JP2003268326A - Double coated self-adhesive film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double coated self-adhesive film for fixing a circuit board, which is easy to handle as a film used in mounting process of CSP in a place of a suction fixing and doesn't cause a malfunction such as a warping of the board. <P>SOLUTION: In the double coated self-adhesive film for fixing a circuit board, A, A is defined below, is 50-300 gf/25 mm, and B/A, B is also defined below, is in the range of 0.01<B/A≤1.0, wherein A is an adhesive power of an adhesive layer affixing to a fixing jig and B is an adhesive power of an adhesive layer affixing to a circuit board, when the adhesive power is measured by JIS Z-0237 (180° peeling method) against a double coated self-adhesive film that is applied with an adhesive layer to the both sides of a heat-resistant plastic film. Preferably, the heat-resistant plastic film is a film made of one of polyimide, polyetherimide, polysulfone, polyethersulfone, polyethylene terephthalate, and polyetheretherketone, or made of a mixture thereof, or a laminated film thereof. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided pressure-sensitive adhesive film for fixing a substrate, which is used in a chip size package mounting and sealing process.

[0002]

2. Description of the Related Art As a process of mounting a chip size package (hereinafter abbreviated as CSP) on a circuit board, a mounting process of mounting a bare chip on a glass epoxy or a polyimide film substrate, bonding of a conductive adhesive, an anisotropic conductive film, etc. Various processes are required depending on the method, such as a process of curing the part, a process of filling an underfill and a process of sealing the entire chip.

When processing is performed in these many steps, the processing is performed while fixing the substrate to a fixing jig such as stainless steel, aluminum or a resin board. As one of fixing methods for a circuit board, a method is used in which a small hole for suction is provided in a fixing jig and a circuit board is sucked and fixed.

However, since fixing by suction requires maintaining suction in all of the multiple steps, the equipment becomes complicated, and it is also difficult to store the steps interrupted between the steps. Further, in the case of a thin circuit board such as a flexible circuit board, the circuit board may be warped by suction, causing a positional deviation and a joint failure, and improvement is required.

[0005]

The object of the present invention is to provide a CS
As a film for the P mounting process, it is an object to provide a double-sided adhesive film for fixing a circuit board, which is easy to handle instead of fixing by suction and does not cause problems such as warpage of the board.

[0006]

Means for Solving the Problems The present invention provides a double-sided pressure-sensitive adhesive film having a heat-resistant plastic film provided with pressure-sensitive adhesive layers on both sides, which has a fixed adhesive strength measured by JIS Z-0237 (180 degree peeling method). Regarding the adhesive force A of the adhesive layer to be adhered to the tool and the adhesive force B of the adhesive layer to adhere the circuit board, A is 50 to 300 gf / 25 mm and B / A is 0.01 <B / A ≦ 1. The present invention relates to a double-sided pressure-sensitive adhesive film for fixing a substrate in a CSP mounting process, which has a range of 0.0. In a preferred embodiment, the heat-resistant plastic film is a film of polyimide, polyetherimide, polysulfone, polyethersulfone, polyethylene terephthalate, polyetheretherketone, alone or in combination, or a laminate thereof. A double-sided adhesive film for mounting process, characterized in that the adhesive layer on the surface for fixing the circuit board uses an acrylic adhesive
Double-sided adhesive film for mounting process.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The film used as the substrate is a heat resistant plastic film, and is preferably polyimide, polyetherimide, polysulfone, polyethersulfone, polyethylene terephthalate, polyetheretherketone or polyphenylene sulfide. These single films may be used, or a plurality of alloys or multiple layers may be used.

The thickness of the pressure-sensitive adhesive film substrate according to the present invention is not particularly limited, but preferably 20 to 200.
μm, more preferably 30 to 100 μm is used. If the base material is too thin, it will be difficult to handle at the time of bonding, and if it is too thick, it will be expensive and the rigidity will be high, which will cause floating from the fixing jig due to the stress of linear expansion in the heating step. Absent. The base material may be subjected to surface modification treatment such as corona treatment or plasma treatment, or may be provided with a primer layer in order to improve the adhesion with the adhesive, if necessary.

Adhesive layers are formed on both sides of the base material by coating, but the base material may be directly coated on the base material by an officially known method such as a knife method, a gravure method, a kiss method, a die method, or PET or paper, A method is generally used in which a release film made of synthetic paper is coated with the above method and then the adhesive layer is transferred to a substrate. The adhesive force of the adhesive layer is JIS Z according to JIS Z
0237 (180 degree peeling method) has an adhesive force of 5
It is desirable that it is 0 to 300 gf / 25 mm. If the adhesive strength is weak, it causes floating or peeling due to the linear expansion of the base material during the heating process, and if it is too large, it becomes difficult to peel it off from the fixing jig after use, resulting in poor workability.

The adhesive force B of the adhesive surface (hereinafter abbreviated as B surface) to which the circuit board is attached is preferably set in the range of 0.01 <B / A <1.0, and polyimide within the range of the above ratio. It may be appropriately set according to the type and thickness of the substrate such as glass or epoxy. The adhesive force ratio is preferably set to 0.01 to 0.5 for a film-shaped substrate such as a polyimide film, and set to 0.3 to 1.0 for a plate-shaped substrate such as glass epoxy. However, it is not limited to this as long as the releasability of the substrate is good.

The pressure-sensitive adhesive to be used on the A side is not particularly limited, and examples thereof include acrylic-based and silicone-based pressure-sensitive adhesives. The adhesive used on the B side is preferably an acrylic adhesive. Rubber-based adhesives have poor heat resistance and can cause floating and peeling during the heating process.Silicone-based heat-resistant adhesives generate gas of the siloxane component of the adhesive during the heating process, which may cause the adhesive to stick to the joint or sealing resin. It may cause poor adhesion, which is not preferable.

Examples of the acrylic pressure-sensitive adhesive used in the B-side pressure-sensitive adhesive layer include, for example, polymers of acrylic acid, methacrylic acid and their esters, acrylic acid, methacrylic acid, and unsaturated monomers copolymerizable with those esters. A copolymer with a polymer such as vinyl acetate, styrene or acrylonitrile is used. Although the thickness of the adhesive layer is not particularly limited, it is preferably 5 to 40 μm, and more preferably 5 to 25 μm for the A surface. 3 for the B side
The thickness is preferably 20 μm, more preferably 5 to 15 μm.

Some pressure-sensitive adhesives include one-component curing type ones, but curing agents such as isocyanate, epoxy and metal chelates may be added to two-component curing type pressure-sensitive adhesives. As a specific example of the curing agent, for example, in the case of isocyanate,
Toluene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylene diisocyanate, diphenylmethane-4-4'-diisocyanate, diphenylmethane-2-4'- Examples thereof include diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4-4′-diisocyanate, dicyclourohexylmethane-2-4′-diisocyanate and lysine isocyanate.

The mixing ratio of the curing agent is 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, relative to 100 parts by weight of the adhesive.
Parts by weight. If the amount is less than 0.1 parts by weight, the cohesive force of the pressure-sensitive adhesive layer will be small and the heat resistance will be insufficient, resulting in problems such as stringing and adhesive residue during re-peeling after processing. If it is used in an amount exceeding 10 parts by weight, the adhesive strength will be insufficient, causing peeling or floating during processing, and excess crosslinking agent will migrate to the substrate or gasify at high temperatures and cause contamination. Not preferable.

The adhesive of the present invention contains a rosin resin, a terpene resin, a coumarone resin, a phenol resin, a styrene resin, an aliphatic petroleum resin and an aliphatic aromatic resin in order to enhance the adhesive force and cohesive force. A tackifier such as a polymerized petroleum resin may be added. The amount of addition is preferably 5 to 80 parts by weight, and more preferably 5 to 80 parts by weight.
30 parts by weight is preferred. If the added amount is too large, it may cause adhesive residue during peeling, so it is necessary to confirm when adding.

Further, an antistatic agent may be added to the above-mentioned pressure-sensitive adhesive layer, if necessary. By adding the antistatic agent, it is possible to prevent damage to the semiconductor circuit or the like due to discharge due to charging when the completed product is peeled from the adhesive layer. Specific examples of the antistatic agent include anionic, cationic, nonionic, or zwitterionic generally known surfactants, carbon black, silver, nickel, antimony-doped tin oxide, and tin-doped indium oxide. Powder such as is used. The antistatic agent is preferably used in the pressure-sensitive adhesive layer in an amount of 0 to 30 parts by weight, more preferably 0 to 20 parts by weight.

The double-sided pressure-sensitive adhesive film according to the present invention can be produced as described above, but in order to obtain a stable pressure-sensitive adhesive force, it is preferable to carry out an aging treatment for a certain period in order to complete the crosslinking with the curing agent.

[0018]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these. Adhesive Film Base Material A 50 μm polyether sulfone film (Sumilite FS-1300: manufactured by Sumitomo Bakelite Co., Ltd.) was used as a double-sided adhesive film base material, and both surfaces were corona treated before use. Coating method A 25 μm-thick PET separator was coated with each adhesive shown in Examples and Comparative Examples by knife edge method and dried on both sides A and B, and laminated on a substrate to form an adhesive.

Evaluation Method The following evaluation methods were used for the evaluation of Examples and Comparative Examples. Adhesive force measurement Adhesive force of the adhesive films obtained in Examples and Comparative Examples was measured according to JIS Z-0237 180 degree peeling method. As a jig for fixing the floating circuit board, an SUS plate having 150 mm square and No. 280 water-resistant abrasive paper finish was used. The separator on the side A of the adhesive films obtained in Examples and Comparative Examples was peeled off, and the pressure was 1 with a rubber roll heated to 100 ° C.
It was attached to a fixing jig with a linear pressure of 0 kgf / cm. At that time, the separator on the B side was also peeled off at the same time. After leaving it at room temperature for 5 minutes, it was heated at 150 ° C. for 2 minutes and returned to room temperature. The adhesive film was observed in each state, and it was visually determined whether or not floating occurred between the adhesive film and the fixing jig.

Circuit Board Releasability In the same manner as above, the adhesive films obtained in Examples and Comparative Examples are attached to a fixing jig. After leaving it for 5 minutes at room temperature, put the circuit board on the B side and set it to 0.1 kgf / c.
It was pressed down with a pressure of m ² and attached. Then at 150 ° C for 2
After heating for a minute, the temperature was returned to room temperature, and it was determined whether the circuit board can be peeled off smoothly and whether the circuit board is not bent or warped. The circuit board has a thickness of 50 μm.
Two types of substrates, that is, a polyimide substrate and a glass epoxy substrate having a thickness of 0.8 mm were evaluated. After evaluating the fixing jig peeling, the adhesive film stuck to the fixing jig can be peeled off smoothly, or the peeling of the interface between the adhesive layer and the base material or the adhesive layer is cohesively destroyed It was visually evaluated that no adhesive layer remained. In addition, all evaluations were performed after applying an adhesive layer, and after aging treatment in an atmosphere of a temperature of 23 ° C. and a relative humidity of 65%.

The contents and evaluation results of Examples and Comparative Examples are shown in Tables 1 and 2. <Example 1> Acrylic adhesive Olivine B as side A
100 parts by weight of PS5227-1 (manufactured by Toyo Ink Mfg. Co., Ltd.), 3 parts by weight of curing agent Olibain BXX5134 (manufactured by Toyo Ink Mfg. Co., Ltd.) and 30 parts by weight of ethyl acetate as a diluting solvent were mixed (the above is Formulation 1), It was applied so that the thickness after drying was 20 μm. Acrylic adhesive Cybinol ATR340 (made by Saiden Chemical Co., Ltd.) 100 parts by weight on the B side, K-200 (made by Saiden Chemical Co., Ltd.) 0.2 part by weight and M-2 (made by Saiden Chemical Co., Ltd.) 1 part by weight as a curing agent. Mixing 30 parts by weight of ethyl acetate as a diluent solvent (the above is compound 2), the thickness after drying is 10 μm.
It was applied so that

<Example 2> Acrylic adhesive Cybinol ATR-207 (manufactured by Saiden Chemical Co., Ltd.) as the A side 10
0.5 parts by weight of TETRAD-X (manufactured by Mitsubishi Gas Chemical Co., Inc.) as a curing agent and 30 parts by weight of ethyl acetate as a diluting solvent were mixed with 0 parts by weight (the above is compounding 3), and the thickness after drying was 10 μm. It was applied so that As the B side, 100 parts by weight of the acrylic adhesive Cybinol ATR-1 (manufactured by Saiden Chemical Co., Ltd.) was mixed with 30 parts by weight of ethyl acetate as a diluting solvent (the above is referred to as compounding 4), and the thickness after drying was 10
It was coated so as to have a thickness of μm.

<Example 3> Acrylic adhesive Olivine BPS5231 (manufactured by Toyo Ink Mfg. Co., Ltd.) 10 as the A side
3 parts by weight of a curing agent Olivine BXX5134 (manufactured by Toyo Ink Mfg. Co., Ltd.) in 0 parts by weight, and ethyl acetate 40 as a diluting solvent.
Parts by weight were mixed (the above is referred to as Formulation 5), and coating was performed so that the thickness after drying was 10 μm. Acrylic adhesive Arontack S-1601 (made by Toagosei Co., Ltd.) as the B side
40 parts by weight of ethyl acetate as a diluting solvent is mixed with 100 parts by weight (the above is referred to as the compound 6), and the thickness after drying is 10 μm.
It was coated so that it would be m.

<Example 4> Acrylic adhesive Cybinol ATR-340 (manufactured by Saiden Chemical Co., Ltd.) as the A side 10
0.2 part by weight of K-200 (manufactured by Saiden Chemical Co., Ltd.) as a curing agent and 0 part by weight of M-2 (manufactured by Saiden Chemical Co., Ltd.)
Parts by weight, 10 parts by weight of Nikanol T-60 (manufactured by Mitsubishi Gas Chemical Co., Inc.) as a tackifier, and ethyl acetate 3 as a diluting solvent.
0 parts by weight (mixing 7 above) was mixed and coated so that the thickness after drying would be 10 μm. On the B side, 3 parts by weight of Coronate L (manufactured by Nippon Polyurethane Co.) as a curing agent and 30 parts by weight of ethyl acetate as a diluting solvent were mixed with acrylic adhesive SK Dyne 1498B (manufactured by Soken Chemical Industry Co., Ltd.) And) so that the thickness after drying is 5 μm.

<Example 5> As surface A, an adhesive of formulation 7 was applied so that the thickness after drying was 10 μm. Similarly, the B-side was coated with the adhesive of formulation 7 so that the thickness after drying was 10 μm. <Example 6> Silicone adhesive TSR15 is used as the A side.
12 parts (Toshiba Silicone Co., Ltd.) 100 parts by weight, CR51 (Toshiba Silicone Co., Ltd.) as a curing agent and 1 part by weight of toluene as a diluting solvent 30 parts by weight are mixed (the above compounding 9), and the thickness after drying is 10 μm. The coating was performed so as to obtain the following, and then a curing treatment was performed at 120 ° C. for 2 minutes. The adhesive of Formulation 7 was applied on the B side so that the thickness after drying would be 5 μm.

<Comparative Example 1> A pressure-sensitive adhesive of formulation 4 was applied as the A side so that the thickness after drying would be 10 μm. The adhesive of Formulation 2 was applied as the B side so that the thickness after drying would be 10 μm. When the floating of the adhesive film was evaluated, floating occurred between the adhesive film and the SUS fixing jig at the time of overheating, and the subsequent evaluation could not be performed.

<Comparative Example 2> As the surface A, a pressure sensitive adhesive of formulation 7 was applied so that the thickness after drying would be 10 μm. The adhesive of Formulation 6 was coated on the B side so that the thickness after drying would be 10 μm. Although the floating evaluation of the adhesive film was good, the substrate peeling evaluation was carried out on each of the polyimide film substrate and the glass epoxy substrate, but the peeling force was large, and if the polyimide film was forcibly peeled off, the substrate would break. In the case of the glass epoxy substrate, the adhesive film was peeled off from the SUS fixing jig.

<Comparative Example 3> A pressure-sensitive adhesive of Formulation 6 was applied as the A side so that the thickness after drying would be 20 μm. The adhesive of Formulation 1 was applied on the B side so that the thickness after drying was 10 μm. The floating evaluation of the pressure-sensitive adhesive film and the evaluation of the peelability of the substrate were good, but when the peelability evaluation of the pressure-sensitive adhesive film and the SUS fixing jig was carried out, the pressure-sensitive adhesive film did not peel smoothly and The transition was also significant.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

EFFECTS OF THE INVENTION According to the present invention, it is possible to provide a double-sided adhesive film for fixing a substrate, which is easy to handle as a film for the CSP mounting process instead of suction fixing and does not cause a problem such as a warp of the substrate. .

Claims (3)

[Claims] 1. A double-sided adhesive film according to JIS Z-02, wherein an adhesive layer is provided on both sides of a heat-resistant plastic film.
The adhesive strength measured by 37 (180 degree peeling method) is
Regarding the adhesive force A of the adhesive layer to be attached to the fixing jig and the adhesive force B of the adhesive layer to be attached to the circuit board, A is 50 to
300 gf / 25 mm and B / A is 0.01 <
A double-sided adhesive film for fixing a substrate in a chip size package mounting process, characterized in that B / A ≦ 1.0. 2. The heat-resistant plastic film is a film of polyimide, polyetherimide, polysulfone, polyethersulfone, polyethylene terephthalate, polyetheretherketone, alone or in combination, or a laminate thereof. Double-sided adhesive film for chip size package mounting process according to 1. 3. The double-sided adhesive film for a chip size package mounting process according to claim 1, wherein an acrylic adhesive is used for the adhesive layer on the surface for fixing the circuit board.