JP4579104B2 - Method for manufacturing resin-encapsulated device and apparatus for manufacturing the same - Google Patents

Description

  The present invention relates to a method for manufacturing a resin-encapsulated device in which a functional surface of a device chip is sealed in a hollow with a resin and an apparatus for manufacturing the resin-encapsulated device. Relates to the device.

  For example, in a SAW (Surface Acoustic Wave) chip or the like, a sealing structure is used to protect an element from the influence of the outside world as in a normal semiconductor device. However, since the SAW chip or the like must hold the functional surface of the element in a hollow state due to its characteristics, it is necessary to apply a sealing structure that can hold the hollow state. As such a sealing structure, a can-type package that has been conventionally used is known, but since it is unavoidable to increase the size of the package, it is difficult to meet the recent demand for downsizing. .

In contrast, for example, Patent Document 1 describes a structure in which the periphery of a device chip is hollow-sealed with a photosensitive resin so that a functional surface of the device chip is in a hollow state. Patent Document 2 describes a structure in which a functional surface is sealed with a high viscosity NCP (Non Conductive Polymer) resin or the like so that the functional surface is held in the hollow.
JP 2001-298102 A JP 2005-110017 A

  However, among the conventional sealing structures, in the structure in which the outer periphery of the device chip is hollow-sealed with a photosensitive resin, the photosensitive resin used has high fluidity, and the resin penetrates to the periphery of the functional surface of the semiconductor chip during application. It had the difficulty of making it easy to degrade element characteristics. On the other hand, in a structure using a high-viscosity NCP resin or the like, since the resin when applied on the device chip has a high viscosity of 100 to 200 Pa · s, it takes time to apply and tends to deteriorate workability. It was in.

  The present invention has been made in order to cope with such problems, and is capable of manufacturing a resin-encapsulated device that can be manufactured easily and with high yield while improving the sealing reliability. An object is to provide a method and an apparatus for manufacturing a resin-encapsulated device.

  The method for producing a resin-encapsulated device according to the present invention includes a step of placing a wiring board on which a functional surface side of a device chip is flip-chip connected so as to support the wiring board side on a stage controlled to a predetermined temperature. And applying a resin having a temperature higher than that of the stage in the vicinity of the end face of the device chip on the wiring board placed above, and sealing the functional surface of the device chip in a hollow, and the applied And a step of thermosetting the resin.

  In other words, this method for manufacturing a resin-encapsulated device is such that the temperature in the vicinity of the end face of a device chip to which the resin is applied is controlled to be lower than the temperature of the resin so that the functional surface is sealed in the hollow. The viscosity of the resin can be increased to make it difficult to fluidize, and the penetration of the resin around the functional surface can be suppressed. Therefore, it is possible to provide a resin sealing device with high sealing reliability. In addition, a resin-encapsulated device can be easily produced without reducing the manufacturing yield.

  In addition, the resin-encapsulated device manufacturing apparatus according to the present invention includes a wiring board holding portion that has a built-in cooling body and can hold a wiring board to which a device chip is flip-chip connected, and the held wiring board. And a resin application part that applies resin in the vicinity of the end face of the device chip.

  That is, the manufacturing apparatus of the resin-encapsulated device can cool the device chip on the held wiring board to have a high viscosity of the applied resin by using the wiring board holding part with a built-in cooling body. it can. Accordingly, it is possible to provide a highly reliable resin-encapsulated device with high yield by suppressing the inflow of the resin when the functional surface is hermetically sealed.

  ADVANTAGE OF THE INVENTION According to this invention, after improving sealing reliability, the manufacturing method of the resin sealing device and the manufacturing apparatus of the resin sealing device which enabled manufacture of the resin sealing device with sufficient yield easily are provided. be able to.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a process diagram schematically showing a method for manufacturing a resin-encapsulated device according to the first embodiment of the present invention in a cross section. FIG. 2 is a schematic plan view showing the state shown in FIG. Here, a SAW device will be described as an example of the resin-encapsulated device.

  First, as shown in FIGS. 1A and 2, a wiring board 1 in which the SAW chip 2 is flip-chip connected so as to face the comb-like electrode 6 (IDT) of the SAW chip 2, and the wiring board 1 side is a stage. 3 so as to touch 3. Here, the configuration on the wiring board 1 side prepared in advance will be described. An electrode pad 7 (eg, about 70 μm) is formed on the SAW chip 2 (eg, 0.1 mm square, thickness 3 mm) so as to surround the comb-like electrode 6. The distance is, for example, about 150 μm. A wiring pattern 9 is formed on a wiring board 1 (for example, a thickness of 0.5 to 1.0 mm) made of a ceramic substrate or the like, and a predetermined position of the wiring pattern 9 and an electrode pad 7 of the SAW chip 2 are Au. They are connected via bumps 8. A through-hole electrode 10 is formed below a predetermined position of the wiring pattern 9 and is connected to an external electrode 11 provided on the back surface of the wiring substrate 1. The stage 3 incorporates a cooling medium circulation line (cooling body) for circulating a cooling medium 5 such as water whose temperature is controlled at 0 to 10 ° C., and the placed wiring board 1 side is placed at 0 to 10 ° C. Can be cooled to. The cooling medium circulation line is connected to a cooler (not shown) using, for example, a Peltier element provided outside the stage 3.

  Next, as shown in FIG. 1B, the dispenser head 4 in which the thermosetting resin 12 is sealed is operated by an operation mechanism (not shown) and an operation control means (not shown), and the SAW on the stage 3 is operated. A resin 12 is applied in a square shape so as to surround the outer peripheral end face of the chip 2. The dispenser head 4 can be controlled to move horizontally and vertically on the SAW chip 2 by an operation mechanism and operation control means, and can discharge the thermosetting resin 12 enclosed inside by compressed air. it can. In order for the thermosetting resin 12 to be easily discharged from the dispenser head 4, the one that has been frozen and stored (−20 ° C.) has a viscosity of 20 Pa · s (25 ° C.) in the dispenser for a certain period of time (25 ° C. ) Stored. When such a thermosetting resin 12 is applied onto the wiring board 1, the temperature of the thermosetting resin 12 is lowered and the viscosity is increased to 100 Pa · s because the wiring board 1 is cooled to 0 to 10 ° C. It becomes difficult to fluidize. As a result, it is possible to prevent the applied resin 12 from flowing into the gap between the SAW chip 2 and the wiring board 1 (for example, a gap of about 50 μm) and adhering to the comb-like electrode 6, and the electrode 6 can be securely attached. It can be sealed in the hollow.

  Thereafter, as shown in FIG. 1C, the entire wiring board 1 is put into, for example, an oven 14 and heated at about 150 ° C. for about 30 minutes to cure the applied resin 12. The resin 12 has a low viscosity and easily fluidizes during the period from the heating until the thermosetting reaction takes place at 100 ° C., but the internal pressure of the sealed space above the comb-like electrode 6 increases, so There is no fear of flowing. A hot stage may be used instead of the oven 14. By placing the wiring board 1 on which the SAW chip 2 is mounted on the hot stage, heat can be supplied directly to the wiring board 1 side, and therefore, when heated to 150 ° C., it can be thermally cured in about 5 minutes.

  Although the following steps are not shown, when the SAW device of the present embodiment is completed, the modes shown in FIGS. 3A and 3B are obtained. FIG. 3 is a cross-sectional view and a plan view showing the final configuration of the SAW device obtained by using the manufacturing method shown in FIG. As shown in FIG. 3, the SAW device 30 is formed with a mold resin 13 such as an epoxy resin so as to cover the SAW chip 2. In forming the mold resin 13, since the thermosetting resin 12 is solidified, there is no possibility that the mold resin 13 flows into the gap between the SAW chip 2 and the wiring substrate 1. After the thermosetting resin 12 is formed, sealing reliability can be further improved by double sealing with the mold resin 13. After the mold resin 13 is completely solidified, the SAW device 30 shown in FIGS. 3A and 3B can be obtained by cutting the mold resin 13 into pieces using a dicing apparatus.

  In the SAW device 30 thus obtained, the thermosetting resin 12 is formed in the gap between the wiring substrate 1 and the SAW chip 2 so as to surround the comb-like electrode 6 and the Au bump 8. The width of the thermosetting resin 12 entering under the chip 2 is preferably within 150 μm in order to reduce the size of the SAW device 30 and improve the reliability.

  Here, the relationship between the temperature and the viscosity of the thermosetting resin according to this embodiment will be described with reference to FIGS. 4 and 5. FIG. 4 is a diagram showing the relationship between the temperature and the viscosity of the thermosetting resin used in the process shown in FIG. FIG. 5 is a diagram showing the change over time of the temperature and viscosity of the thermosetting resin in the process including the process shown in FIG. Note that (a), (b), and (c) shown in FIG. 5 respectively correspond to changes with time in each step of FIGS. 1 (a), (b), and (c).

  As shown in FIG. 4, the thermosetting resin used in this embodiment undergoes a thermosetting reaction at around 100 ° C. That is, when the temperature is lower than 100 ° C., the viscosity becomes low and the fluidization easily occurs as the temperature rises, and when the temperature exceeds 100 ° C., a thermosetting reaction occurs and the viscosity rapidly increases and solidifies.

  In the present embodiment, the viscosity change of the thermosetting resin due to such a temperature difference is utilized. That is, as shown in FIG. 5, a thermosetting resin such as an epoxy resin that has been stored frozen (about −20 ° C.) is left in advance at room temperature (25 ° C.) for a certain period of time, and the viscosity is easily discharged from the dispenser head. -Adjust to s (25 ° C).

  When the viscosity-adjusted resin is applied to the wiring board on the stage cooled to 0 to 10 ° C., the temperature of the resin decreases to 0 to 10 ° C., and the viscosity increases to 100 Pa · s to flow. It becomes difficult to convert. As a result, the resin can be prevented from flowing into the gap between the SAW chip and the wiring board.

  When the applied resin is heat-cured in an oven, the resin has a low viscosity and is easy to fluidize until it reaches 100 ° C., but flows into the periphery of the electrode because the internal pressure of the sealing space above the comb-like electrode increases. There is no fear.

  Therefore, according to the present embodiment, by utilizing the change in the viscosity of the resin due to the temperature difference, the electrode 6 can be securely inserted into the hollow without the resin 12 adhering to the comb-like electrode 6 of the SAW chip 2 in the manufacturing process. It is possible to provide a sealing resin device with high sealing reliability that can be sealed. Even in the case of a small SAW chip 2 (for example, 1 mm or less), since the width of the resin 12 entering the gap between the chip 2 and the wiring substrate 1 can be suppressed to, for example, 150 μm or less, the resin sealing is performed after improving the reliability. The device can be miniaturized. Moreover, the resin-encapsulated device can be easily obtained with a high yield by hollow sealing using the viscosity change of the resin 12.

  Next, a method for manufacturing a resin-encapsulated device according to the second embodiment will be described with reference to FIG. FIG. 6 shows a method for manufacturing a resin-encapsulated device according to the second embodiment. In addition, the same code | symbol is attached | subjected to the component same as 1st Embodiment, and the description is simplified or abbreviate | omitted. A heater for heating the encapsulated resin is provided in the dispenser head used in the present embodiment. The stage does not have a built-in cooling body.

  First, as shown in FIG. 6A, the wiring board 1 flip-chip connected so that the comb-like electrode 6 side of the SAW chip 2 faces is placed so that the wiring board 1 side is in contact with the stage 61. Since the stage 61 used in the present embodiment does not include a cooling body, the stage 61 is at room temperature (25 ° C.). Therefore, the wiring board 1 on which the SAW chip 2 on the stage 61 is mounted is also held at room temperature.

  Next, as shown in FIG. 6B, the dispenser head 62 having the heater 63 is operated, and the thermosetting resin 12 is applied to the outer peripheral end surface of the SAW chip 2 on the wiring substrate 1 placed on the stage 61. Apply in a letter shape. The thermosetting resin 12 is obtained by heating a resin having a viscosity of 100 Pa · s at room temperature up to 50 ° C. with a heater 63 in the dispenser head 62, and is adjusted to about 20 Pa · s that can be easily discharged from the dispenser head 62. Has been. As described above, when the resin 12 has a viscosity of 50 to 100 Pa · s at room temperature, the resin 12 may be heated to a temperature higher than the room temperature with the heater 63 or the like without cooling the stage 61. Since the wiring board 1 on the stage 61 is at room temperature, when the resin 12 heated to 60 ° C. touches the wiring board 1, the temperature drops and becomes highly viscous. Thus, the resin 12 can be prevented from adhering to the electrode 6 without flowing into the vicinity of the comb-like electrode 6.

  Subsequently, as shown in FIG. 6C, the thermosetting resin 12 is thermoset in an oven 14. Thereafter, the SAW chip 2 is sealed with a mold resin.

  Therefore, according to the present embodiment, even when the stage 61 is at room temperature, when the resin 12 enclosed in the dispenser head 62 is heated to about 50 ° C. and applied to the wiring board 1 on the stage 61, the resin 12 can be fluidized with a high viscosity. As a result, it is possible to form a highly airtight sealing space above the comb-like electrode 6 and to obtain a resin-encapsulated device having high sealing reliability with high yield.

  Next, a method for manufacturing a resin-encapsulated device according to the third embodiment will be described with reference to FIG. FIG. 7 shows a method for manufacturing a resin-encapsulated device according to the third embodiment. In addition, the same code | symbol is attached | subjected to the component same as 1st Embodiment, and the description is simplified or abbreviate | omitted. In this embodiment, the same cooling body as that of the first embodiment is built in the stage. In addition, a squeegee and a screen plate are used when applying resin near the end face of the SAW chip.

  First, as shown in FIG. 7A, the wiring substrate 1 to which the SAW chip 2 is flip-chip connected is placed on the stage 71. The stage 71 incorporates a cooling medium circulation line (cooling body) for circulating a cooling medium 72 such as water whose temperature is controlled at 0 to 10 ° C., and the placed wiring board 1 side is placed at 0 to 10 ° C. Can be cooled to.

  Next, as shown in FIG. 7B, a thermosetting resin 12 such as an epoxy resin adjusted to 20 Pa · s at room temperature on a screen plate 73 that has been previously positioned according to a predetermined position of the SAW chip 2. The squeegee 74 is moved while being pressed against the resin 12 on the screen plate 73 to apply the resin 12 near the end face of the SAW chip 2. Since the wiring board 1 on the stage 71 is cooled to 0 to 10 ° C., when the resin 12 (25 ° C.) touches the wiring board 1, the viscosity increases to 100 Pa · s as the temperature decreases and the fluidity is lowered. As a result, the resin 12 can be prevented from entering the gap between the SAW chip 2 and the wiring substrate 1 and reaching the periphery of the comb-like electrode 6.

  Subsequently, as shown in FIG. 7C, the applied thermosetting resin 12 is thermally cured in an oven 14. Thereafter, the SAW chip 2 is sealed with a mold resin such as an epoxy resin.

  Therefore, according to the present embodiment, by utilizing the change in the viscosity of the resin 12 due to the temperature difference, it is possible to stably operate the electrode 6 while improving the sealing reliability of the comb-like electrode 6. A resin-encapsulated device can be provided. Further, by previously patterning the screen plate 73 with an emulsion, it is possible to reliably apply to the outer peripheral end of the SAW chip 2 and to reduce the occurrence of application failure. That is, the application of the resin 12 can be instantaneously performed only by opening and closing the screen plate 73 and the movement of the squeegee 74, and a resin-encapsulated device can be easily obtained with a high yield.

In the above-described embodiment, the SAW device is described as an example of the resin sealing device. However, the present invention is not limited to this, and the MEMS device that requires a sealing space above the functional surface of the element. Even an optical device or the like can be applied.
Further, a Peltier element or the like for supplying a cooling medium whose temperature is controlled at 0 to 10 ° C. may be provided in advance in the stage.

Process drawing which shows the manufacturing method of the resin sealing device which concerns on the 1st Embodiment of this invention with a typical cross section. The figure which shows the state shown to Fig.1 (a) with a typical plane. Sectional drawing and top view which show the final structure of the SAW device obtained using the manufacturing method shown in FIG. The figure which shows the relationship between the temperature and viscosity of the thermosetting resin used at the process shown in FIG. The figure which shows the time-dependent change of the temperature and viscosity of a thermosetting resin in the process including the process shown in FIG. Process drawing which shows the manufacturing method of the resin sealing device which concerns on the 2nd Embodiment of this invention with a typical cross section. Process drawing which shows the manufacturing method of the resin sealing device which concerns on the 3rd Embodiment of this invention with a typical cross section.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Wiring board, 2 ... SAW chip | tip, 3,61,71 ... Stage, 4,62 ... Dispenser head, 5,72 ... Cooling medium, 6 ... Comb-like electrode, 7 ... Electrode pad, 8 ... Au bump, 9 DESCRIPTION OF SYMBOLS ... Wiring pattern, 10 ... Through-hole electrode, 11 ... External electrode, 12 ... Thermosetting resin, 13 ... Mold resin, 14 ... Oven, 30 ... SAW device, 63 ... Heater, 73 ... Screen board, 74 ... Squeegee.

Claims (6)

Placing the wiring board on which the functional surface side of the device chip is flip-chip connected to support the wiring board side on a stage controlled to a predetermined temperature lower than room temperature;
Applying a resin having a temperature higher than the predetermined temperature in the vicinity of the end face of the device chip on the wiring board placed above, and sealing the functional surface of the device chip in a hollow;
And a step of thermosetting the applied resin. A method for manufacturing a resin-encapsulated device. The method for manufacturing a resin-encapsulated device according to claim 1, wherein the predetermined temperature is 0C or higher and 10C or lower .   2. The resin-encapsulated device according to claim 1, wherein the step of encapsulating the functional surface of the device chip in a hollow by applying a resin is performed by raising the temperature of the resin by a temperature raising unit. Manufacturing method.   2. The method of manufacturing a resin-encapsulated device according to claim 1, wherein the step of applying a resin and sealing the functional surface of the device chip in a hollow is performed using a dispenser.   2. The method of manufacturing a resin-encapsulated device according to claim 1, wherein the step of encapsulating the functional surface of the device chip in the hollow by applying resin is performed using screen printing. A built-in cooling body is capable of holding the wiring substrate on which the device chip is flip-chip connected, and a wiring board holding portion which is controlled to a predetermined temperature below room temperature by the cooling body,
A resin application section that applies a resin having a temperature higher than the predetermined temperature near the end face of the device chip on the held wiring board and seals the functional surface of the device chip in a hollow space ; An apparatus for manufacturing a resin-encapsulated device.

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