JPH05201461A - Carrier tape for chip type electronic component packaging - Google Patents

Abstract

PURPOSE:To improve the moistureproofness by a method wherein an embossed tape on which storage pockets to store electronic components are continuously formed is constituted of a composite sheet which includes a thermoplastic resin layer and a metal layer with moistureproof function, and the moisture permeable degree is specified. CONSTITUTION:The title carrier tape 1 is made of either one of crystalline polyester, non-crystalline polyester, polyurethane, polypropylene, polycarbonate, ABS, polyacrylonitrile or poly(vinyl chloride), and is constituted of a composite sheet with a first layer 2 made of a thermoplastic resin, which is emboss- formable, with a thickness of approximate 50-400mum, and a second layer 3, which is a metal layer with moistureproof function, made of Al, Cu, Zn, Sn, Ni, Ti or a compound of these, with a thickness of 1-50mum. This composite sheet is prepared in such a manner that the moisture permeable degree becomes 1.5g/m<2>.24hr or less at a measuring method by JIS Z 028 40 deg.C, 90%RH.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package having a function of protecting the chip-type electronic components from contamination during storage, transportation and mounting of the chip-type electronic components and aligning and removing them for mounting on an electronic circuit board. Of these, the present invention relates to a plastic carrier tape having a storage pocket.

[0002]

2. Description of the Related Art In recent years, ICs, transistors, diodes, capacitors, piezoelectric element resistors,
Chip-type electronic components for surface mounting such as are packaging consisting of a plastic carrier tape in which embossed pockets that can be stored are continuously formed according to the shape of the electronic component, and a cover tape that can be sealed on the carrier tape. It is packaged and supplied by the body. The electronic components of the contents are transported and stored in a carrier tape, the cover tape of the package is peeled off, and then automatically taken out and surface-mounted on the electronic circuit board. With the development of this surface mounting technology, electronic parts to be made into chips are gradually spreading from mechanical parts to highly integrated parts such as IC and LSI. In these highly integrated components, if the sealing resin that protects the electronic circuit absorbs humidity in the atmosphere, it causes cracks during solder mounting, which is a serious problem. After undergoing a baking process, the tape is taped to a carrier tape, sealed in an Al moisture-proof bag called a dry pack, and then transported and stored to prevent moisture absorption. Further, since it takes time to mount the electronic components in one reel of the carrier tape at the time of mounting, it is inevitable to repeat the process of transferring to a tray, baking, and using again. For this reason, the process is complicated and further packing of the carrier tape, re-baking, and the like are required twice, and it is strongly desired to simplify the process while maintaining moisture resistance of the product. The material to be molded for the carrier tape was not selected as a moisture-proof function because it was selected mainly for moldability that can be used for the shape of various electronic components, and it was not a material having heat resistance above the baking temperature.

[0003]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has been earnestly studied to obtain a carrier tape having a moisture-proof function while maintaining molding processability into various embossed shapes. As a result, a carrier tape in which at least one layer of the carrier tape is a thermoplastic resin having good moldability and at least the other layer is a composite sheet of two or more layers composed of a metal layer having a moisture-proof function is good. The present invention has been completed based on the knowledge that it has various characteristics.

[0004]

The present invention is a plastic embossed tape in which storage pockets for storing chip-type electronic components are continuously formed, and at least one layer of the carrier tape is amorphous polyester. (Amorphous P
ET), polyurethane (PU), polypropylene (P
P), polystyrene (PS), polycarbonate (P
C), ABS, polyacrylonitrile (PAN), polyvinyl chloride (PVC), which is an embossable thermoplastic resin, and at least the other layer is Al,
A composite sheet having two or more layers of Cu, Zn, Sn, Ni, Ti, or a compound thereof, and the moisture permeability of the composite sheet is JIS Z 0208 40 ° C., 90% R.
It is 1.5 g / m ² · 24 hr or less as measured by H.
This is a chip-type carrier tape for packaging electronic components, which has excellent moisture resistance while suppressing moisture absorption of electronic components in pockets during product transportation and storage processes.

[0005]

The components of the carrier tape 1 of the present invention will be explained with reference to FIG. 1. The first layer 2 is made of crystalline polyester, amorphous polyester, polyurethane, polypropylene, polystyrene, polycarbonate, ABS, polyacrylonitrile, polyvinyl chloride. It is either and the thickness is 50-4.
It is a thermoplastic resin of 00 μm that can be embossed. 5
If the thickness is less than 0 μm, the sheet strength will be insufficient, and if it exceeds 400 μm, the formability will be significantly reduced. The second layer 3 is made of Al, C
u, Zn, Sn, Ni, Ti, or a compound thereof, which is a metal layer having a moisture-proof function and having a thickness of 1 to 50 μm. If it is less than 1 μm, the moisture-proof function is insufficient,
When it exceeds 50 μm, the formability is remarkably lowered and the cost is increased. The metal layer is formed by a method such as adhesion of a metal foil, vapor deposition of metal or metal oxide, sputtering, ion plating, etc., and any method may be used without any particular limitation. The side of the first layer 2 in contact with the second layer 3 or the side of the second layer 3 in contact with the first layer 2 is subjected to corona treatment, plasma treatment, sand blast treatment, chemical treatment for the purpose of improving the adhesion between the two layers. Surface treatment such as treatment may be applied. Further, for the same purpose, both may be laminated via a thermosetting adhesive layer such as isocyanate type or imine type. For the purpose of imparting antistatic performance, an antistatic agent, a conductive powder or the like may be kneaded or coated on the surface of the resin of one layer or both layers.

Regarding the moisture-proof performance, the moisture permeability of the composite sheet must be at least 1.5 g / m ² · 24 hr or less, preferably 0.6 g / m ² according to JIS Z 0208 40 ° C., 90% RH. m ² · 24 hr or less is good. If it exceeds 1.5 g / m ² · 24 hr, the function of preventing cracks in the encapsulating resin during solder mounting is insufficient, so protection and storage by packaging in a moisture-proof bag in the subsequent process, or rebaking is required. Will be needed. When performing embossing molding, the layer on the side of the carrier tape that is sealed with the cover tape may be either the first layer 2 or the second layer 3, but in order to make the sealing property with the cover tape more stable. It is desirable that the first layer 2 be the surface of the carrier tape that is sealed to the cover tape. Further, the layers constituting the carrier tape may be a composite film of three or more layers having the above two layers as a basic unit.

[0007]

EXAMPLES Examples of the present invention are shown below, but the present invention is not limited to these examples. << Examples 1, 2, 3, 4, 5, 7, 8, 9 and Comparative Examples A, B, C, D >> A first layer made of a thermoplastic resin excellent in embossing moldability and having a sheet thickness of 200 μm. A composite sheet for carrier tape having a total thickness of 210 μm having a two-layer structure is formed by adhering a second layer of a metal layer having a thickness of 10 μm made of a metal foil having excellent moisture resistance to a second layer with a two-component thermosetting urethane adhesive by dry lamination. Obtained. The obtained composite sheet was emboss-molded by a pressure molding machine with a layer having a moisture-proof function outside the embossing to obtain a carrier tape having a width of 24 mm.
In addition, the moisture permeability of the composite sheet is measured according to JIS Z 0208 method 40.
It was measured at 90 ° C. and 90% RH. Next, electronic parts QFP
52P was housed in an embossing, and the biaxially stretched film of the outer layer 5 having the layer structure shown in FIG. 2 was sealed with PET and the sealant layer 7 was covered with a cover tape using an acrylic adhesive. After the sample was placed in an environment of 30 ° C. and 70% RH for 60 days, the cover tape was peeled off and the weight change due to the moisture absorption of the sealing resin of the electronic component was measured to calculate the moisture absorption rate. Next, the electronic parts taken out were subjected to IR reflow (240 ° C, 1
(0 seconds) solder treatment and the presence or absence of cracks are observed with an engineering microscope (× 100), and various evaluation results are shown in Table 1.
It was shown to.

[0008]

Note 1: The raw material name of the resin used is as follows. PVC: Sumitomo Bakelite Co., Ltd. VSS-1
202 PS: Mitsui Toatsu Kagaku Co., Ltd. Topolex PC: GE Co., Ltd. Lexan PP: Sumitomo Chemical Co., Ltd. Noblene PAN: Mitsui Toatsu Kagaku Co., Ltd. Zekron Urethane: Kyowa Hakko Kogyo Co., Ltd. Estan ABS: Sumitomo Nogatac Co., Ltd. Clarastic PET: Eastman Chemical Co., PE
T-G (amorphous) Note 2: The moisture permeability is JIS Z in the state of the composite sheet before molding.
0208 Measured at 40 ° C. and 90% RH. Note 3: Moisture absorption is 30 ℃, 7 after sealing in carrier tape.
QFP in carrier tape treated with 0% RH for 60 days
Calculated from the weight change of 52P (14 mm × 14 mm × 2 mmt). Note 4: The crack was evaluated by soldering the electronic component taken out from the carrier tape and observing the surface of the sealing resin at that time.

[0010]

According to the present invention, the electronic components stored in the carrier tape do not absorb moisture during the transportation and storage of the electronic components even if they are not re-packaged by the dry pack in the subsequent process, and even during the mounting process. Rebaking is not necessary, and it is possible to prevent cracks from occurring in the sealing resin during the soldering process. At the same time, the dry pack packaging process and the rebaking process can be omitted, and the number of steps can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing a layer structure of a carrier tape of the present invention.

FIG. 2 is a cross-sectional view showing an example of a layer structure of a cover tape for sealing the carrier tape of the present invention.

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[Procedure amendment]

[Submission date] January 31, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

Claims (2)

[Claims] 1. A plastic embossing tape in which storage pockets for storing chip-type electronic components are continuously formed, wherein at least one layer is an embossable thermoplastic resin and at least the other layer is a moisture-proof function. A composite sheet having two or more layers including a metal layer having a moisture permeability of JIS Z 020840 ° C. and 90% RH.
A carrier tape for packaging chip-type electronic parts, which has a weight of 1.5 g / m ² · 24 hr or less as measured by. 2. The emboss-moldable thermoplastic resin is any one of amorphous polyester, polyurethane, polypropylene, polystyrene, polycarbonate, ABS, polyacrylonitrile, and polyvinyl chloride, and the metal layer having a moisture-proof function is Al, Cu. The carrier tape for packaging a chip-type electronic component according to claim 1, wherein the carrier tape is any one of Zn, Sn, Ni, Ti and compounds thereof.