JP2009200429A - Manufacturing method of semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a highly reliable semiconductor device at low manufacture cost by eliminating waste of a die attaching film. <P>SOLUTION: The method for manufacturing the semiconductor device formed of a chip 106 and a wiring board 110 includes a process [A] for dicing a wafer and obtaining the chips, a process [B] for fixing only the chip selected by inspection before or after dicing among chips diced in the previous process onto an adhesive layer of the die attaching film formed of a base and the adhesive layer and a process [F] for applying static pressure larger than ordinary pressure by 0.05 MPa to the adhesive layer 108b to which the chip is fixed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a semiconductor device. More specifically, the present invention relates to a method for manufacturing a semiconductor device including a chip and a wiring board.

In one of the manufacturing processes of a semiconductor device, a wafer 104 on which a circuit having a predetermined performance is formed is attached to a die attach film 108 provided with a thermosetting adhesive layer 108b on a base material 108a. There is a dicing process in which 104 is cut and separated into a plurality of chips 106 together with the adhesive layer 108b (FIG. 3-1 of this application, Patent Document 1). Subsequently, the chip 106 having the adhesive layer 108b on the back surface is picked up, a die bonding step (FIG. 3-2) for die-bonding the chip 106 and the wiring substrate 110, and a heat curing step (FIG. 3) for curing the adhesive layer 108b. 3-3) A semiconductor device is manufactured through a wire bonding process, a molding process, and the like.
International Publication No. 2005/004216 Pamphlet

  By the way, a defective circuit may be formed on the wafer, and depending on the type of wafer, a defective circuit having a predetermined performance of about ¼ may be formed. In the dicing process, a chip obtained by dicing the defective circuit portion becomes a defective product. Therefore, there is a problem that the portion of the expensive die attach film attached to the back surface of such a defective chip is wasted.

  Accordingly, an object of the present invention is to provide a method of manufacturing a semiconductor device at a low manufacturing cost by eliminating waste of a die attach film.

As a result of intensive studies, the present inventors have found that the above problem can be solved by performing a process of selecting a specific chip.
That is, the method for manufacturing a semiconductor device according to the present invention is a method for manufacturing a semiconductor device composed of a chip and a wiring board, in which a process of obtaining a chip by dividing a wafer into pieces [A] and the above process [A] A step of fixing only a chip selected by inspection before or after singulation on the adhesive layer of the die attach film composed of the base material and the adhesive layer among the chips separated by And [B], and a step [F] of applying a static pressure larger than the normal pressure by 0.05 MPa or more to the adhesive layer to which the chip is fixed.

  The method for manufacturing a semiconductor device according to the present invention is a method for manufacturing a semiconductor device comprising a chip and a wiring board, wherein the step [a1] for obtaining a chip by dividing a wafer into pieces and the above step [a1] Only chips selected by inspection before or after singulation are separated on the adhesive layer of the die attach film consisting of the base material and the uncured adhesive layer. The step [b1] of arranging and fixing, the step [c1] of cutting the uncured adhesive layer exposed between the chips and picking up the chip having the uncured adhesive layer on the back surface, and the step [c1] The step [d1] of die-bonding the chip picked up to the wiring substrate through the uncured adhesive layer and the wiring substrate obtained in the above step [d1] are heated to cure the uncured adhesive layer. Step [e1] and the curing is completed. Before, the wiring substrate on which the chip is die-bonded, and a step [f1] for applying a high static pressure above 0.05MPa than atmospheric pressure.

Moreover, it is preferable to perform the said process [e1] after the said process [f1], or it is preferable to perform the said process [e1] and the said process [f1] simultaneously.
The method for manufacturing a semiconductor device according to the present invention is a method for manufacturing a semiconductor device comprising a chip and a wiring board, wherein the step [a2] for obtaining a chip by dividing a wafer into pieces and the above step [a2] On the adhesive layer of the die attach film consisting of the base material and the adhesive layer that does not require heat-curing, only the chips selected by inspection before or after the individualization are separated. Step [b2] arranged side by side and fixed, Step [c2] for picking up a chip having an adhesive layer on the back surface by cutting an adhesive layer that does not require heating and curing that is exposed between the chips, and step [c2] The step [d2] of die-bonding the chip picked up in step (d2) to the wiring substrate through an adhesive layer that does not require heat curing, and applying a static pressure of 0.05 MPa or more to the wiring substrate to which the chip is die-bonded. Craft [F2] and preferably contains.

  ADVANTAGE OF THE INVENTION According to this invention, the waste of a die attach film can be eliminated and a semiconductor device can be efficiently manufactured at low manufacturing cost.

Hereinafter, the present invention will be specifically described.
As described above, in the semiconductor device manufacturing process, a defective circuit may be formed on the wafer. A chip obtained by dividing the defective circuit portion into pieces is a defective product. Therefore, there is a problem that the portion of the expensive die attach film attached to the back surface of such a defective chip is wasted.

  For this reason, in the present invention, the step [A] for obtaining chips by dividing the wafer into individual pieces and the chips obtained by the individualization in the above step [A] are selected by inspection before or after the individualization. The above-mentioned problem is solved by performing a step [B] of fixing only the obtained chip on the adhesive layer of the die attach film composed of the base material and the adhesive layer.

  However, in the step [B], if the chip is only fixed on the adhesive layer of the die attach film, air may enter between the chip and the adhesive layer, resulting in a void. By the way, in the conventional manufacturing method, when attaching a wafer to a die attach film, a device with a roller is used, so there is a void between the die attach film adhesive layer and the wafer (chip after cutting and separation). Is relatively difficult to occur. On the other hand, in the step [B] of the present invention, since a plurality of chips, not a wafer, are fixed to the adhesive layer of the die attach film, a roller cannot be used in many cases. That is, since the chip is brought into contact with and pressed against the die attach film vertically from above, voids are likely to occur as compared with the conventional manufacturing method. In any case, there is a problem that the void remains in the semiconductor device after the molding process and becomes a starting point of a package crack.

  Therefore, in the present invention, the step [F] of applying a static pressure larger than the normal pressure by 0.05 MPa or more to the adhesive layer to which the chip is fixed is performed. By this step, the void can be eliminated.

  As described above, according to the present invention, the waste of the die attach film can be eliminated, and the production cost can be suppressed as the whole manufacturing of the semiconductor device. Furthermore, a semiconductor device free from voids that can cause package cracks can be manufactured.

Hereinafter, more specific embodiments will be described.
[Embodiment 1]
A semiconductor device manufacturing method (Embodiment 1) according to the present invention is a method for manufacturing a semiconductor device including a chip and a wiring board, and includes steps [a1] to [f1]. In the first embodiment, step [e1] is performed after step [f1].

<Process [a1]>
In step [a1], the wafer is singulated to obtain chips. Specifically, first, the wafer 104 is stuck on the adhesive layer 102b of the dicing sheet 102 (FIG. 1-1).

  As the dicing sheet 102, a known dicing sheet for dicing is used. Usually, the pressure-sensitive adhesive layer 102b is formed on the substrate 102a such as polyolefin so as not to be peeled off. In order to form the pressure-sensitive adhesive layer 102b, a low pressure-sensitive adhesive, an energy ray-curable pressure-sensitive adhesive, or the like is used.

  The dicing sheet 102 is usually fixed on the dicing apparatus by a ring frame. Next, the wafer 104 is placed on the pressure-sensitive adhesive layer 102b of the dicing sheet 102, and the wafer 104 is adhered by pressing with a roller, for example.

  In step [a1], the wafer 104 is then diced to obtain only the chips 106. Specifically, the wafer 104 is separated into pieces by a cutting means such as a dicing saw, and the cutting depth at this time takes into account the wear of the dicing saw in addition to the thickness of the wafer 104 and the thickness of the adhesive layer 102b. The depth at which the wafer is separated into individual pieces (FIG. 1-1). As described above, since the pressure-sensitive adhesive layer 102b does not peel from the base material 102a, only the chip 106 is obtained.

<Step [b1]>
In the step [b1], only the chips obtained in the step [a1] are arranged and fixed on the adhesive layer 108b of the die attach film 108 composed of the base material 108a and the uncured adhesive layer 108b (FIG. 1-2). ). Specifically, only the chip 106 selected by inspection, that is, only the non-defective chip 106 on which a circuit having a predetermined performance is formed, is arranged and fixed on the adhesive layer 108b of the die attach film 108. In the above inspection, it is determined whether the chip is a non-defective chip in which a circuit having a predetermined performance is formed using a prober or the like, or a defective chip in which a circuit having a predetermined performance is not formed. Sort the chips. The inspection may be performed either before or after the wafer is singulated. When inspection is performed before wafer separation, a plurality of circuits formed on the wafer are inspected, non-defective circuits or defective circuits are marked, and chips selected after separation (non-defective chips) Only fix them side by side on the adhesive layer of the die attach film. When the inspection is performed after the wafer is singulated, chips separated by dicing are selected by inspection. Also in this case, only the selected chip (non-defective chip) is fixed on the adhesive layer of the die attach film. In this way, in the step [b1] of the first embodiment, only the selected good chips are fixed to the expensive die attach film, so that it is possible to eliminate the waste of the die attach film, and to manufacture the entire semiconductor device. As a result, production costs can be reduced. In this step [b1], when the chip 106 is fixed, a void A may be formed at the interface between the adhesive layer 108b and the chip 106. The void A disappears in the process [f1] described later.

In the die attach film 108, an uncured adhesive layer 108b is usually detachably laminated on a base material 108a such as polyolefin.
The adhesive constituting the adhesive layer 108b exhibits adhesiveness when heated at a normal temperature or at a relatively low temperature (for example, 50 ° C.), and is cured by a trigger such as heating (for example, 120 ° C.) to exhibit strong adhesiveness. It consists of a thermosetting resin, a binder resin, a curing agent, and a curing accelerator added as necessary. Examples of the thermosetting resin include resins such as epoxy, phenoxy, phenol, resorcinol, urea, melamine, furan, unsaturated polyester, and silicone, and examples of the binder resin include acrylic, polyester, polyvinyl ether, urethane, and polyamide. And other resins. In order to cure by heating and exhibit sufficiently strong adhesiveness, it is preferable that the content ratio of the thermosetting resin is larger than that of the binder resin.

  The adhesive constituting the adhesive layer 108b may further include an energy ray curable resin such as a urethane acrylate oligomer. In this case, the adhesive layer 108b is easily peeled off from the base material 108a by irradiation with energy rays such as ultraviolet rays. Therefore, when an energy ray is irradiated at an appropriate stage, it is easy to pick up a chip having an uncured adhesive layer on the back surface. become.

The die attach film 108 may be laminated with a doughnut-shaped ring frame fixing adhesive sheet on the outer periphery.
When fixing a plurality of non-defective chips 106, the distance between the chips is about the same as the width of the cutting means such as a dicing blade in consideration of cutting the uncured adhesive layer 108b in the step [c1]. It is preferable to do. Usually 10 to 100 μm.

<Process [c1]>
In step [c1], first, the uncured adhesive layer 108b exposed between the chips is cut (FIGS. 1-3). Specifically, the uncured adhesive layer 108b is cut by a cutting means such as a dicing saw, and the cutting depth at this time is a depth obtained by adding the wear of the dicing saw to the thickness of the adhesive layer 108b. (FIGS. 1-3). In this way, the chip 106 having the uncured adhesive layer 108b on the back surface is obtained.

  Further, a laser or the like may be used as the cutting means. When a laser is used, the interval between chips can be reduced because the cutting width is narrow. Alternatively, the unattached adhesive layer may be physically cleaved by expanding the die attach film.

  In the step [c1], next, a chip 106 that is peeled off at the interface between the base material 108a and the uncured adhesive layer 108b and has the uncured adhesive layer 108b on the back surface is picked up (FIG. 1-3). Here, the void A generated in the step [b1] remains.

  In addition, when the energy ray-curable resin is contained in the adhesive constituting the adhesive layer 108b, the back surface is uncured by irradiating energy rays before or after cutting the uncured adhesive layer. The pickup property of the chip 106 having the adhesive layer 108b can be improved.

<Process [d1]>
In the step [d1], the chip 106 picked up in the step [c1] is die-bonded to the wiring substrate 110 through the uncured adhesive layer 108b (FIGS. 1-4). In this step [d1], when the chip 106 is die-bonded, a void B may be formed at the interface between the adhesive layer 108b and the wiring substrate 110. The void B disappears in the process [f1] described later.

  Examples of the wiring substrate 110 include a lead frame made of metal, a substrate made of an organic material or an inorganic material, and a laminated substrate made of a metal and an organic material or an inorganic material.

  The die bonding is usually performed at a pressure of 0.01 to 10 MPa, a temperature of 100 to 150 ° C., and a time of 0.1 to 3 seconds. As a result, the wiring substrate 110 to which the chip 106 is die-bonded is obtained.

<Step [f1]>
In step [f1], it is obtained in step [d1] before the curing of the uncured adhesive layer 108b is completed (in Embodiment 1, before the uncured adhesive layer 108b is heated and cured). A static pressure larger than the normal pressure by 0.05 MPa or more, preferably a static pressure greater by 0.1 to 1.0 MPa is applied to the wiring substrate 110 to which the obtained chip 106 is die-bonded (FIG. 1-5).

  Thereby, since the void A generated in the step [b1] can be eliminated, according to the first embodiment, it is possible not only to prevent the die attach film from being wasted, but also to manufacture a highly reliable semiconductor device having no void.

  Furthermore, since the void B generated in the step [d1] can be eliminated, according to the first embodiment, a more reliable semiconductor device without voids can be manufactured. Here, a general semiconductor device manufacturing method and the first embodiment will be compared in more detail.

  In a general semiconductor device manufacturing method, void B is likely to occur at the interface between the uncured adhesive layer 108b and the wiring substrate 110 in the die bonding step (FIG. 3-2). The void B exists without disappearing after the heat curing step (FIG. 3-3) for curing the adhesive layer 108b, the wire bonding step, and the molding step, and causes a decrease in reliability in the manufactured semiconductor device. . Thus, the general method for manufacturing a semiconductor device has problems other than the waste of the die attach film.

  On the other hand, an attempt is made to suppress the formation of void B in the die bonding process by using a die attach film having an adhesive layer made of an adhesive having a low elastic modulus (Patent Document 1). However, the production of the die attach film is more costly and the manufacturing cost of the semiconductor device is also increased. Therefore, it is required to manufacture a highly reliable semiconductor device free from voids at low cost.

  On the other hand, in the first embodiment, not only the void A generated in the step [b1] but also the void B generated in the step [d1] can be eliminated by the step [f1]. That is, according to the first embodiment, a highly reliable semiconductor device without voids can be easily manufactured at low cost.

The time for applying the pressure is preferably 1 to 120 minutes, more preferably 5 to 90 minutes.
The pressurizing device for applying the static pressure is not particularly limited as long as the static pressure can be applied to the wiring substrate 110 to which the chip 106 is die-bonded. Preferably, an autoclave (pressure vessel with a compressor) or the like can be used.

  In addition, when pressure is applied within a certain volume, such as an autoclave, the ambient temperature rises. Since it is preferable to keep the temperature constant in order to stably produce the semiconductor device, the atmospheric temperature may be controlled to a temperature at which the uncured adhesive layer 108b is not cured. Further, when the temperature is raised, it can be expected that voids generated by the fluidization of the adhesive layer easily move and disappear easily. Such temperature is appropriately set depending on the composition of the adhesive constituting the adhesive layer 108b, but is usually about 30 to 120 ° C.

<Process [e1]>
In the step [e1], the wiring board 110 that has undergone the step [f1] is heated to cure the uncured adhesive layer 108b (FIG. 1-6).

Here, the adhesive layer 108b of the wiring substrate 110 to which the chip 106 is die-bonded is heated to change from an uncured state to a sufficiently cured state. In the present specification, the uncured state means that the curing reaction of the adhesive is not progressing. A sufficiently cured state, that is, a state where curing is completed means that the reaction proceeds and the adhesive cannot be deformed. As a result, the adhesion performance required as an adhesive for die bonding of a semiconductor device is given. In other words, in the wiring board 110 that has undergone the process [e1], no voids are observed at the interface between the adhesive layer 108b and the chip 106 and the interface between the adhesive layer 108b and the wiring board 110, and the state after the process [f1]. The chip 106 and the wiring substrate 110 are firmly bonded.

Specifically, the wiring board 110 in which the void has disappeared in the step [f1] is released from the pressurizing apparatus and is put into the heating apparatus under atmospheric pressure.
The heating temperature and the heating time are not particularly limited as long as the adhesive layer can be sufficiently cured, and depend on the adhesive composition. The heating temperature is preferably 100 to 200 ° C, more preferably 120 to 160 ° C, and the heating time is preferably 15 to 300 minutes, more preferably 30 to 180 minutes.

A known thermosetting device (oven) can be used as the heating device.
Note that the wiring substrate 110 obtained in the step [e1] becomes a final semiconductor device through a wire bonding step, a molding step, and the like. In the semiconductor device obtained according to the first embodiment, there is no void at the interface between the adhesive layer 108b and the chip 106, and the interface between the adhesive layer 108b and the wiring substrate 110. High reliability.

  Further, as described above, in the step [e1], it has been described that the wiring substrate 110 that has undergone the step [f1] is heated to cure the uncured adhesive layer 108b, but the ambient temperature is increased in the step [f1]. By doing so, the adhesive layer 108b may be cured partway.

  In step [a1], as described above, a wafer may be stuck on the adhesive layer of the dicing sheet, and the wafer may be diced to obtain a chip. After forming a groove smaller than the thickness, a protective tape may be applied to the front surface of the wafer, and a predetermined amount may be ground on the back surface of the wafer to obtain a chip. That is, you may obtain a chip | tip by the tip dicing method.

[Embodiment 2]
A method for manufacturing a semiconductor device according to the present invention (Embodiment 2) is a method for manufacturing a semiconductor device including a chip and a wiring board, and includes steps [a1] to [f1]. In the second embodiment, step [e1] and step [f1] are performed simultaneously. In other words, the application of the static pressure in the step [f1] and the heat curing of the uncured adhesive layer 108b in the step [e1] are performed simultaneously.

  In this second embodiment, it is considered that there is an advantage that voids in the adhesive layer that can be generated at a high temperature where thermosetting is performed can be eliminated at the same time as static pressure is applied. In the wiring board that has undergone the steps [e1] and [f1], voids generated at the interface between the adhesive layer and the chip (voids generated in the step [b1]), and generated at the interface between the adhesive layer and the wiring substrate. Voids (voids generated in step [d1]) have disappeared. Further, the adhesive layer is in a sufficiently cured state, and the chip and the wiring board are firmly bonded.

  In step [e1] and step [f1] in the second embodiment, a static pressure of 0.05 MPa or more, preferably 0.1 to 1.0 MPa larger than normal pressure is applied, and the adhesive layer is sufficiently It is heated to a temperature at which it can be cured, preferably 100-200 ° C, more preferably 120-160 ° C.

The pressurization and heating time are not particularly limited as long as voids can be eliminated and the adhesive layer can be sufficiently cured, but it is preferably 15 to 300 minutes, more preferably 30 to 180 minutes.
Note that the step [e1] and the step [f1] are preferably started at the same time and finished at the same time. In addition, the start and end of the step [e1] and the step [f1] do not have to be performed at the same time, as long as the other step is started before the end of one step.

[Embodiment 3]
A semiconductor device manufacturing method (Embodiment 3) according to the present invention is a method for manufacturing a semiconductor device including a chip and a wiring board, and includes steps [a2] to [f2].

In step [a2], the wafer is singulated to obtain chips in the same manner as in step [a1].
In the step [b2], first, in the same manner as the above step [b1], only the chip obtained in the step [a2], specifically, a non-defective product in which a circuit having a predetermined performance selected by inspection is formed. Only the chip is arranged and fixed on the adhesive layer of the die attach film composed of the base material and the adhesive layer that does not require heat curing. As described above, in the step [b2] of the third embodiment, since only the selected non-defective chips are fixed to the expensive die attach film, the waste of the die attach film can be eliminated, and the entire manufacturing of the semiconductor device is performed. As a result, production costs can be reduced. In this step [b2], when the chip is fixed, a void may be formed at the interface between the adhesive layer and the chip. The void disappears in the process [f2] described later.

  In the die attach film used in Embodiment 3, an adhesive layer that does not require heat curing is usually laminated on a base material such as polyolefin so as to be peelable. In the present specification, the phrase “no need for heat curing” means that it has a hardness that allows wire bonding as it is. That is, it means that it is not necessary to heat and cure the adhesive layer before wire bonding.

  As the adhesive constituting the adhesive layer that does not require heat curing, the same adhesive as that described in the first embodiment is used. In the second embodiment, it is preferable that the content ratio of the binder resin is larger than the thermosetting resin in order to eliminate the need for heat curing of the adhesive layer and to give the adhesive layer a certain degree of hardness. .

The die attach film may have a donut-shaped ring frame fixing adhesive sheet laminated on the outer periphery.
When fixing a plurality of non-defective chips, the interval between the chips is the same as in the above step [b1].

  In step [c2], as in the above step [c1], the adhesive layer that does not require heat curing exposed between the chips is diced, and a chip having an adhesive layer that does not require heat curing on the back surface is picked up.

  In the step [d2], the chip picked up in the step [c2] is die-bonded to the wiring board through the adhesive layer in the same manner as the above step [d1]. In this step [d2], voids may be formed at the interface between the adhesive layer and the wiring board when the chip is die-bonded.

  In step [f2], a static pressure greater than or equal to 0.05 MPa is applied to the wiring substrate on which the chip is die-bonded. According to the step [f2], the void generated in the step [b2] and the void generated in the step [d2] can be eliminated. Therefore, waste of the die attach film can be prevented, and a highly reliable semiconductor device free from voids can be easily manufactured at low cost.

The pressurizing condition in the step [f2] is the same as that in the step [f1].
In Embodiment 3, since a die attach film comprising a base material and an adhesive layer that does not require heat curing is used in Step [b2], it is necessary to perform Step [e1] as in Embodiment 1. Absent. Therefore, the wiring substrate 110 that has undergone the process [f2] becomes a final semiconductor device through a wire bonding process, a molding process, and the like. By heating in the molding process, the adhesive layer of the die attach film is completely cured, and the chip and the wiring board are firmly bonded.

In the third embodiment, step [f2] may be performed after the wire bonding step and before the molding step.
[Embodiment 4]
A method for manufacturing a semiconductor device according to the present invention (Embodiment 4) is a method for manufacturing a semiconductor device including a chip and a wiring board, and includes the following steps [a3] to [e3] and step [f3]. .

  In step [a3] and step [b3], the wafer is singulated to obtain chips in the same manner as in step [a1] and step [b1]. Then, only the chip obtained in the step [a3], specifically, only a good chip on which a circuit having a predetermined performance selected by inspection is formed, is a die attach film comprising a base material and an adhesive layer. Fix on the adhesive layer. In this step [b3], when the chip is fixed, a void may be formed at the interface between the adhesive layer and the chip.

  In step [f3], a static pressure larger than the normal pressure by 0.05 MPa or more is applied to the die attach film on which the chip is fixed in step [b3]. The void at the interface between the adhesive layer and the chip generated in the step [b3] can also be eliminated by applying pressure in a state where non-defective chips are arranged and fixed on the die attach film as in the step [f3].

The pressurizing condition in the step [f3] is the same as that in the step [f1].
In step [c3], after step [f3], as in step [c1], the uncured adhesive layer exposed between the chips is diced, and a chip having an uncured adhesive layer on the back surface is obtained. Pick up.

  In the step [d3] and the step [e3], the chip picked up in the step [c3] is die-bonded to the wiring board through the uncured adhesive layer in the same manner as in the above step [d1] and the step [e1]. . Next, the wiring board obtained in the step [d3] is heated to cure the uncured adhesive layer. In particular, the fourth embodiment is preferable when the occurrence of voids at the interface between the adhesive layer and the wiring board does not become a problem by controlling the die bonding conditions in the step [d3]. According to the fourth embodiment, not only can the die attach film be prevented from being wasted, but also a highly reliable semiconductor device free from voids can be manufactured.

Note that also in the fourth embodiment, the step [f1] in the first and second embodiments may be performed.
[Embodiment 5]
The structure of the semiconductor device obtained by the present invention is not limited to the structure described in Embodiment Mode 1 or the like. For example, the present invention may be applied to the manufacture of multi-stack type or same-size stack type semiconductor devices. In these cases, for example, instead of the wiring substrate 110, a wiring substrate 202a on which chips are already stacked is used (FIGS. 2-1 and 2-2). In other words, since the second-stage chip 106 is stacked via the adhesive layer 108b, the wiring board 202a in which the first-stage chip 202c is stacked via the adhesive layer 202b is used. Of course, when stacking the third and higher-level chips, instead of the wiring board 110, a wiring board on which a plurality of chips are already stacked may be used.

  In the case of the same size stack type, the wire 204 is connected to the chip 202c before the chip 106 is die-bonded to the chip 202c via the adhesive layer 108b (FIG. 2-2). In this embodiment, there is an advantage that voids existing around the wire can be eliminated by applying static pressure.

EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.
[Example]
<Evaluation method>
Test 1: Presence / absence of voids Examples and comparative examples using glass wafers were evaluated by observing the presence / absence of voids from the glass chip side with a digital microscope (magnification 20 times).

  In Example 1, after fixing the glass chip to the die attach film (step [b1]), after die bonding (step [d1]), after pressing (step [f1]), and heat-curing (step [e1]) Evaluation was made later, and in Examples 2 and 3, after fixing the glass chip to the die attach film (step [b1]), after die bonding (step [d1]), pressurization and heat curing (step [f1] and step [f] e1]) later evaluated. In Comparative Example 1, the evaluation was made after fixing the glass chip to the die attach film (step [b1]), after die bonding (step [d1]), and after heat curing (step [e1]).

  After step [b1], the presence or absence of voids at the interface between the adhesive layer and the chip can be evaluated. After step [d1], step [f1] and step [e1], the interface between the adhesive layer and the chip. The presence or absence of voids at the interface between the adhesive layer and the wiring board can be evaluated.

The results are shown in Table 2. In Table 2, Example 1 and Comparative Example 1 indicate the presence or absence of voids after pressurization and heat curing, and Examples 2 and 3 indicate the presence or absence of voids in pressurization and heat curing.
Test 2: Reliability of semiconductor package An example using a silicon wafer and a comparative example were evaluated.

The obtained semiconductor package was left to stand for 168 hours at 85 ° C. and 60% RH for moisture absorption, and then IR reflow (reflow furnace: manufactured by Sagami Riko, WL-
15-20DNX type) was performed three times. At this time, the presence / absence of floating / peeling of the joint between the chip and the wiring substrate was evaluated by a scanning ultrasonic flaw detector (Hy-Focus, manufactured by Hitachi Construction Machinery Finetech Co., Ltd.) and cross-sectional observation. The case where floating / peeling of 0.25 mm ² or more was observed at the joint was judged as “peeled”. The above test was performed on 25 semiconductor packages, and the number of “not peeled” was counted.

The results are shown in Table 3.
<Adhesive>
The adhesives (Coating Liquid 1 and Coating Liquid 2) used in the Examples and Comparative Examples were adjusted to 50 mass% by adding the organic solvent (methyl ethyl ketone) after blending the following components in the proportions shown in Table 1. I got it. In addition, all the compounding parts of Table 1 show solid content (mass part).

A) Acrylic copolymer Coponil N-2359-6 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
B) Epoxy resin component (B1) Flexible liquid epoxy resin with bisphenol A skeleton (Dainippon Ink & Chemicals, EXA-4850-150)
(B2) Solid bisphenol A epoxy resin (Japan Epoxy Resin Co., Ltd., Epicoat 1055)
(B3) Bisphenol A liquid epoxy resin (BPA328 made by Nippon Shokubai)
(B4) Dicyclopentadiene skeleton-containing solid epoxy resin (Dainippon Ink and Chemicals, EXA7200HH)
(B5) Dicyclopentadiene skeleton-containing solid epoxy resin (Nippon Kayaku 1000-L)
C) Thermally active latent curing agent
(C1) Curing agent (Asahi Denka, Adeka Hardener 3636AS)
(C2) Curing accelerator (manufactured by Shikoku Kasei Kogyo Co., Curesol 2PHZ)
D) Silane coupling agent MKC silicate MSEP2 manufactured by Mitsubishi Chemical
E) Cross-linking agent Aromatic polyisocyanate (Nippon Polyurethane Industry Co., Ltd., Coronate L)
F) Radiation (energy ray) curable resin Dicyclopentadiene skeleton-containing acrylate (manufactured by Nippon Kayaku Co., Ltd., R684)
G) Photoinitiator Irgacure 184 (Ciba Specialty Chemicals)
H) Thermoplastic resin Byron 220 (manufactured by Toyobo)

以下の実施例１、４は、上記実施の形態１に対応し、実施例２、３、５、６は、上記実施の形態２に対応する。

The following Examples 1 and 4 correspond to the first embodiment, and Examples 2, 3, 5, and 6 correspond to the second embodiment.

[Example 1]
[Manufacture of die attach film]
Using a roll knife coater, the coating solution 1 was applied to the release-treated surface of a release film (Lintec, thickness 38 μm, SP-PET3811) using a roll knife coater, and then 100 ° C. for 2 minutes. It dried on conditions and the adhesive bond layer which consists of the coating liquid 1 was obtained. Thereafter, an adhesive layer (adhesive layer) was laminated on a 100 μm thick base material (polyethylene film, surface tension 31 mN / m) to prepare a die attach film.

On the other hand, as an adhesive sheet for fixing the ring frame, an adhesive sheet (a shape with a circular shape with an inner diameter of 220 mm cut and removed) is formed by forming a re-peelable acrylic adhesive layer (thickness 10 μm) on a polyvinyl chloride film (thickness 80 μm). Prepared.

Subsequently, the release film of the die attach film was peeled off, and the polyvinyl chloride surface of the ring frame fixing pressure-sensitive adhesive sheet was laminated on the adhesive surface. Subsequently, the die attach film on which the ring frame fixing adhesive sheet was laminated was cut into a circle with an outer diameter of 270 mm so as to be concentric with the circle from which the ring frame fixing adhesive sheet was cut and removed. In this manner, a die attach film having a donut-shaped ring frame fixing adhesive sheet on the outer peripheral portion was obtained.

[Production of Glass Chip (Step [a1])]
Transparent disk glass (NSG Precision, diameter 200mm, thickness 100μm), UV curable dicing tape (Lintech, D-628) and tape mounter (Lintech, Adwill RAD2500m / 8) And attached to the ring frame at the same time. Next, dicing was performed to a size of 8 mm × 8 mm using a dicing apparatus (manufactured by DISCO Corporation, DFD651). Then, ultraviolet rays were irradiated from the base material surface of the dicing sheet using a UV irradiation apparatus (Adwill RAD2000m / 8, manufactured by Lintec Corporation). Thus, the glass wafer (glass chip) separated into pieces was obtained (FIG. 1-1). The amount of cut at the time of dicing was set to cut by 15 μm with respect to the base material of the dicing sheet.

[Fixing of glass chip to die attach film, dicing of adhesive layer and pickup of chip having adhesive layer on back side (step [b1] and step [c1])]
The die attach film was fixed to the ring frame using a tape mounter (Adwill RAD2500m / 8, manufactured by Lintec Corporation). Next, the glass chip was fixed to the die attach film fixed to the ring frame using a die sorter. At this time, the distance between the chips was set to 60 μm, and the glass chips were arranged and fixed in a lattice shape (FIG. 1-2).

  Then, ultraviolet rays were irradiated from the substrate surface of the die attach film using a UV irradiation apparatus (Adwill RAD2000m / 8, manufactured by Lintec Corporation). Next, the adhesive layer exposed between the glass chips was diced using a dicing apparatus (DFD651, manufactured by DISCO Corporation). The amount of cut at the time of dicing was set to cut 20 μm with respect to the base material of the die attach film.

Next, a chip having an adhesive layer on the back surface was picked up (FIGS. 1-3).
[Die bond (process [d1])]
A circuit pattern is formed on the copper foil of a copper foil-clad laminate (Mitsubishi Gas Chemical Co., Ltd., CCL-HL830) as a wiring board, and a solder resist (Taiyo Ink, PSR-4000 AUS303 is formed on the pattern.
) Was used (manufactured by Chino Giken Co., Ltd.). The substrate was baked at 120 ° C. for 5 hours. The picked-up chip is placed on this substrate at 100 ° C via an adhesive layer.
And pressure bonding (die bonding) under the condition of 0.04 MPa for 1 second (FIGS. 1-4).

[Pressure and heat curing (step [f1] and step [e1])]
Using a heating / pressurizing device (RAD9100, RAD9100), the wiring board on which the glass chip is die-bonded, at a gauge thickness of 0.5 MPa (under a static pressure 0.5 MPa larger than normal pressure) at 100 ° C Heated for 30 minutes (FIGS. 1-5).

After removing the wiring board from the heating and pressing apparatus, the adhesive layer was cured by heating in an oven at 120 ° C. for 1 hour and then at 140 ° C. for 1 hour under normal pressure (FIG. 1-6).
[Example 2]
Example 1 was performed in the same manner as Example 1 except that [Pressurization / Heat curing (Step [f1] and Step [e1])] was performed under the following conditions.

[Pressure and heat curing (step [f1] and step [e1])]
Using a heating and pressurizing device (RAD9100, RAD9100), the wiring substrate on which the glass chip is die-bonded, under a gauge thickness of 0.5 MPa (under a static pressure 0.5 MPa larger than normal pressure), 120 ° C., The adhesive layer was cured by heating for 1 hour followed by 140 ° C. for 1 hour.

[Example 3]
The same operation as in Example 2 was performed except that the coating liquid 2 was used instead of the coating liquid 1 in Example 2.
[Example 4]
Except for using a silicon wafer (diameter: 200 mm, thickness: 150 μm) instead of the disk glass, the production of the die attach film in Example 1 to the pressurization and heat curing (step [f1] and step [e1]) The same procedure as in Example 1 was performed.

[Manufacture of semiconductor packages]
The wiring substrate (the substrate after the step [f1] and the step [e1]) after the silicon chip is die-bonded and cured is sealed with a mold resin (KE-1100AS3, manufactured by Kyocera Chemical Co., Ltd.) so that the sealing thickness is 400 μm. Sealing was performed using a sealing device (MPC-06M Trial Press, manufactured by Apic Yamada Co., Ltd.). Next, the sealing resin was cured at 175 ° C. for 5 hours. Next, the sealed wiring board is affixed to a dicing tape (manufactured by Lintec Corporation, Adwill D-510T), and using a dicing device (manufactured by DISCO Corporation, DFD651), it is diced to 12 mm x 12 mm size, A semiconductor package for reliability evaluation was obtained.

[Example 5]
Example 4 [Pressure and heat curing (step [f1] and step [e1])] was carried out in the same manner as in Example 4 except that it was carried out under the following conditions.

[Pressure and heat curing (step [f1] and step [e1])]
Using a heating and pressurizing device (RAD9100, RAD9100), the wiring substrate on which the glass chip is die-bonded, under a gauge thickness of 0.5 MPa (under a static pressure 0.5 MPa larger than normal pressure), 120 ° C., The adhesive layer was cured by heating for 1 hour followed by 140 ° C. for 1 hour.

[Example 6]
It carried out similarly to Example 5 except having used the coating liquid 2 instead of the coating liquid 1 of Example 5. FIG.
[Comparative Example 1]
The same operation as in Example 1 was performed except that [Pressurization (Step [f1])] in Example 1 was not performed.

[Comparative Example 2]
The same operation as in Example 4 was performed except that [Pressurization (Step [f1])] in Example 4 was not performed.

なお、上記実施例では、回路の検査工程を記載しなかったが、ダイアタッチフィルムの固定の際に、本明細書で説明したような検査により選ばれた良品のチップのみを固定することにより、ダイアタッチフィルムの無駄を防止できる。

In the above embodiment, the circuit inspection process was not described, but when fixing the die attach film, by fixing only non-defective chips selected by the inspection as described in this specification, The waste of the die attach film can be prevented.

FIG. 1-1 is a view for explaining the method for manufacturing a semiconductor device of the present invention. FIG. 1-2 is a drawing for explaining the method for manufacturing a semiconductor device of the present invention. FIG. 1-3 is a diagram for explaining the method for manufacturing a semiconductor device of the present invention. 1-4 are diagrams for explaining a method of manufacturing a semiconductor device according to the present invention. FIGS. 1-5 is a figure for demonstrating the manufacturing method of the semiconductor device of this invention. FIGS. 1-6 is a figure for demonstrating the manufacturing method of the semiconductor device of this invention. FIGS. 2-1 is a figure for demonstrating the manufacturing method of the semiconductor device of this invention. FIGS. FIGS. 2-2 is a figure for demonstrating the manufacturing method of the semiconductor device of this invention. FIGS. FIG. 3A is a diagram for explaining a conventional method of manufacturing a semiconductor device. FIG. 3-2 is a diagram for explaining a conventional method of manufacturing a semiconductor device. FIG. 3-3 is a diagram for explaining a conventional method of manufacturing a semiconductor device.

Explanation of symbols

102: Dicing sheet 102a: Base material 102b: Adhesive layer 104: Wafer 106: Chip 108: Die attach film 108a: Base material 108b: Adhesive layer 110: Wiring board 202a: Wiring board 202b: Adhesive layer 202c: Chip 204 : wire

Claims (5)

A method of manufacturing a semiconductor device comprising a chip and a wiring board,
A process [A] for obtaining chips by dividing the wafer into pieces;
Of the chips singulated in the step [A], only the chip selected by inspection before or after singulation is used as an adhesive layer of a die attach film comprising a base material and an adhesive layer. Fixing on top [B],
And a step [F] of applying a static pressure larger than the normal pressure by 0.05 MPa or more to the adhesive layer to which the chip is fixed. A method of manufacturing a semiconductor device comprising a chip and a wiring board,
[A1] a step of obtaining chips by dividing the wafer into pieces,
Of the chips singulated in the step [a1], only the chips selected by inspection before or after singulation are selected from the die attach film comprising a base material and an uncured adhesive layer. A step [b1] of fixing on the adhesive layer side by side;
Cutting the uncured adhesive layer exposed between the chips and picking up a chip having an uncured adhesive layer on the back surface [c1];
A step [d1] of die-bonding the chip picked up in the step [c1] to a wiring board through an uncured adhesive layer;
A step [e1] of curing the uncured adhesive layer by heating the wiring board obtained in the step [d1];
And a step [f1] of applying a static pressure higher than the normal pressure by 0.05 MPa or more to the wiring board to which the chip is die-bonded before the curing is completed.   The method of manufacturing a semiconductor device according to claim 2, wherein the step [e1] is performed after the step [f1].   The method of manufacturing a semiconductor device according to claim 2, wherein the step [e1] and the step [f1] are performed simultaneously. A method of manufacturing a semiconductor device comprising a chip and a wiring board,
A step [a2] of obtaining a chip by dividing a wafer into pieces,
A die attach film consisting of a base material and an adhesive layer that does not require heat curing, only the chips selected by inspection before or after individualization in the individualized chips in the step [a2]. A step [b2] of arranging and fixing on the adhesive layer of
A step [c2] of cutting a heat-curing-free adhesive layer exposed between the chips and picking up a chip having an adhesive layer on the back surface;
A step [d2] of die-bonding the chip picked up in the step [c2] to a wiring board through an adhesive layer that does not require heat curing;
And a step [f2] of applying a static pressure larger than the normal pressure by 0.05 MPa or more to the wiring substrate on which the chip is die-bonded.

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