JPH07138440A - Thermoplastic fluororesin composition and jig for semiconductor production process - Google Patents

Abstract

PURPOSE:To obtain the subject composition useful as a jig for a semiconductor production process, having excellent chemical resistance, heat resistance and mechanical properties and only a slight dimensional change during heating by blending a thermoplastic fluororesin with a specific amount of a liquid crystal polyester having a specific structure. CONSTITUTION:This composition comprises (A) 100 pts.wt. of a thermoplastic fluororesin and (B) 3-90 pts.wt. of a liquid crystal polyester in which the component B is a copolymer of (i) tetrafluoroethylene and (ii) a perfluoroalkyl vinyl ether or a copolymer of the component (i) and (iii) ethylene and the component B comprises structural unit of formula I to formula III or formula I to formula IV in the molar ratio of formula II/I of 0.2-1.0, the molar ratio of (formula III+IV)/formula II of 0.9-1.1 and the molar ratio of the formula IV/formula III of 0-1.0.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermoplastic fluororesin composition having a resin composition which itself has excellent chemical resistance, heat resistance and mechanical properties, and whose molded body has little dimensional change when heated, and The present invention relates to a jig for a semiconductor manufacturing process, which is molded from the thermoplastic fluororesin composition.

[0002]

2. Description of the Related Art Fluororesin is widely used as a material for devices and jigs in semiconductor manufacturing processes because of its excellent chemical resistance. In particular, a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether (P
FA resins) and copolymers of tetrafluoroethylene and ethylene (ETFE resins) have excellent heat resistance and molding processability, and are therefore widely used in the same field.
However, the devices and jigs for semiconductor manufacturing processes molded from these thermoplastic fluororesins have drawbacks such as large shrinkage during molding, poor dimensional accuracy, and large linear expansion coefficient. Problems may occur in the semiconductor manufacturing process performed in a liquid bath at a high temperature of 200 ° C. In order to reduce the linear expansion coefficient of this thermoplastic fluororesin, a liquid crystal polymer blended, for example,
Japanese Unexamined Patent Publication (Kokai) No. 2-110156 relates to a fluororesin molded product obtained by mixing a fluororesin with a polymer exhibiting an anisotropic melting form. Although the present invention relates to a composition containing a polymer, none of them has a sufficient effect of improving the linear expansion coefficient. Further, JP-A-2-32147 discloses a composite composed of a thermoplastic liquid crystal resin and a thermoplastic fluororesin, but describes reduction of shrinkage rate of molded articles and reduction of linear expansion coefficient. Not not.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above problems by providing a resin composition having excellent chemical resistance, heat resistance, and mechanical properties, and at the same time, even when the molded product is heated. It is an object of the present invention to provide a thermoplastic fluororesin composition having a small dimensional change and a jig for a semiconductor manufacturing process, which is molded from the thermoplastic fluororesin composition.

[0004]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that the thermoplastic fluororesin is blended with a liquid crystal polyester having a specific structure in a specific amount to achieve the above object. It was found that a composition capable of achieving the above can be obtained, and that a molded product obtained from the composition has excellent suitability as a jig for a semiconductor manufacturing process, leading to the present invention. That is, the present invention is the invention described below. (1) A thermoplastic fluororesin composition comprising 100 parts by weight of a thermoplastic fluororesin and 3 to 90 parts by weight of a liquid crystal polyester, wherein the fluororesin is a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether or tetrafluoroethylene. Is a copolymer of ethylene and ethylene, wherein the liquid crystal polyester has the following structural unit (I),
(II), (III) or (I), (II), (II
I) and (IV), the molar ratio of (II) / (I) is 0.2 to 1.0, [(III) + (IV)] / (I
The molar ratio of I) is 0.9 to 1.1, (IV) / (II
The thermoplastic fluororesin composition is characterized in that the molar ratio of I) is 0 to 1.0.

[Chemical 2] (2) A jig for a semiconductor manufacturing process, which is molded from the thermoplastic fluororesin composition described in (1) above.

The thermoplastic fluororesin used in the present invention is a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether (perfluoroalkoxy resin: PFA resin), a copolymer of tetrafluoroethylene and ethylene (ETFE). Resin), both of which are polymers made of olefins including fluororesins. Commercially available products of PFA resin are trade names NEOFLON PFA AP-
210 (manufactured by Daikin Industries, Ltd.), trade name Teflon 34
0-J (manufactured by Mitsui DuPont Fluorochemical Co., Ltd.) and the like are commercially available products of ETFE resin, such as trade name NEOFLON ETFEEEP-521 (manufactured by Daikin Co., Ltd.) and Tefzel 200 (manufactured by Mitsui DuPont Fluorochemical Co., Ltd.). And so on. The liquid crystal polyester used in the present invention is
A polyester called a thermotropic liquid crystal polymer, which has the structural units (I), (II) and (III) described above.
Or (I), (II), (III), (IV), wherein the (II) / (I) molar ratio is 0.2 to 1.0,
The molar ratio of [(III) + (IV)] / (II) is 0.
9-1.1, the molar ratio of (IV) / (III) is 0
It is characterized by being 1.0. The liquid crystal polyester comprising the structural units (I), (II), (III) and (IV) is described in JP-B-47-47870.

In the fluororesin composition of the present invention, the mixing ratio of the liquid crystal polyester is 3 to 90 parts by weight, and the particularly preferable mixing ratio is 10 to 70 parts by weight with respect to 100 parts by weight of the fluororesin. When the mixing ratio of the liquid crystal polyester is more than 90 parts by weight, the hot water resistance is deteriorated, which is not preferable. The compounding ratio of liquid crystal polyester is 3
Even when the amount is less than the weight part, the desired effect of improving the dimensional accuracy is insufficient, which is not preferable.

With respect to the composition used in the present invention, glass fibers, silica-alumina fibers, wollastonite, carbon fibers, potassium titanate whiskers and the like in a fibrous or acicular shape are used within the range not impairing the object of the present invention. Reinforcing agent; Calcium carbonate, dolomite, talc, mica, clay, glass beads, and other inorganic fillers; Fluorocarbon resin and other release agents; Dyes, pigments, and other colorants; Antioxidants;
One or more usual additives such as a heat stabilizer, an ultraviolet absorber, an antistatic agent and a surfactant can be added. Further, a small amount of thermoplastic resin, for example, polyamide, polyester, polyphenylene sulfide, polyether ketone, polycarbonate, polyphenylene ether and modified products thereof, polysulfone, polyether sulfone,
It is also possible to add polyether imide or the like and a small amount of thermosetting resin such as one kind or two or more kinds of phenol resin, epoxy resin, polyimide resin and the like.

The means for mixing the raw material components to obtain the resin composition of the present invention is not particularly limited. Fluorine resin and liquid crystal polyester, if necessary, reinforcing agents such as glass fiber, inorganic fillers, release modifiers, heat stabilizers, etc. are mixed using a Henschel mixer, tumbler, etc., and then melted using an extruder. It is preferable to knead.

The jig for semiconductor manufacturing process molded from the thermoplastic fluororesin composition of the present invention means a jig used in processes such as chemical treatment, processing, cleaning and transportation in manufacturing semiconductor substrates and the like. Specific examples thereof include a semiconductor substrate supporting tool and a supporting device for chemical treatment, processing, or cleaning; a semiconductor substrate transfer jig, a transfer device; a container for storing cleaning chemicals, and the like, in whole or in part. Is molded with the thermoplastic fluororesin composition of the present invention. Since the jig for semiconductor manufacturing process molded with the thermoplastic fluororesin composition of the present invention has a small dimensional change during heating, with the increase in size of the semiconductor substrate, dimensional accuracy and a low linear expansion coefficient are required more than ever. It is preferably used for jigs for semiconductor manufacturing processes.

[0010]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto. The measurements and tests of various physical properties in the examples were carried out by the following methods. (1) Molding shrinkage: A flat plate-shaped test piece having a size of 64 mm square and a thickness of 3 mm was molded, and the molding shrinkage in the flow direction was measured. (2) Linear expansion coefficient: ASTM No. 4 dumbbell was molded, the center of the neck portion was cut out, and the linear expansion coefficient in the flow direction was measured using a thermomechanical analyzer. (3) Tensile strength: ASTM No. 4 tensile dumbbell is molded,
It was measured according to ASTM D638. (4) Flexural modulus, deflection temperature under load (hereinafter sometimes referred to as TDUL): length 127 mm, width 12.7 m
m, 6.4 mm thick test pieces were molded and AST
It was measured according to M D790 and ASTM D648. (5) Chemical resistance test: Molded ASTM No. 4 dumbbell,
The weight change after immersion in various chemicals at room temperature for a predetermined time and the retention of tensile strength were evaluated. (6) Moisture and heat resistance evaluation: JIS 1 (1/2) dumbbell (thickness 1.2 mm) was molded, and the obtained molded product was subjected to an accelerated life test apparatus TPC-412 (manufactured by Tabai Co., Ltd.). After the treatment was performed at 140 ° C. and 100% RH for a predetermined time, the tensile strength retention rate was evaluated. (7) Flowing temperature: When a resin heated at a temperature rising rate of 4 ° C./min is extruded from a nozzle having an inner diameter of 1 mm and a length of 10 mm under a load of 100 kgf / cm ² , the melt viscosity is 48.
A temperature of 000 poise.

Examples 1 to 3 and Comparative Examples 1 to 2 NEOFLON PFA AP-210 (manufactured by Daikin Industries, Ltd.) which is a copolymer (PFA resin) of tetrafluoroethylene and perfluoroalkyl vinyl ether, and a repeating structure. The unit is (I), (II), (II
I) and (IV), and (I) :( II) :( II
Liquid crystalline polyester resin A having a molar ratio of I) :( IV) of 60: 20: 15: 5 and a flow temperature of 323 ° C.
1 was mixed in a composition shown in Table 1 with a Henschel mixer, and then granulated at a cylinder temperature of 360 ° C. using a twin-screw extruder (PCM-30 type manufactured by Ikegai Tekko KK) to obtain a fluororesin composition. .

The obtained pellets are manufactured by Nissei Plastic Industry Co., Ltd.
Cylinder temperature of 37 using PS40E5ASE type manufactured by
Injection molding is performed at 0 ° C and a mold temperature of 180 ° C.
No. dumbbell, bending test piece, JIS1 (1/2) No. dumbbell, and test piece for molding shrinkage evaluation were molded, and using these, tensile strength, flexural modulus, molding shrinkage coefficient, linear expansion coefficient, A chemical resistance test and a moist heat resistance test were measured. The results are shown in Tables 1 and 2.

The thermoplastic fluororesin compositions (Examples 1 to 3) containing the liquid crystal polyester of the present invention show extremely low values of molding shrinkage and linear expansion coefficient, as well as excellent heat resistance and mechanical properties. Was. In addition, the compositions of Examples 1 to 3 all had excellent chemical resistance and wet heat resistance.

Further, when the compounding amount of the liquid crystal polyester is less than 3 parts by weight (Comparative Example 1), the effect of reducing the molding shrinkage and the linear expansion coefficient is not sufficient, and the compounding amount of the liquid crystal polyester is 90 parts by weight. In the case of exceeding (Comparative Example 2), the retention rate of tensile strength after the wet heat resistance test was slightly lowered.

Comparative Examples 3 and 4 As the liquid crystalline polyester B, its structural unit is
And (V) below, and the molar ratio of (I) :( V) is
The results of mixing and granulating the composition in the same manner as in Example 1 are shown in Tables 1 and 2 except that a composition having a flow temperature of 73:27 and a flow temperature of 265 ° C. is used. The compositions of Comparative Examples 3 and 4 exhibited higher values of molding shrinkage and linear expansion coefficient than the compositions of Examples 1 to 3.

[Chemical 3] Examples 4 to 6 Copolymers of tetrafluoroethylene and ethylene (ET
FE resin) is NEOFLON ETFE EP-521
(Manufactured by Daikin Industries, Ltd.) and the repeating structural unit is composed of the above (I), (II), (III), (IV),
The molar ratio of (I) :( II) :( III) :( IV) is 6
Liquid crystal polyester resin A2 having a flow temperature of 0: 20: 12: 8 and a flow temperature of 286 ° C. was mixed in a composition shown in Table 1 with a Henschel mixer, and then a twin-screw extruder (P manufactured by Ikegai Tekko KK)
(CM-30 type) was used to granulate at a cylinder temperature of 300 ° C. to obtain a thermoplastic fluororesin composition.

The pellets obtained had a cylinder temperature of 32.
Injection molding and evaluation of physical properties were performed in the same manner as in Example 1 at 0 ° C. and mold temperature of 130 ° C. The results are shown in Tables 1 and 2.
The fluororesin composition containing the liquid crystal polyester resin of the present invention had extremely low molding shrinkage and linear expansion coefficient, and also had excellent heat resistance and mechanical properties. In addition, all had excellent chemical resistance and wet heat resistance.

Comparative Examples 5 and 6 As the liquid crystalline polyester B, the structural unit is composed of the above (I) and the above (V), and the molar ratio of (I) :( V) is 73:27. The results obtained by carrying out the composition obtained by mixing and granulating in the same manner as in Example 4 except that one having a flow temperature of 265 ° C. is used are shown in Table 1 and Table 2.
Shown in. The compositions of Comparative Examples 5 and 6 showed higher values of molding shrinkage and linear expansion coefficient than the compositions of Examples 4 to 6.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

The thermoplastic fluororesin composition of the present invention comprises
The resin composition itself has excellent chemical resistance, heat resistance, and mechanical properties, and its molded body has little dimensional change during heating, and a semiconductor manufacturing process molded with the thermoplastic fluororesin composition. The jig is less dimensional change upon heating and is useful for the application.

Claims (2)

[Claims] 1. A thermoplastic fluororesin composition comprising 100 parts by weight of a thermoplastic fluororesin and 3 to 90 parts by weight of a liquid crystal polyester, wherein the fluororesin is a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether or It is a copolymer of tetrafluoroethylene and ethylene, and the liquid crystal polyester has the following structural units (I), (II), (III) or (I), (I
I), (III), (IV), (II) /
The molar ratio of (I) is 0.2 to 1.0, [(III) +
A molar ratio of (IV)] / (II) is 0.9 to 1.1,
(IV) / (III) molar ratio is 0-1.0, The thermoplastic fluororesin composition characterized by the above-mentioned. [Chemical 1] 2. A jig for a semiconductor manufacturing process, which is molded from the thermoplastic fluororesin composition according to claim 1.