which individual chip-shaped electronic components are packaged with a tape-shaped carrier is used.

[0003] The taping package is formed by forming concave or perforated loading parts (hereinafter sometimes simply referred to as "loading parts") for loading chip-shaped electronic components at regular intervals on a carrier tape base paper, loading predetermined chip-shaped electronic components into the loading parts, and then enclosing them with a cover tape. The loading parts are generally provided in a rectangular shape and may also be referred to as press pockets, pockets, cavities, etc.

[0004] The taping package loaded with chip-shaped electronic components is conveyed in a reel shape, the cover tape is continuously peeled off by an automatic machine for mounting chip-shaped electronic components, and the chip-shaped electronic components are sequentially taken out from the carrier tape base paper and automatically mounted at predetermined positions on the printed wiring board.

[0005] Carrier tape base papers are roughly classified into plastic and paper types. Paper is considered desirable in terms of manufacturing cost, non-chargeability, ease of disposal after use, etc. As paper carrier tape base papers, those made of single-layer or multi-layered cardboard are known (see, for example, Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] In the paper carrier tape base disclosed in Patent Documents 1 to 3, it is required to suppress the keba on the base surface due to the large peel strength of the cover tape. However, simply increasing the penetration depth of the agent applied to the surface does not solve the problem, and changing only the adhesion temperature, pressure, speed, etc. cannot cope with it. Also, when the peel strength is increased, it is difficult to balance the quality such as the occurrence of keba, which has become a major problem in operation. In addition, due to the miniaturization of the chip, chip discharge failure has become a problem due to internal keba during the processing of the loading part.

[0008] Drugs applied to the surface of the base paper widely use starches or water-soluble polymers such as polyacrylamide and polyvinyl alcohol. When the drug is a water-soluble polymer, the penetration depth of the water-soluble polymer affects the peel strength when peeling off the cover tape and the occurrence of kebas from the base paper in the taping package formed using the carrier tape base paper. For example, the greater the penetration depth of the drug, the greater the tendency for the peel strength to increase. However, since the presence of the water-soluble polymer on the surface of the base paper becomes smaller, there is a tendency for kebas to easily occur from the base paper. On the other hand, the smaller the penetration depth, the smaller the peel strength tends to be. However, since the water-soluble polymer is localized on the surface of the base paper, there is a tendency for kebas to be less likely to occur. Therefore, it has been required to provide a carrier tape base paper with a small occurrence of surface kebas while increasing the peel strength. In recent years, there has also been a problem of kebas occurring inside when forming the loading part, and improvement has been demanded not only for surface kebas but also for kebas inside the mounting part. The greater the penetration depth, the more effective it is in suppressing kebas inside the loading part. However, if it becomes deeper than a certain level, the water-soluble polymer diffuses too much and its effect decreases. As described above, it was important to control the penetration depth in a well-balanced manner for each problem, but it has not been clearly defined until now.

[0009] In view of such problems, an object of the present disclosure is to provide a carrier tape base paper for chip-shaped electronic components with a high peel strength when peeling off the cover tape and suppressing kebas from the base paper surface and the loading part, and a manufacturing method thereof. Furthermore, in the present disclosure, it is also an object to provide a carrier tape base paper with excellent processing suitability and a manufacturing method thereof.

[0010] Other objects and effects of the present disclosure will be easily understood by those skilled in the art by referring to the following description.

Means for Solving the Problems

[0011] In order to solve the above problems, the inventors of the present invention have found that in a carrier tape base paper for chip-shaped electronic components having a base paper containing pulp as a main component, the pulp contained in the base paper contains at least LBKP, and the mass mixing ratio of LBKP and NBKP of the pulp satisfies LBKP:NBKP = 65 to 100:35 to 0, and the surface of the base paper in contact with the cover tape contains polyvinyl alcohols, and the average penetration depth of the polyvinyl alcohols is 20 to 65 μm, so that the peeling strength when peeling the cover tape is high and the fluffing from the base paper surface and the fluffing from the loading part are suppressed, and the present invention has been completed. That is, the carrier tape base paper for chip-shaped electronic components according to the present invention is a carrier tape base paper for chip-shaped electronic components having a base paper containing pulp as a main component, wherein the pulp contained in the base paper contains at least LBKP, the mass mixing ratio of LBKP and NBKP of the pulp satisfies (Equation 1), the surface of the base paper in contact with the cover tape contains polyvinyl alcohols, and the average penetration depth of the polyvinyl alcohols from the surface of the base paper in contact with the cover tape is 20 to 65 μm. (Equation 1) LBKP:NBKP = 65 to 100:35 to 0 With such a configuration, it is possible to increase the peeling strength when peeling the cover tape and suppress the fluffing from the base paper surface and the fluffing from the loading part.

[0012] In the carrier tape base paper for chip-shaped electronic components according to the present invention, it is preferable that the pulp contains 65 to 100% by mass of LBKP. By containing LBKP as a main component of the pulp, the generation of fluffing can be further suppressed.

[0013] In the carrier tape base paper for chip-shaped electronic components according to the present invention, it is preferable that the pulp contains only LBKP and NBKP, and the mass mixing ratio of LBKP and NBKP of the pulp satisfies (Equation 2). The generation of fluffing and the decrease in strength can be minimized. (Equation 2) LBKP:NBKP = (65 or more, less than 100):(35 or less, greater than 0)

[0014] In the carrier tape base paper for chip-shaped electronic components according to the present invention, it is preferable that the pulp contains only LBKP. By containing only LBKP as the pulp, the generation of keva can be further suppressed and sufficient strength can be maintained.

[0015] In the carrier tape base paper for chip-shaped electronic components according to the present invention, the polyvinyl alcohols are preferably an anionic polyvinyl alcohol-based resin or a nonionic polyvinyl alcohol-based resin. The pulp used for the base material is anionic, and by using an anionic polyvinyl alcohol-based resin, it is possible to suppress repulsion and adsorption on the surface and penetrate. Also, by using a nonionic polyvinyl alcohol-based resin, it is possible to suppress adsorption on the pulp surface and penetrate.

[0016] In the carrier tape base paper for chip-shaped electronic components according to the present invention, a form in which the opposite surface of the surface where the cover tape of the base paper contacts contains polyvinyl alcohols is included.

[0017] In the carrier tape base paper for chip-shaped electronic components according to the present invention, in a form in which the surface where the cover tape of the base paper contacts contains polyvinyl alcohols and the opposite surface of the surface where the cover tape of the base paper contacts contains polyvinyl alcohols, the air permeability resistance of the base paper measured according to JIS P811751:2009 "Paper and Paperboard - Test Method for Air Permeability and Air Permeance (Intermediate Region) - Gurley Method" is preferably 1000 to 8000 seconds. There is a correlation between the penetration depth of polyvinyl alcohols and the air permeability resistance. When the air permeability resistance is 1000 to 8000 seconds, the peel strength increases, the keva inside the loading part is also improved, and the generation of surface keva is suppressed.

[0018] The manufacturing method of the carrier tape base paper for chip-shaped electronic components according to the present invention includes preparing a raw material slurry containing pulp as a main component, wherein the pulp contains at least LBKP, and the mass blending ratio of LBKP to NBKP in the pulp satisfies (Equation 1); a step of papermaking the raw material slurry to obtain a wet paper; a step of drying the wet paper to obtain a base paper; and a step of applying a sizing liquid containing polyvinyl alcohols on at least one side of the base paper at 0.7 to 1.8 g / m 2 2. The method further includes a step of drying the base paper coated with the sizing liquid to obtain a base paper, wherein the sizing liquid has a concentration of polyvinyl alcohols of 5 to 8% by mass, a temperature of 30 to 70 °C, and a B-type viscosity of 10 to 80 mPa·s. The base paper contains polyvinyl alcohols on the coating surface of the sizing liquid, and the average penetration depth of the polyvinyl alcohols from the coating surface of the sizing liquid is 20 to 65 μm. (Equation 1) LBKP:NBKP = 65 to 100:35 to 0

Advantages of the Invention

[0019] According to the present disclosure, it is possible to provide a carrier tape base paper for chip-shaped electronic components with high peel strength when peeling the cover tape and suppressing keva from the base paper surface and keva from the loading part, and a manufacturing method thereof. Furthermore, the carrier tape base paper of the present disclosure has excellent processing suitability.

Embodiments for Carrying Out the Invention

[0020] Next, embodiments of the present invention will be shown and described in detail, but the present invention is not construed as being limited to these descriptions. As long as the effects of the present invention are achieved, the embodiments may be variously modified.

[0021] The carrier tape base paper for chip-shaped electronic components according to this embodiment has a base paper mainly composed of pulp. Here, the main component refers to the component with the highest content in terms of mass among the components constituting the base paper. In this embodiment, it is preferable that the pulp is 90% by mass or more, and more preferably 100% by mass, among the fiber components constituting the base paper. Although there is no particular limitation on the raw pulp used for the base paper, wood pulp can be preferably used. Examples of wood pulp include chemical pulps such as softwood bleached kraft pulp (NBKP), softwood unbleached kraft pulp (NUKP), hardwood bleached kraft pulp (LBKP), hardwood unbleached kraft pulp (LUKP), mechanical pulps such as groundwood pulp (GP) and thermomechanical pulp (TMP), and wastepaper pulp such as deinked pulp. One or more selected from these raw pulps can be used. Among these raw pulps, LBKP has a fiber length that is less likely to cause keba, and the entanglement between fibers occurs moderately. Therefore, the base paper containing a large amount of LBKP suppresses the occurrence of keba and sufficient strength can be obtained. For example, it is preferable to contain 65 to 100% by mass of LBKP in the pulp slurry, more preferably 70 to 100% by mass, still more preferably 80 to 100% by mass, and most preferably 100% by mass. By setting the proportion of LBKP in the pulp to 65% by mass or more, the occurrence of keba can be further suppressed. Since NBKP has a longer fiber length than LBKP, it is an effective pulp for maintaining the strength of the base paper itself. However, on the other hand, it is more likely to be pulled out from the base paper, so it is more disadvantageous than LBKP in terms of keba generation. Therefore, the proportion of NBKP in the pulp is preferably below a certain amount, for example, 35% by mass or less. Cotton has longer fibers than NBKP and is thus more likely to be pulled out. Also, mechanical pulps such as GP and TMP have short and rigid fibers, so the fibers do not entangle with each other. Therefore, if they are contained in a large amount in the base paper, the density may decrease and the strength may also decrease. For this reason, it is preferable that the pulp does not contain pulp with longer fibers than NBKP and short and rigid pulp such as mechanical pulp, that is, the pulp contains only LBKP and NBKP. The occurrence of keba and the decrease in strength can be minimized.Furthermore, in the carrier tape base paper for chip-shaped electronic components according to the present embodiment, it is preferable that the pulp contains only LBKP. By including only LBKP as the pulp, the generation of keb can be further suppressed and sufficient strength can be maintained.

[0022] The raw material pulp is made into a pulp slurry having an appropriate beating degree using a defibrator and a beater. In the present invention, it is preferably CSF300 ml to 600 ml in terms of Canadian Standard Freeness (JIS P 8121:1995 Test Method for Drainage of Pulp). More preferably, it is CSF350 to 500 ml, and still more preferably CSF390 to 440 ml.

[0023] The pulp slurry adjusted to an appropriate beating degree is used as a raw material slurry, and a base paper of the carrier tape base paper is formed by papermaking with a paper machine. A known paper machine can be used as the paper machine. That is, papermaking can be performed with a fourdrinier paper machine, a cylinder paper machine, a hybrid former, a gap former, or the like. The structure of the base paper may be single-layer or multi-layer of two or more layers. For example, it can be three layers. When it is a multi-layer of two or more layers, for the purpose of improving the interlayer strength, starch may be applied between the layers and then papermaking may be performed. Here, the depth of the loading part preferably has the bottom surface at a position about 60 to 70% of the paper thickness. In this case, the loading part is located at a position straddling the layers. And the starch between the layers acts positively on the strength improvement and also acts in a good direction on the keb inside the mounting part. Also, in the region where polyvinyl alcohols penetrate, the generation of keb inside the mounting part can be suppressed to the same extent both between the layers and within the layers.

[0024] It is preferable to add a paper strength enhancer to the base paper. By adding a paper strength enhancer, sufficient interlayer strength can be ensured, and the occurrence of keba and creases can be suppressed. The paper strength enhancer is not particularly limited, but it is preferable to use starch, modified starch, or polyacrylamide-based resin. In particular, it is preferable to use cationic starch or amphoteric starch. Also, it is preferable to use the paper strength enhancer by adding it internally to the raw material slurry. By internally adding the paper strength enhancer, it becomes possible to suppress not only the keba on the surface but also the paper powder from the wall surface and the cut surface of the loading part of the chip-shaped electronic component. The addition amount of the paper strength enhancer is preferably 0.8 to 1.8 parts by mass, more preferably 1.0 to 1.5 parts by mass, based on 100 parts by mass of pulp. Also, as other papermaking additives, it is also possible to use internally added sizing agents, fillers, yield improvers, dyes, sulfate bands, etc. However, from the viewpoint of suppressing keba and paper powder, the filler is preferably 1 part by mass or less, more preferably 0.5 part by mass or less, based on 100 parts by mass of pulp.

[0025] The drying method of the base paper is not particularly limited, and hot air drying, infrared drying, drum drying, etc. can be used. On the paper machine, the cylinder dryer can be used alone or in combination of a plurality, and the drying temperature is preferably set as appropriate in the range of 80 to 200 °C, more preferably in the range of 80 to 160 °C.

[0026] Also, the carrier tape base paper for chip-shaped electronic components of the present invention is preferably made of neutral paper so as not to have an adverse effect such as metal corrosion on the chip-shaped electronic components loaded in the loading part.

[0027] The surface of the base paper that the cover tape contacts is one of the surfaces of the base paper. Polyvinyl alcohols are applied to at least the surface of the base paper that the cover tape contacts. Therefore, in this embodiment, by including polyvinyl alcohols on the surface of the base paper that the cover tape contacts, the surface strength of the mount paper is increased, and the adhesive of the cover tape penetrates moderately into the mount paper. As a result, the adhesion between the surface of the mount paper and the adhesive of the cover tape becomes appropriate, and the occurrence of fraying due to cover tape peeling can be suppressed. Further, by applying polyvinyl alcohols, a coating layer of polyvinyl alcohols can be formed on the surface where the cover tape contacts, compared to the case where polyvinyl alcohols are only internally contained. Therefore, fraying on the surface when using it as a carrier tape mount paper can be suppressed. As the polyvinyl alcohols, polyvinyl alcohol-based resins with any molecular weight, saponification degree, and modifying group can be used, but anionic polyvinyl alcohol-based resins and nonionic polyvinyl alcohol-based resins are preferred, and anionic polyvinyl alcohol-based resins are more preferred. As the nonionic polyvinyl alcohol-based resin, any nonionic polyvinyl alcohol-based resin such as fully saponified polyvinyl alcohol, partially saponified polyvinyl alcohol, low-saponification polyvinyl alcohol, hydrophilic group-modified polyvinyl alcohol, and alkyl group-modified polyvinyl alcohol can be used. As the anionic polyvinyl alcohol-based resin, any anionic polyvinyl alcohol-based resin such as carboxyl group-modified polyvinyl alcohol and sulfone group-modified polyvinyl alcohol can be used. The pulp used for the base material is anionic, and by using an anionic polyvinyl alcohol-based resin here, it can penetrate while suppressing mutual repulsion and adsorption on the surface. By using a nonionic polyvinyl alcohol-based resin, the effect of repelling the pulp more than an anionic polyvinyl alcohol-based resin cannot be expected, but it can penetrate while suppressing adsorption on the pulp surface. On the other hand, cationic polyvinyl alcohol-based resins may form a strong film on the surface of the mount paper, preventing the adhesive of the cover tape from penetrating and reducing the adhesiveness to the cover tape.Among water-soluble polymers, polyacrylamide-based resins do not penetrate even when applied to the surface of the backing paper and do not remain on the surface. As a result, the adhesive of the cover tape penetrates too much, increasing the adhesiveness with the cover tape but decreasing the surface strength, resulting in keba. Therefore, it is not preferable to use polyacrylamide-based resins alone. In this embodiment, polyvinyl alcohols may be applied to the surface of the base paper on the side opposite to the surface in contact with the cover tape. When polyvinyl alcohols are applied to both sides of the base paper, in the case of punching, the occurrence of keba at the loading part from the back layer is suppressed. Also, in the case of embossing, the bottom can be formed better.

[0028] In this embodiment, resins different from polyvinyl alcohols, such as polyacrylamide resins and starches, may be applied to the surface of the base paper on the side opposite to the surface in contact with the cover tape. When polyvinyl alcohols are applied only to the surface of the base paper in contact with the cover tape, curling may occur due to the asymmetry in the thickness direction. By applying to both sides, it becomes easier to suppress curling. Furthermore, as described above, when polyvinyl alcohols are applied to both sides of the base paper, the symmetry in the thickness direction becomes better, making it even easier to suppress curling.

[0029] The method of applying polyvinyl alcohols is not particularly limited, and a two-roll size press, a gate roll size press, or a metering size press can be used. Among these, it is preferable to use a two-roll size press from the viewpoints of production efficiency, processing suitability, improvement of surface strength, and improvement of paper layer strength. When polyvinyl alcohols are used alone, the coating amount of the water-soluble polymer on the surface in contact with the cover tape is preferably 0.7 to 1.8 g / m 2 in terms of solid content conversion, and 0.9 to 1.4 g / m 2It is more preferable. Polyvinyl alcohols may be mixed and used with starches and water-soluble polymers typified by polyacrylamide resins, but as long as the effects of the invention are not impaired, for example, water-soluble polymers other than polyvinyl alcohols are 20 parts by mass or less with respect to 100 parts by mass of the water-soluble polymer, preferably 10 parts by mass or less, and it is more preferable to use only polyvinyl alcohols. When polyvinyl alcohols are also applied to the surface of the base paper on the side opposite to the surface in contact with the cover tape, the coating amount of the water-soluble polymer is 0.7 to 1.8 g / m in terms of solid content. 2 It is preferably, 0.9 to 1.4 g / m. 2 It is more preferable. The coating amount on the surface of the base paper in contact with the cover tape and the coating amount on the surface of the base paper on the side opposite to the surface in contact with the cover tape are preferably equal.

[0030] Also, in this embodiment, the dried base paper may be smoothed as necessary. The method of the smoothing treatment is not particularly limited, and a machine cander, a soft calender, a super calender, etc. can be used. When heating the base paper during the smoothing treatment, it is also possible to adjust the water content rate of the base paper here.

[0031] The thickness of the carrier tape base paper varies depending on the size of the chip-shaped electronic components to be loaded. However, when forming a bottomed recess by embossing, it is preferably 50 to 550 μm, more preferably 250 to 500 μm. When forming a through hole by punching, it is preferably 280 to 1200 μm, more preferably 500 to 1200 μm. The loading part of this thickness class is 0.6×0.3 mm or 0.4×0.2 mm square and is very small and light, so chip discharge failure is likely to occur, and suppression of burrs inside the loading part is required. Since it is also effective for countermeasures against burrs inside the loading part according to the present invention, it is particularly effective for a base paper provided with a loading part of 0.4×0.2 mm.

[0032] The penetration depth of polyvinyl alcohols into the base paper shall be 20 to 65 μm, preferably 25 to 60 μm, and more preferably 25 to 45 μm. If the penetration depth is less than 20 μm, although the surface fluff is good, the peel strength is small, and there is a risk that fluff will occur inside the loading part, making it difficult to discharge the loaded material. If the penetration depth exceeds 65 μm, the peel strength will increase and the fluff inside the loading part will also be good, but the surface fluff will deteriorate, leading to the risk of paper dust mixing, etc. Here, regarding the fluff inside the loading part, if it exceeds 80 μm, the distribution of polyvinyl alcohols will be low, so it tends to deteriorate. Here, the penetration depth can be estimated by measuring the air permeability resistance of the base paper. That is, when polyvinyl alcohols are localized on the surface of the base paper, the air permeability resistance is high, and when the distribution becomes sparse by penetration, the air permeability resistance is low. For example, the air permeability resistance of the base paper is preferably 1000 to 8000 seconds, more preferably 1500 to 6000 seconds, and most preferably in the range of 2000 to 3000 seconds.

[0033] The penetration depth can be controlled by the viscosity of the surface sizing liquid containing polyvinyl alcohols. The viscosity of the sizing liquid can be controlled by the concentration of polyvinyl alcohols in the sizing liquid, the molecular weight of polyvinyl alcohols, and the sizing liquid temperature. If the concentration of polyvinyl alcohols is lowered, the viscosity will decrease. The concentration of polyvinyl alcohols in the sizing liquid is preferably 5 to 8%, and preferably 6 to 7%. If the molecular weight of polyvinyl alcohols is lowered, the viscosity will decrease. The molecular weight of polyvinyl alcohols is preferably 300 to 2500. If the temperature of the sizing liquid is increased, the viscosity will decrease. The temperature of the sizing liquid is preferably 30 to 70 °C. The viscosity of the sizing liquid can be measured with a B-type viscometer. The B-type viscosity of the sizing liquid is preferably 10 to 80 mPa·s, and more preferably 15 to 70 mPa·s. In addition to viscosity, the penetration depth can also be controlled by the ionic nature of polyvinyl alcohols. If it is anionic, the penetration depth will increase, and if it is cationic, it will be easy to fix to the pulp of the base paper, so the penetration depth will decrease. Incidentally, the penetration depth of polyvinyl alcohols can be measured by staining with iodine and observing the cross-section.

[0034] The taping package is manufactured through, for example, a raw material manufacturing process, a slitting process, a loading portion forming process, a chip loading process, and a chip encapsulation process. The raw material manufacturing process is generally often carried out by a paper manufacturing company, and it is a process in which paper serving as a carrier tape base paper is manufactured and wound into a roll-shaped raw material with a width of 500 to 3000 mm. The slitting process is generally often carried out by a slitting processing company, and it is a process in which the raw material is slit into a width suitable as a carrier tape base paper (for example, a width of 8 mm). Here, generally, it is not directly slit from the raw material into a width suitable as a carrier tape base paper, but rather it is first slit into a predetermined width (for example, a width of 70 to 170 mm) (referred to as primary slitting), and then slit into a width suitable as a carrier tape base paper (referred to as final slitting). Note that the number of primary slittings may be not only once but also divided into two or more times. The loading portion forming process is generally often carried out by a slitting processing company following the slitting process, and it is a process in which loading portions are formed at regular intervals on the carrier tape base paper that has undergone final slitting. The chip loading process and the chip encapsulation process are generally often carried out by an electronic chip manufacturing company, and it is a process in which predetermined chip-shaped electronic components are loaded into the loading portions and then encapsulated with a cover tape.

[0035] The carrier tape base paper for chip-shaped electronic components according to the present embodiment forms loading portions for loading chip-shaped electronic components at regular intervals. After loading the chip-shaped electronic components into the loading portions, it is encapsulated with a cover tape and used as a carrier tape for chip-shaped electronic components (also referred to as a taping package). The loading portion may be either a bottomed recess formed by embossing or a through hole formed by punching. In the case of a through hole, a bottom tape is attached to one surface of the carrier tape base paper to close one hole of the through hole and form the loading portion.

[0036] In the case of the bottomed recess formed by embossing, the depth of the loading portion preferably has its bottom surface at a position about 60 to 70% of the paper thickness. If the thickness of the carrier tape base paper is, for example, 215 to 585 μm, the depth of the loading portion is 150 to 350 μm. In the case of the through hole formed by punching, it is equal to the thickness of the carrier tape base paper, for example, 280 to 1200 μm.

[0037] In this embodiment, the average penetration depth of polyvinyl alcohols is 20 to 65 μm, and is unevenly distributed in a shallower region compared to the recess depth of the embossing and the depth of the through hole of the punching. Due to this uneven distribution, the opening of the recess or through hole and the region shallower from the opening are relatively strengthened compared to the deeper region. In the case of the through hole, when both sides of the base paper are impregnated with polyvinyl alcohols, the opening on the opposite side and the region shallower from the opening are also strengthened in the same manner as one side. By unevenly distributing polyvinyl alcohols in the shallower region, the ease of entry (penetration distance) of the adhesive of the cover tape is controlled. When the average penetration depth of polyvinyl alcohols is less than 20 μm, the polyvinyl alcohols are localized on the surface, which is effective for suppressing surface fluff, but the adhesive of the cover tape does not penetrate and the peel strength decreases. On the other hand, when the polyvinyl alcohols penetrate beyond 65 μm, although the adhesive of the cover tape penetrates, the suppression of surface fluff is not sufficient.

Example

[0038] Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In addition, "parts" and "%" in the examples indicate "parts by mass" and "mass %", respectively, unless otherwise specified. The number of added parts is a value in terms of solid content.

[0039] <Example 1> To a pulp slurry consisting of 100 parts of Canadian Standard Freeness (CSF) 420 ml LBKP, 0.3 part of aluminum sulfate, 1 part of cationic starch (trade name: Neo Tack #30T / manufactured by Nippon Shokuhin Kako Co., Ltd.), and 0.4 part of rosin emulsion sizing agent (trade name: CC - 1404 / manufactured by Seiko PMC Co., Ltd.) were added to obtain a raw material slurry. Using the obtained raw material slurry, a four - layer wet paper consisting of 1 layer on the surface, 2 layers in the middle, and 1 layer on the back was formed by a cylinder - type paper machine, and then it was dewatered in the press part and dried to obtain a base paper. After drying, carboxyl - group - modified polyvinyl alcohol (Gosenex T - 350 / manufactured by Mitsubishi Chemical Corporation) as a water - soluble polymer was prepared in an aqueous solution under the conditions of a polymer mass percentage concentration of 6%, a liquid temperature of 50°C, and a B - type viscosity of 45 mPa·s (measurement rotation speed 60 rpm). The sizing liquid was applied to both sides of the base paper so that the solid content conversion was 2.4 g / m 2 and then dried with a cylinder dryer and subjected to multi - stage calendar treatment to obtain a carrier tape base paper for chip - shaped electronic components. The coating amount of the water - soluble polymer on the surface where the cover tape contacts was 1.2 g / m 2 in terms of solid content conversion. The basis weight of each layer was 75 g / m 2 for the surface layer, 75 g / m 2 for each of the two middle layers with a total of 150 g / m 2 and 75 g / m 2 for the back layer. The thickness of the base paper was 310 μm.

[0040] <Example 2> A carrier tape base paper for chip - shaped electronic components was obtained in the same manner as in Example 1 except that the temperature of the sizing liquid was changed from 50°C to 30°C and the B - type viscosity was changed to 75 mPa·s.

[0041] <Example 3> A carrier tape base paper for chip - shaped electronic components was obtained in the same manner as in Example 1 except that the temperature of the sizing liquid was changed from 50°C to 70°C and the B - type viscosity was changed to 19 mPa·s.

[0042] <Example 4> A carrier tape base paper for chip-shaped electronic components was obtained in the same manner as in Example 1, except that the concentration of the sizing solution was changed to 5%, the temperature was changed to 30 °C, and the B-type viscosity was changed to 40 mPa·s.

[0043] <Example 5> A carrier tape base paper for chip-shaped electronic components was obtained in the same manner as in Example 1, except that the concentration of the sizing solution was changed to 5% and the B-type viscosity was changed to 31 mPa·s.

[0044] <Example 6> A carrier tape base paper for chip-shaped electronic components was obtained in the same manner as in Example 1, except that the concentration of the sizing solution was changed to 5%, the temperature was changed to 70 °C, and the B-type viscosity was changed to 13 mPa·s.

[0045] <Example 7> A carrier tape base paper for chip-shaped electronic components was obtained in the same manner as in Example 1, except that the concentration of the sizing solution was changed to 7% and the B-type viscosity was changed to 70 mPa·s.

[0046] <Example 8> A carrier tape base paper for chip-shaped electronic components was obtained in the same manner as in Example 1, except that the concentration of the sizing solution was changed to 7%, the temperature was changed to 70 °C, and the B-type viscosity was changed to 40 mPa·s.

[0047] <Example 9> A carrier tape base paper for chip-shaped electronic components was obtained in the same manner as in Example 1, except that the sizing solution was changed to fully saponified polyvinyl alcohol (28-98 manufactured by Kuraray Co., Ltd.), the concentration was changed to 5%, the temperature was changed to 50 °C, and the B-type viscosity was changed to 30 mPa·s.

[0048] <Example 10> A carrier tape base paper for chip-shaped electronic components was obtained in the same manner as in Example 1, except that the sizing solution was changed to fully saponified polyvinyl alcohol (5-98 manufactured by Kuraray Co., Ltd.), the concentration was changed to 8%, the temperature was changed to 50 °C, and the B-type viscosity was changed to 14 mPa·s.

[0049] <Example 11> A carrier tape base paper for chip-shaped electronic components was obtained in the same manner as in Example 1, except that a mixture of 80 parts of LBKP and 20 parts of NBKP was subjected to beating and refining to obtain a pulp slurry with a Canadian Standard Freeness (CSF) of 420 ml.

[0050] <Example 12> A carrier tape base paper for chip-shaped electronic components was obtained in the same manner as in Example 1, except that a mixture of 65 parts of LBKP and 35 parts of NBKP was subjected to beating and refining to obtain a pulp slurry with a Canadian Standard Freeness (CSF) of 420 ml.

[0051] <Example 13> A carrier tape base paper for chip-shaped electronic components was obtained in the same manner as in Example 1, except that a mixture of 65 parts of LBKP, 25 parts of NBKP, and 10 parts of cotton linter was subjected to beating and refining to obtain a pulp slurry with a Canadian Standard Freeness (CSF) of 420 ml.

[0052] <Example 14> A carrier tape base paper for chip-shaped electronic components was obtained in the same manner as in Example 1, except that a mixture of 90 parts of LBKP and 10 parts of cotton linter was subjected to beating and refining to obtain a pulp slurry with a Canadian Standard Freeness (CSF) of 420 ml.

[0053] <Comparative Example 1> A carrier tape base paper for chip-shaped electronic components was obtained in the same manner as in Example 1, except that the sizing solution was changed to polyacrylamide (ST5000, manufactured by Starlight PMC) with a concentration of 8%, a temperature of 50 °C, and a B-type viscosity of 24 mPa·s.

[0054] <Comparative Example 2> A carrier tape base paper for chip-shaped electronic components was obtained in the same manner as in Example 1, except that the concentration of the sizing solution was changed to 8%, the temperature was changed to 50 °C, and the B-type viscosity was changed to 150 mPa·s.

[0055] <Comparative Example 3> A carrier tape base paper for chip-shaped electronic components was obtained in the same manner as in Example 1, except that the concentration of the sizing solution was changed to 4%, the temperature was changed to 50 °C, and the B-type viscosity was changed to 13 mPa·s.

[0056] <Comparative Example 4> A carrier tape base paper for chip-shaped electronic components was obtained in the same manner as in Example 1, except that the sizing solution was changed to completely saponified polyvinyl alcohols (5-98 manufactured by Kuraray Co., Ltd.), the concentration was changed to 6%, the temperature was changed to 50 °C, and the B-type viscosity was changed to 7 mPa·s.

[0057] <Comparative Example 5> A carrier tape base paper for chip-shaped electronic components was obtained in the same manner as in Example 1, except that a mixture of 55 parts of LBKP and 45 parts of NBKP was mixed and beaten to change the Canadian Standard Freeness (CSF) to 420 ml of pulp slurry.

[0058] <Measurement of average penetration depth> After dropping several drops of a coloring solution (a coloring solution prepared by dissolving 6.0 g of boric acid, 0.382 g of iodine, and 0.75 g of potassium iodide in water to make a total volume of 500 ml) on the base paper and air-drying it, the cross-section was processed with a microtome after coloring, and the maximum and minimum values of the penetration depth were read with a microscope, and the average was taken as the average penetration depth.

[0059] <Measurement of cover tape peel strength> A cover tape ((No381H-14A: manufactured by Nitto Denko Corporation) was adhered to the carrier tape base papers obtained in the examples and comparative examples using a taping device (PST-150Air, manufactured by PALMEC), and the peel strength was measured using a peel strength tester (PFT-50, manufactured by PALMEC). Taping conditions: Adhesion temperature 140 °C, 4 mm × 50 stamps / seal length 200 mm, Peel strength measurement conditions: Peel speed 300 mm / 30 seconds, Peel angle 170 degrees. The minimum value of the obtained peel strength was calculated. The evaluation criteria are as follows.

[0060] <Surface keva evaluation> The surface of the sample for which the cover tape peel strength was measured was visually observed. The evaluation criteria are as follows. ◎: No keba is observed at all and it is good. (Practical level) ○: Hardly any keba is observed and it is good. (Practical level) △: A little keba is observed. (Lower practical limit level) ×: Keba is clearly observed. (Non - practical level)

[0061] <Loading part keba evaluation> The inner surface forming the loading part was visually observed. The evaluation criteria are as follows. ◎: No keba is observed at all and it is good. (Practical level) ○: Hardly any keba is observed and it is good. (Practical level) △: A little keba is observed. (Lower practical limit level) ×: Keba is clearly observed. (Non - practical level)

[0062] <Air permeability resistance> The air permeability resistance of the mounting board was measured according to JIS P811751:2009 "Paper and paperboard - Test method for air permeability and air permeability resistance (intermediate range) - Gurley method".

[0063]

Table 1

[0064]

Table 2

[0065] As shown in Table 1 and Table 2, the carrier tape base papers for chip-shaped electronic components obtained in Examples 1 to 14 all had good evaluations in terms of both the peel strength of the cover tape and the keva of the surface and the loading part, and were at a level without practical problems. In contrast, for the carrier tape base paper for chip-shaped electronic components obtained in Comparative Example 1, since polyacrylamide was used in the sizing liquid, the permeability was high and the balance between the surface keva and the peel strength could not be achieved. Further, for the carrier tape base paper for chip-shaped electronic components obtained in Comparative Example 2, since the viscosity of the sizing liquid was high, polyvinyl alcohols were localized on the surface of the base paper and the balance between the surface keva and the peel strength could not be achieved. For the carrier tape base paper for chip-shaped electronic components obtained in Comparative Example 3, since the viscosity of the sizing liquid was low, polyvinyl alcohols penetrated too much on the surface of the base paper and the balance between the surface keva and the peel strength could not be achieved. For the carrier tape base paper for chip-shaped electronic components obtained in Comparative Example 4, since it was a low-molecular-weight polyvinyl alcohol, the viscosity of the sizing liquid was low, and therefore polyvinyl alcohols penetrated too much on the surface of the base paper and the balance between the surface keva, the keva of the loading part and the peel strength could not be achieved. For the carrier tape base paper for chip-shaped electronic components obtained in Comparative Example 5, since the blending ratio of LBKP and NBKP did not satisfy (Equation 1) and the amount of LBKP was small, the balance between the surface keva, the keva of the loading part and the peel strength could not be achieved.

Claims

1. In a carrier tape base paper for chip-shaped electronic components having a base paper containing pulp as a main component, the pulp contained in the base paper contains at least LBKP, the mass mixing ratio of LBKP and NBKP of the pulp satisfies (Equation 1), the surface of the base paper in contact with the cover tape contains polyvinyl alcohols, and a carrier tape base paper for chip-shaped electronic components, characterized in that the average penetration depth of the polyvinyl alcohols from the surface of the base paper in contact with the cover tape is 20 to 65 μm. (Equation 1) LBKP:NBKP = 65 to 100:35 to 0

2. The carrier tape base paper for chip-shaped electronic components according to claim 1, characterized in that the pulp contains 65 to 100% by mass of LBKP.

3. The pulp contains only LBKP and NBKP, The carrier tape base paper for chip-shaped electronic components according to claim 1, characterized in that the mass mixing ratio of LBKP and NBKP of the pulp satisfies (Equation 2). (Equation 2) LBKP:NBKP = (65 or more, less than 100):(35 or less, greater than 0)

4. The carrier tape base paper for chip-shaped electronic components according to claim 1, characterized in that the pulp contains only LBKP.

5. The carrier tape base paper for chip-shaped electronic components according to any one of claims 1 to 4, characterized in that the polyvinyl alcohols are anionic polyvinyl alcohol-based resins or nonionic polyvinyl alcohol-based resins.

6. The carrier tape base paper for chip-shaped electronic components according to any one of claims 1 to 4, characterized in that the opposite surface of the surface of the base paper in contact with the cover tape contains polyvinyl alcohols.

7. The carrier tape base paper for chip-shaped electronic components according to claim 6, characterized in that the air permeability resistance of the base paper measured according to JIS P811751:2009 "Paper and paperboard - Test method for air permeability and air permeability resistance (intermediate range) - Gurley method" is 1000 to 8000 seconds.

8. A step of preparing a raw material slurry containing pulp as a main component, wherein the pulp contains at least LBKP, and the mass mixing ratio of LBKP and NBKP of the pulp satisfies (Equation 1); a step of papermaking the raw material slurry to obtain a wet paper; a step of drying the wet paper to obtain a base paper; A step of applying, per one side, a sizing solution containing polyvinyl alcohols in an amount of 0.7 to 1.8 g / m² on at least one side of the base paper ２ and a step of a step of drying the base paper coated with the sizing liquid to obtain a base paper, The sizing liquid has a polyvinyl alcohol concentration of 5 to 8% by mass, a temperature of 30 to 70°C, and a B-type viscosity of 10 to 80 mPa·s, The base paper contains polyvinyl alcohols on the sizing liquid-coated surface, and A method for manufacturing a carrier tape base paper for chip-shaped electronic components, characterized in that the average penetration depth of the polyvinyl alcohols from the sizing liquid-coated surface is 20 to 65 μm. (Equation 1) LBKP:NBKP = 65 to 100:35 to 0

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