JPH04257444A - Carrier tape - Google Patents

Abstract

PURPOSE:To enhance formability, barrier properties, solvent resistance, incineration characteristics and mechanical characteristics of a carrier tape by laminating a thermoplastic polyester having different characteristics on both faces of a specific thermoplastic polyester. CONSTITUTION:A thermoplastic polyester A comprising essentially polybutylene terephthalate whose melting point is 180 deg.C or higher and whose DELTATcg is 50 deg.C or lower is laminated on both faces of a thermoplastic polyester B being a copolymer and comprising essentially polyethylene terephthalate whose DELTATcg is 50 deg.C or higher and whose glass transition temperature is 60 deg.C or higher. In this case, a polyester film which is laminated so that the constitutional thickness ratio A:B of the polyester A to the polyester B is in the range of 1:100-1:5 is used. In order to improve slip properties after forming a carrier tape, inert particles are added to the polyester A.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a carrier tape for housing semiconductor devices, capacitors, resistors, etc., and particularly to a carrier tape with excellent moldability, barrier properties, solvent resistance, incineration properties, and mechanical properties. It is.

0002

2. Description of the Related Art Carrier tapes are used for storing and transporting electronic components such as semiconductor devices. This is, for example, JP-A No. 62-271858 and JP-A No. 6
This is shown in Exhibit No. 2-249444, and by drawing a polyvinyl chloride or polystyrene film with excellent moldability, cavities for filling semiconductor devices, etc. are formed in a row at equal intervals, and a carrier tape is also used. In order to transport the paper, engagement holes for engaging with guide pins of the transport mechanism are provided at a constant pitch. This carrier tape fills the cavity with semiconductor devices, etc.
The opening was used with a cover tape or top tape, such as polyethylene, adhered thereto.

0003

[Problems to be Solved by the Invention] However, when such a carrier tape is used, it easily cracks or breaks due to impact during transportation, and the carrier tape swells and deforms due to solvent, causing damage to internal semiconductor devices, etc. found to be damaged. Furthermore, if a semiconductor device or the like is stored for a relatively long period of time, the semiconductor device absorbs moisture and, for example, the sudden heat generated when it is mounted on a printed circuit board evaporates the moisture in the packaging material that makes up the semiconductor device. There is a problem of cracking or breaking. Furthermore, carrier tapes using polyvinyl chloride, for example, generate chlorine-based gas when incinerated after use, which poses the problem of having a serious impact on environmental pollution.

In other words, the object of the present invention is to create a carrier that has the moldability of polyvinyl chloride, polystyrene, etc. used in conventional carrier tapes, but has excellent barrier properties, solvent resistance, incineration properties, and mechanical properties. The purpose is to provide tapes.

[0005]

Means for Solving the Problems The present invention has the following configuration in order to solve the problems. That is, the melting point is 18
Thermoplastic polyester A with a ΔTcg of 0°C or higher and 50°C or lower is a thermoplastic polyester B with a ΔTcg of 50°C or higher
This carrier tape is characterized by using a polyester film laminated on both sides of the carrier tape.

Polyester A must have a melting point of 180°C or higher, preferably 200°C or higher. If the melting point is too low, it tends to fuse to the mold during thermoforming, causing problems. Also, the cold crystallization temperature (Tc) of the polyester
c) and the difference between the glass transition temperature (Tg) (Tcc - Tg)
ΔTcg defined by is required to be 50°C or less, preferably 40°C or less. If ΔTcg is too large, not only will the films tend to stick to the mold during molding, but the blocking property between the films will increase.

Further, it is preferable that polyester A has a crystal melting energy of 6 cal/g or more, since this has a large effect of improving adhesiveness and blocking properties.

[0008] Examples of resins having such characteristics include polybutylene terephthalate, polybutylene terephthalate/isophthalate copolymer, polybutylene naphthalate, etc., but polybutylene terephthalate is particularly preferred; Even if it contains a copolymerized component, it is 20 mol% or less, and the IV is 0.5 to 1.4.
dl/g range is preferable from the viewpoint of moldability.

[0009] In addition, for the purpose of improving the slipperiness after molding,
It is preferable to add inert particles of 0.01 to 10 μm to polyester A, more preferably 0.1 to 10 μm.
It is in the range of ~5 μm. Here, inert particles are inorganic compounds such as metal and/or metalloid oxides and/or carbonates such as silicon oxide, aluminum oxide, zirconium oxide, calcium carbonate, magnesium carbonate, or cross-linked polystyrene, cross-linked divinylbenzene, Infusible organic compounds such as benzoguanamine and silicone.

Particularly preferred inert particles in the present invention are at least one selected from silicon oxide such as colloidal silica and pulverized silica, crosslinked polystyrene, and silicone, since they are also excellent in terms of transparency.

Polyester B constituting the polyester film used in the carrier tape of the present invention has a ΔTcg
It is necessary that the temperature is 50°C or higher, preferably 6
Preferably, the temperature is 0°C or higher. If ΔTcg is too small, moldability will be poor, causing problems such as uneven wall thickness and whitening during molding. Furthermore, in order to improve moldability and improve the rigidity of the obtained molded product, the glass transition temperature is preferably 60°C or higher, more preferably 70°C or higher.
The temperature is 0°C or higher.

[0012] Preferred resins as polyester B in the present invention are copolyesters containing polyethylene terephthalate as a main component, and particularly preferred copolymerization components include 1,4 butanediol, neopentyl glycol, cyclohexanedimethanol, and cyclohexane. Preferably, the polyethylene terephthalate contains 2 to 45 mol% of at least one copolymer component of dicarboxylic acid, isophthalic acid, and 2,6-naphthalene dicarboxylic acid.

Furthermore, the crystal melting energy is 0.1 to 6.
Cal/g range is preferable because both heat resistance and moldability are good.

Furthermore, the catalyst system for polyester B is preferably a germanium-based or titanium-based catalyst that does not form precipitated particles, in order to improve transparency and moldability, and either the transesterification catalyst or the polymerization catalyst is preferably a germanium-based or titanium-based catalyst. It is preferable that it is a system.

The polyester film used in the carrier tape of the present invention has a structure in which polyester A is laminated on both sides of polyester B, but in this case, the polyester A laminated on both sides of polyester B must be the same. This is preferable in terms of good moldability, but the two layers may be different from each other as long as they are resins that fall within the category of polyester A described above.

The carrier tape of the present invention has a composition thickness ratio (A:B) of polyester A and polyester B on both sides of 1.
:100 to 1:5, preferably 1:80 to 1:10. If the lamination ratio is too large than the above range, problems such as sticking during molding and decreased heat resistance will occur. On the other hand, if the lamination ratio is too small, uniform moldability will decrease and problems such as uneven thickness will occur.

The haze of the film portion of the carrier tape main body of the present invention is preferably in the range of 0.5 to 10% because moldability is improved, and more preferably in the range of 1 to 8%.
It is good if it is within the range of %.

Furthermore, the water vapor permeability of the polyester film used in the carrier tape body of the present invention is 15 g/m.
2 ・24hr/0.1mm or less, preferably 1
0g/m2 ・24hr/0.1mm or less, even 8
g/m2・24hr/0.1mm or less is preferable. If the water vapor transmission rate is high, if a semiconductor device or the like is stored for a relatively long period of time, the semiconductor device may absorb moisture, cause deterioration or deformation of the semiconductor device itself, or may be exposed to sudden heat when mounted on a printed circuit board. There is a problem in that moisture in the packaging material constituting the semiconductor device evaporates, causing the packaging material to crack or break.

[0019] Therefore, it is preferable that the polyester A layer is substantially crystallized. Surface layer polyester A
The presence of crystalline structure in the layer reduces water vapor permeability.

This substantially crystallized state means that when only the polyester A layer is taken out and measured with a differential scanning calorimeter, there is no cold crystallization peak between the glass transition temperature and the melting point, or there is no cold crystallization peak in the 2nd run. This refers to a state in which the peak area is smaller than the cold crystallization peak that sometimes occurs. Therefore, after forming the polyester film or forming the carrier tape, for example, polyester A
It is preferable to carry out the heat treatment at a temperature of Tg to Tcc+50°C. Furthermore, tabular particles may be added to the polyester A layer, or a hydrophobic layer may be coated on the outside of the polyester A layer. Alternatively, a liquid crystalline polymer may be copolymerized or blended, and layer A may be oriented by shear orientation within an extruder, particularly within a die during film formation.

Furthermore, in order to reduce water vapor permeability,
For the polyester B layer, it is preferable to copolymerize components such as diphenylsulfonedicarboxylic acid, diphenyldicarboxylic acid, bis(4-hydroxyethoxyphenyl)sulfone, and cyclohexanedimethanol.

Further, the haze of the polyester film used in the carrier tape body of the present invention when immersed in a ketone solvent is 10% or less, more preferably 8% or less, based on a thickness of 100 μm. This is because while a semiconductor device or the like is being transported by the carrier tape, the carrier tape may swell and deform due to the solvent used in the adhesive or the like, and there is a risk that the semiconductor device or the like inside the carrier tape may be damaged. The ketone solvents mentioned here are acetone, methyl ethyl ketone, and cyclohexanone, and the immersion time is 10 minutes. Therefore, the polyester A layer may be substantially crystallized or oriented as described above. In addition, the polyester A and polyester B layers contain diphenylsulfone dicarboxylic acid, naphthalene dicarboxylic acid, α, β
-Bis(2-chlorophenoxy)ethane It is preferable to copolymerize components such as 4,4'-dicarboxylic acid, diphenyldicarboxylic acid, and bis(4-hydroxyethoxyphenyl)sulfone.

[0023] The molding temperature of the carrier tape formed by thermoforming a polyester film must be higher than the glass transition temperature of polyester B and lower than the melting point of polyester A, preferably lower than the glass transition temperature of polyester B. It is preferably in the range of +5°C or higher and the melting point of polyester A -20°C. If the molding temperature is too low,
Problems such as molding defects and cracks occur. On the other hand, if the molding temperature is too high, transparency may decrease due to adhesion or uneven thickness may occur.

[0024] Here, the molding temperature as used in the present invention refers to the temperature observed as the quasi-crystalline melting temperature when the thermal properties of the polyester molded body are investigated using a differential scanning calorimeter. That is, by heating during molding, a quasicrystal having a melting point equal to the heating temperature is generated. The quasicrystal can be clearly distinguished from the original crystal, and when the thermal properties of a sample obtained by remelting the molded body and then slowly cooling it are similarly examined, the quasicrystal melting peak disappears. Note that the actual molding temperature and the quasi-crystal melting temperature do not necessarily match, and in the present invention, the quasi-crystal melting temperature is defined as the molding temperature.

The polyester film or molded body used in the carrier tape of the present invention contains an antistatic agent, an organic
Inorganic slip agents, heat stabilizers, antioxidants, crystal nucleating agents,
Additives such as weathering agents, UV absorbers, and pigments can be used depending on the purpose.

The thickness of the polyester film used in the carrier tape of the present invention should be determined depending on the intended use, but is usually in the range of 50 to 2000 μm.

[0027] The polyester film may also be subjected to surface roughening treatments such as embossing, sand matting, and satin finishing.

Next, a method for manufacturing the carrier tape of the present invention will be explained, but of course the method is not limited thereto.

Polyester A and polyester B are melt-extruded using separate extruders, and then melt-extruded using a feed block or a manifold composite die into a film or cylinder having an A/B/A configuration. The film or cylinder is then quench cast below the cold crystallization temperature of Polyester A, preferably below the glass transition temperature. The cast film thus obtained is brought into contact with a roll heated to around Tcc-10 to Tcc+50°C of polyester A and wound up. If necessary, discharge treatment such as corona discharge treatment or plasma treatment, coating, embossing, etc. may be performed after or before the heat treatment.

[0030] Next, when forming the carrier tape of the present invention, the forming method is not particularly limited, and various forming methods such as known vacuum forming, pressure forming, plaque assist forming, drawing forming, etc. can be used.

In this way, the cavities filled with semiconductor devices and the like are provided in a line at equal intervals, and in order to transport the carrier tape, engagement holes for engaging guide pins of the transport mechanism are provided at a constant pitch. This carrier tape is
The cavity is filled with semiconductor devices and the like, and the opening is used with a cover tape or top tape, such as polyethylene, adhered to the opening.

[0032]

[Method of measuring physical properties]

(1) 100 μm equivalent haze (H100) JIS
-Measured according to K-6714 and calculated using the following formula.

H100 (%)=H×100/d, where H is the actual value of haze (%), and d is the film thickness (μm) at the haze measurement part.

[0034] The internal haze is also measured in the same manner by immersing it in a quartz cell containing tetralin.

(2) Intrinsic viscosity (IV) Measured at 25°C using o-chlorophenol as a solvent. The unit is dl/
g.

(3) Molding temperature: Cut out a desired area from the molded product, preferably as only the polyester A layer, and use a differential scanning calorimeter DSC2 (manufactured by PerkinElmer) to heat 10 mg of sample at 10°C/min from room temperature. The forming temperature is defined as the quasicrystalline melting temperature peak observed when heating is carried out at a heating rate of . Note that the quasicrystalline melting temperature appears as a melting peak temperature lower than the crystalline melting temperature.

(4) Melting point (Tm), glass transition temperature (
Tg), cold crystallization temperature (Tcc), and melting energy are determined using a differential scanning calorimeter DSC2 (manufactured by PerkinElmer).

In the measurement, 10 mg of the sample was melted and held at 280° C. for 5 minutes under a nitrogen stream, and then cooled using liquid nitrogen.

When the sample thus obtained was heated at a heating rate of 10°C/min, the change in specific heat due to the transition from the glass state to the rubber state was read and this temperature was determined as the glass transition temperature ( Tg). Further, the exothermic peak temperature accompanying crystallization was defined as the cold crystallization temperature (Tcc), and the endothermic peak temperature based on crystal melting was defined as the melting point (Tm).

Further, the crystal melting energy was measured from the melting peak area using the metallic indium melting energy as a reference.

(5) The water vapor permeable polyester film was measured according to JIS-Z0208.

(6) Solvent resistance The sample was immersed in methyl ethyl ketone at 25° C. for 10 minutes, and after drying, the haze in terms of 100 μm was measured.

[0043]

EXAMPLES Next, the present invention will be explained in more detail by way of examples.

Example 1 Polybutylene talephthalate (PBT, Tm=220°C, IV=0.7 dl/g) as polyester A;
As polyester B, poly(ethylene/1,4 cyclohexane dimethylene) terephthalate (P(E/C)T,
Copolymerization ratio (E:C) = 90:10 mol%, Tm = 240
℃, IV = 0.65 dl/g) were prepared and melted and extruded at 270℃ using separate extruders, laminated with a feed block, and a molten sheet consisting of A/B/A was prepared using a T-shaped nozzle. It was extruded, cooled and solidified on a casting drum at 20°C, and then brought into contact with a heated roll at 50°C and wound up. The sheet thus obtained has a total thickness of 200 μm, a lamination ratio (A:B:A) of 1:10:1, and a layer ratio of 110 μm.
When a carrier tape was prepared by drawing at ℃, it was excellent in both formability and transparency.

Examples 2 to 3 As polyester B, polyethylene terephthalate
Table 1 was prepared according to Example 1 using isophthalate PET/I (Example 2) and poly(ethylene/bis(4-hydroxyethoxyphenyl)sulfone) terephthalate P(E/BPS)T (Example 3). When the sheets were obtained as described above and carrier tapes were made, all of them had excellent moldability and transparency.

Examples 4 to 5 As polyester A, polybutylene naphthalate (P
BN, Tm=240°C, IV=0.7 dl/g), poly(ethylene/bis(4-hydroxyethoxyphenyl)sulfone) terephthalate P(E
/BPS)T was extruded in the same manner as in Example 1, and 20
Cool and solidify on a casting drum at °C (Example 4)
As for Example 5, it was further brought into contact with a heated roll at 70°C and wound up. The sheet thus obtained has a total thickness of 200μ
m, the lamination ratio (A:B:A) was 1:10:1, and the carrier tape was further drawn at 110°C to create a carrier tape. Regarding Example 5, after molding, heat treatment was performed again for 5 minutes in a hot air oven at 70°C. All of them had excellent moldability and transparency, and in Example 5, the water vapor barrier properties were improved.

Comparative Example 1 Film formation was carried out in the same manner as in Example 1 except that polyethylene terephthalate (PET) was laminated instead of PBT to obtain a sheet with a thickness of 200 μm. As a result of the moldability test, mold blocking occurred and transparency deteriorated. It can also be seen that the water vapor barrier properties and solvent resistance are poor.

Comparative Example 2 20% of PBT was added to polyethylene terephthalate (PET).
wt% blended, melt-extruded as a single film, and cooled and solidified according to Example 1 to obtain a 200 μm sheet. In the moldability test, uneven thickness occurred and transparency also deteriorated. It was also inferior in water vapor barrier properties and solvent resistance.

Comparative Example 3 Polyester A in Example 1 had a melting point of 140
Polybutylene terephthalate/isophthalate (P
A film was formed in the same manner except that BT/I) was used. It can be seen that there are practical problems in both moldability and transparency.

[0050]

[Table 1]

[0051]

[Table 2]

[0052]

[Table 3]

[0053]

Effect of the invention: Melting point is 180°C or higher, ΔTcg is 50°C
The following thermoplastic polyester A is laminated on both sides of thermoplastic polyester B having a ΔTcg of 60°C or more, and the structural thickness ratio of polyester A and polyester B (A:
By using a polyester film characterized in that B) is in the range of 1:100 to 1:5, moldability,
A carrier tape with excellent barrier properties, solvent resistance, and incineration properties can be provided.

Claims (5)

[Claims] [Claim 1] Melting point is 180°C or higher and ΔTcg is 50
A carrier tape comprising a polyester film in which a thermoplastic polyester A having a temperature of .degree. C. or less is laminated on both sides of a thermoplastic polyester B having a .DELTA.Tcg of 50.degree. Here, ΔTcg is the cold crystallization temperature (Tcc)
and the glass transition temperature (Tg) (Tcc - Tg). 2. Claim 1, wherein the polyester film has a water vapor permeability of 15 g/m2 24 hr/0.1 mm or less and a haze value of 10% or less after immersion in a ketone solvent. Carrier tape as described in section. 3. Claim 1, characterized in that polyester A is a copolymer mainly composed of polybutylene terephthalate and polyester B is a copolymer mainly composed of polyethylene terephthalate having a glass transition temperature of 60° C. or higher. or a carrier tape according to paragraph 2. 4. Polyester B is 1,4 butanediol, neopentyl glycol, cyclohexanedimethanol, cyclohexanedicarboxylic acid, isophthalic acid,
The carrier tape according to claim 1 or 2, which is polyethylene terephthalate containing 2 to 45 moles of at least one copolymer component selected from 2,6-naphthalene dicarboxylic acids. 5. Any one of claims 1 to 4, characterized in that the constituent thickness ratio (A:B) of polyester A and polyester B is in the range of 1:100 to 1:5. Carrier tape described in Crab.