Method for manufacturing electronic component packages and water-soluble protective film

Abstract

To provide a method for manufacturing an electronic component package which can achieve both suppression of deviation of a mounting position of an electronic component on a wiring circuit board, and suppression of damage to the wiring circuit board.SOLUTION: A method for manufacturing an electronic component package (for example, semiconductor package 50) including a wiring circuit board 20a and an electronic component (for example, semiconductor chip 30) mounted on the wiring circuit board executes a bonding step of bonding a water-soluble protective film 10 to one surface of the wiring circuit board, then executes a mounting step of mounting at least one electronic component on the other surface of the wiring circuit board and performing resin sealing with a sealing resin ER after the bonding step, and then executes a removal step of the water-soluble protective film from the one surface side of the wiring circuit board after the mounting step.SELECTED DRAWING: Figure 2C

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing an electronic component package, and a water-soluble protective film used in the method for manufacturing the electronic component package. [Background technology]

[0002] Conventionally, it is known to manufacture an electronic component package (e.g., a semiconductor package) including a wiring circuit board and electronic components (e.g., semiconductor chips) mounted on the wiring circuit board in the following manner (for example, see Patent Document 1 below). (1) In an interconnected wiring circuit board in which multiple wiring circuit boards are connected, an electronic component package interconnect is obtained by mounting electronic components on one surface of each of the multiple wiring circuit boards and encapsulating these electronic components together with resin. (2) Multiple electronic component packages are obtained by dividing the electronic component package connector together with the wiring circuit board.

[0003] Incidentally, in recent years, from the perspective of increasing density, electronic component packages such as semiconductor packages have been made lower in height, and along with this reduction in height, the aforementioned interconnected wiring circuit boards have also been made thinner. Thus, when the connecting wiring circuit board is made thinner, it becomes more prone to bending, making it difficult to handle, and its mechanical strength is also reduced. Therefore, the above-described method for manufacturing the electronic component package is usually carried out with a support sheet attached to the other surface of the interconnected wiring circuit board (the side opposite to the side on which the electronic components are mounted) in order to reinforce the interconnected wiring circuit board. The support sheet is typically constructed by laminating an adhesive layer on a base material, and is attached to the other surface of the connecting wiring circuit board via the adhesive layer. As described above, when the electronic component package assembly is divided into sections corresponding to the size of each wiring circuit board, the support sheet is divided into sections corresponding to the size of each electronic component package (package equivalent size) and attached to the wiring circuit boards of the multiple electronic component packages. Therefore, when obtaining multiple electronic component packages, a support sheet of a size equivalent to that of each electronic component package is removed from the wiring circuit board of each package. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2015-170754 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Incidentally, from the viewpoint of easily removing the support sheet of a package-equivalent size from each electronic component package, it is conceivable to reduce the adhesive strength of the adhesive layer on the support sheet. However, if the adhesive strength of the adhesive layer on the support sheet is reduced, when mounting the electronic components on one surface of each of the multiple wiring circuit boards and encapsulating these electronic components together with resin, the mounting positions of the electronic components on each surface of the multiple wiring circuit boards may be misaligned. Furthermore, if the adhesive strength of the adhesive layer on the support sheet is reduced, the support sheet may peel off from the other surface of the interconnected wiring circuit board during mounting (mounting the electronic components and resin sealing of the electronic components), which may reduce handling ease.

[0006] Furthermore, from the viewpoint of suppressing misalignment of the mounting position of the electronic components on the wiring circuit board, it is conceivable to increase the adhesive strength of the adhesive layer of the support sheet. However, if the adhesive force of the adhesive layer of the support sheet is increased, it becomes difficult to remove a support sheet of a package-equivalent size from each electronic component package. Therefore, when removing a support sheet of a package-equivalent size from each electronic component package, the wiring circuit board may be damaged such as cracked.

[0007] Thus, in the method of manufacturing an electronic component package using a support sheet, although the shift of the mounting position of the electronic component on the wiring circuit board and the occurrence of damage such as cracking of the wiring circuit board are in a trade-off relationship, it is hard to say that sufficient consideration has been given to resolving this trade-off relationship. <�

[0008] Therefore, an object of the present invention is to provide a method for manufacturing an electronic component package that can achieve both suppression of the shift of the mounting position of an electronic component on a wiring circuit board and suppression of damage to the wiring circuit board, and a water-soluble protective film used in the method for manufacturing the electronic component package.

Means for Solving the Problem

[0009] As a result of intensive studies by the present inventors, in the method for manufacturing an electronic component package using a support sheet, by using a water-soluble protective film as the support sheet, it is possible to achieve both suppression of the shift of the mounting position of the electronic component on the wiring circuit board and suppression of damage to the wiring circuit board. And the present invention has been conceived.

[0010] That is, the method for manufacturing an electronic component package according to the present invention is A method for manufacturing an electronic component package including a wiring circuit board and an electronic component mounted on the wiring circuit board, A bonding step of bonding a water-soluble protective film to one surface of the wiring circuit board is performed, After the bonding step, a mounting step of mounting at least one electronic component and resin-sealing on the other surface of the wiring circuit board is performed, After the mounting step, a removing step of removing the water-soluble protective film from one surface side of the wiring circuit board is performed.

[0011] According to such a configuration, after performing a bonding step of bonding a water-soluble protective film having sufficient adhesiveness to one surface of the wiring circuit board, a mounting step of mounting at least one electronic component and resin-sealing it on the other surface of the wiring circuit board is performed. Therefore, it is possible to suppress displacement of the electronic component on the wiring circuit board during resin-sealing in the mounting step. In addition, although the water-soluble protective film has sufficient adhesiveness, it has a property of being easily dissolved in water. Therefore, by performing the removing step such as washing with water, it can be relatively easily removed from one surface side of the wiring circuit board. As a result, when removing the water-soluble protective film, which is a support sheet, from one surface side of the wiring circuit board, it is possible to suppress breakage of the wiring circuit board. As described above, according to the method for manufacturing an electronic component package according to the present invention, it is possible to achieve both suppression of displacement of the mounting position of the electronic component on the wiring circuit board and suppression of breakage of the wiring circuit board.

[0012] In the method for manufacturing the electronic component package, the bonding step is performed on a connected wiring circuit board in which a plurality of wiring circuit boards are connected, after the bonding step, the mounting step is performed on each of the plurality of wiring circuit boards to produce an electronic component package connector in which a plurality of electronic component packages are connected with the water-soluble protective film bonded, It is preferable to perform the removing step before or after dividing the electronic component package connector with the water-soluble protective film bonded into the electronic component packages.

[0013] With this configuration, even in a method for manufacturing an electronic component package using an interconnected wiring circuit board in which multiple wiring circuit boards are connected, it is possible to suppress both the displacement of the mounting position of electronic components on the wiring circuit board and the suppression of damage to the wiring circuit board.

[0014] In the method for manufacturing the aforementioned electronic component package, Preferably, the wiring board is a coreless board.

[0015] Coreless substrates are wiring circuit boards composed only of wiring layers (build-up layers), and are therefore particularly thin and prone to bending (deforming) in the thickness direction. However, by laminating the aforementioned water-soluble protective film, deformation in the thickness direction can be suppressed. This effectively suppresses the shifting of the mounting position of electronic components on the wiring circuit board due to deformation in the thickness direction.

[0016] The water-soluble protective film according to the present invention is It is used in the manufacturing of the above-mentioned electronic component packages. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a method for manufacturing an electronic component package and a water-soluble protective film used in the method for manufacturing the electronic component package, which can simultaneously suppress misalignment of the mounting position of electronic components on a wiring circuit board and suppress damage to the wiring circuit board. [Brief explanation of the drawing]

[0018] [Figure 1] A schematic cross-sectional view showing the structure of a water-soluble protective film according to one embodiment of the present invention. [Figure 2A] A schematic cross-sectional view illustrating an example of the bonding process in a semiconductor package manufacturing method. [Figure 2B] A schematic cross-sectional view illustrating an example of the mounting process of a semiconductor chip in the manufacturing method of a semiconductor package. [Figure 2C] A schematic cross-sectional view showing an example of resin encapsulation, one of the mounting processes in the manufacturing method of semiconductor packages. [Figure 2D] A schematic cross-sectional view showing an example of a semiconductor package assembly placed on a stage with a water-soluble protective film protective layer attached. [Figure 2E] A schematic cross-sectional view illustrating an example of the removal process in a semiconductor package manufacturing method. [Figure 2F] A schematic cross-sectional view illustrating an example of how a semiconductor package assembly is separated into individual semiconductor packages after the removal process. [Figure 2G] A schematic cross-sectional view showing another example of the resin encapsulation process, which is part of the mounting process in semiconductor package manufacturing. [Figure 2H] A schematic cross-sectional view illustrating another example of the removal process in a semiconductor package manufacturing method. [Modes for carrying out the invention]

[0019] The following describes one embodiment of the present invention. In the following, we will first describe the water-soluble protective film used in the method for manufacturing an electronic component package according to the present invention, and then describe the method for manufacturing an electronic component package using the water-soluble protective film, that is, the method for manufacturing an electronic component package according to the present invention.

[0020] [Water-soluble protective film] The water-soluble protective film 10 according to this embodiment is used in a method for manufacturing an electronic component package that includes a wiring circuit board and electronic components mounted on the wiring circuit board, and is used to protect the wiring circuit board during the manufacturing of the electronic component package. Furthermore, protection is a concept that includes both supporting the wiring circuit board to prevent it from bending in the thickness direction, and preventing foreign matter from adhering to the surface of the wiring circuit board. The water-soluble protective film 10 is bonded to one surface of the wiring circuit board. Examples of such electronic component packages include semiconductor packages.

[0021] As shown in Figure 1, the water-soluble protective film 10 according to this embodiment includes a protective layer 10a, a first release liner 10b on one surface of the protective layer 10a, and a second release liner 10c on the other surface of the protective layer 10a (the surface facing the aforementioned surface). In other words, the water-soluble protective film 10 according to this embodiment is constructed by sandwiching the protective layer 10a from both sides between a pair of release liners (first release liner 10b and second release liner 10c). In the water-soluble protective film 10 according to this embodiment, the protective layer 10a is bonded to one surface of the wiring circuit board in the manufacturing method of the electronic component package. More specifically, in the method for manufacturing the electronic component package, the protective layer 10a is bonded to the side of the wiring circuit board on which the electronic component is not mounted.

[0022] In the water-soluble protective film 10 according to this embodiment, the protective layer 10a contains a water-soluble polymer compound. By containing a water-soluble polymer, the protective layer 10a can be bonded to an object such as a wiring circuit board with sufficient adhesive strength. The inventors speculate on the reason as follows: Examples of the aforementioned water-soluble polymers include polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), water-soluble polyester (PES), and polyethylene oxide (PEO), as will be described later. These polymers contain functional groups that contribute to hydrogen bonding, such as hydroxyl groups (PVA, PES, PEO) and pyrrolidone groups (PVP), in their structure. Here, the wiring circuit board is typically configured as a so-called build-up board having a set of wiring layers (build-up layers) and a support (core layer) disposed between the set of wiring layers to support each of these wiring layers, as will be described later, or as a so-called coreless board in which a set of wiring layers is directly laminated without the support. In other words, both sides of the wiring circuit board are typically composed of the wiring layer. The wiring layer is typically constructed by forming a wiring portion on at least one side of a prepreg obtained by impregnating glass cloth or the like with a resin composition containing epoxy resin, as will be described later. Here, since the epoxy resin has functional groups in its structure that contribute to hydrogen bonding, such as hydroxyl groups and ether groups, it is thought that when the protective layer 10a of the water-soluble protective film 10 is bonded to one surface of the wiring circuit board (the surface of the wiring circuit board on which the electronic components are not mounted), hydrogen bonds will be formed between the epoxy resin contained in the wiring layer of the wiring circuit board and the water-soluble polymer contained in the protective layer 10a. Based on the above, it is considered that the protective layer 10a can be adhered to the object to be attached, such as a wiring circuit board, with sufficient adhesive strength. Furthermore, by including a water-soluble polymer, the protective layer 10a exhibits sufficient adhesiveness. Furthermore, if the water-soluble polymer is polyvinyl alcohol (PVA), the tackiness can be adjusted by adjusting the degree of saponification or the average degree of polymerization of the polyvinyl alcohol (PVA).

[0023] Examples of the water-soluble polymers include polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), water-soluble polyester (PES), and polyethylene oxide (PEO). The aforementioned water-soluble polymer may be polyvinyl alcohol or polyvinylpyrrolidone used alone, or polyvinyl alcohol and polyvinylpyrrolidone may be used in combination. It is preferable to use at least one of the water-soluble polymers selected from the group consisting of polyvinyl alcohol, water-soluble polyester, and polyethylene oxide.

[0024] The polyvinyl alcohol is preferably saponified to a degree of 50 to 95, and more preferably to a degree of 60 to 90. Because the degree of saponification is within the above numerical range, the polyvinyl alcohol can exhibit sufficient water solubility. Furthermore, when the polyvinyl alcohol is included in the protective layer forming composition described later, the protective layer forming composition can be applied to the peel-off liner with good workability. Furthermore, by having a degree of saponification of 60 to 90, the glass transition temperature Tg of the polyvinyl alcohol can be increased, so the protective layer 10a formed using such polyvinyl alcohol also has excellent heat resistance. In this context, thermosetting resins such as epoxy resins are typically used as the sealing resin for encapsulating electronic components mounted on a wiring circuit board. Furthermore, during resin encapsulation, a temperature of approximately 175°C is typically applied to ensure that the thermosetting resin encapsulation material is sufficiently cured. Therefore, as described above, by having a saponification degree of polyvinyl alcohol between 60 and 90, the protective layer 10a can exhibit excellent heat resistance even when the above-mentioned temperatures are applied during resin encapsulation. Furthermore, from the viewpoint of achieving a degree of saponification of 60 or higher, it is preferable that the polyvinyl alcohol does not contain oxyalkylene groups.

[0025] The degree of saponification of the aforementioned polyvinyl alcohol is determined by proton magnetic resonance spectroscopy ( 1 It can be measured by 1H-NMR (H-NMR) measurement. If the sample contains an additive and the peak derived from the additive overlaps with the peak used to calculate the degree of saponification, the sample is subjected to methanol extraction or the like to separate the additive, and then the degree of saponification of the polyvinyl alcohol is measured. The degree of saponification of the aforementioned polyvinyl alcohol can be measured under the following conditions. <Measurement conditions> ·Analyzer FT-NMR: Bruker Biospin, AVANCE III-400 Observation frequency: 400MHz (1H) • Measurement solvent: Heavy water or heavy dimethyl sulfoxide (heavy DMSO) ·Measurement temperature 80℃ ·Chemical shift standard External standard TSP-d4 (0.00ppm) (when measuring heavy water) Measurement solvent (2.50 ppm) (when measuring heavy DMSO) The degree of saponification of the polyvinyl alcohol is calculated using the following formula, based on the peaks derived from the methylene group of the vinyl alcohol unit (VOH) (heavy water; 2.0-1.0 ppm, heavy DMSO; 1.9-1.0 ppm) and the peaks derived from the acetyl group of the vinyl acetate unit (VAc) (heavy water; around 2.1 ppm, heavy DMSO; around 2.0 ppm). In the following equation, [VOH(-CH2)-] represents the peak intensity derived from -CH2- in the vinyl alcohol unit, and [VAc(CH3CO-)] represents the peak intensity derived from CH3CO- in the vinyl acetate unit.

[0026]

number

[0027] The polyvinyl alcohol preferably has an average degree of polymerization of 100 to 1000, and more preferably 100 to 800. Because the average degree of polymerization is within the above numerical range, the polyvinyl alcohol can exhibit sufficient water solubility. Furthermore, when the polyvinyl alcohol is included in the protective layer forming composition described later, the protective layer forming composition can be applied to the peel-off liner with good workability. The average degree of polymerization of the polyvinyl alcohol can be measured by an aqueous GPC (Gross Propagation Spectroscopy) system. The average degree of polymerization of the aforementioned polyvinyl alcohol can be measured under the following conditions. <Measurement conditions> ·Analyzer Agilent, 1260Infinity • Columns: TSKgel G6000PWXL (manufactured by Tosoh Corporation) and TSKgel G3000PWXL (manufactured by Tosoh Corporation) The two columns mentioned above are connected in series. Column temperature: 40℃ • Eluent: 0.2M sodium nitrate aqueous solution ·Injection volume 100μL • Detector: Differential Refractometer (RI) • Standard samples: PEG standard samples and PVA standard samples The specific measurements will be carried out as follows: (1) The mass-average molecular weight Mw of the sample under test (PVA) and the PVA standard sample are calculated by GPC measurement using a PEG standard sample. The PVA standard sample is one whose average degree of polymerization is known. (2) Create a calibration curve using the average degree of polymerization of the PVA standard sample and the calculated mass-average molecular weight Mw of the PVA standard sample. (3) Using the calibration curve created, the average degree of polymerization of the sample to be measured (PVA) is determined from the mass-average molecular weight Mw of the sample to be measured (PVA).

[0028] Furthermore, when using polyvinyl alcohol as the water-soluble polymer, a combination of multiple polyvinyl alcohols with different degrees of saponification may be used, or a combination of multiple polyvinyl alcohols with different average degrees of polymerization may be used.

[0029] The water-soluble polyester has a polycarboxylic acid residue and a polyol residue. The aforementioned water-soluble polyester is, for example, a polymerization product of monomer components containing a polycarboxylic acid component and a polyol component. Furthermore, the fact that the aforementioned water-soluble polyester is water-soluble can be determined based on common technical knowledge.

[0030] The water-soluble polyester is preferably one that satisfies at least one of the following (1) to (4). (1) When water at room temperature (23±2℃) is sprayed over the entire surface of a 20μm thick thin film made of the water-soluble polyester at a spray pressure of 0.005MPa for 20 minutes, the entire thin film dissolves in the water. (2) When water at 50°C is sprayed over the entire surface of a 20 μm thick thin film made of the water-soluble polyester at a spray pressure of 0.005 MPa for 10 minutes, the entire thin film dissolves in water. (3) When the water-soluble polyester and room temperature water are mixed in a mass ratio of water-soluble polyester:room temperature water = 1:5 to obtain a mixture, and ultrasonic waves are irradiated onto the mixture for 20 minutes, the water-soluble polyester dissolves completely in the water. (4) The water-soluble polyester and water at 50°C are mixed in a mass ratio of water-soluble polyester:water at 50°C = 1:5 to obtain a mixture, and when ultrasonic waves are irradiated onto the mixture for 10 minutes, the water-soluble polyester dissolves completely in the water.

[0031] The water-soluble polyester preferably has a mass-average molecular weight Mw of 40,000 (40,000) or less. Furthermore, the water-soluble polyester preferably has a mass-average molecular weight Mw of 15,000 (15,000) or more. Because the protective layer 10a contains a water-soluble polyester having a mass-average molecular weight Mw within the above numerical range, the protective layer 10a is difficult to remove from the surface of the wiring circuit board or interconnected wiring circuit board when in contact with relatively low temperature water such as 30°C or below (high water resistance at low temperatures), but is easily removed from the surface of the wiring circuit board or interconnected wiring circuit board when in contact with relatively high temperature water (hot water) such as 40°C or above (low water resistance at high temperatures). Therefore, for example, if the protective layer 10a is attached to the surface of the interconnected wiring circuit board, and the interconnected wiring circuit board is blade-diced into multiple wiring circuit boards while being washed with water at a relatively low temperature of 30°C or less, the protective layer 10a is sufficiently fixed to the surface of the interconnected wiring circuit board and the surface of the wiring circuit board, and these surfaces can be adequately protected. On the other hand, by washing the multiple wiring circuit boards obtained by blade dicing with hot water at 40°C or higher, the individualized protective layer 10a can be easily removed from each of the multiple wiring circuit boards.

[0032] The polyethylene oxide preferably has a mass-average molecular weight Mw of 1,000,000 (1 million) or less. Furthermore, it is preferable that the polyethylene oxide has a mass-average molecular weight Mw of 20,000 (20,000) or more. The protective layer forming composition for forming the protective layer 10a can be made to have a suitable viscosity by including polyethylene oxide having a mass-average molecular weight Mw within the above numerical range. This makes it easier to form the protective layer 10a using the protective layer forming composition (improves film formation efficiency). Furthermore, if the mass-average molecular weight of the protective layer forming composition exceeds 1,000,000, the viscosity of the protective layer forming composition becomes relatively high, making it often difficult to spread the protective layer forming composition when forming the protective layer 10a. Conversely, if the mass-average molecular weight Mw of the protective layer forming composition is below 20,000, the viscosity of the protective layer forming composition becomes relatively low, making it often difficult to form the protective layer 10a to the desired thickness. In other words, the film-forming ability is often poor. Furthermore, because the protective layer 10a contains polyethylene oxide having a mass-average molecular weight Mw within the above numerical range, the protective layer 10a can be removed relatively easily from the surface of the wiring circuit board or connected wiring circuit board by washing with water.

[0033] The mass-average molecular weight Mw of the water-soluble polyester and the polyethylene oxide can be measured by GPC in the same manner as described for the average degree of polymerization of polyvinyl alcohol. However, the eluent should be appropriately selected from a 0.2 M sodium nitrate aqueous solution or DMF (dimethylformamide) depending on the composition of the sample being measured. Specifically, a substance capable of dissolving the object to be measured is appropriately selected as the eluent.

[0034] In the example shown in Figure 1, the water-soluble protective film 10 is constructed by sandwiching the protective layer 10a from both sides between a pair of release liners (first release liner 10b and second release liner 10c), but the configuration of the water-soluble protective film 10 is not limited to this. The water-soluble protective film 10 may consist only of a protective layer 10a, or it may have either a first release liner 10b or a second release liner 10c on only one surface of the protective layer 10a. In short, the water-soluble protective film 10 only needs to include at least a protective layer 10a.

[0035] The water-soluble protective film 10 can be manufactured, for example, by applying a protective layer-forming composition containing the water-soluble polymer onto the first release liner 10b to a predetermined thickness (e.g., 10 μm) using an applicator, drying it at a predetermined temperature for a predetermined time (e.g., 2 minutes at 110°C) to form a protective layer 10a on the first release liner 10b, and then laminating the second release liner 10c to the side of the protective layer 10a opposite to the side to which the first release liner 10b is attached.

[0036] In obtaining the protective layer 10a of the water-soluble protective film 10 according to this embodiment, it is preferable to use a solution in which the water-soluble polymer is dispersed in water (hereinafter referred to as a polymer dispersion composition) as the protective layer forming composition. In the polymer dispersion composition, the amount of the water-soluble polymer is preferably 5 parts by mass or more and 80 parts by mass or less, more preferably 10 parts by mass or more and 70 parts by mass or less, and even more preferably 15 parts by mass or more and 60 parts by mass or less, per 100 parts by mass of water. Furthermore, it is preferable that the polymer dispersion composition is in a state in which a water-soluble polymer is dissolved in water. In the polymer dispersion composition, the water-soluble polymer can be dissolved in water by heating at a temperature of 20°C to 90°C. Furthermore, the polymer dispersion composition preferably has a viscosity of 0.03 Pa·s or higher at 25°C, more preferably 0.05 Pa·s or higher, and even more preferably 0.1 Pa·s or higher. By ensuring that the viscosity at 25°C is above the lower limit mentioned above, when the polymer dispersion composition is applied to a release liner to form a protective layer 10a on the release liner, it is possible to relatively suppress fluctuations in the thickness of the protective layer 10a. Furthermore, the polymer dispersion composition preferably has a viscosity of 15 Pa·s or less at 25°C, more preferably 10 Pa·s or less, and even more preferably 5 Pa·s or less. By keeping the viscosity at 25°C below the upper limit mentioned above, the applicability of the polymer dispersion composition when applied to the release liner can be improved. The viscosity of the polymer dispersion composition at 25°C can be measured using a digital viscometer (product name "DV-I Prime") manufactured by Eiko Seiki Co., Ltd., with an LV-3 spindle and a rotation speed of 50 rpm.

[0037] In the water-soluble protective film 10 according to this embodiment, it is preferable that the adhesion force of the protective layer 10a to the bare wafer is 0.2 N / 100 mm or more. Even when the object to be adhered is a wiring circuit board or a connected wiring circuit board in which multiple wiring circuit boards are connected, the protective layer 10a can be sufficiently adhered to these objects. This makes it possible to suppress misalignment of the mounting positions of electronic components on each surface of the multiple wiring circuit boards that constitute the connected wiring circuit board when mounting electronic components such as semiconductor chips on one surface of each of the multiple wiring circuit boards and encapsulating these electronic components together with resin. Furthermore, during the mounting process (mounting the electronic components and resin sealing the electronic components), the protective layer 10a is less likely to peel off from the other surface of the connecting wiring circuit board (the surface opposite to the surface on which the electronic components are mounted), thus preventing a decrease in handling ease.

[0038] The adhesion force of the protective layer 10a to the bare wafer can be measured as follows. Below, the measurement method will be explained using a water-soluble protective film 10 configured as shown in Figure 1 as an example. (1) One release liner (first release liner 10b) is peeled off from the protective layer 10a to expose one side of the protective layer 10a, and a backing tape is attached to the exposed surface (first exposed surface) to obtain the first test specimen. The backing tape is attached to the first exposed surface using a hand roller at a temperature of 25°C. (2) After cutting the first test specimen to a width of 100 mm, the other release liner (second release liner 10c) of the protective layer 10a is peeled off to expose the other side of the protective layer 10a, and this exposed side (second exposed side) is bonded to a bare wafer to obtain a second test specimen (measurement sample). The bonding of the second exposed side to the bare wafer is performed using a 2 kg standard roller (manual adhesion test press wheel adhesive tape adhesion tester) at a temperature of 90°C and a speed of 10 mm / second. After bonding, natural cooling is performed for 20 minutes or more. (3) Under conditions of a temperature of 23°C, the peeling force of the sample for measurement is measured with a peeling angle of 180° and a peeling speed of 300 mm / min. The measured peeling force is defined as the adhesion force. For example, an Autograph (manufactured by SHIMADZU) can be used as the measuring device.

[0039] In the water-soluble protective film 10 according to this embodiment, the protective layer 10a has a surface free energy of 25 mJ / m 2 More than 85mJ / m 2 Preferably, it is 35 mJ / m 2 More than 75mJ / m 2 The following is more preferable: In the protective layer 10a, it is preferable that the surface free energy is within the above numerical range for both the surface that contacts the first peel liner 10b and the surface that contacts the second peel liner 10c. In the protective layer 10a, if the surface free energy on both sides is within the above numerical range, the adhesion force with the first peel liner 10b and the second peel liner 10c becomes easier to control. Furthermore, by ensuring that the surface free energy of at least the side that is bonded to the wiring circuit board (for example, the side that contacts the first release liner 10b) is within the above numerical range, the adhesion to the wiring circuit board can be made relatively high. This makes it possible to suppress misalignment of the mounting position of electronic components on the wiring circuit board in the method for manufacturing electronic component packages described later.

[0040] The surface free energy can be measured as follows. First, under the conditions of a temperature of 20°C and a relative humidity of 65%RH, the contact angle of a water droplet (H2O) and the contact angle of a methylene iodide (CH2I2) droplet brought into contact with the surface of the protective layer 10a are measured using a contact angle meter, respectively. Next, the surface free energy is calculated as follows from the measured value of the contact angle θw of the water droplet and the measured value of the contact angle θi of the methylene iodide droplet. Specifically, according to the method of Owens et al. described in Journal of Applied Polymer Science, vol.13, p1741 - 1747 (1969), γs d (the dispersive component of the surface free energy) and γs h (the polar component of the surface free energy) are determined. Then, the value γs d and γs h obtained by adding them together, γs (= γs d + γs h ), is taken as the surface free energy of the protective layer 10a. γs d (the dispersive component) and γs h (the polar component) are each obtained as the solution of the simultaneous equations of the following formulas (1) and (2).

[0041]

Equation

[0042] In formulas (1) and (2), γw is the surface free energy of water, γw d is the dispersive component of the surface free energy of water, γw h is the polar component of the surface free energy of water, γi is the surface free energy of methylene iodide, γi d is the dispersive component of the surface free energy of methylene iodide, γi h is the polar component of the surface free energy of methylene iodide, and they are known values as follows. γw = 72.8 [mJ / m2 ] γw d =21.8[mJ / m 2 ] γw h = 51.0 [mJ / m 2 ] γi = 50.8 [mJ / m 2 ] γi d = 48.5 [mJ / m 2 ] γi h =2.3[mJ / m 2 ]

[0043] Specifically, the surface free energy of one side (the side that is bonded to the wiring circuit board) of the protective layer 10a is measured. The contact angles of water droplets and methylene iodide droplets are measured, and the average of five measurements is adopted. The contact angle is measured by dropping 1 mL of liquid onto one of the surfaces and measuring the contact angle within 5 seconds. The dispersion component and polar component are calculated from each measurement of the contact angle, and the surface free energy is determined by adding them together. Furthermore, the surface free energy of the other side of the protective layer 10a (the side opposite to the side bonded to the wiring circuit board) can also be determined in the same manner as described above.

[0044] The thickness of the protective layer 10a is preferably 2 μm or more and 70 μm or less, more preferably 3 μm or more and 50 μm or less, and even more preferably 5 μm or more and 40 μm or less. The thickness of the protective layer 10a can be determined, for example, by measuring the thickness of five randomly selected points using a dial gauge (PEACOCK, model R-205) and taking the arithmetic mean of these thicknesses.

[0045] The first release liner 10b can be, for example, a base sheet made using a resin such as polyethylene terephthalate (PET) that has been subjected to a release treatment. Examples of mold release treatments include silicone mold release treatments. An example of such a peeling liner is the product MRA50 manufactured by Mitsubishi Chemical Corporation. Furthermore, the second peel-off liner 10c can be the same as the first peel-off liner 10b.

[0046] The thickness of the first peel-off liner 10b and the second peel-off liner 10c is preferably 15 μm or more and 75 μm or less, and more preferably 20 μm or more and 60 μm or less. The thickness of the first peel-off liner 10b and the thickness of the second peel-off liner 10c may be the same or different. The thicknesses of the first peel liner 10b and the second peel liner 10c can be determined in the same manner as the thickness of the protective layer 10a.

[0047] [Method for manufacturing electronic component packages] The water-soluble protective film 10 according to this embodiment is used as an auxiliary tool for manufacturing electronic component packages. The following describes a method for manufacturing an electronic component package using the water-soluble protective film 10 according to this embodiment, that is, a method for manufacturing an electronic component package according to this embodiment.

[0048] The method for manufacturing an electronic component package according to this embodiment is: A method for manufacturing an electronic component package, which includes a wiring circuit board and electronic components mounted on the wiring circuit board, A bonding process is performed to bond a water-soluble protective film to one surface of the wiring circuit board. After the bonding process, a mounting process is performed on the other surface of the wiring circuit board, in which at least one electronic component is mounted and then resin-sealed. After the mounting process, a removal process is performed to remove the water-soluble protective film from one surface side of the wiring circuit board.

[0049] Furthermore, in the method for manufacturing the electronic component package using a connected wiring circuit board in which multiple wiring circuit boards are connected, The bonding process is performed on a connected wiring circuit board in which multiple wiring circuit boards are connected, After the bonding process, the mounting process is performed on each of the plurality of wiring circuit boards to produce an electronic component package connector in which a plurality of electronic component packages are connected while bonded to the water-soluble protective film. The removal step is performed before or after dividing the electronic component package connector into the electronic component packages while the water-soluble protective film is attached.

[0050] The following describes a method for manufacturing an electronic component package using a connected wiring circuit board 20, in which multiple wiring circuit boards 20a are connected, with reference to Figures 2A to 2H. The wiring circuit board 20a refers to the board among the interconnected wiring circuit boards 20 on which electronic components are mounted to form a single electronic component package. Furthermore, in Figures 2A to 2E, the dashed lines on the interconnected wiring circuit board 20 indicate the boundary between adjacent wiring circuit boards 20a, and do not indicate that the interconnected wiring circuit board 20 is separated. The following explanation will use an example where the electronic component package is a semiconductor package.

[0051] (Lamination process) In the bonding process, as shown in Figure 2A, a protective layer 10a of the water-soluble protective film 10 is bonded to one surface of the connected wiring circuit board 20, which has multiple wiring circuit boards 20a connected to each other. The bonding of the protective layer 10a of the water-soluble protective film 10 to one surface of the interconnected wiring circuit board 20 can be performed by pressing the protective layer 10a of the water-soluble protective film 10 in contact with one surface of the interconnected wiring circuit board 20 with a predetermined pressure in the thickness direction. The aforementioned pressurization can be carried out, for example, by applying a pressure of 0.1 MPa to 1.0 MPa while sandwiching the laminate of the connecting wiring circuit board 20 and the protective layer 10a in the thickness direction with a pair of plate-shaped members. Furthermore, as explained earlier, the protective layer 10a exhibits sufficient tackiness due to the inclusion of a water-soluble polymer, and also exhibits sufficient adhesion to the interconnected wiring circuit board. Therefore, in the bonding process, it is possible to bond the interconnected wiring circuit board with sufficient adhesive strength.

[0052] Any interconnected wiring circuit board 20 can be used as long as it is a series of interconnected wiring circuit boards used in the manufacture of electronic component packages. The connecting wiring circuit board 20 is preferably 0.03 mm or thicker, more preferably 0.05 mm or thicker, and even more preferably 0.07 mm or thicker. Furthermore, the connecting wiring circuit board 20 is preferably 0.4 mm or less in thickness, more preferably 0.2 mm or less, and even more preferably 0.1 mm or less. Furthermore, the interconnected wiring circuit board 20 may be an interconnected build-up board having a set of wiring layers (build-up layers) and a support (core layer) disposed between the set of wiring layers (build-up layers) to support each of these wiring layers (build-up layers), or it may be an interconnected coreless board having so-called coreless boards constructed by directly laminating a set of wiring layers (build-up layers) without the support (core layer) in between, that is, an interconnected coreless board composed only of a set of wiring layers (build-up layers). On the other hand, since it is composed only of the aforementioned wiring layer (build-up layer), it is preferable to use a coreless substrate as the connecting body for the connecting wiring circuit board 20, as it is prone to bending (deforming) in the thickness direction. When the interconnected wiring circuit board 20 is an interconnected coreless substrate, the protective layer 10a of the water-soluble protective film 10 can support the interconnected coreless substrate from one side, thereby sufficiently suppressing bending (deformation) of the interconnected coreless substrate in the thickness direction. The wiring layer (build-up layer) is obtained by forming a wiring portion on at least one side of a prepreg, which is made by impregnating glass cloth or the like with a resin composition containing epoxy resin.

[0053] (Implementation process) In the mounting process, after the bonding process, at least one electronic component (a semiconductor chip in this embodiment) is mounted and resin-encapsulated on the other surface (the surface opposite to the surface to which the protective layer 10a is bonded) of each of the multiple wiring circuit boards 20a. Specifically, as shown in Figure 2B, the semiconductor chips 30 are attached to the die bond layer (die bond film) 40 and mounted on the other surfaces of each of the multiple wiring circuit boards 20a. Then, as shown in Figure 2C, each semiconductor chip 30 is sealed with a sealing resin ER. In Figure 2C, an example is shown in which each semiconductor chip 30 is encapsulated collectively with encapsulating resin ER. However, as shown in Figure 2G, each semiconductor chip 30 may also be encapsulated individually with encapsulating resin ER. A semiconductor chip 30 with a die bond layer (die bond film) 40 can be obtained by laminating a die bond film having an area equivalent to the area of ​​the semiconductor wafer to one side of a semiconductor wafer of predetermined dimensions (for example, a semiconductor wafer with an outer diameter of 12 inches (300 mm) and a thickness of 40 μm to 50 μm), and then performing various known dicing processes such as stealth dicing. In other words, the die bond layer (die bond film) 40 bonded to the semiconductor chip 30 is obtained by dividing a single die bond film. In the manufacturing method of the electronic component package (semiconductor package) according to this embodiment, a protective layer 10a that exhibits sufficient tackiness and adhesion due to containing a water-soluble polymer is bonded to the interconnected wiring circuit board 20. Therefore, during resin encapsulation in the mounting process, it is possible to suppress misalignment of the mounting position of the electronic component (semiconductor chip) on the wiring circuit board 20a. Furthermore, during the mounting process, the protective layer 10a is less likely to peel off from the other surface of the interconnected wiring circuit board 20, thus preventing a decrease in handling ease.

[0054] The semiconductor chip described above typically comprises a semiconductor chip body and an electrode portion disposed on at least one side of the semiconductor chip body and electrically connected to the electrode portion of another component, wherein at least one side of the semiconductor chip is a circuit-forming surface on which a circuit is formed. The aforementioned semiconductor chips also include, for example, TSV (Through Silicon Via) type chips that have a pair of electrode portions arranged on both sides of the semiconductor chip body and electrically connected to other components, and a conductive portion that penetrates the semiconductor chip body in the thickness direction to allow conductivity between the pair of electrode portions. Furthermore, the semiconductor chip also includes a sensor chip in which the circuit is equipped with a sensor element (for example, a light-receiving element or a vibration element). Examples of the aforementioned sensor chips include CMOS (Complementary Metal-Oxide Semiconductor) chips and MEMS (Micro Electro Systems) chips. Other components include wiring circuit boards and other semiconductor chips configured similarly to the semiconductor chips mentioned above.

[0055] Various known materials can be used as the die bond layer (die bond film) 40. The die bond layer (die bond film) 40 preferably has thermosetting properties. From the viewpoint of having thermosetting properties, the die bond layer (die bond film) 40 preferably contains thermosetting resins such as epoxy resins and phenolic resins, or acrylic polymers that contain monomer units derived from (meth)acrylic acid esters and exhibit thermosetting properties.

[0056] Various known encapsulating resins ER can be used. As the sealing resin ER, epoxy resin is preferably used.

[0057] The mounting of semiconductor chips 30 onto the other surfaces of multiple wiring circuit boards 20a can be carried out, for example, by picking up the semiconductor chips 30 with the die bond layer 40 attached with a collet at room temperature (23±2℃), and pressing (applying) the semiconductor chips 30 with the die bond layer 40 attached onto each of the wiring circuit boards 20a from above under a pressure of 0.1MPa to 1.0MPa. Furthermore, since the mounting of semiconductor chips 30 to the other surfaces of each of the multiple wiring circuit boards 20a is usually performed by placing the interconnected wiring circuit boards 20 on a stage, the stage may be heated to a temperature of up to 170°C when mounting the semiconductor chips 30 as described above. In other words, the mounting of the semiconductor chip 30 may be carried out at temperatures ranging from room temperature to 170°C. The semiconductor chip 30 may be electrically connected to the wiring circuit board 20a by bonding wires or the like after it has been mounted on each of the wiring circuit boards 20a. Resin encapsulation is usually carried out under heating conditions, and the heating conditions are preferably at a temperature of 165-185°C for several minutes (for example, 1-2 minutes). Resin encapsulation may be performed under pressure. The aforementioned pressurization is preferably carried out at a pressure of 1 to 15 MPa, and more preferably at 3 to 10 MPa.

[0058] By performing the above mounting process, a semiconductor package connector 50' is obtained in which a plurality of semiconductor packages 50 are connected together with the protective layer 10a of the water-soluble protective film 10 bonded to them (see Figure 2C).

[0059] (Removal process) The removal step involves removing the protective layer 10a of the water-soluble protective film 10 from one surface side of the wiring circuit board 20a after the mounting step. Specifically, as shown in Figure 2D, the semiconductor package connector 50' is placed on the stage S with the protective layer 10a of the water-soluble protective film 10 facing upwards, that is, with the resin-sealed side facing downwards. Then, as shown in Figure 2E, before separating the semiconductor package connector 50' into individual semiconductor packages 50, the protective layer 10a is dissolved and removed by washing with water. In Figure 2E, an example is shown in which the protective layer 10a is washed with water before the semiconductor package connector 50' is divided into individual semiconductor packages 50. However, as shown in Figure 2H, the protective layer 10a, which is bonded to the individual semiconductor packages 50 after the semiconductor package connector 50' has been divided, may be dissolved and removed by washing with water. In other words, the removal process can be performed either before or after dividing the semiconductor package connector 50' into individual semiconductor packages 50. The division of the semiconductor package connector 50' into individual semiconductor packages 50 can be carried out by blade dicing using a dicing blade DB as shown in Figure 2F.

[0060] As shown in Figure 2E, if the protective layer 10a is dissolved and removed by washing with water before the semiconductor package connector 50' is separated into individual semiconductor packages 50, then, as shown in Figure 2F, the semiconductor package connector 50' is separated into individual semiconductor packages 50 by performing blade dicing using a dicing blade DB. This makes it possible to obtain individual semiconductor packages 50. Furthermore, as shown in Figure 2H, if the semiconductor package connector 50' is divided into individual semiconductor packages 50, the individual semiconductor packages 50 can be obtained by dissolving and removing the protective layer 10a by washing it with water. Although the protective layer 10a of the water-soluble protective film 10 has sufficient adhesiveness, it is easily dissolved in water. Therefore, by performing the removal process with water washing, the protective layer 10a can be removed relatively easily from one surface side of the wiring circuit board 20a.

[0061] The removal process can be carried out using an apparatus equipped with a rotatable stage and a water washing mechanism. The water washing mechanism includes a water injection unit that sprays water toward the divided protective layer 10a. Then, while rotating the stage, water is sprayed from the water injection unit towards the divided protective layer 10a, causing the protective layer 10a to be completely dissolved by the water, or the partially dissolved protective layer 10a to be discharged to the outside of the stage. In such a device, the rotation speed of the stage is preferably 500 rpm to 4000 rpm, the water injection volume (water flow rate) is preferably 0.05 L / min to 5.0 L / min, and the water injection time is preferably 5 seconds to 300 seconds. Furthermore, the removal process may be carried out by spraying water at high pressure. The pressure at which the water is sprayed can be appropriately set considering the size of the semiconductor package 50 and the balance of the adhesion force between the semiconductor package 50 and the protective layer 10a (divided protective layer 10a).

[0062] Furthermore, the method for manufacturing an electronic component package and the water-soluble protective film according to the present invention are not limited to the embodiments described above. Also, the method for manufacturing an electronic component package and the water-soluble protective film according to the present invention are not limited by the effects described above. The method for manufacturing an electronic component package and the water-soluble protective film according to the present invention can be modified in various ways without departing from the spirit of the present invention.

[0063] For example, in the above embodiment, a semiconductor package was used as an example of an electronic component package to describe a method for manufacturing a semiconductor package, but electronic component packages are not limited to semiconductor packages. Examples of electronic component packages other than the aforementioned semiconductor package include a pseudo-wafer comprising a support substrate and a package body in which a plurality of semiconductor chips are arranged on the support substrate and the plurality of semiconductor chips are collectively sealed in resin, i.e., a pseudo-wafer in which the support substrate and the package body are integrated, a pseudo-wafer constructed by removing the support substrate from the package body, i.e., a pseudo-wafer composed only of the package body, and divided pseudo-wafers divided into constituent units containing at least one semiconductor chip. In the manufacturing of the pseudo-wafer segment, the protective layer 10a of the water-soluble protective film 10 according to this embodiment is used when obtaining a wiring circuit board for mounting the pseudo-wafer segment from a connected wiring circuit board. In other words, when separating multiple wiring circuit boards from a connected wiring circuit board that does not have electronic components such as semiconductor chips mounted on it, the protective layer 10a of the water-soluble protective film 10 according to this embodiment is used to protect the connected wiring circuit board. Therefore, in such cases, the protective layer 10a may be bonded to protect both sides of the connecting wiring circuit board. The divided portions of the pseudo-wafer are mounted on a single wiring circuit board obtained from the connected wiring circuit board. [Examples]

[0064] Next, the present invention will be described in more detail with reference to examples. The following examples are provided to further illustrate the present invention and do not limit its scope.

[0065] [Example 1] An aqueous dispersion solution was prepared by dispersing polyvinyl alcohol (saponification value 65, average degree of polymerization 240) in water within a container. Next, the container containing the aqueous dispersion solution was placed in a 90°C water bath, and the container was stirred to dissolve the polyvinyl alcohol in water, thereby obtaining a polymer dispersion composition. Next, the polymer dispersion composition was applied to a thickness of 40 μm using an applicator onto the release-treated surface of a first PET release liner (product name MRA50, manufactured by Mitsubishi Chemical Corporation, thickness 50 μm) which had a silicone release-treated surface. Next, a protective layer was formed on the first PET release liner coated with the polymer dispersion composition by drying it at 110°C for 2 minutes. Next, the release-treated side of a second PET release liner (product name MRA25, manufactured by Mitsubishi Chemical Corporation, thickness 25 μm), which has a silicone release-treated side, was bonded onto the protective layer to obtain the water-soluble protective sheet according to Example 1.

[0066] The saponification value and average degree of polymerization of the polyvinyl alcohol were measured in accordance with the method described in the section on embodiments above.

[0067] [Example 2] A water-soluble protective sheet according to Example 2 was obtained in the same manner as in Example 1, except that polyvinyl alcohol with a saponification value of 80 and an average degree of polymerization of 240 was used. In Example 2, the saponification value of polyvinyl alcohol and the average degree of polymerization of polyvinyl alcohol were determined in the same manner as in Example 1.

[0068] [Comparative Example 1] A water-soluble protective sheet according to Comparative Example 1 was obtained in the same manner as in Example 1, except that polyvinyl alcohol with a saponification value of 98 and an average degree of polymerization of 240 was used. In Comparative Example 1, the saponification value of polyvinyl alcohol and the average degree of polymerization of polyvinyl alcohol were determined in the same manner as in Example 1.

[0069] [Comparative Example 2] A water-soluble protective sheet according to Comparative Example 2 was obtained in the same manner as in Example 1, except that polyvinyl alcohol with a saponification value of 10 and an average degree of polymerization of 240 was used. In Comparative Example 2, the saponification value of polyvinyl alcohol and the average degree of polymerization of polyvinyl alcohol were determined in the same manner as in Example 1.

[0070] <Thickness of the protective layer> The thickness of the protective layer was measured for the water-soluble protective films according to Examples 1 and 2, and for the water-soluble protective films according to Comparative Examples 1 and 2. The thickness of the protective layer was determined by measuring the thickness at five randomly selected points using a dial gauge (PEACOCK, model R-205) and then taking the arithmetic mean of these thicknesses. The results are shown in Table 1 below.

[0071] <Adhesion of protective layer to bare wafer> The adhesion strength of the protective layer to a bare wafer was measured for the water-soluble protective films according to Examples 1 and 2, and for the water-soluble protective films according to Comparative Examples 1 and 2. The adhesion force of the protective layer to the bare wafer was measured as described in the above embodiment. The adhesion of the protective layer to the bare wafer was then evaluated according to the following evaluation criteria. Excellent: The protective layer has an adhesion strength of 0.2 N / 100 mm or more to the bare wafer. Not acceptable. The adhesion strength of the protective layer to the bare wafer is less than 0.2 N / 100 mm. The results are shown in Table 1 below.

[0072] <Removability of protective layer> After attaching a protective layer of the water-soluble protective film according to each example to the surface of a bare wafer, the bare wafer was cut into a plurality of bare chips, and the ease of removing the protective layer from the plurality of bare chips was evaluated. The removal of the protective layer from the aforementioned multiple bare chips was carried out according to the following procedure. (1) Remove the second PET release liner from the prepared water-soluble protective sheet to expose one side of the protective layer of the water-soluble protective sheet. (2) Prepare a bare wafer (outer diameter 12 inches (300 mm), thickness 40 μm) with a dicing tape attached to one side (more specifically, attached to the adhesive layer of the dicing tape). Then, the protective layer of the water-soluble protective sheet is attached to the other side of the bare wafer (the side to which the dicing tape is not attached). Furthermore, a dicing ring is attached to the edge of the adhesive layer of the dicing tape. (3) After placing the bare wafer with the protective layer of the water-soluble protective sheet attached onto the stage of a vacuum mounter (model MV3000, manufactured by Nitto Seiki Co., Ltd.), the stage temperature is set to 90°C to bond the protective layer of the water-soluble protective sheet to the bare wafer (hereinafter referred to as the bare wafer with the water-soluble protective sheet). (4) After placing the bare wafer with the water-soluble protective sheet on the stage of the stealth dicing apparatus (model DFL7361, manufactured by Disco Corporation) so that the first PET peeling liner is in contact with it, laser light is irradiated from the laser irradiation light source of the stealth dicing apparatus along a predetermined dicing line to form a vulnerable area inside the bare wafer. Specifically, after cleavage, multiple bare chips with planar dimensions of 10 mm x 10 mm are obtained by forming a grid-like weak area inside the bare wafer. Furthermore, the irradiation of laser light from the laser light source shall be carried out according to the conditions shown below. After forming a vulnerable area inside the bare wafer, the first PET peeling liner is removed from the other side of the protective layer of the water-soluble protective sheet to expose the other side of the protective layer of the water-soluble protective sheet (hereinafter referred to as the bare wafer with the vulnerable area formed). <Laser light irradiation conditions> (A) Laser light Laser light source; semiconductor laser-pumped Nd:YAG laser Wavelength: 1064nm, 1088nm, 1099nm, or 1342nm Laser beam spot cross-sectional area: 3.14 × 10⁻⁴ -8 cm 2 Oscillation mode: Q-switched pulse Repetition frequency: 100kHz or less Pulse width: 1 μs or less Output; 1mJ or less Laser light quality; TEM00 Polarization characteristics; linear polarization (B) Focusing lens Magnification: 100x or less NA; 0.55 Transmittance relative to laser light wavelength: 100% or less (C) Stage movement speed: 280 mm / second or less (5) After removing the bare wafer with the weakened portion formed from the stage of the stealth dicing apparatus, the bare wafer with the weakened portion formed is expanded in the planar direction using an expander (model DDS2300, manufactured by Disco Corporation) to break the bare wafer with the weakened portion formed into multiple bare chips, and the protective layer of the water-soluble protective sheet is also broken into chip-sized pieces. The expansion of the aforementioned expansion device is performed under the conditions of a temperature of -15°C and an expansion speed of 200 mm / s. (6) While the stage of the expander is rotated at 1000 rpm, water is added (water is sprayed) from the water spray section of the water washing mechanism of the expander toward the fragmented protective layer, thereby removing the fragmented protective layer from the surface of each bare chip toward the outside of the stage, and exposing one surface of each bare chip (the side toward which the dicing tape is not attached). The water injection volume (water flow rate) should be within the range of 100 L / min to 300 L / min, and the water injection time should be within the range of 60 seconds to 90 seconds. The removeability of the protective layer was assessed by analyzing the surface of all 10mm x 10mm bare chips obtained after cutting using a Fourier transform infrared spectrophotometer (FT-IR) after water injection, thereby evaluating the presence or absence of residual organic matter. The following criteria were used to evaluate the ease of removal of the protective layer. • Removability of protective layer Excellent. No residual organic matter was detected in any of the multiple bare chips (800-4000 cm²). -1 (Maximum absorption in ≤ 0.05) Not acceptable. Even one of the multiple bare chips may contain residual organic matter (800-400cm). -1 Maximum absorption in >0.05) The results are shown in Table 1 below.

[0073] [Table 1]

[0074] Table 1 above shows that the water-soluble protective films according to Examples 1 and 2 exhibit excellent adhesion to bare wafers and superior ease of removal of the protective layer from bare chips. In contrast, it can be seen that the water-soluble protective films according to Comparative Examples 1 and 2 fail to meet at least one of the following criteria: adhesion to the bare wafer and removal of the protective layer from the bare chip. These results indicate that the water-soluble protective films according to Examples 1 and 2 exhibit excellent adhesion to the object to be adhered to, and can be easily removed from the object. The above results were obtained when the object to be bonded was a bare wafer or a bare chip, but similar results are expected to be obtained when the object to be bonded is a wiring circuit board or a connected wiring circuit board. From this, it can be seen that the water-soluble protective films according to Examples 1 and 2 can achieve both suppression of misalignment of mounting positions of electronic components on the wiring circuit board and suppression of damage to the wiring circuit board. [Explanation of Symbols]

[0075] 10. Water-soluble protective film, 10a protective layer, 10b first peel-off liner, 10c second peel-off liner, 20 connection wiring circuit board, 20a Wiring circuit board, 30 Semiconductor chip, 40 die bond layer (die bond film), 50 semiconductor package, 50' semiconductor package connector.

Claims

1. A method for manufacturing an electronic component package, which includes a wiring circuit board and electronic components mounted on the wiring circuit board, A bonding process is performed to bond a protective layer of a water-soluble protective film to one surface of the wiring circuit board. The protective layer comprises, as a water-soluble polymer compound, at least one selected from the group consisting of polyvinyl alcohol with a degree of saponification of 60 to 90, water-soluble polyester with a mass-average molecular weight of 15,000 to 40,000, and polyethylene oxide with a mass-average molecular weight of 20,000 to 1,000,000. After the bonding process, a mounting process is performed on the other surface of the wiring circuit board, in which at least one electronic component is mounted and then resin-sealed. After the mounting process, a removal process is performed to remove the protective layer of the water-soluble protective film from one surface side of the wiring circuit board. A method for manufacturing electronic component packages.

2. The bonding process is performed on a connected wiring circuit board in which multiple wiring circuit boards are connected, After the bonding process, the mounting process is carried out on each of the plurality of wiring circuit boards to produce an electronic component package assembly in which a plurality of electronic component packages are connected with the protective layer of the water-soluble protective film bonded to them. The removal process is performed before or after separating the electronic component package connector into the electronic component packages, while the protective layer of the water-soluble protective film is bonded to it. A method for manufacturing an electronic component package according to claim 1.

3. The aforementioned wiring circuit board is a coreless board. A method for manufacturing an electronic component package according to claim 1 or 2.

4. A protective layer used in the manufacture of an electronic component package according to claim 1 or 2. Water-soluble protective film.

5. A protective layer is provided for use in the manufacture of the electronic component package described in claim 3. Water-soluble protective film.

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