JP2003286568A - Adhesive tape for masking - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive tape for masking, which prevents a blister from occurring at a high temperature by exhausting an expanded air through a passage to the outside, and provides a more reliable masking effect. <P>SOLUTION: The adhesive tape for masking, which is used for masking a surplus solder in a step of joining the target material of the sputtering target to the backing plate with solder, comprises an adhesive layer 2 formed on one side of a substrate 1, which has a non-adhesive section in a part of a masking region, and passages 3 for ventilating air from the non-adhesive section to the outside of the masking region. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a masking pressure-sensitive adhesive tape used for masking excess solder when joining a target material of a sputtering target and a backing plate material with solder.

[0002]

2. Description of the Related Art Conventionally, a sputtering target is generally used in which a target material made of a material for forming a thin film is attached to a backing plate made of a material having excellent electric conductivity and thermal conductivity. The sputtering target may be simply screwed to the target material, but generally a structure in which the target material is bonded to the backing plate with a bonding material has been adopted (JP-A-6-293963, JP-A-11-20).
No. 0028). At that time, as the bonding material, the target material is cooled from the backing plate side,
Further, low melting point solder is mainly used in order to surely obtain an electrical contact. In addition, an ITO sintered body or the like is used as the target material, and copper or its alloy or stainless steel is often used as the backing plate.

To manufacture such a sputtering target, it is necessary to once heat the bonding material above its melting point in order to bond the target material and the backing plate. At this time, the bonding material with high fluidity may squeeze out to the outside of the joint,
If the protruding bonding material is not removed, the commercialability will be greatly reduced.

For this reason, Japanese Patent Laid-Open No. 11-200028 discloses that a wall is made of a copper plate or the like and a seam is masked with an adhesive tape. Further, in order to prevent scratches and foreign matters from adhering to the sputtering target, various mask materials are attached with an adhesive tape or masked with the adhesive tape itself. After such a pressure-sensitive adhesive tape is bonded to the target material and the backing plate, it becomes unnecessary and is peeled off.

On the other hand, the backing plate is often provided with through holes and non-through holes such as mounting holes and positioning holes for fixing to the sputtering apparatus. The masking tape is usually attached so as to close the hole.

[0006]

However, when the temperature is raised for bonding, the air in the holes expands, pushing up the masking tape and causing swelling, which may cause the masking tape to rise. In particular, when the tape width is narrow, there is a concern that the end portion may be lifted and solder may enter from there, thus contaminating the surface.

In fact, when the holes are contaminated, the removal work is more difficult than the adhesion on the upper surface, and when the holes cannot be completely removed, the diameter of the holes changes, which causes problems such as installation failure.

Therefore, an object of the present invention is to allow the air expanded by the flow passage to escape to the outside to prevent the expansion under high temperature,
An object of the present invention is to provide an adhesive tape for masking that can obtain a more reliable masking effect.

[0009]

The above object can be achieved by the present invention as described below. That is, the masking pressure-sensitive adhesive tape of the present invention is a masking pressure-sensitive adhesive tape used for masking excess solder when joining the target material of the sputtering target and the backing plate material with solder, The pressure-sensitive adhesive layer formed on one side has a non-adhesive portion in a part of the masking region, and a flow passage through which air can flow from the non-adhesive portion to the outside of the masking region is provided.

In the above, it is preferable that the pressure-sensitive adhesive layer is formed in a plurality of streaks, and the non-formed portion constitutes the flow passage. At that time, it is more preferable that the pressure-sensitive adhesive layer is formed in a stripe shape in the longitudinal direction of the substrate.

Alternatively, it is preferable that the flow passage is formed of a porous film. At that time, it is more preferable that the porous film is a fluororesin film.

[Advantages] According to the adhesive tape for masking of the present invention, the adhesive layer has a non-adhesive portion in a part of the masking region, and a flow passage through which the non-adhesive portion can ventilate to the outside of the masking region. Since the air is provided, the expanded air can be released to the outside through the flow passage, so that the expansion under high temperature can be prevented and a more reliable masking effect can be obtained.

Further, when the pressure-sensitive adhesive layer is formed in a plurality of streaks and the non-formed portion constitutes the flow passage, the flow passage can be formed by a simple method, which is cost and manufacturing process-friendly. To be advantageous. In particular, when the pressure-sensitive adhesive layer is formed in a stripe shape in the longitudinal direction of the base material, continuous production can be easily performed, and solder is less likely to flow from the side surface of the tape.

When the flow passage is formed of a porous film, the porous film makes it difficult for molten solder to flow into the holes, so that a more reliable masking effect can be obtained. In particular, when a film made of a fluororesin is used, the molten solder hardly flows into the holes due to the surface characteristics of the fluororesin, which is advantageous in terms of heat resistance.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are perspective views showing examples of the masking adhesive tape of the present invention.

The masking adhesive tape of the present invention is used for masking excess solder when the target material of the sputtering target and the backing plate material are joined by solder.

As the target material of the sputtering target and the backing plate, any conventionally known material can be used. For example, as the material of the target material,
An ITO sintered body or the like can be used, and as the material of the backing plate, copper or its alloy, stainless steel or the like can be used. As the solder for joining the two, for example, an In-based metal, a Sn-based metal, or the like can be used. The joining method and joining form of the two are described in JP-A-6-293963 and JP-A-11-2.
[00028], JP-A-61-250167,
The details are described in JP-A-5-25620, JP-A-2-43362, JP-A-4-365857, and the like.

In the masking pressure-sensitive adhesive tape of the present invention, for example, as shown in FIG. 1, the pressure-sensitive adhesive layer 2 formed on one surface side of the substrate 1 has a non-tacky portion in a part of the masking region, It is characterized in that a flow passage 3 is provided which allows ventilation from the portion to the outside of the masking region. A preferred embodiment of the adhesive masking tape of the present invention is illustrated in FIGS. 1 to 4 show a state in which the masking adhesive tape of the present invention is attached to the masking object 10.

The embodiment of FIG. 1 is an example in which the pressure-sensitive adhesive layer 2 is formed into a plurality of streaks, and the non-formed portion constitutes the flow passage 3, and thus the pressure-sensitive adhesive layer 2 is a base. It is preferable that the material 1 is formed in a stripe shape in the longitudinal direction. As a method for forming the pressure-sensitive adhesive layer 2 in a streak shape, there is a method of applying the pressure-sensitive adhesive in a streak shape. Good. In any case, since the adhesive on the convex portion adheres to the adherend, the hollow portion serves as the air flow passage 3.

Further, as an advantage of this method, the flow passage 3 can be secured in the longitudinal direction of the adhesive tape. For this reason, in a place far from the part where the solder is used, such as the back surface,
Since the air outlet can be secured, the solder can be effectively prevented from entering.

In the embodiment shown in FIG. 2, the flow passage 3 is formed by a porous film 4, in which case the pressure-sensitive adhesive layer 2 is formed on the entire surface of one side of the substrate 1, and the porous layer is formed in the central longitudinal direction. This is an example in which the quality film 4 is attached. When the flow passage 3 is formed by the porous film 4 as described above, the porous film 4 may be adhered to the base material 1 without using the pressure-sensitive adhesive layer 2. For example, it is possible to bond the two by heat fusion or another adhesive.

The embodiment shown in FIG. 2 is effective in the case where the pressure-sensitive adhesive is softened at a high temperature and the step disappears due to the progress of wetting, and the air flow passage 3 is blocked, and the porous film 4 is used. The flow passage 3 is secured inside, and the air is discharged more reliably. Further, in this case, since the adhesive tape can be produced by pasting it on an ordinary adhesive tape which is not streak-coated, there are less restrictions on the production of the adhesive tape such as the type of adhesive and the type of substrate.

The embodiment shown in FIG. 3 is an example of forming the flow passage 3 by deforming the adhesive tape itself. Such a flow passage 3 is formed by extruding the base material 1 with a cross section having a recess,
The flat sheet can be formed by embossing the concave portions in a streak shape using an embossing roller or the like. Further, at the time of applying and forming the pressure-sensitive adhesive layer 2, the shape of the pressure-sensitive adhesive tape may be restored after the pressure-sensitive adhesive is applied so that the base material 1 is temporarily flat.

The embodiment of FIG. 4 is an example in which the opening of the flow passage 3 is provided on one of the long sides of the adhesive tape. In this case, when the pressure-sensitive adhesive is applied to the base material 1, it may be applied in a comb shape, for example, by screen printing. Alternatively, the pressure-sensitive adhesive layer 2 may be formed into a comb shape by using a lithography technique.

Hereinafter, a substrate that can be used in the present invention,
The adhesive and the like will be described. Considering the heat resistance, the pressure sensitive adhesive is preferably a silicone pressure sensitive adhesive, but
For example, any adhesive such as an acrylic or rubber adhesive may be used as long as it has heat resistance at 200 ° C. As the silicone adhesive, a silicone adhesive having a toluene insoluble content of 35% or more is particularly preferable. In general, silicone adhesives are said to have excellent heat resistance, but if there is no cohesive force, adhesive residue will not escape and the toluene insoluble content of silicone adhesives will be 3
When it is 5% or more, a tape in which adhesive residue hardly occurs even at high temperature (130 ° C or more) can be obtained. Specifically, 130 ℃
Those which can be peeled off without waiting for the adhesive to remain without waiting for cooling are more preferable, and those which can be peeled off without waiting for cooling to 200 ° C. are more preferable. When peeling off at 200 ℃ or higher, in order to eliminate glue residue, toluene insoluble content should be 45
% Or more is preferable.

Toluene-insoluble matter is the composition of the base polymer, the type and amount of the crosslinking agent, the drying temperature (curing temperature).
It can be adjusted by changing, for example, but in the present invention, the amount of insoluble matter in the case of using the pressure-sensitive adhesive tape only needs to exceed the above-mentioned number, and the blending of the crosslinking agent and the drying temperature are not particularly limited.

Such a silicone-based pressure-sensitive adhesive contains, for example, silicone rubber or silicone resin containing organopolysiloxane as a main component, and a crosslinking agent is added to this to cure it to form a pressure-sensitive adhesive layer. be able to. As described above, the pressure-sensitive adhesive is usually added with a crosslinking agent to form a three-dimensional structure to increase cohesive force. In addition, a tackifier, an antioxidant, other additives, and the like can be added to the pressure-sensitive adhesive, if necessary.

As the silicone rubber, various kinds of silicone-based pressure-sensitive adhesives can be used without particular limitation. For example, organopolysiloxane containing dimethylsiloxane as a main constituent unit can be preferably used. A vinyl group and other functional groups may be introduced into the organopolysiloxane as needed. The weight average molecular weight of the organopolysiloxane is usually 180,000 or more, preferably 280,000 to 1,000,000, particularly preferably 500,000 to 900,000.

As the silicone resin, various resins used in silicone pressure-sensitive adhesives can be used without particular limitation. For example, M unit (R ₃ SiO _1/2 ),
Q unit (SiO ₂ ), T unit (RSiO _3/2 ) and D
At least one selected from the units (R ₂ SiO)
An organopolysiloxane composed of a copolymer having a unit of a kind (in the unit, R represents a monovalent hydrocarbon group or a hydroxyl group) can be preferably used. In addition to having an OH group, the organopolysiloxane made of the above-mentioned copolymer may have various functional groups such as a vinyl group introduced if necessary. The functional group to be introduced may be one that causes a crosslinking reaction. The copolymer may be M composed of M units and Q units.
Q resin is preferred. The ratio (molar ratio) of M unit to Q unit, T unit or D unit is not particularly limited, but former: latter = about 0.3: 1 to 1.5: 1, preferably 0.5:
It is preferable to use one having a ratio of 1 to 1.3: 1.

The blending ratio (weight ratio) of silicone rubber and silicone resin is: former: latter = 100: 40 to 10
About 0: 220 is preferable, and 100: 100 to 100 :.
It is more preferable to use the one having about 180. The silicone rubber and the silicone resin may be used by simply blending them, or may be a partial condensate thereof.

The above-mentioned composition usually contains a cross-linking agent in order to make it a cross-linked structure. As a cross-linking agent, SiH
Examples thereof include a siloxane-based crosslinking agent having a group and a peroxide-based crosslinking agent. As the peroxide cross-linking agent, various ones conventionally used in silicone pressure-sensitive adhesives can be used without particular limitation. For example, benzoyl peroxide, t
-Butylperoxybenzoate, dicumyl peroxide, t-butylcumyl peroxide, t-butyl oxide, 2,5-dimethyl-2,5-di-t-butylperoxyhexane, 2,4-dichloro-benzoylper Oxide, di-t-butylperoxy-di-isopropylbenzene, 1,1-bis (t-butylperoxy) -3,3,5-trimethyl-cyclohexane, 2,
Examples thereof include 5-dimethyl-2,5-di-t-butylperoxyhexyne-3.

As the siloxane-based cross-linking agent, for example, polyorganohydrogen siloxane having at least two hydrogen atoms bonded to silicon atoms in the molecule on average is used. Examples of the organic group bonded to the silicon atom include an alkyl group, a phenyl group, a halogenated alkyl group and the like, but a methyl group is preferable because it is easy to synthesize and handle. The siloxane skeleton structure may be linear, branched, or cyclic, but linear is often used.

The thickness of the pressure-sensitive adhesive layer is preferably 5 to 100 μm, and more preferably 25 to 75 μm, when the pressure-sensitive adhesive layer is formed into a plurality of streaks and the non-formed portion is used as the flow passage.
Is more preferable. In other cases, in consideration of peelability, sealability, adhesiveness, etc. as an adhesive tape for masking,
It is preferably 5 to 100 μm.

As the method for forming the pressure-sensitive adhesive layer, the pressure-sensitive adhesive is applied to the base material by a reverse coating method, a fan-ten coating method, a dipping method or the like, and each crosslinking method (heating, UV irradiation, etc.) is applied. It can be formed by curing.

The base material of the pressure-sensitive adhesive tape is only required to have heat resistance, and examples thereof include heat-resistant plastics such as fluororesin, polyimide, and aramid. Depending on the shape of the site to be used, the characteristics such as stretchability and rigidity can be obtained. The time may be selected taking into consideration. For example, when a fluororesin film having excellent flexibility is used, the base material stretches and follows even in a place where distortion such as a corner portion occurs, and a reliable sealing effect is obtained without floating or wrinkling.

Examples of the fluororesin film include polytetrafluoroethylene (PTFE), copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether (PFA), copolymer of tetrafluoroethylene and hexafluoropropylene (FEP), Examples thereof include polychlorotrifluoroethylene (PCTFE), a copolymer of tetrafluoroethylene and ethylene (ETFE), and polyvinylidene fluoride (PVdF).

Further, when the pulling force of the adhesive tape when hand-attached was examined, it was about 10 to 20 N although there were individual differences.
It was about. Elongation can be obtained by pulling strongly, but this reduces workability. Also, if it grows too much,
Workability deteriorates, such as the base material being cut when the tape is peeled off. Therefore, the base material has a 10% modulus of 3 to 30 N.
/ 19 mm width is preferable, and 3 to 25 N / 19 mm width is more preferable. This 10% modulus can be adjusted by the type and thickness of the substrate.

Further, the thickness of the base material may be selected so that it does not break when the substrate follows. If it is thin, it easily stretches and breaks easily, and if it is thick, the cost increases and the shape following property deteriorates, resulting in a decrease in workability. More effective range is 10% above
0.025-0.1m in consideration of the relationship with the modulus
m.

In order to enhance the anchoring force of the pressure-sensitive adhesive, the base material may be subjected to a surface treatment, such as corona discharge treatment, sputtering treatment, low-pressure UV treatment, plasma treatment, alkali metal etching treatment, etc. Surface treatment. Among these surface treatment methods, a sputter treatment is preferable because it has good heat resistance and can physically roughen the surface to increase the surface area for forming the adhesive layer.

When the porous film is used, a material having heat resistance is preferable because it is heated to 200 ° C. or higher. Fluororesin materials such as polytetrafluoroethylene (PTFE), copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether (PFA), copolymer of tetrafluoroethylene and hexafluoropropylene (FEP), polychlorotrifluoro Examples thereof include ethylene (PCTFE), a tetrafluoroethylene / ethylene copolymer (ETFE), and polyvinylidene fluoride (PVdF).

In addition, as long as it is heat-resistant and porous, a material such as polyimide, polyamide, especially aromatic polyamide may be used. However, in consideration of heat shrinkage, it is preferable to heat-treat at or above the use temperature before use.

When the heat resistance of the porous film is low, it is not preferable because it melts or deteriorates and sticks to the back plate or flows into the holes. Even if it contracts further, the masking tape may be lifted, and reliable masking may not be obtained.

Further, since it is possible to ventilate even if the hole diameter is small, it is preferable that the hole diameter is small in consideration of solder penetration. Therefore, the average pore size is preferably 0.05 mm or less. In this case, even if the opening of the ventilation path is close to the solder, the solder does not easily enter the inside.

The thickness of the porous film is not particularly limited,
Adhesiveness may be secured by changing the pressure-sensitive adhesive thickness, tape width, and film width as necessary. However, in order to obtain a stable masking effect, the thickness of the porous film is 2 to 1000.
μm is preferred. The adhesiveness of the pressure-sensitive adhesive layer on the outer side may be secured by reducing the thickness near the edge of the porous film.

The adhesive tape for masking of the present invention can be used by attaching the adhesive tape to the masking area. At that time, it is preferable that the air passage of the adhesive tape is attached so as to be located at least in the opening of the non-through hole.

[0046]

EXAMPLES Examples and the like specifically showing the constitution and effects of the present invention will be described below.

Example 1 A silicone adhesive (SH-4280 made by Toray Dow Corning Silicone) was mixed with 1.2 parts solid content ratio of BPO (Nyper BW: made by NOF CORPORATION) and dispersed by stirring with a disper. , 0.05 mm in thickness and 25 mm in width (No. 901, manufactured by Nitto Denko Corporation) at 5 mm intervals with a width of 5 mm, and cured at a temperature of 200 ° C.
After being dried, a streak-coated sample 1 having a pressure-sensitive adhesive layer thickness (convex surface) of 0.03 mm and a tape thickness of 0.08 mm was obtained.

Example 2 PTFE porous film (NTF-1122, pore size 0.
2 μm) was heated at 200 ° C. for 1 hour, and then adhered to an adhesive tape having the same adhesive layer as in Example 1 formed on the entire surface at 5 mm intervals with a width of 5 mm to obtain Sample 2.

Comparative Example 1 A sample 3 made of a conventional adhesive tape was obtained in the same manner as in Example 2 except that the porous film was not attached. 15m on an oxygen-free copper plate with a thickness of 20mm
An unpenetrated hole having a depth of about 15 mm was opened, and Samples 1 to 3 cut into a width of 25 mm were masked on the hole.
Place the solder on the masking tape on the hole and leave it as it is.
It was left at 00 ° C. for 2 hours. Immediately after taking out, the state of masking was visually observed. Further, it was cooled in a room at 25 ° C., and when the surface temperature became 150 ° C. or less, the masking tape was peeled off and contamination was confirmed. The results are shown in Table 1.

[0050]

[Table 1] In Examples 1 and 2, the masking tape was not deformed and the solder was not contaminated. After peeling the tape, in Comparative Example 1,
There was a part where the tape was swollen by the air and the solder penetrated.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a masking adhesive tape of the present invention.

FIG. 2 is a perspective view showing another example of the masking adhesive tape of the present invention.

FIG. 3 is a perspective view showing another example of the masking adhesive tape of the present invention.

FIG. 4 is a partially cutaway perspective view showing another example of the masking adhesive tape of the present invention.

[Explanation of symbols]

1 base material 2 Adhesive layer 3 flow passages 4 Porous film

Claims (5)

[Claims] 1. An adhesive tape for masking, which is used for masking excess solder when joining a target material of a sputtering target and a backing plate material with solder, the adhesive tape being formed on one side of a substrate. An adhesive tape for masking, wherein the agent layer has a non-adhesive portion in a part of the masking area, and a flow passage is provided which allows ventilation from the non-adhesive portion to the outside of the masking area. 2. The pressure-sensitive adhesive tape for masking according to claim 1, wherein the pressure-sensitive adhesive layer is formed into a plurality of streaks, and the non-formed portion constitutes the flow passage. 3. The pressure-sensitive adhesive tape for masking according to claim 2, wherein the pressure-sensitive adhesive layer is formed in a stripe shape in the longitudinal direction of the substrate. 4. The masking adhesive tape according to claim 1, wherein the flow passage is formed of a porous film. 5. The masking adhesive tape according to claim 4, wherein the porous film is a fluororesin film.