JP2006199304A - Sheet for packaging electronic component, electronic component packaging container using the sheet, and electronic component packaging body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet for packaging an electronic component which conserves the electronic component under a favorable dry state, does not require a baking process prior to a solder reflowing, and suppresses the generation of cracks when reflowing the solder, to provide an electronic component packaging container using the sheet, and to provide an electronic component package. <P>SOLUTION: This sheet for packaging the electronic component has a resin layer containing a desiccant. The resin layer preferably contains a foaming agent, and the desiccant preferably is at least one kind selected from silica gel, zeolite, calcium chloride and magnesium sulfate. Also, for this electronic component packaging container using the sheet, at least the outermost layer of the surface which comes into contact with the electronic component preferably is a resin layer containing the desiccant. In addition, the electronic component packaging container preferably is one for which the sheet having been draw-processed is used. Also, the electronic component packaging body houses the electronic component in the electronic component packaging container. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet for packaging electronic components, an electronic component packaging container using the sheet, and an electronic component package.

  Conventionally, in an electronic component packaging container such as an embossed carrier tape used for packaging, transporting and mounting an electronic component, a conductive three-layer sheet having front and back layers in which conductive carbon is kneaded into a polystyrene resin, polycarbonate ( Hereinafter, abbreviated as PC) PC-based resin / acrylonitrile-butadiene-styrene (hereinafter abbreviated as ABS) / PC-based resin layer in which conductive carbon is kneaded into a resin is used. Yes.

For example, the electronic component is stored in an embossed carrier tape by a taping machine, and the upper surface is sealed with a cover tape. And this electronic component package is conveyed etc. in the state wound up on the reel etc. generally.
When an electronic component is supplied by this so-called “tape and reel method”, the electronic component package is enclosed with a desiccant in a resin bag deposited with aluminum and heat-sealed. As a result, electronic components are stored in good dry condition, and are exported domestically as well as overseas.

However, when taking out an electronic component with a mounting machine, the operation may be stopped halfway due to the convenience of the quantity. At this time, the electronic component left on the carrier tape absorbs moisture in the air and has a problem that cracks are generated due to rapid moisture expansion when passing through the solder reflow furnace.
On the other hand, in order to evaporate the moisture contained in the electronic component before passing through the solder reflow furnace, a so-called “baking” process is generally performed at a temperature of about 100 ° C. When performing this baking process, it is necessary to transfer the electronic parts to the baking tray or use a combination of embossed carrier, reel, cover tape, etc. that can be baked. It has become.

As an improvement measure, for example, a method for forming an embossed carrier tape using a sheet having a moisture-proof resin or a metal layer has been proposed (see, for example, Patent Documents 1 and 2).
However, although the moisture-proof resin and metal material have excellent moisture-proof properties in the sheet state, fine cracks are generated in the layer by vacuum forming, pressure forming, press forming, etc. Moisture can easily pass through it.
Therefore, in the case of electronic components in the middle of mounting, the sealing resin used with the semiconductor or semiconductor absorbs moisture in the air, and when the moisture passes through the solder reflow furnace, the absorbed moisture causes rapid expansion due to heating, There is a problem that the semiconductor itself and the sealing resin are broken.

In addition, a proposal has been made to store an electronic component under good drying by providing a hygroscopic polymer member on an inner surface of an electronic component storage body (hereinafter abbreviated as an electronic component storage recess) (for example, a patent). Reference 3).
However, the method of pasting the hygroscopic polymer member on the electronic component housing recess with adhesive tape or the like is costly and is equivalent to the hygroscopic polymer member pasting the size of the electronic component housing recess on the inner surface. There is a problem that it is necessary to increase the size and storage efficiency deteriorates.

Furthermore, a method of printing a mixture of magnesium sulfate in a printing ink resin and an organic solvent on the inner surface of a container has been proposed (for example, see Patent Document 4).
However, in this method, although the hygroscopicity is good, an organic solvent is used, and particularly when printing on a paper box or the like, a large amount of the organic solvent is absorbed by the paper. When this is dried, a large amount of solvent volatilizes, which is not preferable for mass production.

In addition, a method has been proposed in which an electronic component is stored in each of the electronic component storage recesses of the embossed carrier tape, and then an inert gas is sealed and the cover tape is fixed individually (for example, see Patent Document 5).
However, since this method uses an inert gas, the running cost is high and it is not economical. In addition, there is a problem because the taping device itself needs to be significantly modified.
JP-A-5-193670 Japanese Patent Application Laid-Open No. 5-201461 Japanese Patent Laid-Open No. 6-1383 JP 2000-178495 A JP 2003-95216 A

  The present invention has been made in view of the above circumstances, and is an electronic device that stores electronic components under good drying, does not need to be baked before solder reflow, and suppresses the occurrence of cracks during solder reflow. An object is to provide a component packaging sheet, an electronic component packaging container using the sheet, and an electronic component package.

As a result of intensive studies, the present inventors have found that crack generation during solder reflow is suppressed by using a resin layer kneaded with a desiccant for a sheet for packaging electronic parts, and to complete the present invention. It came.
In order to achieve the above object, the present invention employs the following configuration.
The sheet for packaging electronic parts of the present invention is characterized by having a resin layer containing a desiccant. The resin layer preferably contains a foaming agent. Furthermore, the desiccant is preferably at least one selected from silica gel, zeolite, calcium chloride, and magnesium sulfate.
Moreover, this invention is an electronic component packaging container using the said sheet | seat for electronic component packaging, It is preferable that the outermost layer of the surface which contacts at least an electronic component is a resin layer containing a desiccant.
Furthermore, it is preferable that the electronic component packaging container of the present invention is obtained by stretching the electronic component packaging sheet.
The present invention further provides an electronic component package in which an electronic component is stored in the electronic component packaging container.

  According to the present invention, an electronic component is stored under good drying, and there is no need to perform a baking process before solder reflow, and a sheet for packaging electronic components that suppresses the occurrence of cracks during solder reflow, and the sheet are provided. The used electronic component packaging container and the electronic component package can be provided.

≪Sheet for packaging electronic parts≫
The electronic component packaging sheet of the present invention is a sheet having a resin layer containing a desiccant.
Hereinafter, the present invention will be described in more detail.

<Layer structure>
The electronic component packaging sheet of the present invention has a resin layer containing a desiccant, and is composed of the resin layer in the case of a single layer structure, and has at least the resin layer in the case of a multilayer structure. . Here, the multilayer structure refers to a structure in which the electronic component packaging sheet has, for example, a two-layer structure, a three-layer structure, or four or more layers.

〔resin〕
As the material of the resin, a commonly used known resin can be used, and a synthetic resin such as a thermoplastic resin or a thermosetting resin is preferably used.
Synthetic resins include polyurethane, polystyrene, polyvinyl chloride, polyester, polyamide, polyimide, polyacetal, polycarbonate (PC), polyolefin, acrylic, vinyl acetate, fluorine, acrylonitrile Examples thereof include a butadiene-styrene (ABS) resin alone or a mixture, an alloy or a copolymer. Of these, polystyrene resin, PC resin, ABS resin, and ethylene-vinyl acetate copolymer are more preferably used because of easy molding.

〔desiccant〕
The desiccant is kneaded into the resin to form a resin layer, absorbs moisture, and exhibits a drying effect.
As the desiccant, for example, silica gel, zeolite, calcium chloride, magnesium sulfate and the like are preferably used. Among these, silica gel is more preferable because of its excellent drying effect and good mixing with the resin. These desiccants may be used alone or in combination of two or more.

The blending amount of the desiccant is preferably 5 to 300% by mass with respect to 100% by mass of the resin. Furthermore, 10-250 mass% is preferable, and 30-200 mass% is more preferable.
When the desiccant is 5% by mass or more, a drying effect can be obtained. When the desiccant is 300% by mass or less, the drying effect is sufficient, and mixing with the resin is good.
In the case of a multilayer structure, the resin layer containing the desiccant is preferably provided on at least the outermost layer of the sheet in contact with the electronic component in order to more effectively exhibit the drying effect.

[Foaming agent]
In the present invention, not only the desiccant but also the foaming agent is kneaded into the resin, so that the electronic component can be stored in a better dry state.
Although it does not specifically limit as a foaming agent, Azodicarbonamide (ADCA), N, N'- dinitrosopentamethylenetetramine, 4,4'-oxybis (benzenesulfonyl dolazide), sodium hydrogencarbonate, 5,5'- Bis-1H-tetrazole and the like are preferably used. Of these, azodicarbonamide (ADCA), which has an excellent drying effect and good mixing with the resin, is more preferable. These foaming agents may be used alone or in combination of two or more.

Although the mechanism for improving the drying effect by the combined use of the foaming agent is not clear, it is presumed as follows.
A resin layer in which not only a desiccant but also a foaming agent is combined and kneaded with the resin is formed, and then the electronic component packaging sheet of the present invention is produced by extrusion molding, calendar molding, or the like.
At this time, the foaming agent is decomposed by heating to generate gas. Since the gas is volatilized toward the surface of the outermost layer, the path becomes a fine continuous hole. It is considered that the formation of these fine continuous holes increases the surface area of the layer and further increases the adsorption efficiency of moisture in the air, thereby improving the drying effect.

[Optional ingredients]
In addition to the above-described components, materials used for a sheet for forming an electronic component packaging container such as a general embossed carrier tape or tray can be appropriately added to the electronic component packaging sheet.
In order to prevent generation of static electricity due to contact with an electronic component or the like, a conductive material, an antistatic agent, or the like is often used for the outermost layer.
Examples of the conductive material include conductive carbon materials such as ketjen black and acetylene black, conductive metal materials such as tin oxide, and organic conductive materials such as aniline, pyrrole, and thiophene. Examples of the antistatic agent include surfactants such as nonionic surfactants, cationic surfactants, and anionic surfactants. These may be used alone or in combination of two or more.

≪Electronic parts packaging container≫
The electronic component packaging container of the present invention uses the electronic component packaging sheet of the present invention. Moreover, the electronic component package of the present invention refers to an electronic component stored in the electronic component packaging container.
Since the electronic component packaging container can obtain a drying effect more effectively, it is preferable that at least the outermost layer in contact with the electronic component is a resin layer containing a desiccant. Thereby, an electronic component can be preserve | saved under further favorable drying.
Here, the surface in contact with the electronic component refers to the inner surface of the electronic component packaging container where the electronic component is stored (electronic component storage recess).

<Extension process>
It is preferable that the electronic component packaging container of the present invention is obtained by stretching the electronic component packaging sheet. Thereby, a drying effect can be acquired more effectively.
This stretching process may be performed at the sheet stage for molding a sheet stretched from the sheet, or may be performed at the container molding stage for molding an electronic component packaging container from the sheet, or both the sheet stage and further the container molding stage. You may go on.
Here, when the sheet area (container surface area) after the stretching process relative to the sheet area before the stretching process is expressed as a stretching ratio (%), it is preferable that this stretching ratio is 120% or more in the container forming stage. More preferably, it is 125% or more.
In the sheet stage, it is preferable that a sheet is once produced, and a stretching ratio becomes 110% or more by the subsequent stretching treatment. More preferably, it is 125% or more.
Although the mechanism for improving the drying effect by stretching the sheet is not clear, by causing fine cracks in the resin layer by stretching, the surface area of the layer increases, as in the case of the foaming agent, It is presumed that the drying effect is improved by further increasing the adsorption efficiency of moisture in the air.
As a method for stretching the sheet, a general molding method can be used at the stage of molding the container from the sheet, and vacuum molding, pressure molding, press molding, or the like is preferably used. In the step of forming the sheet, extrusion molding, calendar molding, or the like is used.

According to the present invention, when an electronic component such as a semiconductor housed in an electronic component packaging container is mounted on a substrate by a mounting machine and passed through a solder reflow furnace, a baking process previously performed can be omitted. In addition, the desiccant that has been inserted separately when the electronic component is stored can be omitted.
Furthermore, even when the operation is stopped in the middle of mounting and the electronic component is put on the mounting machine again, it is possible to pass through the solder reflow furnace without requiring re-baking processing.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to this. Further, “parts” and “%” are solid contents excluding water unless otherwise specified, and indicate mass parts and mass%, respectively.

First, electronic component packaging sheets were prepared, and electronic component packaging containers were manufactured by various molding processes. In this container, a SOP (Small Outline Package: semiconductor package) 4.5 mm square and 1 mm thick sealed with epoxy resin is housed and sealed by each method. Examples 1 to 5 and Comparative Examples The electronic component package shown in 1 and 2 was obtained.
With respect to these electronic component packages, the substrate mounting operation was stopped halfway, and each electronic component package was left for 7 days in a room at a temperature of 25 ° C. and a humidity of 60%, which is almost the same as the conditions for indoor storage. Thereafter, the SOP was taken out from the electronic component packaging container, immediately mounted on the substrate, and then put into a solder reflow furnace. After the treatment at 260 ° C. for 10 minutes, it was taken out from the reflow furnace, and the presence or absence of cracks in the SOP was observed with the naked eye, and the electrical functionality was evaluated together.
In addition, it evaluated also about each moldability in the case of sheet | seat preparation and electronic component packaging container manufacture. Moreover, about the extending | stretching process, the sheet area (container surface area) ratio after the extending | stretching process with respect to the sheet area before an extending | stretching process was represented by extending | stretching rate (%). Evaluation is performed according to the following criteria, and the obtained evaluation results are shown in Table 1.

<Evaluation of presence or absence of cracks, electrical functionality, and formability>
[Presence of cracks]
The presence or absence of cracks in the SOP was evaluated with the naked eye.
○: No crack ×: Crack present [Electrical functionality]
Electrical functionality was evaluated by operability.
○: Operating normally ×: Not operating normally [Formability]
In the production of the sheet, extrusion molding was performed, and in the production of the electronic component packaging container, each formability by vacuum forming, pressure forming, and press forming was evaluated.
○: Good formability ×: Poor formability △: Intermediate

Example 1
Styrene-butadiene-styrene block copolymer (SBS, manufactured by Asahi Kasei Co., Ltd.) 60%, general-purpose polystyrene (GPPS, manufactured by Asahi Kasei Co., Ltd.) 30%, impact-resistant polystyrene (HIPS, manufactured by Asahi Kasei Co., Ltd.) 10 100 parts of a blended polystyrene compound consisting of% crushed silica gel (Fuji Silysia Co., Ltd.) as a desiccant is pulverized with a fine powder crusher (spiral jet, Hosokawa Micron Co., Ltd.). A mixture containing 20% of finely pulverized silica gel having a particle size of about 10 to 20 μm was molded with a sheet extruder (Nippon Steel Works (manufactured)) to produce a polystyrene sheet having a thickness of 0.3 mm.
This sheet is folded to produce a box-shaped electronic component packaging container 10 mm long, 10 mm wide, and 10 mm deep, in which an epoxy resin-sealed 4.5 mm square, approximately 1 mm thick SOP is stored. 1 side was left and all 7 sides were sealed with cellophane tape to obtain an electronic component package.

(Example 2)
The sheet of Example 1 was stretched 19% in length and 5% in width in a 100 ° C. atmosphere. The stretch ratio at this time was about 125%.
This sheet is folded to produce a box-shaped electronic component packaging container 10 mm long, 10 mm wide, and 10 mm deep, in which an epoxy resin-sealed 4.5 mm square, approximately 1 mm thick SOP is stored. 1 side was left and all 7 sides were sealed with cellophane tape to obtain an electronic component package.

(Example 3)
A sheet in the same manner as in Example 1 except that 1% of azodicarbonamide (ADCA, manufactured by Eiwa Chemical Industry Co., Ltd.) was added as a foaming agent to the mixture of the mixed polystyrene compound of Example 1 and finely pulverized silica gel. Was made. The extruded sheet had minute holes (continuous holes) through which the blowing agent gas escaped from the sheet surface.
This sheet is folded to produce a box-shaped electronic component packaging container 10 mm long, 10 mm wide, and 10 mm deep, in which an epoxy resin-sealed 4.5 mm square, approximately 1 mm thick SOP is stored. 1 side was left and all 7 sides were sealed with cellophane tape to obtain an electronic component package.

Example 4
A mixture obtained by adding 1% sodium hydrogen carbonate (manufactured by Eiwa Kasei Kogyo Co., Ltd.) as a foaming agent to the mixture of the blended polystyrene compound of Example 1 and finely pulverized silica gel and a mixture without addition are molded by coextrusion. And the sheet | seat with which each 0.15 mm layer was laminated | stacked was produced. Similar to Example 3, the surface of the sodium hydrogen carbonate-added layer to which sodium hydrogen carbonate had been added had minute holes (continuous holes).
Thereafter, the laminated sheets were formed by vacuum forming, pressure forming, and press forming to produce an embossed carrier tape having a width of 12 mm and a length of about 20 m, and wound around a polystyrene reel. In this embossed carrier tape, an electronic component housing recess having a length of 5 mm, a width of 5 mm, and a depth of 0.5 mm was continuously formed so that the outermost surface layer in contact with the electronic component was a sodium hydrogen carbonate added layer. The stretch ratio at this time was about 144%.
The embossed carrier tape contains an epoxy resin-sealed 4.5 mm square SOP with a thickness of about 1 mm, and two sides are sealed with a cover tape from above. A parts package was obtained.

(Example 5)
A mixture of 20% calcium chloride as a desiccant with 100 parts of vinyl chloride compound and a mixture obtained by adding ADCA 1% as a foaming agent and a mixture not added are co-extruded and each 0.15 mm A sheet in which these layers were laminated was prepared.
After that, as in Example 4, the laminated sheets were formed by vacuum forming, pressure forming, and press forming to produce an embossed carrier tape having a width of 12 mm and a length of about 20 m, and wound on a polystyrene reel. It was. In this embossed carrier tape, an electronic component housing recess having a length of 5 mm, a width of 5 mm, and a depth of 0.5 mm was continuously formed so that the outermost layer on the surface in contact with the electronic component was a layer to which ADCA was added. The stretch ratio at this time was about 144%.
The embossed carrier tape contains an epoxy resin-sealed 4.5 mm square SOP with a thickness of about 1 mm, and two sides are sealed with a cover tape from above. A parts package was obtained.

(Comparative Example 1)
Only the mixed polystyrene compound obtained by removing the desiccant finely pulverized silica gel from the mixture of Example 1 was molded with a sheet extruder (Nippon Steel Works (manufactured)) to produce a polystyrene sheet having a thickness of about 0.3 mm. .
This sheet was stretched 19% in length and 5% in width in an atmosphere of 100 ° C. The stretch ratio at this time was about 125%.
This sheet is folded to produce a box-shaped electronic component packaging container 10 mm long, 10 mm wide, and 10 mm deep, in which an epoxy resin-sealed 4.5 mm square, approximately 1 mm thick SOP is stored. 1 side was left and all 7 sides were sealed with cellophane tape to obtain an electronic component package.

(Comparative Example 2)
A mixed polystyrene compound of Comparative Example 1 was formed by coextrusion of a mixture obtained by adding ADCA 1% as a foaming agent and a mixture not added, and each 0.15 mm layer was laminated to form a 0.3 mm thick polystyrene. A system sheet was prepared.
After that, as in Example 4, the laminated sheets were formed by vacuum forming, pressure forming, and press forming to produce an embossed carrier tape having a width of 12 mm and a length of about 20 m, and wound on a polystyrene reel. It was. In this embossed carrier tape, an electronic component housing recess having a length of 5 mm, a width of 5 mm, and a depth of 0.5 mm was continuously formed so that the outermost layer on the surface in contact with the electronic component was a layer to which ADCA was added. The stretch ratio at this time was about 144%.
The embossed carrier tape contains an epoxy resin-sealed 4.5 mm square SOP with a thickness of about 1 mm, and two sides are sealed with a cover tape from above. A parts package was obtained.

As is clear from this result, when the electronic component packaging sheets of Examples 1 to 5 having a resin layer containing a desiccant are used, no cracks are observed in the SOP, which is electrically good. It worked.
On the other hand, when the electronic component packaging sheet of Comparative Examples 1 and 2 having a resin layer not containing a desiccant was used, cracks were observed in the SOP and it did not function electrically.
Therefore, when the electronic component packaging sheet of the present invention having a resin layer containing a desiccant was used, it was confirmed that there was an effect of suppressing the occurrence of cracks during solder reflow.

Claims (7)

  A sheet for packaging electronic parts, comprising a resin layer containing a desiccant.   The sheet | seat for electronic component packaging of Claim 1 which contains a foaming agent in the said resin layer.   The electronic component packaging sheet according to claim 1 or 2, wherein the desiccant is at least one selected from silica gel, zeolite, calcium chloride, and magnesium sulfate.   The electronic component packaging container using the sheet | seat for electronic component packaging in any one of Claims 1-3.   The electronic component packaging container according to claim 4, wherein at least the outermost layer on the surface in contact with the electronic component is a resin layer containing a desiccant.   The electronic component packaging container according to claim 4 or 5, wherein the electronic component packaging sheet is used after being stretched.   The electronic component package which stored the electronic component in the electronic component packaging container in any one of Claims 4-6.