JP5825124B2 - Multilayer paper substrate for chip-type electronic component storage mount and method for manufacturing the same - Google Patents

Description

  The present invention relates to a multilayer paper substrate for chip-type electronic component storage board and a method for producing the same. More specifically, in manufacturing a chip-type electronic component storage board having cavities for individually storing a plurality of chip-type electronic components at a pitch of 1.1 mm or less, the chip-type electronic component can be formed with high processing accuracy. The present invention relates to a multilayer paper base material for storage board and a manufacturing method thereof.

A chip-type electronic component storage mount (hereinafter abbreviated as “storage mount”) used as a carrier for chip-type electronic components is usually formed in a tape shape and embossed or perforated to form a cavity. It is manufactured by doing.
In the case of a storage board obtained by embossing a paper base, a chip manufacturer fills the cavity with chip-type electronic components, adheres a top cover tape to the surface (top side), winds it around a cassette reel, and inserts it into a chip mold. Supply to users of electronic components.
On the other hand, in the case of a storage board obtained by perforation, a bottom cover tape is adhered to the back surface (bottom side) to provide a bottom surface, and then the chip-type electronic components are filled into the cavity, and the top cover is applied to the surface (top side). Glue the tape, wind it around the cassette reel, and supply it to the chip-type electronic component mounting manufacturer.
In any case, the mounting manufacturer takes out the chip-type electronic component filled in the cavity by peeling the top cover tape and mounts it on the printed circuit board.

The storage board is required to have good accuracy in forming a cavity for inserting a chip-type electronic component and to smoothly fill and take out the electronic component.
If the inner wall surface of the cavity is not sharp (accurate dimensions), the chip-type electronic component is easily caught. For this reason, trouble may occur when the chip type electronic component is filled by the chip manufacturer or when the chip type electronic component is taken out by the mounting manufacturer.
In order to improve the cavity formation accuracy, it is possible to take measures such as refinishing or renewing the mold, but the loss of time and yield occurs and the operability is reduced, resulting in higher costs. .

In order to improve the formation accuracy of the cavity, the mold itself has been improved to improve the wear resistance of the mold, but improvements on the side of the storage board that stores chip-type electronic components are also required. It has been.
For example, in Patent Document 1, pulp fibers and inorganic fillers derived from waste paper are positively contained in layers other than the surface layer, the reinforcing effect of thick fibers by short fibers derived from waste paper, and the binding strength of fibers by inorganic fillers A multilayer paper base material for chip-type electronic component storage board has been proposed in which the effect of reducing stress on the mold due to the reduction is used, the formation accuracy of the cavity is improved, and the wear resistance of the mold is also improved.

JP 2010-30676 A

In recent years, as an effort to reduce the amount of chip-type electronic component storage mount used for cost reduction, a storage mount with a reduced pitch between cavities has been used. In particular, in the 0603 size and 1005 size chip component storage mounts, the cavity spacing was conventionally 2.0 mm ± 0.05 mm, but the chip type electronic component storage mount is reduced to 1.0 mm ± 0.05 mm. Is adopted.
As a result of confirmation by the present inventors, a chip-type electronic component storage board having a cavity interval of 1.0 ± 0.05 mm using the multilayer paper base material for chip-type electronic component storage board of Patent Document 1, It has been found that the formation accuracy of the cavities may not be sufficient.
The present invention has been made in view of the above circumstances, and is a chip-type electronic device that can provide good cavity formation accuracy and mold wear resistance for making a storage board with a short pitch between cavities. It is an object of the present invention to provide a multilayer paper base material for component storage board.

The inventors of the present invention have not only the wear resistance of the mold when forming a storage board with a short pitch between cavities, but also the multilayer paper base material for chip type electronic component storage board. The following invention was made by finding out that it depends on the content of adhesive foreign matter.
[1] A multilayer paper base material for a chip-type electronic component storage board having a plurality of cavities for individually accommodating chip-type electronic components at a pitch of 1.1 mm or less, and the content of adhesive foreign matter per 100 g of dry solid content and a 100 mm ² or less, and an inorganic filler, Ri 0.1-10% by mass ash content of the dry solids, consist of the surface layer and other layers, dry solids of the layers other than the surface layer chip-type electronic component storing multilayer paper base carrier sheet which minute over 20 wt% and wherein the used paper pulp der Rukoto.
[2] The multilayer paper base material for chip-type electronic component storage board according to [1], which contains an inorganic filler in a layer other than the surface layer.
[ 3 ] It consists of a surface layer and other layers, and 20% by mass or more of the dry solid content of the layers other than the surface layer is waste paper pulp, and a plurality of cavities that individually accommodate chip-type electronic components are pitches of 1.1 mm or less A method for producing a multilayer paper substrate for a chip-type electronic component storage board having:
Used paper pulp manufacturing process for manufacturing waste paper pulp containing inorganic filler with 1-15% by weight of dry solids as pulp fiber and ash content from waste paper, and paper making multilayer paper base material using fresh pulp and waste paper pulp A paper making process,
In the used paper pulp manufacturing process, the used paper disaggregation process, foreign matter removal process, coarse dust removal process, dehydration concentration process, dilution process, selective dust removal process, and washing process are sequentially performed.
In the paper making process, the waste paper pulp is used for paper making of layers other than the surface layer ,
Do not perform a dispersion process using a kneading and dispersing machine between the dehydration concentration process and the fine dust removal process.
In selected dedusting step, the chip-type method for manufacturing an electronic component housing base sheet for multi-layer paper substrate slit width and said Rukoto using the following slit screen 0.25 mm.
[ 4 ] The method for producing a multilayer paper base material for chip-type electronic component storage board according to [ 3 ], wherein in the dehydration concentration step, dehydration concentration is performed so that the dry solid content concentration is 8 to 40% by mass.
[ 5 ] The method for producing a multilayer paper base material for chip-type electronic component storage board according to [ 3 ] or [ 4 ], wherein in the dilution step, the dry solid content concentration is diluted to 0.5 to 5% by mass. .
[ 6 ] The method for producing a multilayer paper base material for chip-type electronic component storage board according to any one of [ 3 ] to [ 5 ], wherein a slit screen having a slit width of 0.15 mm or less is used in the selective dust removal step. .
[ 7 ] The multilayer paper base material for chip-type electronic component storage board according to any one of [ 3 ] to [ 6 ], further comprising a deinking step between the rough dust removal step and the dehydration concentration step. Manufacturing method.

In addition, the mass (dry solid content amount) in the present invention indicates the mass (absolute dry mass) when dried at 110 ° C. in accordance with JIS P 8225. Unless otherwise specified, it is only pulp fiber. The mass includes other coexisting materials such as ash.
That is, the dry solid content of 100 g means that the absolute dry mass is 100 g, the dry solid content x mass% means that xg is contained per 100 g of the absolute dry mass, and the dry solid content concentration y The mass% means that the absolute dry mass is yg per 100 g of the sample.

The dry solid content of each layer is obtained by immersing in hot water or immersing in hot water to which an amylolytic enzyme is added, and separating each layer. For example, the dry solid content of the layers other than the surface layer means the remaining dry solid content that is immersed in hot water or immersed in hot water to which an amylolytic enzyme is added and the surface layer is divided and removed.
In order to determine the dry solid content of a sample having a high water content, such as pulp slurry, prior to the drying at 110 ° C., a Buchner funnel was used. Dehydration is performed using filter paper No. 2 (obtained by determining the absolute dry mass in advance).

  According to the multilayer paper base material for chip-type electronic component storage board of the present invention, the multi-layer paper base for chip-type electronic component storage board that can obtain good cavity formation accuracy can be obtained for creating a storage board with a short pitch between cavities. Can provide material.

It is sectional drawing of the multilayer paper base material for chip | tip type | mold electronic component storage board based on one Embodiment of this invention.

<Multilayer paper base>
An embodiment of a multilayer paper substrate for chip-type electronic component storage board of the present invention (hereinafter abbreviated as “multilayer paper substrate”) will be described.
As shown in FIG. 1, the multilayer paper substrate 1 of the present embodiment is composed of a surface layer 10 and an inner / back layer 20 having an intermediate layer 21 and a back layer 22. Here, the surface layer 10 is an outer layer on the side to which the top cover tape is bonded, and the back layer 22 is an outer layer on the side opposite to the side to which the top cover tape is bonded. Moreover, it is preferable that the middle layer 21 in the middle back layer 20 is a multilayer. One surface layer 10 and one back layer 22 are sufficient.
The multilayer paper substrate 1 preferably has a basis weight of 200 to 1000 g / m ² . The surface layer 10 and the back layer 22 each preferably have a basis weight of 30 to 120 g / m ² . The front and back layers 20 preferably have a basis weight of 140 to 970 g / m ² .

[Surface]
Usually, in a storage board, after a chip-type electronic component is stored in a cavity, a top cover tape is attached, and the top cover tape is peeled off by a mounting manufacturer, and the chip-type electronic component is taken out. Therefore, since the surface layer 10 of the multilayer paper substrate 1 for storage board is required to have high adhesiveness to the top cover tape and appropriate peelability, it is preferable to use only fresh pulp containing no inorganic filler. .
Fresh pulp is pulp obtained from wood or non-wood plants. Fresh pulp made from plants does not contain inorganic fillers.
Fresh pulp includes bleached chemical pulp (NBKP, which is a pulp obtained by chemically treating softwood, LBKP, etc., which is obtained by chemically treating hardwood, etc.), unbleached chemical pulp (NUKP, which is unbleached chemical pulp made from softwood, and hardwood. And unbleached chemical pulp such as LUKP), mechanical pulp, non-wood fiber pulp and the like.
For the surface layer 10, bleached chemical pulp is suitable among fresh pulp because it is easy to develop strength and is difficult to be colored.

  The Canadian standard freeness of the entire pulp fiber constituting the surface layer 10 is preferably 300 to 560 ml, and more preferably 300 to 500 ml. If the Canadian standard freeness of the pulp fiber as a whole is 300 ml or more, it is possible to prevent a decrease in the pulp yield and a quantity loss due to high density, and if it is 560 ml or less, the interlayer strength can be further increased.

The surface layer 10 may be appropriately coated or impregnated with a surface treatment agent in order to improve the adhesion to the top cover tape and to prevent the occurrence of chipping.
Examples of the surface treatment agent include polyvinyl alcohol, starch, polyacrylamide, acrylic resin, styrene-butadiene copolymer resin, styrene-isoprene copolymer resin, polyester resin, ethylene-vinyl acetate copolymer resin, vinyl acetate-vinyl alcohol. Examples thereof include copolymer resins and urethane resins.
Moreover, a styrene-maleic acid copolymer resin and an olefin-maleic acid copolymer resin can also be used as the surface treatment agent. When a styrene-maleic acid copolymer resin or olefin-maleic acid copolymer resin having a hydrophilic group (carboxy group) is applied, not only the surface coating but also the carboxy group forms a hydrogen bond with the pulp fiber. Can be crosslinked. Therefore, the interfiber bonding can be further improved. By improving the fiber-to-fiber bond, the resistance force when peeling the top cover tape or the bottom cover tape is improved, the peel strength can be increased, and the occurrence of chipping can be further prevented.

  Examples of means for applying and impregnating the surface treatment agent to the surface layer 10 include a bar coater, a blade coater, an air knife coater, a rod coater, a gate roll coater, a roll coater such as a size press and a calendar coater, and a bill blade coater. A coating device can be used. Among these, the calender coat is a coating method that allows the surface treatment agent to penetrate deeply into the base paper, so that styrene / maleic acid copolymer resin, olefin / maleic acid copolymer resin, etc. were used as the surface paper strength agent. In this case, the bond between fibers can be improved, which is preferable. In addition, since the bar coater is a coating method that increases the surface coverage, it is preferable because it can suppress the generation of cracks.

The coating amount of the surface treatment agent is preferably 0.1 to 1.1 g / m ² in terms of dry coating amount, and more preferably 0.6 to 1.1 g / m ² . If the surface treatment agent is applied so that the dry coating amount is 0.1 g / m ² or more, the generation of scraps and paper dust can be sufficiently suppressed, and the dry coating amount is 1.1 g / m ² or less. As a result, sufficient adhesion to the top cover tape can be secured.

[Inner layer]
The layers other than the surface layer 10, that is, the layers constituting the inner / back layer 20, may be ones in which all layers are made using the same papermaking raw material, or papers made using different papermaking raw materials.
The inner back layer 20 is preferably a waste paper pulp having a dry solid content of 20% by mass or more. That is, it is preferable that 20% by mass or more of the dry solid content is derived from waste paper. Waste paper pulp is pulp obtained by recycling used paper.
In general, fresh pulp fibers are often relatively hard, have a long fiber length, and have a cross section close to a perfect circle. On the other hand, the waste paper pulp has been shortened by chemical treatment and mechanical treatment after the steps (history) of pulping and pulping, disaggregation, beating, drying, and papermaking. In addition, the fiber is softer than fresh pulp. Furthermore, the inorganic filler contained in waste paper pulp can inhibit the bonding between fibers and reduce the bonding force between fibers.
For this reason, a backing base material that uses a large amount of waste paper pulp reduces the load on the mold when the cavity is press-formed, and is excellent in wear resistance.
The ratio of the waste paper pulp to the dry solid content of the inner backing layer 20 is more preferably 20 to 100% by mass, and further preferably 30 to 100% by mass.

As used paper, for example, white paper and ruled white paper that has been used once, but has few printed parts, printed matter such as cards, imitations, color, Kent, white art, and colored paper that has been used once, Used high-quality used paper such as coated paper for printing, beverage packs, office paper, etc., and other medium-quality used paper such as special cutting, separate upper cutting, medium anti-recycled, Kent Manila, newspapers, magazines, miscellaneous paper, etc. General medium-sized waste paper, tea-based waste paper such as cut tea, plain tea, miscellaneous bags, cardboard, and the like.
Among these, since the ink content derived from the waste paper in the multilayer paper base material is reduced, paper having few printed portions is preferable.
The waste paper pulp is preferably uncolored, such as disintegrated pulp of waste paper that has not been printed, or deinked waste paper pulp that has been deinked to remove ink. If the inside of the cavity for storing the electronic component is colored, there is a possibility that it is erroneously identified as the component in the image processing in the inspection process after the component is stored or after the component is taken out.

Waste paper pulp made from waste paper usually contains an inorganic filler. Here, the inorganic filler is derived from the filler internally added to the waste paper and the pigment in the coating layer. That is, the inner back layer 20 contains an inorganic filler by including waste paper pulp as a raw material.
The mass average particle diameter of the inorganic filler is preferably less than 50 μm, and more preferably less than 40 μm. When the inorganic filler has a mass average particle diameter of less than 50 μm, it is easy to prevent the mold from being worn because the inorganic filler easily moves when the mold for forming the cavity comes into contact.
Further, the content of the inorganic filler having a particle diameter of 50 μm or more in the inorganic filler is preferably less than 40% by mass and more preferably less than 30% by mass with respect to 100% by mass of the total inorganic filler. An inorganic filler having a particle diameter of 50 μm or more has a high probability of coming into contact with a mold when forming a cavity for housing a chip-type electronic component. Therefore, when a large inorganic filler having a particle size of 50 μm or more is contained in an amount of 40% by mass or more, the mold is easily worn.

The particle diameter in this specification is the longest length of each inorganic filler in an image obtained by photographing a cross section with an electron microscope. For example, when the inorganic filler looks like a rod, it is the length, and when it looks like an ellipse, it is the major axis.
The content of the inorganic filler having a mass average particle diameter and a particle diameter of 50 μm or more is determined as follows.
First, as in the example shown in Table 1, inorganic fillers having a particle diameter of 5 μm or more and less than 250 μm are classified into any one of sections i every particle diameter of 10 μm (A). The intermediate particle size between the upper limit particle size and the lower limit particle size in section i is defined as Bi. Further, the ratio of the number of inorganic fillers included in the particle diameter range of the section i to the total number of inorganic fillers having a particle diameter of 5 μm or more and less than 250 μm is a number ratio Ci. Here, the total number of inorganic fillers having a particle diameter of 5 μm or more and 250 μm was set to 100 mass% because inorganic fillers having a particle diameter of less than 5 μm do not affect the wear of the mold. When an inorganic filler having a particle diameter of 250 μm or more is present, the calculation is performed by increasing the section i so that the filler having the maximum diameter is included.
Next, the mass ratio Di of the section i is obtained by [Equation 1]. Then, the mass average particle diameter is obtained by [Equation 2]. The content of the inorganic filler having a particle diameter of 50 μm or more is obtained by [Equation 3].

In [Equation 1], the square value of Bi is used because the inorganic filler derived from waste paper, in particular, the inorganic filler derived from the coating layer of the coated paper has a thin flat plate shape. This is because there are many.
Further, in the present specification, it is inappropriate to define the average particle diameter of the inorganic filler on the basis of a number for the following reason. That is, even if the proportion of the number of inorganic fillers having a small particle size is large, the presence of a small number of large inorganic fillers having a particle size exceeding 100 μm increases the probability that the mold will cut large particles, Mold wear is likely to occur.

  In order to make the particle size distribution of the inorganic filler within the above-described range, the treatment conditions (for example, dispersion time, shear efficiency, treatment temperature, etc.) of the dispersion treatment described later may be appropriately adjusted. For example, the longer the dispersion time and the higher the shear efficiency, the smaller the mass average particle size and the smaller the content of inorganic fillers with a particle size of 50 μm or more.

It is preferable that all pulp fibers contained in the inner back layer 20 have a fiber length distribution in which the proportion of ultrafine fibers having a length of 0.2 mm or less is 20% or more. The fiber length distribution in this specification refers to the fiber length of the measurement sample disaggregated by the pulp disaggregation method of JIS P 8220. 52 is a fiber length distribution measured by a pulp fiber length test method using an optical automatic measurement method defined in 52 and obtained on the basis of a number.
When the ratio of the ultrafine fibers having a length of 0.2 mm or less is 20% or more, the bonding force between the fibers having a length exceeding 0.2 mm can be increased, and the cavity forming property is further improved.
Moreover, it is preferable that the ratio of the ultrafine fiber of 0.2 mm or less is 70% or less. If the ratio of the ultrafine fibers is 70% or less, paper drainage is easily made because the drainage of the pulp fibers is hardly inhibited.
In order to adjust the proportion of ultrafine fibers having a length of 0.2 mm or less, the proportion of waste paper pulp forming the inner back layer 20 may be adjusted. Specifically, the proportion of fibers having a length of 0.2 mm or less increases as the proportion of used paper pulp increases. In addition, after obtaining waste paper pulp from waste paper, it may be adjusted by performing a beating process described later.

  The Canadian standard freeness of the whole pulp fibers constituting the inner backing layer 20 is preferably 250 to 500 ml, and more preferably 250 to 450 ml. If the Canadian standard freeness of the pulp fiber as a whole is 250 ml or more, the pulp yield can be prevented from decreasing, and if it is 500 ml or less, the paper layer can be prevented from peeling off and the strength can be prevented from decreasing.

Among the middle back layer 20, the middle layer 21 preferably contains an inorganic filler. Moreover, it is preferable that the raw material of the middle layer 21 contains a waste paper pulp, and it is preferable that 20 mass% or more of dry solid content is a waste paper pulp, ie, 20 mass% or more of dry solid content is derived from a waste paper.
The Canadian standard freeness of the whole pulp fibers constituting the middle layer 21 is preferably 250 to 500 ml, and more preferably 250 to 450 ml.

On the other hand, the back layer 22 preferably has a small content of inorganic filler, and more preferably contains no inorganic filler. Further, the back layer 22 preferably has a small content of used paper in the raw material, and more preferably contains no used paper pulp, that is, uses only fresh pulp.
If the content of the inorganic filler in the back layer 22 is small, the surface smoothness of the back layer 22 can be increased. Since a bottom cover tape may be bonded to the back layer 22, higher surface smoothness is preferable in terms of adhesiveness.

However, if a raw material that is largely different in drainage from the raw material of the middle layer 21 is used, when it is formed as a multilayer paper, there is a difference in drying shrinkage due to the difference in water content of each layer in the drying process. The back layer 22 is preferably made of a pulp raw material having a drainage equivalent to that of the middle layer 21 because there is a possibility of causing a delamination trouble called blistering between the layers.
The Canadian standard freeness of the entire pulp fibers constituting the back layer 22 is preferably 250 to 500 ml, and more preferably 250 to 450 ml.

The back layer 22 may be appropriately coated with or impregnated with a surface treatment agent in order to improve adhesion to the bottom cover tape and to prevent the occurrence of chipping.
Preferred types of surface treatment agents, preferred application and impregnation modes are the same as described for the surface layer 10.

[Adhesive foreign matter content]
The multilayer paper substrate 1 as a whole has an adhesive foreign matter content of 100 mm ² or less. The content of the adhesive foreign matter is preferably 90 mm ² or less, and more preferably 80 mm ² or less.
The content of adhesive foreign matter is the cumulative area of adhesive foreign matter per 100 g of dry solid content determined by the following procedure.

(1) Separation of residual foreign matter The multilayer paper substrate 1 for chip-type electronic component storage board (for the adhesive foreign matter content of each layer, the layer separated from other layers) is cut to 1 cm square or less, cut and dried. It dilutes with water so that solid content concentration may be 1-3 mass%. After dilution, 2.5% by mass of NaOH is further added to the dry solid content. Subsequently, a disaggregation treatment is performed for 20 minutes with a standard disaggregator (3000 rpm) defined in JIS P 8221 to obtain a disaggregation liquid.
This disaggregated solution is filtered through a test flat screen plate having a slit having a width of 6/1000 inches to separate residual foreign matters that have not passed through the slit.

(2) Accumulated area of adhesive foreign matter Residual foreign matter on the flat screen is received by the first filter paper (No. 2), and a polyethylene film having a thickness of 0.06 mm and a thickness of 200 mm × 300 mm is stacked thereon, and a pressure of 5 kg / Pressure treatment is performed at cm ² for 1 minute to transfer the sticky foreign matter from the filter paper to the film. The foreign matter transferred to the film is further transferred to the second filter paper (No. 2) by pressurizing at a pressure of 5 kg / cm ² for 1 minute. Palpate the re-transferred foreign material with a needle and remove foreign material other than adhesive foreign material.
Thereafter, the area of the foreign matter (adhesive foreign matter) on the second filter paper is individually measured, and the accumulated value is taken as the cumulative area of the adhesive foreign matter.

  In order to obtain the cumulative area, it is preferable to perform image analysis processing using a measuring instrument that measures pulp impurities. For example, SpecScan 2000/2001 (Apogee) or DIP200 (Oji Scientific Co., Ltd.) using a scanner method can be used. Furthermore, DIP-2000 (manufactured by Oji Scientific Co., Ltd.) capable of measuring with high accuracy by driving a microscope and an XY stage can be used.

Among the multilayer paper substrate 1, in particular, the surface layer 10 has an adhesive foreign matter content of preferably 20 mm ² or less, more preferably 10 mm ² or less, so as to have an appropriate peelability from the top cover tape. More preferably, it is 0 mm ² .
The inner back layer 20 preferably has an adhesive foreign matter content of 120 mm ² or less, more preferably 100 mm ² or less, so that the adhesive foreign matter content of the entire multilayer paper substrate 1 satisfies the scope of the present invention. More preferably, it is 80 mm ² or less.
However, since the inner back layer 20 preferably has a waste paper pulp of 20% by mass or more of the dry solid content, from the viewpoint of using a sufficient waste paper pulp, the content of the adhesive foreign matter is within the scope of the present invention. It may not be 0 mm ² .

[Ash content]
The multilayer paper base material 1 contains an inorganic filler, and the ash content as a whole is 0.1 to 10% by mass with respect to the dry solid content. The ash content of the entire multilayer paper substrate 1 is preferably 1 to 8% by mass.
The ash content is a value obtained by firing the multilayer paper base material 1 (the layer separated from the other layers for the ash content of each layer) at 525 ° C. according to JIS P 8251, and calculating the following formula.
β1 = (P1 / Q1) × 100 (%)
Here, β1 is ash, P1 is the mass of the residue after firing, and Q1 is the dry solid content of the multilayer paper substrate 1 before firing.

If the ash content is less than 1% by mass, the wear of the mold may be affected. If the ash content exceeds 10% by mass, problems such as a decrease in interlayer strength and generation of paper dust tend to occur. The ash content corresponds to the amount of inorganic filler.
Since the ash content is derived from waste paper pulp, the ash content is adjusted by the proportion of the used paper pulp and the proportion of the inorganic filler contained in the used paper to obtain the used paper pulp. Moreover, it can adjust also with the conditions of a used paper pulp manufacturing process, for example, the conditions of a washing process, etc.

Among the multilayer paper base materials 1, in particular, the surface layer 10 has an ash content of preferably 1% by mass or less, and 0.5% by mass or less so that the surface layer 10 has appropriate adhesiveness and peelability to the top cover tape. More preferably, it is more preferably 0% by mass.
The back layer 22 has an ash content of preferably 10% by mass or less, and more preferably 8% by mass or less so as to have appropriate adhesiveness with the bottom cover tape.
The inner back layer 20 preferably has an ash content of 0.5 to 10% by mass, and 0.5 to 8% by mass so that the ash content of the entire multilayer paper substrate 1 satisfies the scope of the present invention. More preferably.

<Method for producing multilayer paper substrate>
The method for producing a multilayer paper base material of the present invention includes a waste paper pulp production process for producing waste paper pulp containing pulp fibers and an inorganic filler from waste paper, and papermaking for making a multilayer paper base material using fresh pulp and waste paper pulp. Process.

[Paper pulp manufacturing process]
In the waste paper pulp manufacturing process, a waste paper disaggregation process, a foreign matter removal process, a coarse dust removal process, a dehydration concentration process, a dilution process, a selective dust removal process, and a washing process are sequentially performed. Furthermore, you may perform a deinking process between a rough-separation dust removal process and a dehydration concentration process. Furthermore, you may perform a dispersion | distribution process between a selective dust removal process and a washing | cleaning process.
As the waste paper used as a raw material, one containing 5% by mass or more, more preferably 7% by mass or more of an inorganic filler is preferably used. Moreover, it is preferable that the inorganic filler in a used paper is 40 mass% or less in the point of utilizing a used paper pulp fiber effectively.

  In the disaggregation processing step, disaggregation processing is performed to disaggregate waste paper to form a slurry. For the disaggregation process, a disaggregator generally called a pulper is used. As the pulper, for example, a low-concentration pulper that is processed at a dry solid content concentration of 3 to 5% by mass, a medium-concentration pulper that is processed at a dry solid content concentration of 5 to 18% by mass, and a dry solid content concentration of 18 to 25% by mass. Examples include high-concentration pulpers. The medium concentration pulper or the high concentration pulper is preferable for the purpose of suppressing the fineness of the adhesive foreign matter. However, it is also preferable to use a low concentration pulper from the viewpoint of disaggregation processing capability.

  Examples of the low-concentration pulper include those in which a stirring blade called a rotor is attached to the bottom surface or inner wall surface of a tank. The medium concentration pulper is the same as the above low concentration pulper, and includes a rotor with a larger rotor shape and a disaggregation tank with a horizontal drum shape. An example of the high-concentration pulper is a kneading pulper in which stirring blades are installed in multiple stages in the tank. In addition, when used paper is difficult to disaggregate, a defibrating machine can be used in addition to the disaggregating machine.

Although there is no restriction | limiting in particular about the disaggregation process in this invention, As a preferable process, raw material waste paper is made into dry solid content concentration 1-18 mass%, More preferably, it becomes 12-18 mass%, or 2-5 mass%. Add dilution water. Further, sodium hydroxide may be added in an amount of 0.6 to 3.5% by mass, preferably 1.0 to 2.5% by mass, based on the dry solid content of the raw material waste paper.
In the case of adding a deinking agent, those having strong permeability to pulp fibers and strong ink peelability are preferable, and the deinking agent is 0.01 to 0.5 mass based on the dry solid content of the raw waste paper. %, Preferably 0.03 to 0.3% by mass.
The disaggregation time is 10 to 30 minutes, preferably 10 to 25 minutes, more preferably 10 to 18 minutes, and the disaggregation temperature is 10 to 50 ° C, preferably 30 to 50 ° C.

In the foreign matter removing step, foreign matter removal using a cleaner is performed mainly for the purpose of removing large foreign matters generated after the disaggregation step. The cleaner has a conical shape, and can remove foreign substances having a specific gravity larger than that of pulp fibers such as sand and metal particles by the principle of centrifugal separation.
Since the dry solid content concentration of the slurry when treating with a cleaner is preferably 1 to 7% by mass, more preferably 2 to 5% by mass, if necessary, it is diluted with water after the disaggregation step. The foreign matter removing step is performed.

In the coarse dust removal process, as in the foreign matter removal process, a coarse dust removal process using a coarse selection screen is performed for the purpose of removing large foreign matters generated after the disaggregation treatment process. As the coarse selection screen, for example, a basket type screen in which holes or slits having a predetermined opening area are formed is used.
The coarse screen has a different screen hole size from the screen described later, and the coarse screen uses a round hole screen (1.5 to 2.5 mmΦ) and a slit screen (0.2 to 0.25 mm slit). It is done.
Since it is preferable that the dry solid content concentration of the slurry when processing with a coarse selection screen is 0.5 to 5% by mass, if necessary, dilute with water after the foreign matter removal step, and then perform the coarse selection step. .

In the case where used printed paper is used, it is preferable to perform a deinking step of performing a deinking process with a floatator or the like before the dehydration concentration step. By the deinking process, coarse inorganic foreign matters can be removed from the slurry together with the remaining ink.
The dry solid content concentration of the slurry when treating with a floatator is preferably 0.5 to 2% by mass, and more preferably 0.5 to 1% by mass. After the process, it is diluted with water and then treated with a floatator.
In the deinking step, a deinking agent may be further added immediately before processing with the floatator. As the deinking agent used immediately before the treatment with the floatator, those having strong ink aggregating properties are preferable. In the case of fatty acids, DI-254 (oleic acid), DI-268, Daiichi manufactured by Kao Corporation. K-4004-D manufactured by Kogyo Seiyaku Co., Ltd. In the case of the fatty acid derivative system, there are DIY-23543 manufactured by Kao Corporation, Paper Aid W manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Daihope 1000, and the like, but not limited thereto.

In the dehydration and concentration step, dehydration and concentration are performed so that the dry solid content concentration of the slurry is increased. The present inventors have found that the content of adhesive foreign matter in the obtained waste paper pulp can be reduced by performing dehydration concentration prior to the selective dust removal step described later.
The reason is not clear, but in the slurry after the coarse dust removal process, the sticking foreign matter exists in a colloidal state or a fine particle state. Fine particles are easy to deform. Therefore, as it is, it is considered that efficient removal is difficult because it easily passes through the slit in the selective dust removal process described later.
On the other hand, when the dehydration concentration is performed, the contact frequency between the pulps increases. When the pulps come into contact with each other, it is considered that the sticky foreign matter adhering to the pulp simultaneously grows in contact with each other.
In addition, since the grown adhesive foreign matter is pressurized by contact with each other in the process of growing large, it is considered to be a particle that is dense, hard and not easily deformed, and is not easily dispersed unless mechanical shearing is applied. . Therefore, it is considered that it becomes difficult to pass through the slit in the subsequent selective screen, and the dust removing effect is enhanced.

The dry solid content concentration of the slurry after the dehydration and concentration step is preferably 8% by mass or more in order to ensure contact between fine adhesive foreign substances and sufficiently obtain the effect of reducing the content of adhesive foreign substances. It is more preferable to set it as mass% or more, and it is still more preferable to set it as 15 mass% or more.
On the other hand, dehydrating and concentrating to an excessively high concentration is not preferable because it is technically difficult and excessive power consumption is required for dehydrating and concentrating. Therefore, the dry solid content concentration of the slurry after the dehydration concentration step is more preferably 40% by mass or less, more preferably 35% by mass or less, and further preferably 30% by mass or less.

The apparatus for concentrating the slurry in the dehydration and concentration step is not particularly limited, but a pressure dehydrator such as a screw press is preferably used. Examples of the uniaxial screw press include V45LM-H type manufactured by Aikawa Tekko, Metso Paper, and Optimum Screw Press manufactured by AFT. Twin press and twin wire dehydrators include Ishigaki's twin screw press and Maruishi Seisakusho's twin wire press.
In the case of the slurry that has undergone the deinking process, the dry solid content concentration is low, and it is difficult to instantaneously concentrate to the target dry solid content concentration by only one stage of the pressure dehydrator. Therefore, it is preferable to devise such as dehydrating in advance with a press dehydrator such as an inclined extractor and subsequently using a pressure dehydrator together.

In the dehydration concentration step, a polymer flocculant may be added to the slurry. As a result, even a low-concentration slurry that cannot be sufficiently squeezed by mechanical force alone can be raised relatively quickly to the target dry solid content concentration with a normal pressure dehydrator.
When the polymer flocculant is added, it is added before the treatment with the dehydrator or during the treatment with the dehydrator. It is preferable that the pulp in the slurry is sufficiently immersed in the polymer flocculant before the treatment with the dehydrator. The addition rate of the polymer flocculant is preferably 0.005 to 0.05% by mass with respect to the dry solid content of the slurry, although it depends on the dry solid content concentration and equipment of the slurry. It is more preferable that it is 0.04 mass%. When the addition rate is low, a sufficient concentration effect cannot be obtained. If the addition rate is too high, the dry solid content concentration of the slurry after the dehydration concentration step may exceed the target dry solid content concentration, and the production cost is excessive, which is not practical.

  The polymer flocculant is not particularly limited as long as the dry solid concentration can be increased to the target concentration in the dehydration concentration step, but the acrylic ester-based cationic polymer flocculant can increase the dry solid concentration most efficiently. Therefore, it is preferable. Examples of the cationic polyacrylate include C-525M and C-500N manufactured by MT Aqua Polymer Co., Ltd., High Holder 725 manufactured by Kurita Industries, and High Form K162.

In the dilution step, the slurry concentrated in the dehydration concentration step is diluted to a concentration suitable for the subsequent selective dust removal step.
The dry solid content concentration of the slurry after the dilution step is preferably 0.5 to 5% by mass, more preferably 0.5 to 20% by mass, and 0.5 to 1.5% by mass. Is more preferable. When the dry solid content concentration of the slurry after the dilution step is 0.5% by mass or more, foreign matters can be efficiently removed. When the dry solid content concentration of the slurry after the dilution step is 5% by mass or less, clogging of the screen can be prevented.
In the diluting step, it is preferable to use clean water that does not contain foreign matter so that the adhesive foreign matter grown in the dehydration and concentration step is not refined again.

In the selective dust removal process, a selective dust removal process using a selective screen is performed for the purpose of removing foreign substances including adhesive foreign substances after the dilution process. As the selection screen, for example, a basket type screen in which holes or slits having a predetermined opening area are formed is used.
The selection screen is preferably a slit screen. The slit width is preferably 0.10 to 0.25 mm, more preferably 0.10 to 0.20 mm, still more preferably 0.1 to 0.15 mm, and 0.1 to 0 Particularly preferred is .13 mm.
If the slit width of the selection screen is too wide, it is difficult to sufficiently reduce the content of adhesive foreign matter. On the other hand, if the slit width is too narrow, the yield of waste paper pulp decreases.
The fine dust removal step may be performed a plurality of times, but if the number of fine dust removal steps is too many, the yield of waste paper pulp is lowered, so it is preferably 1 to 3 times. When the selective dust removal process is performed several times, it is preferable to continue the process.

In the dispersion step, a dispersion treatment for dispersing the inorganic filler and the like in the slurry is performed. By the dispersion treatment, not only the inorganic filler but also the remaining ink can be reduced.
For example, when using magazine waste paper that contains a large amount of coated paper (especially coated paper with a thick coat layer) that contains an inorganic filler, the inorganic filler that did not disperse sufficiently during the disaggregation process was compared. May remain as a large lump. When this lump is contained in waste paper pulp, the multilayer paper base material obtained by using this lump may accelerate the wear of the mold. Therefore, when used paper containing a large amount of coated paper is used, it is preferable to perform a dispersion process.
In addition, it is not preferable to perform a dispersion | distribution process between a dehydration concentration process and a selective dust removal process. This is because the adhered foreign matter that has grown in the dehydration and concentration step is refined again.

Machines that can be used in distributed processing include, for example, disintegrators such as finalers, conifers, top finalers, conical discs, deflakers, conical flakers, and power finers, refiners such as refiners, double disc refiners, and beaters, kneaders and dispersers. And kneading / dispersing machines such as new dispersers and hot dispersers (hot dispersion equipment).
Of these, a disperser or a hot disperser is preferred. When the treatment is performed using a disperser or a hot disperser, the inorganic filler can be made fine with high efficiency without extremely reducing the freeness even in the case of a high concentration slurry having a dry solid content concentration of 25% by mass or more.
When processing with a disperser or a hot disperser, it is preferable to heat to 80 to 120 ° C. with a steam / heater because the efficiency of the dispersion process is improved.

  The washing step is a step of performing a pulp washing treatment as a final step of waste paper pulp production. If the pulp washing treatment is performed, the amount of ash in the waste paper can be easily reduced. Specifically, when a pulp washing treatment is performed after the dispersion treatment, the amount of ash content of the used paper pulp can be easily adjusted to 1 to 15% by mass even if a large amount of used paper having an ash content exceeding 2% by mass is used. Therefore, in the multilayer paper base material 1 in which the middle back layer 20 is formed using waste paper pulp, the ash content of the middle back layer 20 can be easily adjusted to 0.5 to 10% by mass.

Examples of machines that can be used for the pulp cleaning treatment include cleaning devices such as DNT washers, compact washers, fall washers, bario splits, SP filters, DP Cosmo, and gap washers.
Since the ash removal efficiency in the pulp washing process is improved as the dry solid content concentration is lower, it is preferable to dilute the slurry before the pulp washing process.
The dry solid content concentration of the slurry before the pulp washing treatment is preferably 0.5 to 5% by mass, more preferably 1 to 4% by mass, and further preferably 1 to 3% by mass. .

The content of adhesive foreign matter contained in the used paper pulp obtained in the used paper pulp manufacturing process is preferably 120 mm ² or less, more preferably 100 mm ² or less, and more preferably 80 mm ² or less per 100 g of dry solid content. preferable.
The content of adhesive foreign matter contained in waste paper pulp is the cumulative area of adhesive foreign matter per 100 g of dry solid content of waste paper pulp determined by the following procedure.
(1) Separation of residual foreign matter Waste paper pulp is filtered through a test flat screen plate having a slit having a width of 6/1000 inches to separate residual foreign matter that has not passed through the slit.

(2) Accumulated area of adhesive foreign matter Residual foreign matter on the flat screen is received by the first filter paper (No. 2), and a polyethylene film of 200 mm × 300 mm having a thickness of 0.06 mm is stacked thereon, and the pressure is 5 kg / cm. ² for 1 minute to transfer the sticky foreign matter from the filter paper to the film. The foreign matter transferred to the film is further transferred to the second filter paper (No. 2) by pressurizing at a pressure of 5 kg / cm ² for 1 minute. Palpate the re-transferred foreign material with a needle and remove foreign material other than adhesive foreign material.
Thereafter, the area of the foreign matter (adhesive foreign matter) on the second filter paper is individually measured, and the accumulated value is taken as the cumulative area of the adhesive foreign matter.

The inorganic filler contained in the used paper pulp obtained in the used paper pulp manufacturing process is preferably 1 to 15% by mass, more preferably 1 to 10% by mass as the ash content, and more preferably 1 to 10% by mass. More preferably, it is -8 mass%.
Prior to firing at 525 ° C., Buchner funnel was used to measure the ash content of waste paper pulp. The method for obtaining the ash content of the multilayer paper base material 1 is the same as the method for obtaining the ash content of the multilayer paper base material 1 except that it is dehydrated and dried using the filter paper of No. 2 (filter paper not containing the ash content whose absolute dry mass was obtained in advance).

[Paper making process]
In the present invention, a multilayer paper substrate is produced using waste paper pulp and fresh pulp.
Waste paper pulp is mainly used for papermaking of the inner back layer 20. For papermaking of the surface layer 10, it is preferable to use only fresh pulp. In addition, when used paper pulp is used for the surface layer 10, the strength in the layer is lowered, and it becomes easy to generate a fluff when adhering to and peeling from the top cover tape, so various internal additives of the paper strength agent are increased. Good.
Moreover, you may make the papermaking raw material of another layer contain the various internal additives mentioned above as needed.
The basis weight of the multilayer paper base is appropriately selected depending on the chip size of the electronic component to be accommodated in the cavity, it is preferably 200 to 1000 g / ^{m 2,} a 300 to 800 g / ^{m 2} More preferred. If it exceeds 1000 g / m ² , the rigidity of the base material becomes high, so that there is a concern that peeling occurs at the interlayer when used as a chip storage board, leading to a machine stoppage trouble during the mounting operation.

As the papermaking method, 3 to 10 layers of multi-layer papermaking is preferable because it is easy to form. Examples of the paper machine used for the multilayer paper making include a circular mesh paper machine, a circular mesh short combination paper machine, a short mesh multilayer paper machine, and a long mesh multilayer paper machine.
When coating or impregnating a surface treatment agent on the front or back surface of the multilayer paper substrate 1, for example, a roll coater such as a bar coater, blade coater, air knife coater, rod coater, gate roll coater, size press or calendar coater A coating device such as a bill blade coater can be used. Among these, a size press or a calendar coater is preferable because the surface treatment agent can be deeply penetrated by the nip pressure.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to the following Example. In addition, the numerical value which shows a mixing | blending, a density | concentration, etc. is a numerical value of the mass reference | standard of dry solid content.

<Example 1>
[Manufacture of waste paper pulp]
Waste magazine paper was treated with a pulper (low concentration pulper) at a temperature of 20 ° C. for 20 minutes to obtain a disaggregation solution having a dry solid content concentration of 3.5%. This disaggregation liquid was processed with a cleaner (stack cleaner A type, manufactured by Aikawa Tekko Co., Ltd.) to remove foreign matters.
Then, after diluting with water to a dry solids concentration of 2%, after coarsely removing dust with a 0.2 mm slit screen (coarse screen), diluting with water to a dry solids concentration of 1% and deinking 0.1% of the agent (Kao DI7510) was added to the dry solid content, and deinking treatment was performed with a flowator (MAC 2, manufactured by Aikawa Tekko Co., Ltd.) to obtain slurry 1.

  Next, slurry 1 was dehydrated and concentrated to a dry solid content concentration of 10% using a gradient extractor (M-9, manufactured by Aikawa Tekko Co., Ltd.) to obtain slurry 2. Furthermore, it concentrated to about 30% of dry solid content concentration with the screw press dehydrator (V45 LM, Aikawa Tekko), and the slurry 3 was obtained. Then, it diluted with water until the dry solid content density | concentration was set to 1%, and selected and removed dust with the 0.15 mm slit screen (selection screen). Further, it was passed through a pulp washing machine (DNT washer: manufactured by Aikawa Tekko Co., Ltd.) and concentrated to a dry solid content concentration of 10% by an inclined extractor (M-9 type, manufactured by Aikawa Tekko Co., Ltd.) to obtain used paper pulp A.

[Manufacture of multilayer paper substrate]
NBKP; 30% and LBKP; 70% were mixed and beaten with a double disc refiner to prepare 460 ml of CSF (Canadian Standard Freeness) to obtain a surface layer forming pulp slurry (dry solid concentration 3%). For the middle and back layers, use 100% of the waste paper pulp A obtained by the above method, beaten with a double disc refiner, and prepare to 410 ml of CSF (Canadian Standard Freeness). A slurry (dry solid content concentration of 3%) was obtained.

  A sulfuric acid band was added to each pulp slurry at 2.0% based on the dry solid content of the pulp slurry. Moreover, size pine N-111 (Arakawa Chemical Industries make, rosin emulsion sizing agent) was added as a sizing agent at 0.50% with respect to the dry solid content of the pulp slurry. Moreover, Polystron 1250 (Arakawa Chemical Industries, Ltd., amphoteric polyacrylamide type paper strength enhancer, molecular weight 3 million) was added as a paper strength enhancer by 2.0% with respect to the dry solid content of the pulp slurry.

Thereafter, the basis weight of each pulp slurry was changed to a surface layer (1 layer) of 60 g / m ² , a middle layer (3 layers) of 225 g / m ² , and a back layer (1 layer) of 60 g / m ² , using a long web 5 layer paper machine. In addition, a multilayer paper was made, and a surface coating was coated with 1.0 g / m ² of polyvinyl alcohol having a saponification degree of 88 mol% and a polymerization degree of 1000 on the surface side with a bar coater. A multilayer paper base having a basis weight of 500 g / m ² and a thickness of 0.42 mm was manufactured.

<Example 2>
A multilayer paper base as in Example 1 except that 100% of used paper pulp A was used instead of 100% used paper pulp A as a raw material for the inner layer forming pulp slurry, and that 40% used paper pulp and 60% LBKP were used. The material was obtained.

<Example 3>
A multilayer paper base material was obtained in the same manner as in Example 1 except that the selection screen was changed from the 0.15 mm slit screen to the 0.20 mm slit screen.

<Example 4>
A multilayer paper substrate was prepared in the same manner as in Example 1 except that after concentration to a dry solids concentration of 10%, dilution was performed with water until the dry solids concentration became 1% without concentration by a screw press dehydrator. Obtained.

<Example 5>
A multilayer paper substrate was obtained in the same manner as in Example 1 except that the selection screen was changed from the 0.15 mm slit screen to the 0.13 mm slit screen.

<Example 6>
A multilayer paper base material was obtained in the same manner as in Example 1 except that selective dust removal using a 0.13 mm slit screen was additionally performed following the selective dust removal using a 0.15 mm slit screen.

<Example 7>
After the slurry 3 was obtained, a dispersion treatment was performed using a disk-type hot dispersion equipment (KRIMA manufactured by Cellwood) under the conditions of a disk gap of 1.0 mm and a temperature of 70 ° C., and then a dry solid content concentration A multilayer paper base material was obtained in the same manner as in Example 1 except that the content was 1%. That is, a multilayer paper substrate was obtained in the same manner as in Example 1 except that the dispersion treatment was performed between the dehydration concentration step and the dilution step.

<Example 8>
[Manufacture of waste paper pulp]
Waste magazine paper was treated with a pulper (low concentration pulper) at a temperature of 20 ° C. for 20 minutes to obtain a disaggregation solution having a dry solid content concentration of 3.5%. This disaggregation liquid was processed with a cleaner (stack cleaner A type, manufactured by Aikawa Tekko Co., Ltd.) to remove foreign matters.
Then, after diluting with water to a dry solid content concentration of 2%, coarsely dusting with a 0.2 mm slit screen (coarse screen), then diluting with water to a dry solid content concentration of 1%. Fine dust removal (first time) was performed with a 15 mm slit screen (selection screen).
Next, 0.1% of deinking agent (Kao DI7510) was added to the dry solid content, and deinking treatment was performed by a flowator (MAC 2, manufactured by Aikawa Tekko).

  Subsequently, it was dehydrated and concentrated to a dry solid content concentration of 10% using a gradient extractor (M-9 type, manufactured by Aikawa Tekko). Furthermore, it concentrated to about 30% of dry solid content concentration with the screw press dehydrator (V45LM, Aikawa Tekko). Then, it diluted with water until the dry solid content density | concentration was set to 1%, and performed selective dust removal (2nd time) with a 0.15 mm slit screen (selection screen). Further, it was passed through a pulp washer (DNT washer: manufactured by Aikawa Tekko Co., Ltd.) and concentrated to a dry solid content concentration of 10% by a gradient extractor (M-9 type, manufactured by Aikawa Tekko Co., Ltd.) to obtain waste paper pulp A ′ of Example 8. It was.

[Manufacture of multilayer paper substrate]
A multilayer paper substrate was obtained in the same manner as in Example 1 except that the used paper pulp A ′ of Example 8 was used.

<Comparative Example 1>
A multilayer paper base material was obtained in the same manner as in Example 1 except that 100% of LBKP was used instead of 100% of used paper pulp A as a raw material for the pulp slurry for forming the inner back layer.

<Comparative Example 2>
A multilayer paper base material was obtained in the same manner as in Example 1 except that the selective dust removal using a 0.15 mm slit screen was not performed.

<Comparative Example 3>
A multilayer paper base material was obtained in the same manner as in Example 7 except that selective dust removal using a 0.15 mm slit screen was not performed.

<Comparative Example 4>
A multilayer paper base material was obtained in the same manner as in Example 8, except that the fine dust removal (second fine dust removal) with a 0.15 mm slit screen was not performed.

<Comparative Example 5>
As follows, other performing distributed processing between the dehydration concentration step and dilution step, to obtain a multi-layer paper substrate in the same manner as in Example 8.
[Manufacture of waste paper pulp]
Waste magazine paper was treated with a pulper (low concentration pulper) at a temperature of 20 ° C. for 20 minutes to obtain a disaggregation solution having a dry solid content concentration of 3.5%. This disaggregation liquid was processed with a cleaner (stack cleaner A type, manufactured by Aikawa Tekko Co., Ltd.) to remove foreign matters.
Then, after diluting with water to a dry solid content concentration of 2%, coarsely dusting with a 0.2 mm slit screen (coarse screen), then diluting with water to a dry solid content concentration of 1%. Fine dust removal was performed with a 15 mm slit screen (selection screen).
Next, 0.1% of deinking agent (Kao DI7510) was added to the dry solid content, and deinking treatment was performed by a flowator (MAC 2, manufactured by Aikawa Tekko).

  Subsequently, it was dehydrated and concentrated to a dry solid content concentration of 10% using a gradient extractor (M-9 type, manufactured by Aikawa Tekko). Furthermore, after concentrating to a dry solid concentration of about 30% with a screw press dehydrator (V45 LM, manufactured by Aikawa Tekko), using a disk-type hot dispersion facility (KRIMA manufactured by Cellwood), a disk gap of 1.0 mm, Dispersion treatment was performed at a temperature of 70 ° C. Then, it diluted with water until the dry solid content density | concentration was set to 1%, and selected and removed dust with the 0.15 mm slit screen (selection screen). Further, it was passed through a pulp washer (DNT washer: manufactured by Aikawa Tekko Co., Ltd.), and concentrated to a dry solid content concentration of 10% using a gradient extractor (M-9, manufactured by Aikawa Tekko Co., Ltd.) to obtain waste paper pulp A ″ of Comparative Example 5. It was.

[Manufacture of multilayer paper substrate]
A multilayer paper substrate was obtained in the same manner as in Example 1 except that the used paper pulp A ″ of Comparative Example 5 of Comparative Example 5 was used.

<Evaluation of slurry during used paper manufacture>
About the slurry 1-3 in the said Example 1, and used paper pulp A, the following method measured the adhesion foreign material content and ash content.

[Adhesive foreign matter content]
(1) Separation of residual foreign matter Slurry or waste paper pulp A was filtered through a test flat screen plate having a slit having a width of 6/1000 inches, and the residual foreign matter that did not pass through the slit was separated.

(2) Accumulated area of adhesive foreign matter Residual foreign matter on the flat screen is received by the first filter paper (No. 2), and a polyethylene film of 200 mm × 300 mm having a thickness of 0.06 mm is stacked thereon, and the pressure is 5 kg / cm. ² for 1 minute, and the foreign material having adhesiveness was transferred from the filter paper to the film. The foreign matter transferred to the film was further re-transferred to the second filter paper (No. 2) by pressurizing for 1 minute at a pressure of 5 kg / cm ² . The retransferred foreign matter was palpated with a needle to remove foreign matter other than adhesive foreign matter.
Thereafter, the foreign matter (adhesive foreign matter) on the second filter paper was classified and measured by size with a dirt counter DIP200 (manufactured by Oji Scientific Co., Ltd.).
The analysis is roughly divided into foreign matters of 0.05 mm ² to 0.5 mm ² (micro-adhesive foreign matter) and 0.5 mm ² (macro-adhesive foreign matter) or more, and the respective accumulated areas (macro and micro) are obtained, and their total Was defined as the total cumulative area.

[Ash content]
About the slurry 1-3 in the said Example 1, and used paper pulp A, it is Buchner funnel, No. Using the filter paper of No. 2 (filter paper that does not contain ash for which the absolute dry mass was obtained in advance), dehydrated and dried (110 ° C.) to obtain the absolute dry mass excluding the filter paper, JIS P 8251 “Paper, paperboard and pulp The ash content was measured by baking at 525 ° C. according to the “ash content test method”.

As shown in Table 2, the content of adhesive foreign matter in slurry 2 was higher in both the micro-adhesive foreign matter and macro-adhesive foreign matter compared to slurry 1. The reason for this is that the low-concentration (less than 10%) slurry 1 has a fine adhesive foreign substance and a shape that passes through the test flat screen, whereas the slurry 2 after dehydration and concentration up to 10% has no adhesive foreign substance. This is thought to be due to the deformation and growth to be separable on the test flat screen.
Moreover, in the slurry 3, compared with the slurry 2, the micro adhesion thing decreased and the macro adhesion foreign material increased. This is thought to be because what was a micro-adhesive foreign matter in the slurry 2 further grew to a macro-adhesive foreign matter by further concentration to 25% or more.
Further, the content of adhesive foreign matter in the waste paper pulp A was significantly reduced as compared with the slurry 3.
From these results, it was found that the sticky foreign matter in the pulp is easily removed by growing the sticky foreign matter through the dehydration concentration process and then performing a selective dust removal process.

Moreover, even if it is the slurry which does not pass through a dehydration concentration process and the subsequent selective dust removal process like the slurry 1, if it is as it is, since the content of the adhesion foreign material is low, as a material of the multilayer paper base material of the present invention, It can be used.
However, since the finished waste paper pulp is usually dehydrated and concentrated to 5 to 30% and stored in a storage tank, there is a risk that adhesive foreign matter may increase in the storage process like the slurry 2 and 3.
On the other hand, although the waste paper pulp A has been dehydrated and concentrated again after selective dust removal, the content of adhesive foreign matter has not increased. In other words, once the sticky foreign matter was grown through the dehydration and concentration step, and after the fine dust removal step, the content of the sticky foreign matter did not increase even after dewatering and concentration after the fine dust removal, it was found that it can be stored without problems. .

<Evaluation of multilayer paper base>
About the multilayer paper base material manufactured in the said Examples 1-7 and Comparative Examples 1-3, adhesive foreign material content, ash content, mold wear property, and cavity formation precision were evaluated by the following method. The evaluation results are shown in Table 3. In addition, the following measurement and evaluation were performed after performing the pre-processing which adjusted the paper-made multilayer paper base material to the state of temperature 23 degreeC +/- 1 degreeC and relative humidity 50% +/- 2% according to JISP8111.

[Measurement of adhesive foreign matter]
(1) Residual foreign matter content The multilayer paper base material is cut to 1 cm square or less, and after cutting, diluted with water so that the dry solid content concentration is 1 to 3% by mass. After dilution, 2.5% by mass of NaOH is further added to the dry solid content. Subsequently, a disaggregation treatment was performed for 20 minutes with a standard disaggregator (3000 rpm) defined in JIS P 8221 to obtain a disaggregation solution.
This disaggregation liquid was filtered with a test flat screen plate having a slit having a width of 6/1000 inch, and the residual foreign matter that did not pass through the slit was separated.

(2) Accumulated area of adhesive foreign matter Residual foreign matter on the flat screen is received by the first filter paper (No. 2), and a polyethylene film having a thickness of 0.06 mm and a thickness of 200 mm × 300 mm is stacked thereon, and a pressure of 5 kg / A pressure treatment was performed at cm ² for 1 minute, and the sticking foreign matter was transferred from the filter paper to the film. The foreign matter transferred to the film was further re-transferred to the second filter paper (No. 2) by pressurizing for 1 minute at a pressure of 5 kg / cm ² . The retransferred foreign matter was palpated with a needle to remove foreign matter other than adhesive foreign matter.
Thereafter, the foreign matter (adhesive foreign matter) on the second filter paper was classified and measured by size with a dirt counter DIP200 (manufactured by Oji Scientific Co., Ltd.).
The analysis is roughly divided into foreign matters of 0.05 mm ² to 0.5 mm ² (micro-adhesive foreign matter) and 0.5 mm ² (macro-adhesive foreign matter) or more, and the respective accumulated areas (macro and micro) are obtained, and their total Was defined as the total cumulative area.

[Ash content]
The ash content was measured by firing at 525 ° C. according to JIS P 8251 “Method for testing ash content of paper, paperboard and pulp”.

[Evaluation of mold wear resistance]
A multi-layer paper base without slits slit into a tape shape with a width of 8 mm is continuously used according to JIS C 0806-3 using an ACP505S type half press machine (1 mm pitch half press type mold) manufactured by Nippon Automatic Machine Co., Ltd. Specifically, 15 million embossing (depth 0.35 mm) was performed to form a cavity. At that time, a new mold immediately after polishing was used as the mold. In addition, the cavity shape was 1.12 mm in the width direction and 0.62 mm in the flow direction. Then, the tip of the mold after 15 million shots was photographed with a microscope, the dimensions were measured, and compared with the mold dimensions before processing (wear rate). The results are shown in the following table. If the wear rate at the tip is 10% or less, the effect of extending the mold life can be expected.
Abrasion rate (%) = (Lead tip length before processing-Tip length after processing) ÷ Tip length before processing

[Evaluation of cavity formation accuracy]
The cavities for 20 times before the 15 millionth press work in the mold wear evaluation were observed from the surface side with a stereomicroscope (200 times), and visual evaluation was performed.
Evaluation is as follows. Evaluations ○ and Δ are practically usable levels.
Evaluation (circle): There is nobody and a cutting mark on the wall surface of a cavity.
Evaluation (triangle | delta): Slightly and a cutting | disconnection mark are seen in the cross section of a cavity.
Evaluation x: Nobody or cutting marks are seen in the cavity cross section.

In all examples, although waste paper was used as a raw material, the content of adhesive foreign matter was low, and good results were obtained with respect to the accuracy of cavity formation. In particular, in Example 2, although the mold wear rate is slightly higher, good cavity accuracy is obtained, and it can be seen that the content of adhesive foreign matter has an influence on the cavity accuracy.
On the other hand, in Comparative Example 1 in which only fresh pulp was used and the ash content was zero, both mold wear resistance and cavity formation accuracy were inferior to those of the examples.
Moreover, in Comparative Example 2 and Comparative Example 3 in which the selective dust removal process was not performed, the content of adhesive foreign matter was high, and the cavity formation accuracy was inferior to that of the example.
Further, Comparative Example 4 and Comparative Example 5 in which the selective dust removal process is performed before the dehydration concentration process and the selective dust removal process is not performed after the dehydration concentration process are not sufficiently reduced in the content of adhesive foreign matter. The formation accuracy was inferior to that of the example.

  Comparing Example 1 and Example 4, Example 4 had a higher content of micro-adhesive foreign matter and a lower content of macro-adhesive foreign matter. This is because in Example 4, the concentration in the dehydration concentration process was limited to 10%, whereas in Example 1, the concentration was reduced to about 30%. This is thought to be due to the high growth rate of macro-adhesive foreign matter.

  Moreover, when Example 1 and Example 7, Comparative Example 2 and Comparative Example 3, and Comparative Example 4 and Comparative Example 5 are respectively compared, Example 7, Comparative Example 3, and Comparative Example 5 that have undergone a dispersion step after the dehydration concentration step. In this case, the ratio of macro-adhesive foreign matter is reduced. From this, it was found that if the dispersion step is performed after the dehydration concentration step, the adhesive foreign matter once grown may be refined.

  The multilayer paper substrate of the present invention is a multilayer paper substrate for chip-type electronic component storage board having a plurality of cavities for individually accommodating chip-type electronic components at a pitch of 1.1 mm or less. Specifically, it is preferably used for manufacturing a chip-type electronic component storage board having a cavity interval of 1.0 mm ± 0.05 mm.

DESCRIPTION OF SYMBOLS 1 ... Multilayer paper base material, 10 ... Surface layer, 20 ... Middle back layer, 21 ... Middle layer, 22 ... Back layer

Claims (7)

A multilayer paper base material for a chip-type electronic component storage board having a plurality of cavities for individually accommodating chip-type electronic components at a pitch of 1.1 mm or less, wherein the adhesive foreign matter content is 100 mm ² or less per 100 g of dry solid content , and the containing inorganic filler, the ash content of Ri 0.1-10% by mass relative to the dry solids, consist of the surface layer and other layers, 20 dry solids of the layers other than the surface layer chip-type electronic component storing multilayer paper base carrier sheet that more mass% and wherein the used paper pulp der Rukoto.   The multilayer paper base material for chip-type electronic component storage board of Claim 1 which contains an inorganic filler in layers other than surface layer. A chip comprising a surface layer and other layers, wherein 20% by mass or more of the dry solid content of the layers other than the surface layer is waste paper pulp, and has a plurality of cavities individually accommodating chip-type electronic components at a pitch of 1.1 mm or less A method of manufacturing a multilayer paper base material for a mold electronic component storage mount,
Used paper pulp manufacturing process for manufacturing waste paper pulp containing inorganic filler with 1-15% by weight of dry solids as pulp fiber and ash content from waste paper, and paper making multilayer paper base material using fresh pulp and waste paper pulp A paper making process,
In the used paper pulp manufacturing process, the used paper disaggregation process, foreign matter removal process, coarse dust removal process, dehydration concentration process, dilution process, selective dust removal process, and washing process are sequentially performed.
In the paper making process, the waste paper pulp is used for paper making of layers other than the surface layer ,
Do not perform a dispersion process using a kneading and dispersing machine between the dehydration concentration process and the fine dust removal process.
In selected dedusting step, the chip-type method for manufacturing an electronic component housing base sheet for multi-layer paper substrate slit width and said Rukoto using the following slit screen 0.25 mm. The method for producing a multilayer paper base material for chip-type electronic component storage board according to claim 3 , wherein in the dehydration concentration step, the dehydration concentration is performed so that the dry solid content concentration is 8 to 40% by mass. The manufacturing method of the multilayer paper base material for chip-type electronic component storage board of Claim 3 or 4 which dilutes so that a dry solid content concentration may be 0.5-5 mass% in the said dilution process. The method for producing a multilayer paper base material for chip-type electronic component storage board according to any one of claims 3 to 5 , wherein a slit screen having a slit width of 0.15 mm or less is used in the selective dust removal step. The method for producing a multilayer paper base material for chip-type electronic component storage board according to any one of claims 3 to 6 , further comprising a deinking step between the rough dust removal step and the dehydration concentration step.

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