JP5376147B2 - Liquid resin composition, semiconductor element with adhesive layer, method for producing the same, and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid resin composition giving an adhesive layer capable of mounting a semiconductor element on a support at a low temperature and nonsticky at room temperature (25&deg;C). <P>SOLUTION: The liquid resin composition comprises an epoxy resin ingredient (A) and a curing agent ingredient (B), wherein the epoxy resin ingredient (A) is liquid at room temperature and the curing agent ingredient (B) is a combination of a compound (B1) having a phenolic hydroxy group and soluble in the epoxy resin ingredient (A) and a compound (B2) having a phenolic hydroxy group and insoluble in the epoxy resin ingredient (A). <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a liquid resin composition, a semiconductor element with an adhesive layer, a method for producing the same, and a semiconductor device.

  In recent years, there has been a remarkable progress in high functionality, miniaturization, and weight reduction of cellular phones, personal digital assistants, DVC (Digital Video Camera), etc., and there is a strong demand for high functionality, miniaturization, and weight reduction of semiconductor devices. ing. Therefore, a plurality of semiconductor elements having different functions or a plurality of semiconductor elements having the same function are mounted on one semiconductor device to enhance the function of the semiconductor device, and the size of the semiconductor element and the size of the semiconductor device can be reduced in size or weight. Attempts have been made to make the size as close as possible. For this reason, the thickness of the semiconductor element is further reduced, and the distance between the semiconductor element and the wire bond pad of the support such as a metal or an organic substrate is becoming closer.

In the conventional die attach process in the assembly process of a semiconductor device, a liquid die attach material is applied to a support and the semiconductor element is mounted at room temperature and then cured by heating. The problem of adhesion of the die attach material to the element surface or wire bond pad and the contamination problem due to the bleed of the die attach material (a phenomenon in which only the liquid component of the die attach material is transmitted by capillary action) have become ignorable.
Therefore, instead of using a liquid die attach material, a film die attach material is used, and after the film die attach material is attached to a support, a die (semiconductor element) is mounted while heating, A method of mounting on a support while heating a semiconductor element with a die attach material obtained by further separating and attaching to a dicing sheet with a film die attach material attached, and having a dicing sheet function A method of mounting a semiconductor element with a die attach material obtained by pasting a semiconductor wafer on a die attach film and separating the semiconductor element into a semiconductor element while heating is employed. (For example, see Patent Documents 1 and 2.)

On the other hand, not only semiconductor elements but also supports have been made thinner for further multilayering of semiconductor elements and further thinning of semiconductor devices. When a thin support is used, the warp of the semiconductor device based on the difference in coefficient of thermal expansion of the semiconductor constituent material becomes more remarkable. In addition, in order to reduce the transmission delay due to the decrease in signal propagation speed due to parasitic capacitance between wirings for higher device speed, low dielectric constant insulating films are generally used for interlayer insulating films. The insulating film has a low mechanical strength, and warping of the semiconductor element sometimes causes destruction of the insulating film.
Here, since the warp of the semiconductor device or the semiconductor element occurs due to the difference in the coefficient of thermal expansion of each constituent member, it is desired to lower the temperature for mounting the semiconductor element when using a film-like die attach material. However, in order to lower the semiconductor element mounting temperature of the film-like die attach material, it is necessary to use a thermoplastic component having a low glass transition temperature or increase a component having a low molecular weight. ) Will occur.

The stickiness around room temperature often causes deterioration of pick-up performance in the process of peeling the semiconductor element from the dicing sheet, and the stage in the process of temporarily placing the picked-up semiconductor element on another stage (see, for example, Patent Documents 3 to 5). It causes sticking to.
Here, with respect to a material having no tack at room temperature, several attempts have been proposed as a sealing material for a wafer level chip size package (see, for example, Patent Documents 6 to 8).
In these inventions, a liquid resin composition is applied to a semiconductor wafer with bumps such as solder and heat-treated to make it tack free at room temperature and then separated into semiconductor elements. In order to perform sealing and solder bonding simultaneously, it was necessary to bond at a temperature higher than the melting point of the solder.
As described above, there is no satisfactory one for the requirement of a semiconductor element with an adhesive layer that can be mounted even at low temperatures and does not have stickiness at room temperature.

JP 2002-294177 A (Claims) JP 2003-347321 A (Claims) JP-A-6-132327 (Claims) Japanese Patent Laid-Open No. 7-201897 (Claims) JP 2000-252303 A (Claims) JP 2000-174044 A (Claims) JP 2001-93940 A (Claims) JP 2003-221964 A (Claims)

  The present invention provides a liquid resin composition capable of mounting a semiconductor element on a support at a low temperature and providing an adhesive layer having no stickiness at room temperature (25 ° C.). It is to provide a semiconductor element with an adhesive layer produced by using the same and a method for producing the same, and further to provide a semiconductor device with excellent reliability produced using the semiconductor element with an adhesive layer.

Such an object is achieved by the present invention described in the following (1) to (7).
(1) An adhesive layer is formed on a semiconductor wafer or semiconductor element,
The adhesive layer is a liquid resin composition containing an epoxy resin component (A) and a curing agent component (B) , the epoxy resin component (A) is liquid at room temperature, and the curing agent component (B) is A combination of a compound (B1) having a phenolic hydroxyl group and having a softening point or a melting point of 200 ° C. or less and a compound (B2) having a phenolic hydroxyl group and a melting point exceeding 200 ° C. In the test, 90 g of the epoxy resin component (A) and 10 g of the compound (B1) were placed in a 300 cc separable flask, and the internal temperature of the compound (B1) was 145 to 45 using an oil bath while stirring with a stirrer. After heating to 155 ° C. and stirring for 30 minutes after the internal temperature reached 145 ° C., the mixture was cooled to room temperature, then allowed to stand at 25 ° C. for 72 hours and visually observed. The compound (B2) is prepared by adding 90 g of the epoxy resin component (A) and 10 g of the compound (B2) into a 300 cc separable flask and stirring the mixture with an agitator using an oil bath. Is heated to 145 to 155 ° C, and after stirring for 30 minutes from the time when the internal temperature reaches 145 ° C, it is cooled to room temperature, then left at 25 ° C for 72 hours, and then visually observed to, coated with a transparent and not compound der Ru liquid-like resin composition to a semiconductor wafer or a semiconductor device, then, is characterized in that an adhesive layer obtained by heating at a heating temperature of 60 to 150 ° C. A semiconductor wafer with an adhesive layer or a semiconductor element with an adhesive layer.
(2) said any compound (B1) and (B2), 1 above, wherein the phenolic hydroxyl groups in the molecule is a compound having two or more (1) Symbol placement of the semiconductor wafer or adhesion with an adhesive layer Layered semiconductor element .
( 3 ) The semiconductor with an adhesive layer obtained by cutting the semiconductor wafer with an adhesive layer according to any one of (1) or (2) above by dicing and dividing into a semiconductor element with an adhesive layer element.
( 4 ) A semiconductor device manufactured by mounting the semiconductor element with an adhesive layer described in any one of (1) to (3) on a circuit board.
( 5 ) A liquid resin composition comprising an epoxy resin component (A) and a curing agent component (B), wherein the epoxy resin component (A) is liquid at room temperature, and the curing agent component (B) is phenol. A combination of a compound (B1) having a functional hydroxyl group and a softening point or a melting point of 200 ° C. or less and a compound (B2) having a phenolic hydroxyl group and a melting point of more than 200 ° C. in the following dissolution test The internal temperature of the compound (B1) is 145 to 155 ° C. using an oil bath while stirring with a stirrer in 90 g of the epoxy resin component (A) and 10 g of the compound (B1) in a 300 cc separable flask. And after stirring for 30 minutes from the time when the internal temperature reached 145 ° C., it was cooled to room temperature, then left at 25 ° C. for 72 hours, and then transparent when observed visually. The compound (B2) has an internal temperature of 145 using an oil bath while stirring with a stirrer in 90 g of the epoxy resin component (A) and 10 g of the compound (B2) in a 300 cc separable flask. When heated to ˜155 ° C., stirring was continued for 30 minutes from the time when the internal temperature reached 145 ° C., then cooled to room temperature, then allowed to stand at 25 ° C. for 72 hours, and visually observed, An application step of applying a liquid resin composition , which is a compound that does not become transparent, to one surface of a semiconductor wafer to obtain a semiconductor wafer to which the liquid resin composition has been applied; By heating at a heating temperature of ˜150 ° C. to form an adhesive layer, an adhesive layer forming step, an attaching step of attaching the semiconductor wafer with the adhesive layer to a dicing sheet, and dicing A method for producing a semiconductor element with an adhesive layer, comprising a step of dividing the semiconductor wafer with an adhesive layer into pieces into semiconductor elements with an adhesive layer.
( 6 ) A method of manufacturing a semiconductor device, comprising a step of mounting a semiconductor element with an adhesive layer produced by the method for manufacturing a semiconductor element with an adhesive layer according to ( 5 ) above on a circuit board by thermocompression bonding. .

  According to the present invention, there is provided a liquid resin composition capable of mounting a semiconductor element on a support at a low temperature and providing an adhesive layer having no stickiness at room temperature, using the liquid resin composition It is possible to provide the manufactured semiconductor element with an adhesive layer and a method for manufacturing the same, and further to provide a highly reliable semiconductor device manufactured using the semiconductor element with an adhesive layer.

  In the liquid resin composition containing the epoxy resin component (A) and the curing agent component (B), the epoxy resin component (A) is liquid at room temperature (25 ° C.), and the curing agent component (B ) Has a phenolic hydroxyl group and dissolves in the epoxy resin component (A), and a compound (B2) that has a phenolic hydroxyl group and does not dissolve in the epoxy resin component (A) A liquid resin composition characterized in that it is a liquid resin composition that can be mounted on a support at a low temperature and gives a non-sticky adhesive layer at room temperature, and produced using the liquid resin composition A semiconductor device with an adhesive layer and a method for manufacturing the same are provided, and further, a semiconductor device using the semiconductor element with an adhesive layer and having excellent reliability is provided.

  The epoxy resin component (A) according to the present invention refers to the entire epoxy resin in the liquid resin composition, and when only one kind of epoxy resin is used, it refers to that one kind of epoxy resin, When two or more types of epoxy resins are used in combination, it refers to a mixture of all the two or more types of epoxy resins. The epoxy resin component (A) is liquid at room temperature. That is, when only one type of epoxy resin is used as the epoxy resin component (A), the one type of epoxy resin is liquid at room temperature. Moreover, when 2 or more types of epoxy resins are used in combination as an epoxy resin component (A), the mixture which mixed all these 2 or more types of epoxy resins is liquid at room temperature. Therefore, when two or more epoxy resins are used in combination as the epoxy resin component (A), the epoxy resin component (A) may be a combination of epoxy resins that are all liquid at room temperature, or If some of the epoxy resin is solid at room temperature and mixed with another epoxy resin that is liquid at room temperature, the mixture becomes liquid at room temperature. A combination with a resin may also be used. In addition, when two or more types of epoxy resins are used in combination as the epoxy resin component (A), the liquid resin composition is not necessarily mixed after mixing all the epoxy resins to be used. It is not necessary to produce a product, and the epoxy resin to be used may be mixed separately to produce a liquid resin composition. In the present invention, that the epoxy resin component (A) is liquid at room temperature means that when all epoxy resins used as the epoxy resin component (A) are mixed, the mixture becomes liquid at room temperature. is there.

  The epoxy resin which comprises an epoxy resin component (A) is a compound which has a glycidyl group, and it is preferable to have 2 or more glycidyl groups in 1 molecule from a reactive viewpoint. In addition, the epoxy resin preferably contains less ionic impurities because the use of the liquid resin composition of the present invention is for semiconductors, and a compound having a phenolic hydroxyl group as a curing agent as described later. Since it uses, the compound which has a glycidyl ether group couple | bonded with an aromatic ring from a reactive viewpoint is preferable.

  Among the epoxy resins constituting the epoxy resin component (A), the epoxy resin that is liquid at room temperature is a compound obtained by epoxidizing bisphenols such as bisphenol A and bisphenol F. Examples of such compounds include, but are not limited to, compounds that are liquid compounds at room temperature and compounds that are aromatic glycidyl ether compounds having an alkylene oxide skeleton in the molecule and are liquid at room temperature. Among the epoxy resins constituting the epoxy resin component (A), the epoxy resin that is solid at room temperature and is used in combination with an epoxy resin that is liquid at room temperature as needed includes phenol novolac type epoxy resin, cresol novolac type epoxy resin, phenol Examples include, but are not limited to, aralkyl epoxy resins, biphenyl aralkyl epoxy resins, dicyclopentadiene epoxy resins, other epoxy resins having a triphenylmethine skeleton, epoxy resins having a naphthalene skeleton, and epoxy resins having an anthracene skeleton. Is not to be done.

  In the present invention, a monofunctional epoxy compound that is liquid at room temperature, such as phenyl glycidyl ether and cresyl glycidyl ether, is also included in the epoxy resin constituting the epoxy resin component (A). A monofunctional epoxy compound that is liquid at room temperature is suitably used to make the entire epoxy resin component liquid at room temperature by combining with an epoxy resin that is solid at room temperature when using an epoxy resin that is solid at room temperature.

  In the present invention, that the epoxy resin component (A) is liquid at room temperature means that the epoxy resin component (A) has fluidity at room temperature (25 ° C.), preferably room temperature (25 ° C. ) Indicates a viscosity of 1000 Pa · s or less. The viscosity at 25 ° C. of the epoxy resin component (A) is a value measured by a capillary viscometer method of JIS K 7233.

The curing agent component (B) according to the present invention is a curing agent for the epoxy resin component (A), which has a phenolic hydroxyl group and a compound (B1) that dissolves in the epoxy resin component (A), and a phenolic hydroxyl group. It is a combination with the compound (B2) that has and does not dissolve in the epoxy resin component (A). That is, the curing agent component (B) is composed of the compound (B1) and the compound (B2).
Here, the compound (B1) dissolved in the epoxy resin component (A) is an oil bath with 90 g of the epoxy resin component (A) and 10 g of the compound (B1) used in a 300 cc separable flask and stirring with a stirrer. Was used to heat the internal temperature to 145 to 155 ° C., and stirring was continued for 30 minutes from the time when the internal temperature reached 145 ° C., followed by cooling to room temperature, and then standing at 25 ° C. for 72 hours. Observed by visual observation, refers to a transparent one. On the other hand, the compound (B2) that does not dissolve in the epoxy resin component (A) refers to a compound that is not transparent after being visually observed after the same operation.

  The compound (B1) generally has a softening point or a melting point of 200 ° C. or lower. Specifically, bisphenols such as bisphenol A and bisphenol F or derivatives thereof, phenol or derivatives thereof such as phenol novolac and cresol novolac, and formaldehyde Compound obtained by reaction, compound obtained by reaction of phenol or its derivative and benzaldehyde, phenol aralkyl type phenol resin, biphenyl aralkyl type phenol resin, other compound having naphthalene skeleton, one having anthracene skeleton and phenol in one molecule And compounds having two or more functional hydroxyl groups (including hydroxyl groups bonded directly to an aromatic ring such as a naphthol type hydroxyl group). On the other hand, the compound (B2) is generally a compound having high crystallinity and a melting point exceeding 200 ° C., and specific examples thereof include biphenol and triphenylethane.

The reason why the compound (B1) that dissolves in the epoxy resin fat component (A) and the compound (B2) that does not dissolve in the epoxy resin fat component (A) are used as the curing agent component (B) is that the liquid resin composition of the present invention is heated at the first temperature. This is because the adhesive layer has no tackiness at room temperature and changes to an adhesive layer that exhibits tackiness at the first temperature or higher. That is, by using together the compound (B1) that dissolves in the epoxy resin component (A) and the compound (B2) that does not dissolve as the curing agent component (B), there is no stickiness at room temperature after heating at the first temperature. And the adhesive layer which shows adhesiveness is obtained above 1st temperature.
On the other hand, when only the compound (B1) is used, after heating at the first temperature, the adhesiveness is not exhibited at a temperature equal to or higher than the first temperature, and when only the compound (B2) is used, Even after heating at the first temperature, it exhibits tackiness at room temperature or does not exhibit tackiness at a temperature equal to or higher than the first temperature.
That is, by heating the liquid resin composition of the present invention at a first temperature, the epoxy resin component (A) and the compound (B1) are all or partly reacted to increase the molecular weight. The liquid resin composition changes in properties to such an extent that it does not exhibit tackiness at room temperature. However, since the curing reaction is not completed, it exhibits tackiness at a temperature higher than the first temperature. Next, the adhesive layer obtained by heating at the first temperature is heated at the second temperature to react the remaining glycidyl group with the compound (B2) and the unreacted compound (B1). It can be cured and permanent adhesion of the bonding object can be performed.

  As the compound (B1), a compound having 2 or more phenolic hydroxyl groups contained in one molecule is preferably 80% by weight or more of the entire compound (B1). If it is less than this, the adhesiveness after heating at the second temperature may be insufficient. The compounding ratio of the compound (B1) and the compound (B2) (compound (B1): compound (B2)) is preferably 1: 5 to 5: 1, more preferably 1: 4 to 4: 1 by weight. is there. Moreover, it is preferable that both a compound (B1) and a compound (B2) are compounds which have 2 or more of phenolic hydroxyl groups in 1 molecule.

  Here, the first temperature means that the semiconductor wafer or semiconductor element coated with the liquid resin composition is heated, and the liquid resin composition does not exhibit adhesiveness at room temperature and exhibits adhesiveness at or above the first temperature. The temperature to be changed to the adhesive layer is preferably 60 to 200 ° C, more preferably 80 to 150 ° C, and particularly preferably 100 to 120 ° C. The second temperature is a temperature at which the adhesive layer obtained by heating at the first temperature is cured, and is a temperature higher than the first temperature. The second temperature is preferably 200 ° C. or lower in terms of low temperature curing. The first temperature and the second temperature are appropriately selected depending on the types of the epoxy resin component (A) and the curing agent component (B) used.

  The liquid resin composition of the present invention preferably contains a reaction catalyst of a glycidyl group and a phenolic hydroxyl group. The reaction catalyst that can be used is not particularly limited as long as it is a compound generally known as a reaction catalyst for a glycidyl group and a phenolic hydroxyl group. Examples of such a catalyst include phosphorus catalysts such as triphenylphosphine and tetraphenylphosphine salts, and nitrogen-based catalysts such as diazabicycloundecene, dicyandiamide, hydrazine derivatives, and imidazoles. Considering heating at the first temperature and heating at the second temperature, combined use of reaction catalysts such as phosphorus-based, tertiary amines, and low-melting imidazoles with reaction catalysts such as dicyandiamide and high-melting imidazoles Is also preferable. As the imidazoles having a high melting point, those having a melting point of 180 ° C. or more are preferable. Specifically, an adduct of 2-methylimidazole and 2,4-diamino-6-vinyltriazine, 2-phenyl-4-methyl- Examples include 5-hydroxymethylimidazole and 2-phenyl-4,5-dihydroxymethylimidazole.

The liquid resin composition of the present invention can contain a filler. As filler, metal powder such as silver powder, gold powder, copper powder, aluminum powder, nickel powder, palladium powder, ceramic powder such as silica powder, alumina powder, titania powder, aluminum nitride powder, boron nitride powder, polyethylene powder And polymer powders such as polyacrylate powder, polytetrafluoroethylene powder, polyamide powder, polyurethane powder, polysiloxane powder, and polysilsesquioxane powder. When applying the liquid resin composition, a nozzle may be used, and from the viewpoint of flatness after printing using a blade, the average particle size of the filler is preferably 15 μm or less, more preferably 10 μm or less. Moreover, it is preferable that there are few coarse particles and what passed through the sieve with the opening diameter of 30 micrometers is preferable. Furthermore, it is preferable that there are few ionic impurities, such as sodium and chlorine.
In particular, silver powder is preferably used when electrical conductivity or thermal conductivity is required. The silver powder may be any silver powder that is usually commercially available for electronic materials, and examples thereof include reduced powder and atomized powder. The average particle diameter of the silver powder is preferably 1 μm or more and 15 μm or less. If the average particle diameter of the silver powder is less than this range, the viscosity of the liquid resin composition becomes too high, and if it exceeds this range, it may cause nozzle clogging during dispensing or deterioration of flatness after printing as described above. In addition, silver powder other than for electronic materials requires a caution because the amount of ionic impurities may be large. The shape of the filler is not particularly limited, such as flaky or spherical, but is preferably flaky. The content of silver powder is usually 70% by weight or more and 95% by weight or less in the liquid resin composition. If the silver powder content is less than this range, the conductivity tends to be low, and if it is more than this range, the viscosity of the liquid resin composition becomes too high.

  The liquid resin composition of the present invention can further contain a coupling agent. As coupling agents, epoxy silane coupling agents such as 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane, vinylsilane coupling agents such as vinyltrimethoxysilane and vinyltriethoxysilane, 3 -(Meth) acryloxysilane coupling agents such as methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3 -Aminosilane coupling agents such as aminopropyltrimethoxysilane, mercaptosilane coupling agents such as 3-mercaptopropyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane. But it is not limited thereto. Of these, sulfide silane coupling agents such as bis (3- (triethoxysilyl) propyl) disulfide and bis (3- (triethoxysilyl) propyl) tetrasulfide are particularly preferred.

  Furthermore, the liquid resin composition of the present invention can also contain additives such as a low stress agent, an antifoaming agent, a leveling agent, and a surfactant as necessary.

  The liquid resin composition of the present invention has fluidity at room temperature (25 ° C.). The liquid resin composition of the present invention has a viscosity of 10 to 100 Pa · s, preferably 15 to 80 Pa · s, particularly preferably 20 to 60 Pa · s at 25 ° C. The viscosity of the liquid resin composition is a value measured at 25 ° C. and 5.0 rpm using a BF viscometer (CP51 cone).

  The liquid resin composition of the present invention is produced, for example, by premixing each component, kneading using three rolls, and degassing under vacuum.

  As a method for manufacturing the semiconductor device of the present invention, a known method may be mentioned. For example, after a liquid resin composition is applied to a semiconductor element or a semiconductor wafer and heated to obtain a semiconductor element with an adhesive layer, the semiconductor element with an adhesive layer is mounted on a circuit board, mounted by thermocompression bonding, and cured. A method is mentioned. Then, a semiconductor device is manufactured by wire bonding and transfer molding using an epoxy resin. The semiconductor device of the present invention includes a diode, a transistor, and the like.

Hereinafter, a method for manufacturing a semiconductor element with an adhesive layer and a method for manufacturing a semiconductor device using the liquid resin composition of the present invention will be described.
[Coating process]
First, the liquid resin composition of the present invention is applied to the back surface (the back surface of the circuit surface) of a semiconductor wafer having a bonding pad for wire bonding. Here, as the semiconductor wafer, one having no circuit formed on the surface may be used. Usually, a semiconductor wafer is subjected to back surface grinding before dicing for the purpose of controlling the thickness. And after grinding a back surface, a liquid resin composition is apply | coated. Examples of the application method of the liquid resin composition include screen printing, stencil printing, spin coating, and the like, and known methods are applicable. For example, set the semiconductor wafer with the back grind tape (tape attached to the circuit surface for the purpose of protecting the circuit surface of the semiconductor wafer during back surface grinding) on the printing machine so that the back surface of the semiconductor wafer faces up, Use a screen mask or stencil mask and apply a liquid resin composition to a uniform thickness using a metal or polymer blade, or place it on a spin coater and place the liquid resin composition in the center of the semiconductor wafer. There is a method in which the liquid resin composition is uniformly applied to the entire back surface of the semiconductor wafer by rotating the semiconductor wafer. In addition, there are a method of applying to a stationary wafer by moving a single or a plurality of nozzles, and a method of applying while moving a nozzle to a rotating wafer.

  The back grind tape to be used is preferably one having excellent heat resistance that can withstand heating in the subsequent stage, and one having a semiconductor wafer support function (function to suppress warping and deformation of a semiconductor wafer thinned after back surface polishing) is also preferred.

[Adhesive layer forming step]
Next, the semiconductor wafer coated with the liquid resin composition is heated at a first temperature, and the liquid resin composition is changed to an adhesive layer that does not exhibit tackiness at room temperature and exhibits tackiness at or above the first temperature. Then, an adhesive layer forming step is performed in which an adhesive layer that does not exhibit tackiness at room temperature and exhibits tackiness at or above the first temperature is formed. Examples of the heating method at the first temperature include heating on a hot plate, heating in an oven, heating in a reflow furnace, and the like. The heating temperature (first temperature) is preferably 60 to 200 ° C. More preferably, it is 80-150 degreeC, Most preferably, it is 100-120 degreeC. The warp after the heat treatment becomes smaller when the heating temperature (first temperature) is lowered. The heating time is preferably 1 hour or less. When the heating time is longer than this, the productivity is deteriorated and the semiconductor wafer is warped after the heating. Particularly preferable heating conditions are 150 ° C. or less and 30 minutes or less, and more preferably 120 ° C. or less and 30 minutes or less.
The thickness of the adhesive layer after heating is preferably 200 μm or less, more preferably 5 μm or more and 50 μm or less. The thickness can be controlled by adjusting the coating conditions and the viscosity of the liquid resin composition. For example, if a low viscosity liquid resin composition is used, a thinner adhesive layer can be obtained. When a film-like die attach material is used, a film-like die attach material having a target thickness must be prepared. However, in the liquid resin composition of the present invention, the adjustment of coating conditions and the liquid resin composition The thickness can be controlled by adjusting the viscosity.

  If the adhesive layer contains a large amount of volatile matter after heating, it may cause stickiness of the adhesive layer, which will be described later, cause deterioration of pick-up property, and cause voids when mounted on the support. It is preferable that the adhesive layer has a volatile content of 1% by weight or less after being applied to the back surface of the semiconductor wafer with a thickness of 50 μm and heat-treated at 110 ° C. for 30 minutes. Here, the thickness of the liquid resin composition after application is a value measured by a non-contact thickness meter. Volatile matter refers to a semiconductor wafer coated with a liquid resin composition at 50 ± 5 μm, heated for 30 ± 5 minutes in a dryer controlled at 110 ± 5 ° C., then taken out and spatula before the semiconductor wafer is cooled. 5 to 30 mg of the adhesive layer was sampled at, and the weight loss at 200 ° C. in the weight loss curve measured by heating the obtained sample from room temperature to 300 ° C. at a rate of 10 ° C./min. Rate. A more preferable weight loss rate is 0.5% by weight or less, and particularly preferably 0.1% by weight or less.

  The adhesive layer obtained by performing the adhesive layer forming step does not exhibit tackiness at room temperature. If there is adhesiveness, there is a possibility that a conveyance failure may occur in the attaching step for attaching to the dicing sheet, and a defect may also occur in the pickup step described later.

  The thickness accuracy of the adhesive layer in the semiconductor wafer with an adhesive layer is preferably within ± 5 μm, more preferably within ± 3 μm. Here, the thickness accuracy is a distance from the average value of the surface profile obtained by measuring a change in unevenness in the surface of the semiconductor element with a laser roughness meter. When the thickness accuracy is larger than this, it is difficult to obtain a stable thickness.

[Attaching process, individualizing process]
Next, an affixing step of affixing the obtained semiconductor wafer with an adhesive layer to a dicing sheet, and then an individualizing step of cutting the semiconductor wafer with an adhesive layer by dicing and dicing into a semiconductor element with an adhesive layer (dicing) Do. Here, a commercially available dicing sheet can be used. The dicing sheet is fixed to the wafer ring by sticking it to the wafer ring. Also, it is usually separated into pieces using a dedicated device such as a dicing saw to obtain a semiconductor element with an adhesive layer. Here, as described above, when the smoothness of the adhesive layer is not sufficient, air may remain between the adhesive layer and the dicing sheet. For this reason, chips are chipped during dicing (a phenomenon in which an edge portion of a semiconductor element is chipped). , Chip cracks (a phenomenon in which the edge portion of a semiconductor element cracks), chip jumping (a phenomenon in which the semiconductor element is detached from the dicing sheet during dicing), etc., resulting in deterioration of the yield of the semiconductor element with an adhesive layer There is.

[Method for Manufacturing Semiconductor Device]
The semiconductor element with an adhesive layer obtained in this manner is set on a dibonder in a state of being attached to a dicing sheet, and a pick-up process for taking the semiconductor element with an adhesive layer from the dicing sheet, and then the semiconductor element with an adhesive layer is A mounting process is carried out in which the substrate is mounted by pressure bonding under heating. When picking up, it must be peeled off at the interface between the semiconductor element with the adhesive layer and the dicing sheet. When the adhesive layer shows tackiness at room temperature, it cannot be picked up. There is a possibility that problems such as a part remaining on the dicing sheet may occur. At the time of pickup, the dicing sheet is fixed to the wafer ring.

  The support on which the semiconductor element with an adhesive layer according to the present invention is mounted is a lead frame, an organic substrate, or the like. When the semiconductor elements are stacked, the second semiconductor element is mounted on the lead frame, the organic substrate, or the like. is there. The temperature at which the semiconductor element is mounted (mounting temperature) is equal to or higher than the first temperature. And the mounting temperature of a semiconductor element has preferable 200 degrees C or less, More preferably, it is 175 degrees C or less. Mounting a semiconductor element at a high temperature often causes warping. A load is applied when the semiconductor element is mounted, but the load differs depending on the type of die bonder. Some models, such as some LOC (Lead On Chip) bonders, can apply a load of about 20 N per semiconductor element, but the load is usually about 3 to 5 N. In consideration of thinning of the semiconductor element and a semiconductor element having low mechanical strength, a load of 5N or less, more preferably 1 to 4N is preferable. The mounting time, that is, the time during which the semiconductor element is pressed against the support is preferably 10 seconds or less, more preferably 3 seconds or less, and particularly preferably 1 second or less, from the viewpoint of productivity.

  Moreover, it is preferable that the adhesive force in 25 degreeC of the contact bonding layer before hardening after mounting is 1N or more. The adhesive strength at 25 ° C. of the adhesive layer after mounting and before curing was as follows: a semiconductor element with an adhesive layer separated into 6 × 6 mm was picked up on a die bonder, a bond load of 1.0 N, a support heating temperature of 165 ° C., Lead frame for QFP (package size 14 × 20 mm, die pad size 7.5 × 7.5 mm, under the condition of mounting time 8 seconds (including 7 seconds for the temperature of the support surface to rise to 165 ° C.) This is a value obtained by measuring a sample mounted on a die pad surface and a lead-plated copper frame (thickness: 0.15 mm) with a die shear tester (manufactured by Dage, series 4000). If the adhesive strength at 25 ° C. of the adhesive layer after mounting and before curing is lower than this, the semiconductor element may fall off during transportation. The adhesive force at 25 ° C. of the adhesive layer after mounting and before curing is more preferably 10 N or more, and further preferably 20 N or more.

  The support on which the semiconductor element is mounted is cured by heating at a second temperature, and then wire bonding is performed. The conditions for wire bonding are not particularly limited, and normal conditions can be selected. However, considering the above-described problem of warpage, it is preferably performed at a low temperature. A particularly preferred wire bond temperature is 200 ° C. or lower. If the adhesive force of the adhesive layer is too low at the time of wire bonding, the semiconductor element may fall off or the strength of the wire bond may not be sufficient. Therefore, the adhesive strength at 175 ° C. of the adhesive layer after curing is preferably 30 N or more. Here, the adhesive strength of the cured adhesive layer at 175 ° C. is that the semiconductor element with the adhesive layer separated into 6 × 6 mm is picked up on the die bonder, the bond weight is 1.0 N, the support heating temperature is 165 ° C., and the mounting is performed. Lead frame for QFP (package size 14 × 20 mm, die pad size 7.5 × 7.5 mm, die pad surface and leads under the condition of time 8 seconds (including time 7 seconds for the temperature of the support surface to rise to 165 ° C.) The sample was mounted on a silver-plated copper frame (thickness: 0.15 mm) and then cured at 175 ° C. for 60 minutes, using a die shear tester (Dage, series 4000). The adhesive strength at 175 ° C. of the cured adhesive layer is more preferably 50 N or more, and further preferably 100 N or more.

Next to the wire bond, a resin sealing process is performed. Usually, a sealing material for transfer molding in which a filler is dispersed in an epoxy resin is used. The sealing material for transfer molding is not particularly limited, but it is preferable that an antimony compound or brominated compound is not used because of environmental problems. Sealing using biphenyl aralkyl type epoxy resin and / or biphenyl aralkyl type phenol resin It is more preferable that the material does not use an antimony compound or a brominated compound. Sealant using biphenyl aralkyl type epoxy resin and / or biphenyl aralkyl type phenol resin shows good flame resistance (UL test) and good reflow crack resistance without using antimony compound or brominated compound It is because it shows.
After resin sealing, post mold curing is performed as necessary. When a lead frame is used as a support, lead processing, exterior plating, or the like is performed as necessary to obtain a semiconductor device. When an organic substrate is used as the support, a semiconductor device is obtained by performing solder ball attachment or the like as necessary.

  EXAMPLES Next, although an Example is given and this invention is demonstrated more concretely, this is only an illustration and does not restrict | limit this invention.

[Example 1]
As epoxy resin component (A), diglycidyl bisphenol A (epoxy equivalent 180, liquid at room temperature, hereinafter referred to as bis A epoxy) obtained by reaction of bisphenol A and epichlorohydrin, cresyl glycidyl ether (epoxy equivalent 185, below) CGE), as compound (B1), phenol novolak (hydroxyl equivalent 104, softening point 80-90 ° C., hereinafter referred to as phenolic B11), as compound (B2), 3,3 ′, 5,5′-tetramethylbiphenol (Honshu) Chemical Industry Co., Ltd., hereinafter referred to as phenol-based B2), 2-phenyl-4,5-dihydroxymethylimidazole (Shikoku Kasei Kogyo Co., Ltd., hereinafter referred to as 2PHZ) as a reaction catalyst, diazabicycloundecene, dicyandiamide, filler As a flaky silver powder having a particle size of 1-30 μm The silver powder) were blended in proportions shown in Table 1, to obtain a liquid resin composition by kneading through three rolls. A compounding quantity is a weight part.
The liquid resin composition was defoamed at 2 mmHg for 30 minutes in a vacuum chamber, and various performances were evaluated by the following methods.
The viscosity at 25 ° C. of the epoxy resin component (A) is a mixture of diglycidyl bisphenol A and cresyl glycidyl ether obtained by the reaction of bisphenol A and epichlorohydrin, and the capillary viscosity of JIS K 7233. It was a viscosity measured at 25 ° C. by a measuring method, and was 14 Pa · s.

[Evaluation method]
-Viscosity of liquid resin composition: BF type viscometer (CP51 cone) was used, and the value at 25 ° C and 5.0 rpm was measured after the liquid resin composition was prepared.
-Viscosity of epoxy resin component (A): A value at 25 ° C was measured by a capillary viscometer method of JIS K7233.
-Adhesive layer thickness: The thickness of the adhesive layer after heat-treating the semiconductor wafer coated with the liquid resin composition at a first temperature (110 ° C for 30 minutes) was determined. The semiconductor wafer before application and the liquid resin composition were applied to the semiconductor wafer, the thickness after heat treatment was measured, and the difference was calculated.
Volatile content and appearance: The above liquid resin composition was applied to a semiconductor wafer, and immediately after heat treatment at 110 ° C. for 30 minutes, a part of the adhesive layer was scraped with a spatula to obtain a sample for measuring volatile content. The volatile content is a weight loss value at 200 ° C. measured by TGA (differential thermal balance) with a sample weight of 10 mg and a temperature rising rate of 10 ° C./min from room temperature. The reason for sampling immediately after the heat treatment is that when it is cooled to room temperature, the adhesive layer becomes solid and sampling may be difficult. Moreover, the external appearance was visually observed using parts other than sampling. Appearance was counted for pinholes, voids, and foreign objects. Those without pinholes, voids and foreign matter were considered good.

-Tack property: Said liquid resin composition was apply | coated to the slide glass, the Teflon (trademark) tape (Nitto Denko Co., Ltd. make, NITFLON ADHESIVE TAPES) was affixed after heat-processing for 110 degreeC for 30 minutes. Thereafter, the Teflon (registered trademark) tape was peeled off, and the liquid resin composition adhering to the Teflon (registered trademark) tape was visually observed. The case where the liquid resin composition did not adhere to the Teflon (registered trademark) tape was determined to be satisfactory.
-Adhesive strength: A semiconductor element with an adhesive layer separated into 6 × 6 mm is picked up on a die bonder, bond weight 1.0 N, support heating temperature 165 ° C., mounting time 8 seconds (the temperature of the support surface is 165) Lead frame for QFP (package size 14 x 20 mm, die pad size 7.5 x 7.5 mm, copper frame with silver plating on the pad surface and lead tips, thickness 0) .15 mm), and the adhesive strength of the sample after curing after mounting the semiconductor element with the adhesive layer was measured at 25 ° C. Similarly, a sample in which a semiconductor element with an adhesive layer was mounted on a QFP lead frame was cured at 175 ° C. for 60 minutes, and the adhesive strength of the cured sample was measured at 175 ° C. The adhesive strength was measured with a die shear tester (Dage, series 4000). The case where the adhesive strength at 175 ° C. after curing was 30 N or more was regarded as acceptable.

・ Moisture resistance test: 50 μm thickness on the back side of a simulated semiconductor wafer (Phase 8 manufactured by Hitachi ULSI) whose circuit surface side was protected with a polyimide resin (CRC-8800 manufactured by Sumitomo Bakelite Co., Ltd.) using the above liquid resin composition It was applied with. Next, after heat-treating at 110 ° C. for 30 minutes, a semiconductor element with an adhesive layer prepared by being separated into 6 × 6 mm pieces is bonded by an auto die bonder with a bond load of 1.0 N, a support heating temperature of 165 ° C., and a mounting time of 8 Lead frame for QFN (package size 14 x 20 mm, die pad size 7.5 x 7.5 mm, pad surface and lead tips) under the conditions of seconds (including the time for the surface temperature of the support to rise to 165 ° C for 7 seconds) Was mounted on a silver-plated copper frame (thickness 0.15 mm) and then cured at 175 ° C. for 60 minutes. This was molded at 175 ° C. for 90 seconds with a semiconductor sealing material (EME-G700 manufactured by Sumitomo Bakelite Co., Ltd.), followed by curing for 4 hours to obtain a semiconductor device. This semiconductor device was subjected to a moisture absorption treatment at 60 ° C. and a relative humidity of 60% for 120 hours, followed by an IR reflow treatment (260 ° C., 10 seconds, 3 times reflow). The degree of peeling of the treated semiconductor device was measured by an ultrasonic flaw detector (transmission type). The case where the peeling area of the die attach part was less than 10% was regarded as acceptable. The unit of the peeled area is%.

[Examples 2 to 5]
A liquid resin composition was prepared in the same manner as in Example 1 with the ratio shown in Table 1, and the same evaluation as in Example 1 was performed.
The materials different from those in Example 1 are as follows.
As a compound (B1), phenol aralkyl resin (hydroxyl equivalent 180, manufactured by Sumitomo Bakelite Co., Ltd., PR-54869, hereinafter referred to as phenol-based B12)
The viscosity at 25 ° C. of the epoxy resin component (A) of Example 3 was obtained by mixing a mixture obtained by mixing only diglycidyl bisphenol A and cresyl glycidyl ether obtained by the reaction of bisphenol A with epichlorohydrin according to JIS K 7233. The viscosity at 25 ° C. measured by a capillary viscometer method was 11 Pa · s.

[Comparative Examples 1-2]
A liquid resin composition was prepared in the same manner as in Example 1 and evaluated in the same manner as in Example 1.

  The liquid resin composition of the present invention provides an adhesive layer that is not sticky at room temperature and can be mounted with a semiconductor element at low temperatures. Therefore, according to the present invention, a highly reliable semiconductor device can be manufactured with high manufacturing efficiency. Can do.

Claims (6)

An adhesive layer is formed on the semiconductor wafer or semiconductor element,
The adhesive layer is a liquid resin composition containing an epoxy resin component (A) and a curing agent component (B) , the epoxy resin component (A) is liquid at room temperature, and the curing agent component (B) is A combination of a compound (B1) having a phenolic hydroxyl group and having a softening point or a melting point of 200 ° C. or less and a compound (B2) having a phenolic hydroxyl group and a melting point exceeding 200 ° C. In the test, 90 g of the epoxy resin component (A) and 10 g of the compound (B1) were placed in a 300 cc separable flask, and the internal temperature of the compound (B1) was 145 to 45 using an oil bath while stirring with a stirrer. After heating to 155 ° C. and stirring for 30 minutes after the internal temperature reached 145 ° C., the mixture was cooled to room temperature, then allowed to stand at 25 ° C. for 72 hours and visually observed. The compound (B2) is prepared by adding 90 g of the epoxy resin component (A) and 10 g of the compound (B2) into a 300 cc separable flask and stirring the mixture with an agitator using an oil bath. Is heated to 145 to 155 ° C, and after stirring for 30 minutes from the time when the internal temperature reaches 145 ° C, it is cooled to room temperature, then left at 25 ° C for 72 hours, and then visually observed to, coated with a transparent and not compound der Ru liquid-like resin composition to a semiconductor wafer or a semiconductor device, then, is characterized in that an adhesive layer obtained by heating at a heating temperature of 60 to 150 ° C. A semiconductor wafer with an adhesive layer or a semiconductor element with an adhesive layer. 2. The semiconductor wafer with an adhesive layer or the semiconductor element with an adhesive layer according to claim 1, wherein both of the compounds (B1) and (B2) are compounds having two or more phenolic hydroxyl groups in one molecule. A semiconductor element with an adhesive layer obtained by cutting the semiconductor wafer with an adhesive layer according to claim 1 or 2 by dicing and separating the semiconductor wafer with an adhesive layer. Wherein a said adhesive layer-attached semiconductor element as set forth in any one of claims 1 to 3 mounted on the circuit board was produced. A liquid resin composition comprising an epoxy resin component (A) and a curing agent component (B), wherein the epoxy resin component (A) is liquid at room temperature, and the curing agent component (B) has a phenolic hydroxyl group. A combination of the compound (B1) having a softening point or a melting point of 200 ° C. or less and the compound (B2) having a phenolic hydroxyl group and a melting point exceeding 200 ° C. In the following dissolution test, the compound In (B1), 90 g of the epoxy resin component (A) and 10 g of the compound (B1) are placed in a 300 cc separable flask so that the internal temperature becomes 145 to 155 ° C. using an oil bath while stirring with a stirrer. The compound which becomes transparent when it is visually observed after standing at 25 ° C. for 72 hours after stirring for 30 minutes from the time when the internal temperature reaches 145 ° C. The compound (B2) has an internal temperature of 145 to 155 using an oil bath while stirring with a stirrer in 90 g of the epoxy resin component (A) and 10 g of the compound (B2) in a 300 cc separable flask. When the internal temperature reached 145 ° C., the mixture was stirred for 30 minutes, cooled to room temperature, and then allowed to stand at 25 ° C. for 72 hours. The liquid resin composition which is a compound which must not be applied is applied to one surface of a semiconductor wafer to obtain a semiconductor wafer coated with the liquid resin composition, and the semiconductor wafer coated with the liquid resin composition is 60 to 150 An adhesive layer forming step of forming an adhesive layer by heating at a heating temperature of ° C., an attaching step of attaching the semiconductor wafer with the adhesive layer to a dicing sheet, and the adhesive layer by dicing Production method of the adhesive layer-attached semiconductor element and having a singulation step cutting the can semiconductor wafer, singulated semiconductor element with the adhesive layer. A method for manufacturing a semiconductor device, comprising: a step of mounting a semiconductor element with an adhesive layer produced by the method for manufacturing a semiconductor element with an adhesive layer according to claim 5 on a circuit board by thermocompression bonding.