JP2017211617A - Photosensitive resin composition, photosensitive resin film, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition that can achieve an opening having excellent metal embedding properties, and a photosensitive resin film and an electronic apparatus obtained using the same.SOLUTION: A photosensitive resin composition is a negative photosensitive resin composition containing an epoxy resin, a curing agent, and a photosensitizer. The taper angle of an opening formed in accordance with a predetermined over-exposure condition is smaller than 90 degrees and larger than 45 degrees.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a photosensitive resin composition, a photosensitive resin film, and an electronic device.

  In recent years, a photosensitive resin composition has been used for the purpose of processing a fine wiring pattern in a liquid crystal display manufacturing process. There exists a thing of patent document 1 as this kind of technique. This document describes forming a wiring pattern on a substrate by a lift-off method. The lift-off method is a method for removing a metal film formed on the top surface of the resist film together with the resist film. Thereby, the wiring pattern can be formed by leaving the metal film in the region where the resist film is not formed.

  Specifically, a resist resin having a pattern shape is formed by applying a photosensitive resin composition and exposing and developing it. This document describes that the resist film preferably has a reverse taper shape. When a metal is vapor-deposited on a reverse taper-shaped resist film, the side wall and upper part of the resist film do not adhere directly below the protruding cliff portion. Thereby, the resist stripping solution can be permeated from the side wall of the resist film, and an unnecessary portion of the metal film can be removed cleanly. It is described that a fine wiring pattern can be formed as described above.

  Patent Documents 2 to 4 describe the film thickness of a resist film used for photolithography. For example, Patent Document 2 describes 300 nm or less, Patent Document 3 describes 20 nm to 50 nm, and Patent Document 4 describes 100 nm to 300 nm.

JP 2006-243207 A JP 2013-68840 A JP 2013-219099 A JP2013-11900A

When the inventor examined, the following problems were found.
As described in the above document, the resist film is required to have a structure in which the metal film does not adhere to the side wall for the purpose of penetration of the stripping solution. That is, the composition of the photosensitive resin composition has been determined in accordance with the demand for a general resist film for photolithography. On the other hand, in order to form a tapered shape, a positive-type sensitive resin composition is usually used.
For this reason, in the negative photosensitive resin composition for resist films described in the above documents, when used in a wiring layer in which a through electrode is formed on the photosensitive resin film, the embedding property of the through electrode is improved and the through electrodes are connected to each other. There was room for improvement in terms of connection reliability such as prevention of short circuits.

  The present inventor further examined. First, by increasing the exposure amount, the inverse taper shape of the opening of the photosensitive resin film of the thin film described in the above document is made substantially rectangular, thereby improving the embedding characteristic. I found out that However, when the photosensitive resin film is made to be a considerably thick film, an excessive undercut that spreads at the bottom may occur at the lower end of the opening. In this excessive undercut, it was difficult to deposit metal when using a vapor deposition technique such as sputtering.

  Based on these findings, we conducted further research. Second, even with thick films, the patterning of the photosensitive resin film was improved, and the entire opening was tapered, but undercuts occurred. It was found that can be suppressed. As a result, it was found that the short circuit between the through electrodes can be prevented while improving the adhesion of the metal by sputtering or the like, and the present invention has been completed.

  Furthermore, by embedding a metal film in the opening of the pattern shape of the photosensitive resin film, the photosensitive resin composition is used for a new application of a wiring layer having a through electrode, which is different from a mere resist film. I understood that I could do it.

According to the present invention,
Epoxy resin,
A curing agent;
A negative photosensitive resin composition comprising a photosensitive agent,
A photosensitive resin composition is provided in which the taper angle of the opening corresponding to the following overexposure exposure conditions is less than 90 degrees and 45 degrees or more.
(Exposure conditions: a photosensitive resin film having a film thickness of 50 μm is formed using the photosensitive resin composition. The photosensitive resin film is irradiated with a plurality of different exposure amounts. After exposure, heating and development are performed. A plurality of openings are formed in the photosensitive resin film by performing a treatment, and a cured film is obtained by performing a curing treatment on the photosensitive resin film.
Optimum exposure amount: The exposure amount that satisfies the condition in which the angle formed between the bottom surface of the cured film and the side surface of the opening is closest to a right angle is defined as the optimum exposure amount.
Taper angle: The opening formed under the overexposure exposure condition having an exposure amount larger than the optimum exposure amount has a tapered shape in which the width at the lower end is narrower than the width at the upper end. The angle formed by the bottom surface of the cured film and the side surface of the opening is defined as the taper angle. )

  According to this invention, the photosensitive resin film which uses the said photosensitive resin composition is provided.

  According to this invention, an electronic device provided with the hardened | cured material of the said photosensitive resin composition is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the negative photosensitive resin composition which can implement | achieve the opening part excellent in connection reliability, the photosensitive resin film using the same, and an electronic device are provided.

It is sectional drawing which shows the opening part of the photosensitive resin film which concerns on this embodiment. It is process sectional drawing which shows the manufacture procedure of the wiring layer which concerns on this embodiment. It is sectional drawing which shows the structure of the semiconductor device which concerns on this embodiment. FIG. 3 is a cross-sectional view showing an opening of the photosensitive resin assembled film of Example 1. It is sectional drawing which shows the opening part of the photosensitive resin assembled film of Example 2. FIG. It is sectional drawing which shows the opening part of the photosensitive resin assembled film of Example 3. FIG. It is sectional drawing which shows the opening part of the photosensitive resin assembled film of Example 4. It is sectional drawing which shows the opening part of the photosensitive resin assembled film of the comparative example 1. It is sectional drawing which shows the opening part of the photosensitive resin assembled film of the comparative example 2.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

[Photosensitive resin composition]
The outline | summary of the photosensitive resin composition of this embodiment is demonstrated.

  The photosensitive resin composition of this embodiment is a negative photosensitive resin composition that can contain an epoxy resin, a curing agent, and a photosensitive agent. The opening formed in the photosensitive resin assembly made of the photosensitive resin composition has a tapered shape as a whole in a sectional view in the thickness direction. The taper shape of the present embodiment is a shape in which the opening is tapered with respect to the exposure direction. That is, in the opening, the width of the lower end is narrower than the width of the upper end. In the present embodiment, the taper angle θ of the opening of the photosensitive resin film can be made smaller than 90 degrees and 45 degrees or larger.

The shape of the opening 112 of the photosensitive resin film 32 in this embodiment will be described.
Fig.1 (a) is the sectional view on the AA line of FIG.1 (b). FIG. 1B is a cross-sectional view of a photosensitive resin film having a pattern shape.

The taper shape of the opening 112 of this embodiment will be described.
The opening 112 of the present embodiment has a tapered shape in which the overall shape is tapered toward the exposure direction. As a result, the metal easily adheres to the side wall 35 of the opening 112 by sputtering or the like, and the metal embedding characteristic can be improved.

  Here, when an opening having a reverse taper structure as a whole is formed using the negative resist described in the above-mentioned prior art document, the opening has a reverse taper shape in which the opening widens in the exposure direction. In this case, the opening width at the lower end of the opening is wider than the width (design width) of the light blocking region of the photomask. On the other hand, in the present embodiment, the opening width of the lower end portion 4 in the opening 112 can be made narrower than the width (design width) of the light blocking region of the photomask. For this reason, since the distance between the metal films (through electrodes 34) embedded in the opening 112 can be shortened, the integration density of the plurality of through electrodes 34 can be increased.

  In the present embodiment, the taper angle θ of the opening 112 is preferably less than 90 degrees and 45 degrees or more. This makes it easier for metal to adhere to the side wall 35 of the lower end 4 of the opening 112 by sputtering or the like. Moreover, a short circuit between the through electrodes 34 can be suppressed. In addition, since the contact area between the surface 36 of the photosensitive resin film 32 and the base can be increased, the adhesion between the through electrode layer 30 and the base can be enhanced.

In the exposure and development methods described in the above documents, in the photosensitive resin film 32 made of a negative photosensitive resin composition, (ii) the overall shape of the opening 112 is tapered while (i) the film is thick. It was difficult to achieve both shape.
For example, in order to make the entire shape of the opening substantially rectangular, for example, a method of increasing the exposure amount can be mentioned. By setting the optimal exposure amount, the entire shape of the opening can be controlled.
However, even when the optimum exposure amount condition is adopted, when the photosensitive resin film is thick, the exposure amount on the lower surface side of the photosensitive resin film is insufficient and sufficient curing does not proceed. In addition, excessive undercut may occur at the lower end of the opening.
As a result of the study by the present inventors, for example, the patterning property of the photosensitive resin film 32 is improved by using a highly reactive alicyclic epoxy resin, optimizing the amount of phenol resin added to the epoxy resin, and the like. Thus, the present invention has been completed by finding that the entire shape of the opening 112 is tapered while (ii) the thick film is formed and (ii) the occurrence of undercuts is suppressed.

  According to the present embodiment, it is possible to realize the shape of the opening 112 in which metal easily adheres not only to the side wall 35 of the central portion 33 but also to the side wall 35 of the lower end portion 4. Thereby, it is possible to realize a photosensitive resin composition capable of forming the opening 112 having excellent metal embedding characteristics. Moreover, it can utilize for the new use about the photosensitive resin composition of this embodiment by embedding a metal film (penetration electrode 34) in the opening part 112 of the photosensitive resin film 32 which has a pattern shape. For example, it can be used for applications such as a wiring layer (through electrode layer 30) having the through electrode 34. Therefore, the photosensitive resin composition of the present embodiment can be used for forming a thick film insulating layer constituting the through electrode layer.

Next, the opening process of the photosensitive resin film of this embodiment and the manufacturing process of the through electrode layer 30 will be described.
FIG. 2 is a process cross-sectional view of a procedure for manufacturing a wiring layer (through electrode layer 30) using the photosensitive resin composition of the present embodiment. In this embodiment, an example in which a negative photosensitive resin composition is used as the photosensitive resin composition will be described. In FIG. 2, the shape of the opening 112 is not shown in detail, but is a tapered shape.

  First, as shown in FIG. 2A, a photosensitive resin film 132 made of a photosensitive resin composition is formed on a base layer (for example, a lower wiring layer 142). The photosensitive resin film 132 may be a coating film obtained by applying a varnish-like photosensitive resin composition to a substrate, or may be a resin sheet obtained by forming the coating film into a film. By using a resin sheet, material loss can be reduced. Before the opening 112 is formed, the photosensitive resin film 132 can be in a B-stage state. Thereby, handleability can be improved. On the other hand, after the opening 112 is formed, the photosensitive resin film 132 is cured to be a cured film. Thereby, it can be set as the structure excellent in mechanical strength.

  Specific methods for forming the photosensitive resin film 132 include a coating process and a laminating process. In the coating step, a varnish-like photosensitive resin composition is prepared. And the varnish of the photosensitive resin composition is apply | coated on a base material. Thereby, a coating film can be formed on a coating surface. On the other hand, in the laminating step, a film-like photosensitive resin film made of a photosensitive resin composition is prepared. A photosensitive resin film is pasted on the substrate by thermocompression bonding or the like. Thereby, the photosensitive resin film can be formed on the pasting surface.

  After the photosensitive resin film 132 is formed, the photosensitive resin film 132 can be pre-baked at a predetermined temperature before the exposure process. The prebaking temperature is not particularly limited, but may be, for example, 100 ° C. or higher and 150 ° C. or lower, and preferably 110 ° C. or higher and 140 ° C. or lower. The pre-bake time can be, for example, 1 minute or more and 10 minutes or less. Thereby, excess solvent can be evaporated and the film-forming characteristic can be stabilized.

  The film thickness of the photosensitive resin film 132 after pre-baking is designed according to the final film thickness of the cured film, and can be, for example, 50 μm or more and 200 μm or less.

  In the present embodiment, in the photosensitive resin film 132 after pre-baking under a predetermined condition, the lower limit value of the light transmittance of light with respect to the exposure wavelength is, for example, preferably 50% or more, and 60% or more. More preferred is 70% or more. Thereby, even when the thick photosensitive resin film 132 is used, the patterning property in the region on the lower surface side (opposite to the exposure side) of the photosensitive resin film 132 can be improved. Although the upper limit of the light transmittance is not particularly limited, for example, it may be less than 100% or 90% or less. Thereby, since the photosensitive agent etc. in the photosensitive resin composition can absorb the light of an exposure wavelength effectively, reactivity, such as photocuring, can be improved. For example, the transmittance of the photosensitive resin film can be increased by optimally selecting the type of epoxy resin or the type of solvent.

  In this embodiment, as a method for measuring light transmittance, for example, a visible ultraviolet spectrophotometer can be used. The light transmittance is measured, for example, by preparing a coating film of a varnish-like photosensitive resin composition and pre-baking the coating film at 120 ° C. for 5 minutes to form a photosensitive film having a thickness of 10 μm. A functional resin film can be used.

  Subsequently, the mask 102 is disposed in a predetermined region on the photosensitive resin film 132. An exposure process is performed on the photosensitive resin film 132 through the mask 102. When the negative photosensitive resin composition is used, the opening 112 is formed in the mask formation region (light blocking region that is not exposed to irradiation). In this embodiment, as the exposure wavelength, for example, ultraviolet rays of 365 nm can be used.

  Subsequently, post-exposure heat treatment may be performed on the photosensitive resin film 132 under predetermined conditions. The temperature of the post-exposure heat treatment is not particularly limited, but may be, for example, 50 ° C. or higher and 120 ° C. or lower, and preferably 60 ° C. or higher and 110 ° C. or lower. The post-exposure heat treatment time can be, for example, from 1 minute to 10 minutes. The post-exposure heat treatment does not completely cure, but the degree of curing of the photosensitive resin composition can be controlled. Thereby, the resin-type curing reaction with high reactivity can be advanced.

  Subsequently, the photosensitive resin film 132 is developed. As the developer, for example, an organic solvent or a water-soluble developer can be used. Thereby, a plurality of through portions (openings 112) can be formed by patterning in the photosensitive resin film 132. The plurality of penetrating portions penetrate the back surface from the front surface of the photosensitive resin film 132 and are separated from each other.

  After the opening 112 is formed, the photosensitive resin film 132 is cured by heat treatment under predetermined heating conditions. The temperature of the curing treatment of the photosensitive resin film 132 is not particularly limited, but may be, for example, 160 ° C. or higher and 250 ° C. or lower, and preferably 180 ° C. or higher and 230 ° C. or lower. The time for the curing treatment can be, for example, 30 minutes or more and 120 minutes or less. Curing can be suppressed by curing at a low temperature. For example, the curing temperature may be set according to the heat resistance of the semiconductor chip. By the curing treatment, a resin-based curing reaction that is not cured by the post-exposure heat treatment can be sufficiently advanced.

  As described above, the opening 112 as shown in FIG. 1 can be formed in the photosensitive resin film 132.

  Here, as the formation condition of the opening 112 in the present embodiment, it is preferable to adopt an optimum exposure amount obtained under the following exposure conditions. Hereinafter, a description will be given with reference to FIG.

  Exposure conditions: A photosensitive resin film 32 having a thickness of 50 μm is formed using the photosensitive resin composition of the present embodiment. The photosensitive resin film 32 is irradiated with a plurality of different exposure amounts. After the exposure, a plurality of openings are formed in the photosensitive resin film 32 by performing heating and development processing. Then, a cured film is obtained by performing a curing process on the photosensitive resin film 23.

Further, the following conditions are used as more specific exposure conditions. For example, a varnish of a photosensitive resin composition is applied onto a silicon wafer using a spin coater, and prebaked at 120 ° C. for 5 minutes using a hot plate to obtain a coating film having a thickness of 50 μm. The coating film is subjected to step exposure with an I-line stepper at 50 to 1250 mJ / cm ² after making the exposure time constant. Thereafter, post-exposure heating is performed on a hot plate at 80 ° C. for 5 minutes. The coating film is developed using an organic solvent such as PGMEA. Then, the cured film in which the pattern is formed is obtained by curing at 200 ° C. for 90 minutes. In the present embodiment, the aspect ratio (opening height / opening width) of the opening under the above exposure conditions may be set to 5. The opening width of the opening may be 10 μm. This makes it possible to evaluate even in an exposure condition where the influence of undercut is more concerned, such as a high aspect ratio. In the present embodiment, the exposure interval in the step exposure may be set to 20 [mJ / cm ² ], for example, but may be an arbitrary numerical value. The opening width may be the opening width R1 of the opening 112 in FIG.
In the present embodiment, by setting the upper limit value of the exposure amount to, for example, 1250 mJ / cm ² or less, the opening 112 having a tapered shape is formed within a range in which the patterning property of the photosensitive resin film 32 is not deteriorated. be able to. Therefore, according to the present embodiment, it is possible to suppress a decrease in patterning property such that the pattern is crushed by overexposure.

  Optimum exposure amount: The average angle (angle on the acute angle side) formed by the bottom surface (surface 36) of the cured film of the photosensitive resin film 32 and the side surface of the opening 112 (for example, the side wall 35 in the central portion 33) is a right angle (90 The exposure amount that satisfies the exposure condition closest to (degree) is set as the optimum exposure amount (FIG. 1B).

  A more specific definition of the average angle will be described. In the opening 112, a point of the side wall 35 located between the upper end 2 and the lower end 4 is defined as a point P0. The diameter of the opening 112 at the point P0 is R0. A point on the front end edge of the opening 112 on the lower end 4 side is defined as a point P1. Let L be the straight line connecting P0 and P1. On the other hand, the tangent to the bottom surface (surface 36) of the photosensitive resin film 32 is L3. The angle formed by these L and L3 can be the angle of the central portion 33. The angle of the central portion 33 can indicate the overall shape of the opening 112. For example, the cross-sectional view shown in FIG. 1B can be a cross-sectional view in the film thickness direction in which the diameter R0 is maximum.

  Taper angle θ: In the present embodiment, the opening 112 formed under the overexposure exposure condition that is an exposure amount larger than the optimum exposure amount has a lateral width R1 of the lower end 4 rather than a lateral width R2 of the upper end 2. A narrow taper shape is formed. That is, the opening 112 is gradually reduced in diameter from the upper end 2 toward the lower end 4, the entire shape has a tapered shape, and the lower end 4 does not have an undercut. it can. In this case, an angle θ formed by the bottom surface (surface 36) of the cured film and the side surface (side wall 35) of the opening 112 is defined as a taper angle (FIG. 1B).

In the present embodiment, the exposure amount (overexposure amount) in the overexposure is not particularly limited as long as it is larger than the optimal exposure amount and 1250 mJ / cm ² or less. In the exposure amount ratio (overexposure exposure amount / optimum exposure amount) of the overexposure amount with respect to the optimum exposure amount, the lower limit value thereof may be, for example, 1.1 or more, 1.2 or more, or 1.3 or more. On the other hand, the upper limit value may be, for example, 3.0 or less, 2.5 or less, or 2.0 or less. By setting the overexposure amount within the above exposure amount range, the taper angle θ can be controlled to be small. Moreover, the patterning property of the photosensitive resin film 32 can also be improved.

  A more specific definition of the taper angle θ will be described. The position of the front end edge on the lower end 4 side of the opening 112 is defined as a point P1. The position of the front end edge on the upper end 2 side of the opening 112 is defined as a point P2. A straight line connecting the point P2 and the point P1 is defined as L1. On the other hand, the tangent to the bottom surface (surface 36) of the photosensitive resin film 32 is L3. The angle (angle on the acute angle side) formed by L1 and L3 can be the taper angle θ. For example, the cross-sectional view shown in FIG. 1B can be a cross-sectional view in the film thickness direction in which the diameter R0 is maximum. In addition, let the perpendicular line which pulled the tangent with respect to the surface 36 of the photosensitive resin film 32 from the point P2 to L0 be L3.

  In the present embodiment, the lower limit value of the taper angle θ can be, for example, 70 degrees or more, more preferably 75 degrees or more, and further preferably 80 degrees or more. Thereby, the contact area between the surface 36 of the photosensitive resin film 32 and the base can be increased, so that the adhesion between the through electrode layer 30 and the base can be enhanced. In addition, since the area of the lower end portion 4 of the through electrode 34 can be secured, even if a positional shift occurs in the manufacturing process, a connection failure with the base layer (for example, the wiring 143 shown in FIG. 2) is prevented. Can be prevented. On the other hand, the upper limit value of the taper angle θ is, for example, smaller than 90 degrees, may be 89 degrees or less, and may be 88 degrees or less. Thereby, since sputter | spatter can adhere also to the side wall 35 of the lower end part 4, generation | occurrence | production of the void of the penetration electrode 34 can be suppressed. Further, the lateral width R1 of the lower end 4 of the opening 112 can be made narrower than the lateral width R2 of the upper end 2. For this reason, a short circuit between the through electrodes 34 can be suppressed.

  Here, the point P2 will be described. As shown in FIG. 1, when the inclination of the side wall 35 at the upper end portion 2 of the photosensitive resin film 32 is viewed, a position where the inclination direction of the side wall 35 is the same as or similar to the direction of L2 is indicated by a point P2. It is good. As shown in FIG. 1, L2 may be a tangent line in contact with the upper surface 39 of the photosensitive resin film 32, but corresponds to the average film thickness of the photosensitive resin film 32 (for example, the average film thickness when 10 points are measured). It may be a tangent line that touches the surface of the position to be.

  In the present embodiment, the average angle can be, for example, 70 degrees or more and 90 degrees or less, preferably 75 degrees or more and 90 degrees or less, and more preferably 80 degrees or more and 90 degrees or less. can do. The average angle is preferably close to a substantially right angle. Thereby, since the filling property of the metal which comprises the penetration electrode 34 can be improved, it can be set as the connection structure excellent in reliability.

  In the present embodiment, selection of the type of epoxy resin, specifically, using a highly reactive alicyclic epoxy resin, and appropriately controlling the film thickness of the photosensitive resin film 32, The patterning property of the photosensitive resin film 32 can be improved. As a result, while (i) the film is thick, (ii) the entire shape of the opening 112 can be tapered.

  In the present embodiment, the lower limit value of the aspect ratio (height H / diameter W) of the opening 112 of the photosensitive resin film 32 may be, for example, 3 or more, preferably 3.5 or more, and more preferably. May be 4 or more. On the other hand, the upper limit of the aspect ratio is not particularly limited, but may be, for example, 10 or less, preferably 9 or less, and more preferably 8 or less. By setting the aspect ratio of the opening 112 to be equal to or higher than the lower limit value, it is possible to increase the density of the through electrodes 34. Moreover, rigidity can be improved by making the photosensitive resin film 32 thick. On the other hand, by setting the aspect ratio of the opening 112 to be equal to or lower than the above upper limit value, the electrical resistance value of the through electrode 34 can be lowered. By setting the aspect ratio within the above range, the balance between high density and high transmission speed can be improved. The diameter W may be the opening width R1 of the opening 112 in FIG.

  In the present embodiment, it is possible to suppress the occurrence of excessive undercut even in the case of the opening 112 having a high aspect ratio. Thereby, it is possible to realize a connection structure with excellent reliability. For example, it is possible to form the opening 112 having a high aspect ratio by improving the patternability of the photosensitive resin composition.

  In the present embodiment, R1 / R2 is preferably less than 1 when the opening width (R2) of the upper end portion 2 and the opening width (R1) of the lower end portion 4 are used. In this case, the upper limit value of R1 / R2 may be 0.95 or less, 0.90 or less, or 0.85 or less, for example. As a result, the high density of the through electrode layer 30 can be realized. Further, the lower limit value of R1 / R2 is not particularly limited as long as the connectivity of the through electrode 34 at the lower end portion 4 is sufficient, but may be 0.1 or more, for example, 0.2 or more, and 0 It is good also as 3 or more. As a result, the connectivity of the through electrode 34 can be improved, and the connection resistance can be lowered, so that high speed can be realized.

  In the present embodiment, when the opening width (R2) of the upper end portion 2 and the opening width (R0) of the central portion 33 are set, R0 / R2 is preferably less than 1. In this case, the upper limit value of R0 / R2 may be 0.98 or less, 0.94 or less, or 0.90 or less, for example. From this, since the adhesiveness of a metal film can be improved by making the side wall 35 into a taper shape, it can be set as the shape excellent in manufacturing stability. The lower limit of R0 / R2 is not particularly limited as long as the connectivity of the through electrode 34 at the lower end portion 4 is sufficient. For example, it may be 0.3 or more, or may be 0.4 or more. It may be 5 or more. Thereby, since the embedding characteristic can be improved, a structure having excellent manufacturing stability can be obtained. Further, since the connection resistance of the through electrode 34 can be lowered, high speed can be realized.

  In the present embodiment, the side wall 35 in the vicinity of the upper end 2 of the opening 112 may have a curved shape without corners. Since there is no corner, local stress is not generated in the through electrode 34, so that a structure with excellent connection stability of the through electrode 34 can be realized.

  In the lower end portion 4 of the opening 112 of the present embodiment, a cut portion in which the photosensitive resin film 32 cuts toward the opening 112 may be formed. However, this cut portion does not include an undercut in which the opening 112 cuts into the photosensitive resin film 32 side. The cut width of the cut portion may be, for example, 5% or less of the opening width (R1) of the lower end portion 4, may be 4% or less, and may be 3% or less. Even in the case where there is a notch at the tip, the notch width can be suppressed small, so that the through electrode 34 having excellent connection stability can be realized.

  Subsequently, returning to FIG. 2B, a method for manufacturing the through electrode layer 30 will be described. As shown in FIG. 2B, the seed layer 108 is formed on the surface of the patterned photosensitive resin film 132. The seed layer 108 is formed on the upper surface 139 together with the inside (side wall and bottom surface) of the opening 112 of the photosensitive resin film 132. The seed layer 108 is formed by a method such as sputtering.

  The seed layer 108 may be made of the same kind of metal as the through electrode 134, but may be made of a different kind of metal having good adhesion to the through electrode 134. In the present embodiment, for example, a copper seed layer is formed as the seed layer 108.

  A resist layer 104 is formed on the seed layer 108 on the upper surface 139 of the photosensitive resin film 132. In other words, the resist layer 104 is formed on the photosensitive resin film 132 in a region excluding the opening 112. For example, a film-like resist layer 104 can be used. The patterned resist layer 104 may be laminated, or the film-like resist layer 104 may be laminated and then patterned using a drill or a laser.

  Subsequently, as shown in FIG. 2C, the penetrating portion (opening 112) is embedded with a metal layer (plating film 115). For example, an electrolytic plating method can be used. For example, the opening 112 may be embedded with copper by electrolytic plating. Thereby, the through electrode 134 penetrating the upper surface and the lower surface of the photosensitive resin film can be formed in the opening 112. The through electrode 134 is electrically joined to the lower wiring layer 142. The through electrode 134 can be made of copper, for example.

  Subsequently, as shown in FIG. 2D, the resist layer 104 is peeled off. Thereafter, the seed layer 108 on the photosensitive resin film 132 is removed. For example, flash etching or the like can be used.

  As described above, the through electrode layer 130 having the structure shown in FIG. 2E can be formed.

  The photosensitive resin film 132 of the present embodiment can be used for an insulating layer (photosensitive resin film 132) constituting such a through electrode layer 130. Further, the photosensitive resin film 132 of the present embodiment can be used in a wafer level process using a large area substrate such as a semiconductor wafer.

Each component of the photosensitive resin composition of this embodiment is demonstrated.
The photosensitive resin composition of the present embodiment is preferably a negative type from the viewpoint of realizing a high aspect structure.

<Negative photosensitive resin composition>
The negative photosensitive resin composition can contain an epoxy resin, a curing agent, and a photosensitive agent A.

(Epoxy resin)
As an epoxy resin, what has two or more epoxy groups in 1 molecule can be used, for example. For example, phenol novolac type epoxy resin, cresol novolac type epoxy resin, cresol naphthol type epoxy resin, biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, phenoxy resin, naphthalene skeleton type epoxy resin, diallyl bisphenol A type epoxy resin, bisphenol A diester Glycidyl ether type epoxy resin, bisphenol F diglycidyl ether type epoxy resin, bisphenol S diglycidyl ether type epoxy resin, glycidyl ether type epoxy resin, cresol novolac type epoxy resin, aromatic polyfunctional epoxy resin, aliphatic epoxy resin, aliphatic A polyfunctional epoxy resin, an alicyclic epoxy resin, a polyfunctional alicyclic epoxy resin, etc. are mentioned. These may be used alone or in combination.

  It is preferable to use a compound having a benzene ring as the epoxy resin. Thereby, the transparency of the photosensitive resin film can be improved. For example, the following polyfunctional epoxy resin can be used as the compound having a benzene ring. On the other hand, it is preferable that the said epoxy resin does not contain the compound which has a naphthalene ring. Thereby, it can suppress that the transmittance | permeability of the photosensitive resin film in an exposure wavelength falls. For example, any of the following alicyclic epoxy resins and polyfunctional epoxy resins is preferably a compound having no naphthalene skeleton.

  The epoxy resin preferably includes an alicyclic epoxy resin having two or more alicyclic epoxy groups in one molecule. The alicyclic epoxy resin has good reactivity, and by using such an epoxy resin with good reactivity, the patterning property can be improved. Further, the curing reaction can be advanced even under low-temperature heating conditions such as post-exposure heat treatment. Moreover, the softness | flexibility of the hardened | cured material of the photosensitive resin composition of this embodiment can be improved.

  Although it does not specifically limit as said alicyclic epoxy resin, For example, CEL8000 (made by Daicel Corporation), CEL2081 (made by Daicel Corporation), CEL2021P (made by Daicel Corporation), limonene dioxide, etc. are used. . These may be used alone or in combination.

  Moreover, as said epoxy resin, it is preferable that a polyfunctional epoxy resin more than trifunctional is included. The rigidity of the cured product of the photosensitive resin composition of the present embodiment can be improved. Thereby, it becomes possible to raise a glass transition temperature and to suppress a linear expansion coefficient low by using resin which provides rigidity.

  Although it does not specifically limit as said polyfunctional epoxy resin, For example, VG-3101L (made by Printec Co., Ltd.), EPPN-501H (made by Nippon Kayaku Co., Ltd.), jER-1031S (made by Mitsubishi Chemical Corporation) ), JER-1032H60 (Mitsubishi Chemical Corporation), HP-4700 (DIC Corporation), HP-4710 (DIC Corporation), HP-6000 (DIC Corporation), HP-7200L (Made by DIC Corporation) is used. These may be used alone or in combination.

  Moreover, in this embodiment, you may use together an alicyclic epoxy resin and a polyfunctional epoxy resin. Thereby, it becomes possible to realize both the elongation characteristics indicating flexibility and the film characteristics of the mechanical strength characteristics indicating rigidity such as Tg and CTE. Here, by using an alicyclic epoxy resin, the patternability (development characteristics) of the photosensitive resin film can be improved even under thick film conditions. In the present embodiment, by using an alicyclic epoxy resin and a polyfunctional epoxy resin in combination, it is possible to realize both the above-described film characteristics and development characteristics.

(Curing agent)
Although it will not specifically limit as a hardening | curing agent if it accelerates | stimulates the polymerization reaction of an epoxy resin, For example, the hardening | curing agent which has a phenolic hydroxyl group can be included. Specifically, a phenol resin can be used. As a phenol resin, it can select suitably from well-known things, For example, a novolak type phenol resin, a resol type phenol resin, a trisphenyl methane type phenol resin, and an aryl alkylene type phenol resin can be used.

(Photosensitive agent A)
As the photosensitive agent A, a photoacid generator can be used. As a photo-acid generator, the photo-acid generator which generate | occur | produces an acid by irradiation of active rays, such as an ultraviolet-ray, is contained. Examples of the photoacid generator include onium salt compounds, and examples include sulfonium salts and iodonium salts.

(Other additives)
The photosensitive resin composition of the present embodiment may be added with additives such as antioxidants, fillers such as silica, surfactants, sensitizers, filming agents, adhesion aids, etc., as necessary. Good.

(solvent)
The photosensitive resin composition of this embodiment can contain a solvent.
Examples of the solvent include acetone, methyl ethyl ketone, toluene, propylene glycol methyl ethyl ether, propylene glycol dimethyl ether, propylene glycol 1-monomethyl ether 2-acetate, diethylene glycol ethyl methyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, benzyl alcohol, One or more selected from organic solvents such as propylene carbonate, ethylene glycol diacetate, propylene glycol diacetate, and propylene glycol monomethyl ether acetate can be included.

  The preparation method of the photosensitive resin composition of this embodiment is not specifically limited, Generally it can manufacture by a well-known method. For example, the following method is mentioned. A photosensitive resin composition is obtained by blending the raw material and the solvent and mixing them uniformly.

  The photosensitive resin composition may be in the form of a varnish. A resin sheet (photosensitive resin film) is obtained by forming the varnish-like photosensitive resin composition into a film.

  The resin sheet can be obtained, for example, by subjecting a coating film (resin film) obtained by applying a varnish-like thermosetting resin composition to a solvent removal treatment. The resin sheet may have a solvent content of 10% by weight or less with respect to the entire photosensitive resin composition. For example, the solvent removal treatment can be performed under conditions of 80 ° C. to 150 ° C. and 1 minute to 10 minutes. Thereby, it becomes possible to remove the solvent sufficiently while suppressing the curing of the photosensitive resin composition.

  In this embodiment, the method for forming the photosensitive resin composition on the carrier substrate is not particularly limited. For example, various coater apparatuses are prepared by dissolving and dispersing a thermosetting resin in a solvent to prepare a resin varnish. And a method of drying the resin varnish after applying the resin varnish to the carrier substrate using a spray device, and the like. Among these, the method of drying the resin varnish after applying the resin varnish to the carrier substrate using various coaters such as a comma coater and a die coater is preferable. Thereby, the resin sheet with a carrier base material which has no void and has a uniform resin sheet thickness can be efficiently produced.

  The resin sheet can include a film obtained from the photosensitive resin composition. The resin sheet may have a sheet shape or a roll shape that can be wound.

[Semiconductor device]
An electronic device according to the present embodiment will be described.
An electronic device (semiconductor package 100) according to the present embodiment will be described with reference to FIG. FIG. 3 is a cross-sectional view showing a configuration of the semiconductor package 100 according to the present embodiment.

An outline of the semiconductor package 100 of the present embodiment will be described.
The semiconductor package 100 of this embodiment includes a wiring layer 20, a through electrode layer 30, an interposer (silicon interposer 40), a semiconductor chip 50, and a sealing material layer 70. The photosensitive resin film 32 of the through electrode layer 30 can be composed of a cured product of the photosensitive resin composition.

  As shown in FIG. 3, the semiconductor package 100 of this embodiment may include an external terminal (solder bump 80) and a main board (printed circuit board 10) such as a mother board.

  The wiring layer 20 has a plurality of solder bumps 80 (external terminals) formed on the lower surface. The through electrode layer 30 and the solder bump 80 can be electrically connected.

  The through electrode layer 30 can be formed by the above-described manufacturing process using the photosensitive resin composition of the present embodiment. The through electrode layer 30 is provided on the upper surface of the wiring layer 20. The through electrode layer 30 includes a photosensitive resin film 32 and a plurality of through electrodes 34 (conductive columnar bodies). The through electrode 34 penetrates from the upper surface to the lower surface of the photosensitive resin film 32. Further, the through electrodes 34 are spaced apart from each other. The through electrode 34 can electrically connect the wiring layer 20 and the lower wiring layer 42 of the silicon interposer 40.

  The silicon interposer 40 is provided on the upper surface of the through electrode layer 30. The silicon interposer 40 may have a stacked structure in which a lower wiring layer 42, a silicon substrate 44, and an upper wiring layer 46 are stacked in this order. A through via (not shown) penetrating from the upper surface to the lower surface is formed in the silicon substrate 44. The through via can electrically connect the lower wiring layer 42 and the upper wiring layer 46 formed respectively on the lower surface and the upper surface of the silicon substrate 44. The silicon interposer 40 can electrically connect the through electrode layer 30 and the semiconductor chip 50.

  The semiconductor chip 50 is provided on the upper surface of the upper wiring layer 46. A single semiconductor chip 50 may be provided, or a plurality of semiconductor chips 50 may be provided. Different types of chips may be used. The plurality of semiconductor chips 50 (LSI chip 52, LSI chip 54) are arranged apart from each other in plan view.

  The sealing material layer 70 can seal the semiconductor chip 50. Specifically, the sealing material layer 70 can seal the periphery (upper surface and side surfaces) of the semiconductor chip 50. Further, as shown in FIG. 3, the sealing material layer 70 is provided in contact with the upper surface of the wiring layer 20, and can seal the side surface of the through electrode layer 30 and the side surface of the silicon interposer 40. it can.

  In this embodiment, it can have the penetration electrode layer 30 which can be connected to a lamination direction, and the wiring layer 20 which can be connected to a horizontal direction. With this simple connection structure, the silicon interposer 40 and the external terminal can be connected. Compared with the case where a package substrate such as a printed circuit board is used for these connections, the height (thickness) of the entire semiconductor device can be reduced.

  According to the present embodiment, it is possible to provide an electronic device (semiconductor package 100) capable of realizing a structure with a reduced height. In addition, the manufacturing cost can be reduced as compared with the case where a package substrate is used.

  Each configuration of the semiconductor package 100 will be described in detail.

  In the present embodiment, a plurality of semiconductor chips 50 are mounted on the main surface of the silicon interposer 40. The plurality of semiconductor chips 50 (LSI chip 52, LSI chip 54) are arranged at different positions in plan view. The number of semiconductor chips 50 is not particularly limited, but may be 2 or more, or 3 or more. In FIG. 3, an LSI chip is shown as an example of an electronic component to be mounted. However, the present invention is not limited to this, and various electronic components may be mounted.

  The interposer (silicon interposer 40) of this embodiment is used as a rewiring unit for the semiconductor chip 50. That is, it is possible to convert the pad interval of the semiconductor chip 50 and the pad interval and pins suitable for processing. Thereby, the three-dimensional mounting using TSV can be used efficiently. For example, it is possible to apply an electrode wiring design of a chip such as a memory lip or a logic chip without excessive change. Since the design burden is reduced, productivity efficiency can be increased.

  Although it does not specifically limit as an interposer, An organic resin substrate, a ceramic substrate, a silicon substrate, a glass substrate, etc. are used. A glass substrate is preferable from the viewpoint of low cost and excellent characteristics in a high frequency region. A silicon substrate is preferable from the viewpoints of high density, high speed, power saving, heat dissipation, and the like. The interposer of this embodiment is preferably made of silicon or glass.

  The main surface of the silicon interposer 40 refers to the surface on the side where the upper wiring layer 46 is formed. A lower wiring layer 42 is formed on the back side of the silicon interposer 40. The upper wiring layer 46 and the lower wiring layer 42 are electrically connected via a TSV penetrating the silicon interposer 40. The metal wiring constituting the upper wiring layer 46 and the lower wiring layer 42 can have an arbitrary shape. For example, as the metal wiring, a pattern conductive circuit, a columnar electrode, a bump electrode or the like extending in the plane direction can be used. These metal wirings may be embedded in the insulating resin layer.

  The through electrode layer 30 of the present embodiment can have a photosensitive resin film 32 and a through electrode (penetrating electrode 34) that penetrates the photosensitive resin film 32. The through electrodes 34 are spaced apart from each other in the in-layer direction of the photosensitive resin film 32. That is, the through electrodes 34 can be structured not to be connected to each other through the wiring in the layer of the photosensitive resin film 32. The photosensitive resin film is preferably composed of a cured product of the photosensitive resin composition. The composition of the photosensitive resin composition of this embodiment will be described later. By using the photosensitive resin composition, it is possible to improve desired characteristics such as mechanical characteristics while improving the processing characteristics of the opening 112 for embedding the through electrode 34.

  Although the metal which comprises the penetration electrode 34 is not specifically limited, For example, copper, gold | metal | money, silver, nickel etc. are used. You may use 1 type, or 2 or more types of these. In the present embodiment, the through electrode 34 is preferably in the form of a copper pillar using copper. Further, a barrier layer may be formed between the wall surface of the through electrode 34 and the opening 112 of the photosensitive resin film 32. The barrier layer can suppress diffusion of metal atoms constituting the through electrode 34 into the photosensitive resin film 32.

  The lower limit value of the thickness of the through electrode layer 30 or the photosensitive resin film 32 may be, for example, 50 μm or more, more preferably 60 μm or more, and even more preferably 70 μm or more. Further, the upper limit value of the thickness of the through electrode layer 30 or the photosensitive resin film 32 may be, for example, 200 μm or less, more preferably 150 μm or less, and further preferably 100 μm or less. By setting the film thickness of the through electrode layer 30 (cured film of the photosensitive resin film 32) to be equal to or higher than the lower limit value, the mechanical strength can be improved. Thus, sufficient mechanical strength can be obtained instead of the package substrate. In addition, the aspect ratio of the through electrode 34 can be increased. On the other hand, it is possible to realize a through electrode 34 having a high aspect ratio. By setting the thickness of the through electrode layer 30 (photosensitive resin film 32) to be equal to or less than the upper limit, the height of the semiconductor package 100 can be reduced. For example, the film characteristics of the photosensitive resin film 32 can be improved by adding a filming agent or adjusting the curing temperature.

The lower limit value of the aspect ratio (height H / diameter W) of the through electrode 34 may be, for example, 3 or more, preferably 3.5 or more, and more preferably 4 or more. On the other hand, the upper limit of the aspect ratio is not particularly limited, but may be, for example, 10 or less, preferably 9 or less, and more preferably 8 or less. By setting the aspect ratio of the through electrodes 34 to be equal to or higher than the lower limit, it is possible to increase the density of the through electrodes 34 in the through electrode layer 30. In addition, the electrical resistance value can be lowered by setting the aspect ratio of the through electrode 34 to be equal to or lower than the above upper limit value. By setting the aspect ratio within the above range, the balance between high density and high transmission speed can be improved. For example, it is possible to form the opening 112 having a high aspect ratio by improving the patternability of the photosensitive resin composition.
The diameter of the through electrode 34 is not particularly limited, but may be, for example, 5 μm or more and 50 μm or less, or 10 μm or more and 30 μm or less.

  By using the photosensitive resin composition of the present embodiment, the thickness can be increased as compared with a normal photosensitive resin film, so that an opening 112 having a high aspect ratio is formed in a cured product of the photosensitive resin composition. it can. Thereby, in the penetration electrode layer 30, the structure of the penetration electrode 34 which is a high aspect ratio, and the thick photosensitive resin film 32 is realizable. Further, by using a negative photosensitive resin composition, patterning with high resolution and high aspect ratio becomes possible.

  In the photosensitive resin film 32 (cured film) of the present embodiment, the lower limit value of the glass transition temperature (Tg) of the photosensitive resin film 32 is, for example, preferably 150 ° C. or higher, more preferably 160 ° C. or higher, 170 More preferably, it is not lower than ° C. Thereby, the heat resistance of the photosensitive resin film 32 in contact with the silicon interposer 40 having a heat dissipation function can be improved. On the other hand, the upper limit of the glass transition temperature is not particularly limited, but may be, for example, 250 ° C. or lower. For example, the glass transition temperature can be increased by using a polyfunctional epoxy resin or adjusting the curing temperature at a high temperature.

  In the photosensitive resin film 32 of the present embodiment, the lower limit value of the linear expansion coefficient (CTE) in the temperature range of 50 to 100 ° C. of the photosensitive resin film 32 may be, for example, 5 ppm / ° C. or more, and 10 ppm / ° C. or more. Or 15 ppm / ° C. or higher. On the other hand, the upper limit of the linear expansion coefficient is, for example, preferably 80 ppm / ° C. or less, more preferably 70 ppm / ° C. or less, and further preferably 60 ppm / ° C. or less. Thus, by reducing the linear expansion coefficient of the photosensitive resin film 32, the difference in the linear expansion coefficient from the silicon interposer 40 is reduced, and the occurrence of warpage can be suppressed. In addition, a highly reliable semiconductor package 100 can be obtained. For example, the linear expansion coefficient can be kept low by using a polyfunctional epoxy resin that imparts rigidity.

  In the photosensitive resin film 32 of this embodiment, the lower limit value of the elongation rate in the tensile test at 25 ° C. of the photosensitive resin film 32 is, for example, preferably 10% or more, preferably 12% or more, and more preferably 15% or more. . Thereby, in the penetration electrode layer 30, the outstanding durability is implement | achieved and a crack, a crack, etc. can be suppressed reliably. On the other hand, the upper limit of the elongation rate may be, for example, 50% or less, and preferably 40% or less. In the present embodiment, by setting the tensile elongation rate of the organic insulating layer within the above range, the through electrode layer 30 having a connection structure with excellent reliability can be realized. For example, the tensile elongation can be increased by using an alicyclic epoxy resin that imparts flexibility.

  In the present embodiment, an epoxy resin imparting rigidity and an epoxy resin imparting flexibility are used in combination, a low-temperature heat treatment (for example, post-exposure heat treatment) and a high-temperature heat treatment (for example, a curing heat treatment). In the cured product of the photosensitive resin composition, it is possible to achieve both high Tg and patternability or low CTE and patternability.

  In this embodiment, the glass transition temperature (Tg) and the linear expansion coefficient are determined by using a thermomechanical analyzer (TMA) for a predetermined test piece (width 4 mm × length 20 mm × thickness 0.005 to 0.015 mm). And calculated from the results of measurement under the conditions of a starting temperature of 30 ° C., a measurement temperature range of 30 to 400 ° C., and a heating rate of 5 ° C./min.

  In the present embodiment, the elongation percentage in the tensile test can be measured as follows. First, a predetermined test piece (width 6.5 mm × length 20 mm × thickness 0.005 to 0.015 mm) is subjected to a tensile test (tensile speed: 5 mm / min) in an atmosphere at a temperature of 25 ° C. and a humidity of 55%. To implement. The tensile test is performed using a tensile tester (Tensilon RTA-100) manufactured by Orientec Co., Ltd. Next, the tensile elongation percentage is calculated from the result of the tensile test. Here, the tensile test is performed with the number of tests n = 10, and an average value of five times with a large measured value is obtained and used as a measured value.

As the test piece, for example, a cured film obtained by heat-treating the photosensitive resin composition can be used. Specifically, the photosensitive resin composition is applied on a silicon wafer substrate with a spin coater or the like, and then dried on a hot plate at 120 ° C. for 5 minutes to obtain a coating film. The entire surface of the coating film is exposed at 700 mJ / cm ² , subjected to PEB (Post Exposure Bake) at 80 ° C. for 5 minutes, and heated at 200 ° C. for 90 minutes to obtain a cured film.

  The wiring layer 20 of the present embodiment may be mounted on the mother board (printed circuit board 10) via external terminals (solder bumps 80). A gap between the wiring layer 20 and the printed circuit board 10 may be filled with an under filler 82. The wiring layer 20 can connect the through electrode 34 of the through electrode layer 30 to the printed circuit board 10 through the solder bumps 80.

  As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail with reference to an Example, this invention is not limited to description of these Examples at all.

[Preparation of negative photosensitive resin composition]
First, the raw materials of each component blended according to Table 1 were dissolved in propylene glycol monomethyl ether acetate (PGMEA) to obtain a mixed solution. Thereafter, the mixed solution was filtered through a 0.2 μm polypropylene filter to obtain a negative photosensitive resin composition.
The detail of the raw material of each component in Table 1 is as follows.

(Epoxy resin)
Epoxy resin 1: bisphenol A type epoxy resin (LX-01, manufactured by Daiso Corporation)
Epoxy resin 2: alicyclic epoxy resin (3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, manufactured by Daicel Chemical Industries, CEL2021)
Epoxy resin 3: polyfunctional epoxy resin (VG-3101L, manufactured by Printec)
Epoxy resin 4: polyfunctional epoxy resin (jER-1032H60, manufactured by Mitsubishi Chemical Corporation)
Epoxy resin 5: polyfunctional epoxy resin (EPPN-501H, manufactured by Nippon Kayaku Co., Ltd.)
(Curing agent)
Curing agent 1: Novolac type phenolic resin (Sumitomo Bakelite Co., Ltd., PR-55617)
(Photosensitive agent)
Photosensitizer 1: Cationic photopolymerization initiator (Irgacure 290, manufactured by BASF Japan Ltd.)
(Adhesion aid)
Adhesion aid 1: γ-glycidylpropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., KBM-403E)
(Surfactant)
Surfactant 1: Polyacrylate-based surface conditioner (BYK-365N, manufactured by BYK Japan)

(Patternability)
The obtained negative photosensitive resin composition was applied onto a silicon wafer using a spin coater and then pre-baked on a hot plate at 120 ° C. for 5 minutes to obtain a coating film having a thickness of 50 μm. This coating film was step-exposed with an I-line stepper in an exposure dose range of 50 to 1250 mJ / cm ² . The exposure interval of the exposure dose was 20 mJ / cm ² . Then, after exposure for 5 minutes at 80 ° C. on a hot plate, heating was performed. Next, the unexposed portion was dissolved and removed by spray development with PGMEA for 20 seconds, and then rinsed with IPA (isopropyl alcohol) for 10 seconds. Then, the cured film of the negative photosensitive resin composition in which the predetermined pattern was formed was obtained by curing at 200 ° C. for 90 minutes.

Explaining based on FIG. 1, in the case of Examples 1 to 8, the angle formed by the bottom surface of the cured film and the side surface of the opening portion was substantially a right angle at an exposure amount of about 300 mJ / cm ² . The exposure amount corresponding to such an angle was determined as the optimum exposure amount. Then, by performing overexposure with an exposure amount larger than the optimum exposure amount, the taper angle θ shown in FIG. 1 could be made smaller than 90 degrees. In Examples 1 to 3, for example, at an exposure amount of around 580 mJ / cm ² , the taper angle θ was 84 degrees to 86 degrees as shown in Table 1. In Examples 4 to 8, for example, at an exposure amount of around 400 mJ / cm ² , the taper angle θ was 86 ° to 88 ° as shown in Table 1. In any of Examples 1 to 8, the shape of the opening was a tapered shape in which no undercut occurred.

  The results of the measurement of the structure of the opening of the obtained cured film (aspect ratio of opening, shape, ratio of opening width (R0 / R2, R1 / R2), taper angle θ) with reference to FIG. 1 are shown. It is shown in 1. Moreover, sectional drawing of the opening part of Examples 1-4 in Table 1 is shown in FIGS. 4 to 7 are cross-sectional photographs with a magnification of 2000 times obtained with a scanning electron microscope. The aspect ratio, the aperture width ratio, and the taper angle θ were calculated using a cross-sectional view at a magnification of 2000 times.

On the other hand, in the case of Comparative Example 1, since the sensitivity of the negative photosensitive resin composition is poor, a pattern is formed. However, as a result of insufficient exposure amount at the exposure amount in the above exposure amount range, even at 1200 mJ / cm ² . It was found that the exposure amount was insufficient, and the shape of the opening became an inversely tapered shape. A cross-sectional photograph (magnification 2000 times) of the opening of Comparative Example 1 is shown in FIG.
In the case of Comparative Example 2, an undercut occurred at the lower end of the opening when the exposure amount was 980 mJ / cm ² which was larger than the optimum exposure amount. Further, undercutting occurred even at the maximum exposure amount in the above exposure amount range. For this reason, although the upper limit of the exposure amount was increased to 1700 mJ / cm ² , an undercut remained. A cross-sectional photograph (magnification 2000 times) of the opening of Comparative Example 2 is shown in FIG.

(Glass transition temperature, linear expansion coefficient)
The obtained negative photosensitive resin composition is applied onto a silicon wafer substrate with a spin coater or the like and then dried on a hot plate at 120 ° C. for 5 minutes to obtain a coating film. The entire surface of the coating film is exposed at 700 mJ / cm ² , PEB (Post Exposure Bake) is performed at 80 ° C. for 5 minutes, and heated at 200 ° C. for 90 minutes to obtain a cured film. The obtained cured film was used as a test piece.
The glass transition temperature (Tg) and the coefficient of linear expansion were measured at a starting temperature of 30 ° C. using a thermomechanical analyzer (TMA) for a test piece (width 4 mm × length 20 mm × thickness 0.005 to 0.015 mm). It was calculated from the results of measurement under the conditions of a measurement temperature range of 30 to 400 ° C. and a heating rate of 5 ° C./min.

(Tensile elongation)
A test specimen (width 6.5 mm × length 20 mm × thickness 0.005 to 0.015 mm) obtained as described above was subjected to a tensile test (tensile speed: 5 mm / min) at a temperature of 25 ° C. and a humidity of 55. % Atmosphere. The tensile test was conducted using a tensile tester manufactured by Orientec Co., Ltd. (Tensilon RTA-100). Next, the tensile elongation was calculated from the results of the tensile test. Here, the tensile test was performed with the number of tests n = 10, and an average value of five times with a large measured value was obtained, and this was used as a measured value.

(Regarding Examples)
It was found that by using the negative photosensitive resin composition of each example, a thick cured film having good patterning properties was obtained. The shape of the opening in the cured film showed a taper shape. The metal film embedding property in such an opening was good without generation of voids. Moreover, it turned out that a cured film is excellent in balance of patterning property and mechanical physical properties, such as Tg and a linear expansion coefficient. Furthermore, it was found that the cured film has an excellent balance between mechanical properties and elongation characteristics. From the above, it was found that a semiconductor device (semiconductor package 100 as shown in FIG. 3) having excellent reliability can be realized by using the photosensitive resin film made of the photosensitive resin composition of the present invention.

(Comparative example)
When the negative photosensitive resin composition of each comparative example was used, it turned out that the shape of the opening part of the cured film using the same becomes not a taper shape but a reverse taper shape or an undercut shape. When a metal film is embedded in the opening of a thick cured film having a reverse taper shape or an undercut shape, defects such as void generation may occur.

  As described above, the present invention has been described more specifically based on the embodiments. However, these are exemplifications of the present invention, and various configurations other than the above can be adopted.

2 upper end 4 lower end 10 printed circuit board 20 wiring layer 23 photosensitive resin film 30 through electrode layer 32 photosensitive resin film 33 central part 34 through electrode 35 side wall 36 surface 39 upper surface 40 silicon interposer 42 lower wiring layer 44 silicon substrate 46 Upper wiring layer 50 Semiconductor chip 52 LSI chip 54 LSI chip 70 Sealing material layer 80 Solder bump 82 Underfiller 100 Semiconductor package 102 Mask 104 Resist layer 108 Seed layer 112 Opening 114 Seed layer 115 Plating film 130 Through electrode layer 132 Photosensitive Conductive resin film 134 penetrating electrode 139 upper surface 142 wiring layer 143 wiring

Claims (13)

Epoxy resin,
A curing agent;
A negative photosensitive resin composition comprising a photosensitive agent,
The photosensitive resin composition whose taper angle of the opening part corresponding to the exposure conditions of the following overexposure is 90 degree | times smaller than 45 degree | times.
(Exposure conditions: a photosensitive resin film having a film thickness of 50 μm is formed using the photosensitive resin composition. The photosensitive resin film is irradiated with a plurality of different exposure amounts. After exposure, heating and development are performed. A plurality of openings are formed in the photosensitive resin film by performing a treatment, and a cured film is obtained by performing a curing treatment on the photosensitive resin film.
Optimum exposure amount: The exposure amount that satisfies the condition in which the angle formed between the bottom surface of the cured film and the side surface of the opening is closest to a right angle is defined as the optimum exposure amount.
Taper angle: The opening formed under the overexposure exposure condition having an exposure amount larger than the optimum exposure amount has a tapered shape in which the width at the lower end is narrower than the width at the upper end. The angle formed by the bottom surface of the cured film and the side surface of the opening is defined as the taper angle. ) The photosensitive resin composition according to claim 1,
The photosensitive resin composition whose said taper angle is smaller than 90 degree | times and is 70 degree | times or more. The photosensitive resin composition according to claim 1 or 2,
The photosensitive resin composition whose aspect-ratio (height / diameter) of the said opening part is 3 or more on the said exposure conditions. It is the photosensitive resin composition of any one of Claim 1 to 3, Comprising:
A photosensitive resin composition having a light transmittance of 50% or more for light having an exposure wavelength of 365 nm in the photosensitive resin film having a thickness of 10 μm formed by pre-baking under a temperature condition of 120 ° C. It is the photosensitive resin composition of any one of Claim 1 to 4, Comprising:
The said epoxy resin is a photosensitive resin composition containing an alicyclic epoxy resin. It is the photosensitive resin composition of any one of Claim 1 to 4, Comprising:
The said epoxy resin is a photosensitive resin composition containing resin which has a benzene ring. The photosensitive resin composition according to claim 6,
The epoxy resin is a photosensitive resin composition having no naphthalene ring.   The photosensitive resin film which uses the photosensitive resin composition of any one of Claim 1 to 7.   An electronic device provided with the hardened | cured material of the photosensitive resin composition of any one of Claim 1 to 7. The electronic device according to claim 9, comprising:
A wiring layer;
A through electrode layer provided on the wiring layer;
Provided on the through electrode layer, a lower wiring layer and an upper wiring layer are formed on the lower surface and the upper surface, respectively, and has a through via that electrically connects the lower wiring layer and the upper wiring layer With an interposer,
A semiconductor chip provided on the upper wiring layer;
A sealing material layer for sealing the semiconductor chip,
The through electrode layer includes:
A photosensitive resin film;
A plurality of through electrodes penetrating the lower surface from the upper surface of the photosensitive resin film,
The photosensitive resin film is composed of the cured product,
The penetrating electrode is disposed electronically and is electrically connected to the wiring layer and the lower wiring layer. The electronic device according to claim 10, comprising:
An electronic device, wherein the photosensitive resin film has a thickness of 50 μm or more and 200 μm or less. The electronic device according to claim 10 or 11,
An electronic device, wherein the through electrode has an aspect ratio (height / diameter) of 3 or more. The electronic device according to any one of claims 10 to 12,
The electronic device whose glass transition temperature of the said photosensitive resin film is 150 degreeC or more.