KR20200060647A - The double-faced adhesive tape for RDL forming process, Laminate containing the same, and Manufacturing process of Fan-out package - Google Patents

Abstract

The present invention relates to a double-sided adhesive tape and, more specifically, to a double-sided adhesive tape, which is used to bond / de-bond a carrier wafer and a device wafer for a redistribution layer (RDL) forming process during a fan-out package manufacturing process. The double-sided adhesive tape for the RDL forming process comprises: a first adhesive layer; a laser degradable film layer; and a second adhesive layer.

Description

The double-faced adhesive tape for RDL forming process, Laminate containing the same, and Manufacturing process of Fan-out package}

The present invention relates to a novel double-sided adhesive tape used as a temporary bonding means used to bond and peel a device aper and a carrier wafer during an RDL forming process in a fan-out package manufacturing process.

Semiconductor devices are used in various electronic applications such as personal computers, mobile phones, digital cameras, and other electronic devices. Semiconductor devices are generally manufactured by sequentially depositing (patterning) various material layers using lithography to sequentially deposit an insulating or dielectric layer, a conductive layer, and a semiconductor material layer over a semiconductor substrate and form circuit components and elements thereon. do. Dozens or hundreds of integrated circuits are typically fabricated on a single semiconductor wafer. Each die is individualized by cutting this integrated circuit along a cutting line. The individual dies are then individually packaged into, for example, multi-chip modules or other types of packages.

The semiconductor industry continually improves the integration density of various electronic components (eg transistors, diodes, resistors, capacitors, etc.) by reducing the size of its minimum features, which will integrate more elements into a given area. Enabled. Small electronic devices, such as integrated circuit dies, also require a small package that utilizes less space than some of the past packages in some applications. Due to this demand, instead of the conventional wire bonding method using a metal wire as a mounting method for a semiconductor chip, flip chip connection is formed by forming a projection electrode called a bump electrode on the electrode of the chip to directly connect the substrate electrode and the chip electrode through the bump. The way is getting attention. In recent years, through-via technology (TSV), which is a three-dimensional mounting technology that connects chips with the shortest distance as a function of higher functionality and higher speed, has attracted attention. The silicon through-electrode (TSV) technology is gradually becoming an essential technology to realize higher density and higher capacity.

It is desired that the thickness of the semiconductor wafer is as thin as possible, and that the mechanical strength is not lowered. Further, in accordance with the demand for further thinning of semiconductor devices, so-called back grinding is performed to grind the back surface of the wafer to make the semiconductor wafer thinner, and the manufacturing process of the semiconductor device is complicated. Therefore, as a method suitable for simplifying the semiconductor manufacturing process, there is a demand for a resin that has both a function of holding a semiconductor wafer and an underfill function when backgrinding.

In order to realize this, a step of grinding a non-circuit-forming surface (also referred to as a "back surface") of a substrate on which a semiconductor circuit is formed, and forming an electrode containing TSV on the back surface is required. In the backside grinding process of the silicon substrate, a back surface protection tape is applied to the opposite side of the grinding surface to prevent wafer damage during grinding. However, this tape uses an organic resin film as a base material, but the organic resin film base material is flexible, but is not suitable for performing a wiring layer forming process on the back side because of insufficient strength and heat resistance. Accordingly, a system has been proposed that can sufficiently endure the processes of backside grinding and backside electrode formation by bonding a semiconductor substrate to a support such as silicon or glass through an adhesive. An important problem here is the adhesive and the bonding method when bonding the substrate to the support. In particular, the adhesive can bond the substrate to the support without gaps, requires sufficient durability to withstand subsequent processes, and should be able to easily peel the thin wafer from the support. Since the wafer and the support are finally peeled off, the adhesive is also called a temporary adhesive.

As a conventional peeling method, an adhesive containing a light-absorbing material is used, and a high-strength light is irradiated to decompose the adhesive layer, thereby using a technique of peeling the adhesive layer from the support and a heat-soluble hydrocarbon-based compound for the adhesive. It was limited to techniques such as bonding / peeling in a hot melt state.

The former technology has had problems such as a long processing time per substrate. In addition, the latter technique is simple because it is controlled only by heating, whereas the range of application is narrow due to insufficient thermal stability at high temperatures exceeding 200 ° C. In addition, although a technique of using a silicone adhesive for a temporary adhesive layer has been proposed, it is bonded to a substrate using an addition-curable silicone adhesive for a support, and when peeling, it is immersed in a drug that dissolves or decomposes a silicone-based pressure-sensitive adhesive resin. Since the substrate is separated from the support, it takes a very long time to peel, and it is difficult to apply it in an actual manufacturing process.

Korean Registered Patent No. 10-1806596 (announcement date 2017.12.01) Korean Patent Publication No. 10-2016-0123959 (published 2016.10.26)

The object of the present invention is a novel laser capable of easily bonding a carrier wafer and a device wafer to perform a semiconductor process, and easily separating the device wafer and the carrier wafer without damaging the device wafer by saving process time. It is intended to provide a process for manufacturing a decomposable double-sided adhesive tape, a laminate including the same, and a fan-out package using the same.

In order to solve the above problems, the double-sided adhesive tape of the present invention includes a first pressure-sensitive adhesive layer; Laser degradable film layer; And a second pressure-sensitive adhesive layer; these are sequentially stacked.

As a preferred embodiment of the present invention, a release film layer may be further included on the top of any one of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer.

As a preferred embodiment of the present invention, the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer may have an average thickness of 5 ~ 50㎛.

As a preferred embodiment of the present invention, the laser-decomposable film layer may be an average thickness of 5 ~ 75㎛.

As a preferred embodiment of the present invention, when the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer is irradiated with a laser of 50 W intensity for 1 minute, the reduction rate of the adhesive force measured according to Equation 1 below may be 85% or more. have.

[Equation 1]

Adhesion reduction rate (%) = {(Adhesion of the pressure-sensitive adhesive layer before laser irradiation-Adhesion of the pressure-sensitive adhesive layer after laser irradiation) / Adhesion of the pressure-sensitive adhesive layer before laser irradiation} × 100 (%)

In Equation 1, the adhesive force is measured according to the ASTM D3330 method, and the adhesive force unit is gf / 25mm.

As a preferred embodiment of the present invention, when the double-sided adhesive tape of the present invention is applied to an RDL forming process during a fan-out package manufacturing process, the first pressure-sensitive adhesive layer may be applied to adhere to the carrier wafer. .

As a preferred embodiment of the present invention, the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer may include at least one selected from urethane-based pressure-sensitive adhesive resins, curable silicone-based pressure-sensitive adhesive resins, and acrylic pressure-sensitive adhesive resins.

As a preferred embodiment of the present invention, the laser-decomposable film layer may have a viscosity of 2,500 to 300,000 cps when irradiated with a laser of 50 W intensity for 1 minute and when measuring viscosity based on ISO 6721-10 method.

[Equation 2]

Viscosity change rate (%) = │ (viscosity of film layer before laser irradiation-viscosity of film layer after laser irradiation) / viscosity of film layer before laser irradiation × 100% │

In Equation 2, the unit of viscosity is cps.

As a preferred embodiment of the present invention, the laser decomposable film layer may have a viscosity change rate of 88.0% to 99.9% before and after laser irradiation measured according to Equation 2 below.

As a preferred embodiment of the present invention, the laser-decomposable film layer may include a black polyimide film.

 As a preferred embodiment of the present invention, the black polyimide film is a mixed solution containing a polyamic acid resin, a catalyst and a solvent; And laser reactant; is an imide of a polyamic acid varnish containing.

As a preferred embodiment of the present invention, the polyamic acid varnish may include 0.40 to 1.30% by weight of the laser reactant and the remaining amount of the mixed solution.

As a preferred embodiment of the present invention, the mixed solution may include 15 to 50 parts by weight of the catalyst and 15 to 40 parts by weight of the solvent with respect to 100 parts by weight of the polyamic acid resin.

As a preferred embodiment of the present invention, the polyamic acid resin is based on 100 parts by weight of N, N'-dimethylformamide (DMF), 4,4'-diaminophenylene ether (ODA) 8 to 15 parts by weight, and Pyromellitic dianhydride (PMDA) may include a polyamic acid compound that is a reactant reacted by 8 to 15 parts by weight.

The polyamic acid resin contains 16.5 to 22.0% by weight of solids, and the viscosity may be 2,200 to 3,000 poise.

As a preferred embodiment of the present invention, the catalyst may include at least one selected from acetic anhydride, isoquinoline, acetic anhydride and pyridine.

As a preferred embodiment of the present invention, the catalyst may include isoquinoline and acetic anhydride in a ratio of 1: 1.5 to 5.

As a preferred embodiment of the present invention, the solvent may include one or more selected from dimethylformamide (DMF), N, N'-dimethylacetamide and N-methyl-pyrrolidone.

As a preferred embodiment of the present invention, the laser reactant may include one or more selected from carbon black, carbon nanotube, carbon node, carbon fiber, and graphite nano powder.

As a preferred embodiment of the present invention, the black polyimide film which is an imide of the polyamic acid varnish may include 3.0 to 10% by weight of the laser reactant and a residual amount of the polyimide compound.

Another object of the present invention is a laminate using a double-sided adhesive tape of the various types described above, the device wafer layer; A carrier wafer layer supporting the device wafer; And a temporary adhesive layer formed between the device wafer layer and the carrier wafer layer, and the temporary adhesive layer may include the double-sided adhesive tape.

Another object of the present invention relates to a fan-out package manufacturing process using the double-sided adhesive tape, and in the RDL forming process during the fan-out package manufacturing process, the device wafer and the carrier wafer are bonded (bonding). ), And the double-sided adhesive tape can be used as a temporary bonding means used to de-bond the carrier wafer from the device wafer.

As a preferred embodiment of the present invention, the carrier wafer may include a glass material or a transparent acrylic material.

As a preferred embodiment of the present invention, the peeling is performed by irradiating a pressure-sensitive adhesive layer with a laser having a strength of 30 to 100 W for 30 seconds to 5 minutes in the direction of the carrier wafer, after decomposing the laser-decomposable film layer of the double-sided adhesive tape, and then carrying the carrier wafer Can be performed by peeling from the device wafer.

The double-sided adhesive tape of the present invention has excellent adhesion to a device wafer and a carrier wafer for RDL formation, but can easily separate a device wafer and a carrier wafer for easy application by applying a laser-decomposable film. It is possible to omit the solvent dipping applied when forming the RLD layer, thereby increasing the production of the fan-out package and minimizing the use of a cleaning agent.

1A and 1B are schematic cross-sectional views of a double-sided adhesive tape of the present invention of the present invention.
2 shows a schematic diagram of an RDL forming process in a conventional fan-out package manufacturing process.
3 shows a schematic diagram of the RDL forming process in the process of manufacturing the fan-out package of the present invention.

Hereinafter, the present invention will be described in more detail.

The double-sided adhesive tape of the present invention includes a first pressure-sensitive adhesive layer 10 as shown in a schematic cross-sectional view in FIG. 1A; Laser degradable film layer 20; And a second pressure-sensitive adhesive layer 10 ';

In addition, as shown in a schematic cross-sectional view in FIG. 30 ').

Each of the first pressure-sensitive adhesive layer 10 and the second pressure-sensitive adhesive layer 10 'of the present invention may be the same as each other, or may be composed of pressure-sensitive adhesives of different components, and may have the same or different adhesive strength.

In addition, when the first pressure-sensitive adhesive layer 10 and / or the second pressure-sensitive adhesive layer 10 'is irradiated with a laser of 50 W intensity for 1 minute, based on Equation 1 below, the adhesive force reduction rate is 85% or more. , Preferably 88 to 99%, more preferably 89 to 98%. At this time, if the adhesive strength reduction rate is less than 85%, the laser decomposable film layer 20 is laser irradiated to decompose and melt the film, and then, when separating the carrier wafer and the device wafer, the first pressure-sensitive adhesive and / or the second pressure-sensitive adhesive component It may not be neatly separated from the laser-decomposable film layer, and the removal of the pressure-sensitive adhesive layer from the carrier wafer is not easy, so that the recycling process cost of the carrier wafer may increase. And, when the laser is irradiated in the direction of the first pressure-sensitive adhesive layer, the first pressure-sensitive adhesive layer is present above the laser-decomposable film layer, and the second pressure-sensitive adhesive layer is present below the laser-decomposable film layer, so the first pressure-sensitive adhesive layer And the second pressure-sensitive adhesive layer may have different adhesive strength.

[Equation 1]

Adhesion reduction rate (%) = {(Adhesion of the pressure-sensitive adhesive layer before laser irradiation-Adhesion of the pressure-sensitive adhesive layer after laser irradiation) / Adhesion of the pressure-sensitive adhesive layer before laser irradiation} × 100 (%)

In Equation 1, the adhesive force is measured according to the ASTM D3330 method. In addition, when measuring the adhesive strength, the thickness of the electrosensitive adhesive layer may be 5 to 50 μm, preferably 8 to 20 μm, and more preferably 9 to 12.5 μm.

Each of the first pressure-sensitive adhesive layer 10 and / or the second pressure-sensitive adhesive layer 10 'is a composition comprising at least one selected from urethane-based pressure-sensitive adhesive resins, curable silicone-based pressure-sensitive adhesive resins, and acrylic pressure-sensitive adhesive resins. It can be prepared by blending.

For one embodiment of the pressure-sensitive adhesive composition used to form the first and / or second pressure-sensitive adhesive layer, the curable silicone-based pressure-sensitive adhesive resin is 0.5 to 2 parts by weight of the catalyst and 80 to 80 parts by weight of the catalyst relative to 100 parts by weight of the curable silicone resin. It may include 140 parts by weight, preferably, 0.5 to 1.5 parts by weight of the catalyst with respect to 100 parts by weight of the curable silicone resin, and 90 to 120 parts by weight of the solvent.

And, the curable silicone-based pressure-sensitive adhesive resin may be used polydialkylsiloxane gum dispersion resin (polydialkylsiloxane gum and resin dispersion), preferably polydi (C ₁ ~ C ₃ alkyl) siloxane gum dispersion resin, More preferably, a polydimethylsiloxane gum dispersion resin may be included.

In addition, the catalyst in the pressure-sensitive adhesive composition may include at least one selected from butyl peroxide (BPO, benzoyl peroxide), TBPO (tert-butyl peroxide) and TBPB (tert-butylperoxybenzonate).

Further, the solvent in the pressure-sensitive adhesive composition may include at least one selected from toluene, methyl ethyl ketone (MEK), ethyl acetate (EA), cyclohexane, DMF (dimethylformamide), and tetrahydrofuran (THF).

And, the curable silicone-based pressure-sensitive adhesive resin may have a solid content of 23 to 35% by weight, preferably 25.5 to 31.2% by weight.

In addition, for another embodiment of the pressure-sensitive adhesive composition used to form the first and / or second pressure-sensitive adhesive layer, the acrylic pressure-sensitive adhesive resin may include an acrylic acid copolymer, a curing agent, and a solvent, preferably acrylic acid With respect to 100 parts by weight of the copolymer, 0.05 to 2 parts by weight of the curing agent and 5 to 25 parts by weight of the solvent, more preferably 0.1 to 1.2 parts by weight of the curing agent and 7.5 to 18 parts by weight of the solvent, based on 100 parts by weight of the acrylic acid copolymer Can be.

And, the acrylic acid copolymer is 2- (C1 ~ C5 alkyl) (C3 ~ C10 alkyl) acrylate acrylic acid copolymer, preferably 2- (C1 ~ C3 alkyl) (C4 ~ C8 alkyl) acrylate Acrylic acid copolymers, more preferably 2-ethylhexylacrylate acrylic acid copolymers.

In addition, the curing agent may be used a glycidyl prepolymer, preferably a glycidyl prepolymer represented by the following formula (1).

[Formula 1]

이며, R₃는 C1 ~ C3의 알킬렌기이다.In Formula 1, R ₁ is a C1 ~ C5 alkylene group, R ₂ is

And R ₃ is a C1 to C3 alkylene group.

In addition, the solvent of the acrylic pressure-sensitive adhesive resin may include at least one selected from toluene, methyl ethyl ketone (MEK), ethyl acetate (EA), cyclohexane, DMF (dimethylformamide), and tetrahydrofuran (THF). .

And, the acrylic pressure-sensitive adhesive resin may have a solids content of 32 to 40% by weight, preferably 34.5 to 38.0% by weight.

In the present invention, the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer may have an average thickness of 5 ~ 50㎛, preferably an average thickness of 10 ~ 30㎛. At this time, if the average thickness of the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer is less than 5 μm, there may be a problem that the adhesive layer coating property is deteriorated and the device wafer adhesion is lowered. When bonding, there may be a problem that the adhesive layer remains excessively.

Next, the laser-decomposable film layer 20 constituting the double-sided adhesive tape of the present invention has a viscosity of 2,500 to 500,000 cps, preferably 2,500 to 300,000 cps, more preferably when irradiated with a 50 W laser for 1 minute. It is a film of 3,000 to 120,000 cps.

In addition, the laser decomposable film layer may have a viscosity change rate of 88.0% to 99.9%, preferably a viscosity change rate of 90.0 to 99.8%, before and after laser irradiation measured according to Equation 2 below.

[Equation 2]

Viscosity change rate (%) = │ (viscosity of film layer before laser irradiation-viscosity of film layer after laser irradiation) / viscosity of film layer before laser irradiation × 100% │

At this time, the unit of viscosity in Equation 2 is cps.

The laser-decomposable film layer having these properties is a black polyimide film, a mixed solution containing a polyamic acid resin, a catalyst and a solvent; And laser reactant; is an imide of a polyamic acid varnish containing.

The polyamic acid varnish may include 98.65 to 99.25% by weight of the mixed solution and 0.40 to 1.30% by weight of the laser reactant, preferably 0.60 to 1.20% by weight of the laser reactant and a residual amount of the mixed solution, more preferably the laser reactant It may contain a mixed solution of 0.70 to 1.10% by weight and the balance. At this time, if the laser reactant content is less than 0.40% by weight, when the laser decomposable film layer is irradiated to lower the viscosity, the intensity of the laser should be increased too much or the laser irradiation time may be too long, resulting in a problem that productivity decreases. And, when the content of the laser reactant exceeds 1.30% by weight, the laser reactant in the laser decomposable film made of the varnish is excessively contained, and thus, when the laser is irradiated, there may be a problem that the double-sided adhesive tape is discolored, so it is used within the above range. It is good to do.

The mixed solution is based on 100 parts by weight of the polyamic acid resin, 15 to 50 parts by weight of the catalyst and 15 to 40 parts by weight of the solvent, preferably 22 to 35 parts by weight of the catalyst and 16 to 35 parts of the solvent relative to 100 parts by weight of the polyamic acid resin Part by weight, more preferably, it may contain 25 to 35 parts by weight of catalyst and 17 to 27 parts by weight of catalyst with respect to 100 parts by weight of polyamic acid resin.

The polyamic acid resin may be a general polyamic acid resin used in the art, preferably 4,4'-diaminophenylene ether (with respect to 100 parts by weight of N, N'-dimethylformamide (DMF)) ODA) 8 to 15 parts by weight and pyromellitic dianhydride (PMDA) 8 to 15 parts by weight of the reacted polyamic acid compound, more preferably, DMF 100 parts by weight, ODA 9.5 to 13.5 parts by weight and PMDA 10 It may include a polyamic acid compound that is a reaction product of ~ 14 parts by weight.

In addition, the polyamic acid resin may have a solid content of 16.5 to 22.0 wt% and a viscosity of 2,200 to 3,000 poise, preferably a solid content of 17.5 to 19.5 wt% and a viscosity of 2,250 to 2,850 poise.

In addition, the catalyst in the mixed solution component may include at least one selected from acetic anhydride, isoquinoline, acetic anhydride and pyridine, preferably isoquinoline and acetic anhydride in a ratio of 1: 1.5 to 5, more preferably It may contain isoquinoline and acetic anhydride in a weight ratio of 1: 2.5 to 3.5.

In addition, the solvent in the mixed solution component may include one or more selected from dimethylformamide (DMF), N, N'-dimethylacetamide and N-methyl-pyrrolidone.

The laser reactant may include at least one selected from carbon black, carbon nanotube, carbon node, carbon fiber, and graphite nano powder.

The black polyimide film, which is an imide of the polyamic acid varnish, volatilizes the solvent and catalyst components in the mixed solution during the imidization reaction, so that the laser reactant 3.0 to 10% by weight and the residual amount of the polyimide compound are preferred. The laser reactant may contain 4.2 to 9.2% by weight and a residual amount of the polyimide compound, and more preferably, the laser reactant may contain 5.0 to 8.7% by weight and the residual amount of the polyimide compound.

In addition, the laser-decomposable film layer may have an average thickness of 5 to 75 μm, preferably an average thickness of 10.0 to 50 μm, and more preferably 10.0 to 22.5 μm. At this time, if the average thickness of the laser-decomposable film layer is less than 5 μm, there may be a problem that the adhesion reduction rate due to laser decomposition decreases, and when the average thickness exceeds 75 μm, the laser irradiation time becomes too long, resulting in poor productivity. There may be a problem.

The double-sided adhesive tape of the present invention in a process of forming a redistribution layer (RDL) during a fan-out package manufacturing process, bonds a device wafer and a carrier wafer, and peels the carrier wafer from the device wafer It can be used as a temporary bonding means used for (de-bonding).

In the conventional RDL forming process, as shown in a schematic diagram in FIG. 2, after forming a laminate by forming a temporary adhesive between a carrier wafer and a device wafer, a protective layer is formed to protect the device wafer (device wafer protection process) Order. Then, in order to remove the temporary adhesive, a solvent dipping process is performed in a solvent capable of dissolving the temporary adhesive to remove the temporary adhesive, and the solvent dipping process usually takes about 3 to 4 hours. Next, after removing the carrier wafer, a process of removing the protective layer is additionally performed, and in this case, a large amount of cleaning agent is used, which is unfriendly.

On the other hand, the RDL forming process to which the double-sided adhesive tape of the present invention is applied produces a laminate in which a carrier wafer and a device wafer are laminated with double-sided adhesive tape, as shown in the schematic process in FIG. 3. In this case, the device wafer is a general wafer, and may include a semiconductor wafer such as silicon and gallium, a crystal wafer, sapphire, and glass. In addition, the carrier wafer supports the device wafer 10, serves to prevent the device wafer from being destroyed, and is made of, for example, a glass material or a transparent acrylic material as a material capable of transmitting light energy such as a laser. It can contain.

Next, the laser in the direction of the carrier wafer of the laminate is 30 seconds to 5 minutes at 30 to 100 W intensity, preferably 30 seconds to 3 minutes at 40 to 70 W intensity, more preferably 30 seconds to 42 to 65 W intensity When irradiated for 2 minutes and 30 seconds, the laser decomposable film layer of the double-sided adhesive tape decomposes and / or melts the film components. Next, the carrier wafer is separated from the device wafer. At this time, the first pressure-sensitive adhesive layer 10 bonded to the carrier wafer is also separated. The laser-decomposable film may be partially separated together with the first pressure-sensitive adhesive layer. . Next, the second pressure-sensitive adhesive layer 10 'and / or the laser-decomposable film can be easily removed from the device wafer by applying a physical force.

In this process, the RDL forming process in the fan-out package manufacturing process of the present invention can significantly shorten the production time by omitting the solvent dipping process for dissolving the adhesive as compared with the conventional method, and also reduces the amount of cleaning agent used. As it can be minimized, it is eco-friendly and economical.

Hereinafter, the present invention will be described in more detail through examples, but the following examples are not intended to limit the scope of the present invention, which should be interpreted to help understand the present invention.

[ Example ]

Preparation example  1-1: Preparation of black PI film

A polyamic acid resin having a solid content of 18.5% by weight and a viscosity of 2500 poise was prepared. In this case, the polyamic acid resin is 4,4'-diaminophenylene ether (ODA) 11.4 parts by weight and pyromellitic dianhydride (PMDA) 12.4, based on 100 parts by weight of N, N'-dimethylformamide (DMF). It is prepared by reacting a composition mixed with parts by weight.

Next, a mixed solution was prepared by mixing 100 parts by weight of the polyamic acid resin, 7.5 parts by weight of isoquinoline as a catalyst, 22.5 parts by weight of acetic anhydride and 20.5 parts by weight of DMF as a solvent.

Next, using a carbon black as a laser reactant, a polyamic acid varnish was prepared by mixing the laser reactant with the mixed solution in the composition ratio shown in Table 1 below.

Next, after coating the polyamic acid varnish to 100 μm on a glass substrate, it was heat-treated at 260 ° C. and imidized and cured to prepare black polyimide (Film) having a thickness of 12.5 μm. The laser reactant content in the prepared film was 0.82% by weight.

Preparation example  1-2 to 1-18 and Comparative Preparation  One

A black PI film was prepared in the same manner as in Preparation Example 1-1, but after preparing a polyamic acid varnish to have the composition shown in Table 1, a black PI film having the same thickness was prepared to prepare a black PI film, respectively. ~ 1-18 were performed respectively.

Experimental Example  1: Measurement of viscosity change of black PI film

To confirm the laser reactivity of the black PI film, the black PI film prepared in Preparation Examples 1-1 to 1-18 and Comparative Preparation Example 1 was irradiated with a CW IR laser of 1064 nm and 50 W intensity for 1 minute, followed by ISO 6721- The viscosity was measured at room temperature (about 21 to 25 ° C) by 10 methods, and the results are shown in Tables 1 to 3 below. And the rate of change in viscosity was measured based on Equation 2 below.

[Equation 2]

Viscosity change rate (%) = │ (viscosity of film layer before laser irradiation-viscosity of film layer after laser irradiation) / viscosity of film layer before laser irradiation × 100% │

In Equation 2, the unit of viscosity is cps.

division Material name Comparative Preparation Example 1 Preparation Example 1-1 Preparation Example 1-2 Preparation Example 1-3 Preparation Example 1-4 Preparation Example 1-5 Preparation Example 1-6 Mixed solution
(weight%) Polyamic acid + catalyst + solvent 100 99.9 99.8 99.7 99.6 99.5 99.4 Laser reactant (% by weight) Carbon black - 0.1 0.2 0.3 0.4 0.5 0.6 Total (% by weight) 100 100 100 100 100 100 100 Laser reactant content in black PI film (% by weight) 0 0.82 1.62 2.41 3.18 3.95 4.7 laser
Reactivity Viscosity before laser irradiation (cps) 1,053,160 1,054,633 1,070,763 1,087,624 1,092,453 1,100,015 1,087,563 Viscosity after laser irradiation (cps) 876,554 800,543 710,923 600,832 99,132 65,832 6,523 Viscosity change rate (%) 16.77 24.09 33.61 44.76 90.93 94.02 99.40

division Material name Preparation Example 1-7 Preparation Example 1-8 Preparation Example 1-9 Preparation Example 1-10 Preparation Example 1-11 Preparation Example 1-12 Preparation Example 1-13 Mixed solution (% by weight) Polyamic acid + catalyst + solvent 99.3 99.2 99.1 99 98.9 98.8 98.7 Laser reactant (% by weight) Carbon black 0.7 0.8 0.9 One 1.1 1.2 1.3 Total (% by weight) 100 100 100 100 100 100 100 Laser reactant content in black PI film (% by weight) 5.45 6.189 6.89 7.6 8.3 8.99 9.66 laser
Reactivity Viscosity before laser irradiation (cps) 1054169 1098776 1115426 1103569 1098756 1173579 1199324 Viscosity after laser irradiation (cps) 5636 5361 5083 4921 4536 4361 3216 Viscosity change rate (%) 99.47 99.51 99.54 99.55 99.59 99.63 99.73

division Material name Preparation Example 1-14 Preparation Example 1-15 Preparation Example 1-16 Preparation Example 1-17 Preparation Example 1-18 Mixed solution (% by weight) Polyamic acid + catalyst + solvent 98.6 98.5 99.2 99.2 99.2 Laser reactant
(weight%) Carbon black 1.4 1.5 - - - Carbon nanotube - - 0.8 - - Carbon fiber - - - 0.8 Graphite nano powder - - - - 0.8 Total (% by weight) 100 100 100 100 100 Laser reactant content in black PI film (% by weight) 10.33 10.99 6.18 6.18 6.18 laser
Reactivity Viscosity before laser irradiation (cps) 1199564 1245360 1099873 1082564 1101254 Viscosity after laser irradiation (cps) 4326 4126 5469 5413 5711 Viscosity change rate (%) 99.64 99.67 99.50 99.50 99.48

Looking at the results of measuring the laser reactivity of the black PI films of Tables 1 to 3, Comparative Preparation Example 1 and Preparation Examples 1-1 to 1-3 in which the laser reactant content in the film is less than 3.0 wt%, the viscosity change rate is very low. It was confirmed that there was a problem. And, in the case of Preparation Example 1-14 and Preparation Example 1-15 in which the content of the laser reactant in the film exceeded 10.0% by weight, the laser reactivity was slightly lower than the Preparation Example 1-13 in which the laser reactant in the film was 9.66% by weight. Showed.

In addition, in the case of Preparation Examples 16 to 18 using carbon nanotubes, carbon fibers, and graphite nanopowders in addition to carbon black as a laser reactant, it was confirmed that it has a similar viscosity change rate to carbon black.

Preparation example  2: Preparation of curable silicone-based pressure-sensitive adhesive resin and film

With respect to 100 parts by weight of polydimethylsiloxane gum and resin dispersion (Q2-7735 manufactured by Dow Corning), 0.8 parts by weight of butyl peroxide (BPO) as a catalyst and 100 parts by weight of toluene as a solvent are mixed, and a pressure-sensitive adhesive is used. Resin was prepared. Next, the pressure-sensitive adhesive resin was cast, dried, and cured on a glass substrate to prepare a pressure-sensitive adhesive film having a thickness of 10 μm.

Example  1 to 18

The pressure-sensitive adhesive film of Preparation Example 2 was bonded to the upper and lower parts of the black PI film of Preparation Example 1-1 to form a first pressure-sensitive adhesive layer (thickness 10 µm) -laser degradable film layer (thickness 12.5 µm) -second pressure-sensitive adhesive layer (thickness) 10 µm) were sequentially stacked, and double-sided adhesive tapes for redistribution layer (RDL) forming processes were prepared as shown in Table 4 below. Then, the release film layer was adhered to the outer surfaces of the first and second pressure-sensitive adhesive layers of the double-sided adhesive tape to protect the adhesive tape.

Experimental Example  2: double-sided Of adhesive tape Of pressure-sensitive adhesive layer  Adhesion change rate measurement

After removing the release film layer of the double-sided adhesive tapes prepared in Examples 1 to 18, it was adhered to the device wafer in the direction of the first pressure-sensitive adhesive layer, and then CW CW laser of 1064nm, 50W intensity in the direction of the first pressure-sensitive adhesive layer After irradiation for 1 minute, the change in adhesive strength of the first pressure-sensitive adhesive layer was measured. At this time, the adhesive force measurement method was measured according to the ASTM D3330 method, and the adhesive force reduction rate was measured according to Equation 1 below.

[Equation 1]

Adhesion reduction rate (%) = {(Adhesion of the pressure-sensitive adhesive layer before laser irradiation-Adhesion of the pressure-sensitive adhesive layer after laser irradiation) / Adhesion of the pressure-sensitive adhesive layer before laser irradiation} × 100 (%)

In Equation 1, the adhesive force is measured according to the ASTM D3330 method when the pressure-sensitive adhesive layer has a thickness of 10 μm.

division Example 1 Example 2 Example 3 Example 4 Example 5 rescue First pressure-sensitive adhesive layer Preparation Example 2 Laser degradable film layer Preparation Example 1-1 Preparation Example 1-2 Preparation Example 1-3 Preparation Example 1-4 Preparation Example 1-5 Second pressure-sensitive adhesive layer Preparation Example 2 Adhesion
(gf / 25mm) Before laser irradiation 836 863 821 839 829 After laser irradiation 800 765 167 85 45 Adhesion reduction rate (%) 4.3 11.4 79.7 89.9 94.6 Uniqueness Bad device panel separation Good

division Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 rescue First pressure sensitive adhesive layer Preparation Example 2 Laser degradable film layer Preparation Example 1-6 Preparation Example 1-7 Preparation Example 1-8 Preparation Example 1-9 Preparation Example 1-10 Preparation Example 1-11 Second pressure-sensitive adhesive layer Preparation Example 2 Adhesion
(gf / 25mm) Before laser irradiation 853 847 843 828 870 858 After laser irradiation 25 23 24 20 21 18 Adhesion reduction rate (%) 97.1 97.3 97.2 97.6 97.6 97.9 Uniqueness Good

division Example 12 Example 13 Example 14 Example 15 Example 16 Example 17 Example 18 rescue First pressure-sensitive adhesive layer Preparation Example 2 Laser degradable film layer Preparation Example 1-12 Preparation Example 1-13 Preparation Example 1-14 Preparation Example 1-15 Preparation Example 1-16 Preparation Example 1-17 Preparation Example 1-18 Second pressure-sensitive adhesive layer Preparation Example 2 Adhesion
(gf / 25mm) Before laser irradiation 853 847 852 850 846 849 848 After laser irradiation 15 8 7 21 21 23 26 Adhesion reduction rate (%) 98.2 99.1 99.2 99.4 97.5 97.3 96.9 Uniqueness Good Device discoloration Good

Looking at the rate of change in the adhesive strength of the first pressure-sensitive adhesive layer of the double-sided adhesive tapes of Tables 4 to 6, in Examples 1 to 3, the decrease in the adhesive strength was low, resulting in defects in device panel separation. In addition, in the case of Examples 14 to 15, the adhesive force reduction rate is very excellent, but a problem that device discoloration occurs occurred. On the other hand, in Examples 4 to 13 and Examples 16 to 18, as a result of the adhesive force reduction rate of 88% or more, device panel separation was good, and device discoloration problems did not occur.

DESCRIPTION OF SYMBOLS 1 Carrier wafer 2 Device wafer
3: temporary bonding means 10: first pressure-sensitive adhesive layer
10 ': 2nd pressure-sensitive adhesive layer 20: laser-decomposable film layer
30, 30 ': release film layer

Claims (12)

A first pressure-sensitive adhesive layer; Laser degradable film layer; And a second pressure-sensitive adhesive layer; a double-sided adhesive tape for a redistribution layer (RDL) forming process, characterized in that they are sequentially stacked.
The double-sided adhesive tape for an RDL forming process according to claim 1, further comprising a release film layer on one of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer.
The method of claim 1, wherein the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer when the laser of 50W intensity is irradiated for 1 minute, the RDL formation characterized in that the reduction rate of the adhesive force measured according to the following Equation 1 is 85% or more. Double-sided adhesive tape for processing;
[Equation 1]
Adhesion reduction rate (%) = {(Adhesion of the pressure-sensitive adhesive layer before laser irradiation-Adhesion of the pressure-sensitive adhesive layer after laser irradiation) / Adhesion of the pressure-sensitive adhesive layer before laser irradiation} × 100 (%)
In Equation 1, the adhesive force is measured according to the ASTM D3330 method, and the adhesive force unit is gf / 25mm.
The method of claim 1, wherein the laser-decomposable film layer is irradiated with a laser of 50 W intensity for 1 minute, and when measuring the viscosity according to the ISO 6721-10 method, the viscosity is 2,500 to 300,000 cps. Adhesive tape.
The method of claim 4, wherein the laser-decomposable film layer is a double-sided adhesive tape for RDL forming process characterized in that the rate of change in viscosity before and after laser irradiation measured according to the following equation (2) is 88.0% to 99.9%;
[Equation 2]
Viscosity change rate (%) = │ (viscosity of film layer before laser irradiation-viscosity of film layer after laser irradiation) / viscosity of film layer before laser irradiation × 100% │
In Equation 2, the unit of viscosity is cps.
According to claim 1, The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer is a double-sided for the RDL forming process, characterized in that it comprises at least one selected from urethane-based pressure-sensitive adhesive resin, curable silicone-based pressure-sensitive adhesive resin and acrylic pressure-sensitive adhesive resin. Adhesive tape.
The method of claim 1, wherein the laser-decomposable film layer comprises a black polyimide film,
The black polyimide film is a mixed solution containing a polyamic acid resin, a catalyst and a solvent; And a laser reactant; an imide of a polyamic acid varnish containing
The black polyimide film is characterized in that it comprises a laser reactant containing at least one selected from carbon black, carbon nanotubes, carbon nodes, carbon fiber and graphite nanopowder 3.0 to 10.0% by weight and the residual amount of polyimide compound Double sided adhesive tape for RDL forming process.
According to claim 1, The first pressure-sensitive adhesive layer has an average thickness of 5 ~ 50㎛,
Laser decomposable film layer average thickness is 5 ~ 75㎛,
The second pressure-sensitive adhesive layer is a double-sided adhesive tape for the RDL forming process, characterized in that the average thickness is 5 ~ 50㎛.
In the process of forming the RDL during the manufacturing process of the fan-out package,
As a temporary bonding means used to bond the device wafer and the carrier wafer and to de-bond the carrier wafer from the device wafer, the double-sided adhesive tape of any one of claims 1 to 8 is used. Fan-out package manufacturing process, characterized in that.
10. The method of claim 9, The carrier wafer is a fan-out package (Fan-out package) manufacturing process characterized in that it comprises a glass material or a transparent acrylic material.
10. The method of claim 9, The peeling by irradiating the pressure-sensitive adhesive layer 30 ~ 100W intensity laser in the direction of the carrier wafer for 30 seconds to 5 minutes, after decomposing the laser-decomposable film layer of the double-sided adhesive tape, the carrier wafer is a device wafer Fan-out package (Fan-out package) manufacturing process, characterized in that performed by peeling from.
A device wafer layer;
A carrier wafer layer supporting the device wafer; And
Includes; temporary bonding layer formed between the device wafer layer and the carrier wafer layer,
The temporary adhesive layer is a laminate comprising a double-sided adhesive tape of any one of claims 1 to 8.

Images