JP6859634B2 - Hollow package manufacturing method - Google Patents

Description

The present invention relates to a method of manufacturing a hollow package, in particular for implementing the SAW filter chip or a MEMS element, or the like, a method of manufacturing a hollow package obtained by hollowing the upper surface of the device.

In recent years, electronic components equipped with SAW (Surface Acoustic Wave) filter elements, MEMS (Micro Electro Mechanical Systems) elements, and the like on a mounting substrate have become widespread. These electronic components are devices that require mechanical operation on the surface of the element (chip), and a hollow package in which the surface of the chip is hollow is used.

In this type of hollow package, ceramic is often used as a mounting substrate. For example, a method in which a chip is mounted on a substrate on which a recess is formed and then the recess of this substrate is sealed with low melting point glass, or a method in which a chip is mounted on a plate-shaped ceramic substrate and then a metal lid is mounted. A method of solder bonding or the like is adopted (for example, Patent Document 1).

On the other hand, a chip is formed on a silicon substrate to be a mounting substrate, another silicon substrate or the like is processed into a shape having recesses and joints suitable as a lid, and these silicon substrates are bonded to each other, and then individually. A method of collectively manufacturing an electronic component having a hollow package by disassembling it has also been proposed (for example, Patent Document 2).

Further, the applicant of the present application applies a silicone that can be removed in a later process to the chip surface after wire bonding the chip to the substrate, transfers molding using a sealing resin, and then removes the silicone to open the chip surface. (Patent Document 3). Specifically, as shown in FIG. 10, after the IC chip 20 is mounted on the substrate 21, the IC chip 20 and the substrate 21 are electrically connected by a wire 22, and a silicone resin is dropped on the surface of the IC chip 20. By doing so, the silicone mass 23 solidified into a gel is formed. Next, the substrate 21 is set in the mold with the upper surface of the silicone lump 23 in contact with the inner surface of the mold, and the cavity is filled with the sealing resin 24 for molding (FIG. 10a). After that, as shown in FIG. 10B, the silicone mass 23 is removed with a dissolving agent to form a hollow portion 25 that exposes a part of the surface of the IC chip 20. Further, a hollow package can be formed by laminating the lid 26 on the upper surface of the sealing resin 24 so as to cover the hollow portion 25 (FIG. 10c).

Japanese Unexamined Patent Publication No. 2014-241495 Japanese Unexamined Patent Publication No. 2012-84681 Japanese Unexamined Patent Publication No. 2009-267272

By the way, in the conventionally proposed method for manufacturing a hollow package, metal lids must be individually joined one by one, which is a method with low productivity.

On the other hand, in the method of laminating a silicon substrate to be a mounting substrate and a silicon substrate to be a lid into individual pieces, the silicon substrate to be a lid is processed into a concave shape or a joining member for joining the silicon substrates is formed. There was a problem that it was necessary and the manufacturing process was complicated. In addition, there is a problem that a special device is required when the silicon substrates are bonded to each other.

Furthermore, the method of forming a hollow structure by forming a silicone lump to form a hollow structure and removing it with a solvent has a problem that the manufacturing process becomes complicated and it is difficult to realize miniaturization. there were.

In the present invention to solve the above problems, in forming a hollow package for mounting a chip such as SAW filter elements and MEMS devices, to provide a hollow package manufacturing method to achieve both productivity improvement and cost reduction The purpose.

To achieve the above object, the invention according to the claims 1, Oite method of manufacturing a hollow package for mounting the chip inside the package, a plurality of chip mounting portion, a wall portion surrounding each said chip mounting portion A step of preparing an assembly substrate having a concave step portion communicating with the chip mounting portion adjacent to the upper surface of the wall portion, a step of mounting the chip on each of the chip mounting portions, and a reduced pressure atmosphere. A sheet-shaped lid is placed on the wall portion via an adhesive layer, and the adhesive layer made of an adhesive is filled between the step portion and the upper surface of the wall portion and the lid. , The step of bonding the lid and the stepped portion and the upper surface of the wall portion without a gap by the adhesive layer, and using a dicing saw, the lid, the wall portion and a part of the assembly substrate are cut and removed. It is characterized by including a step of clearing.

According to the second aspect of the present application, in the method for manufacturing a hollow package according to the first aspect , the step of bonding the lid and the stepped portion and the upper surface of the wall portion without a gap by the adhesive layer is performed in a reduced pressure atmosphere. The lid with a sheet-like adhesive is placed on the wall portion, and the lid is bonded to at least the outer peripheral portion of the assembly substrate without a gap, and then the pressure of each chip mounting portion and each chip are used as normal pressure. The adhesive layer is filled between the lid and the stepped portion and the upper surface of the wall portion surrounded by the outer peripheral portion due to the pressure difference from the external pressure of the mounting portion .

According to the hollow package manufacturing method of the di of the present invention, using a set substrate, for singulation by bonding a sheet-like lid to the upper surface of the wall portion, it can be easily formed a plurality of electronic components simultaneously It becomes. In particular, in the present invention, since the upper surface of the wall portion is provided with concave stepped portions communicating with both side surfaces, when the lid is placed on the upper surface of the wall portion in a reduced pressure atmosphere, each chip mounting portion is concave. The pressure becomes equal throughout the assembly substrate through the stepped portion of the shape. Therefore, the lid can be attached to the upper surface of the wall portion with good uniformity over the entire assembly substrate when the atmosphere is changed to normal pressure thereafter.

Here, by laminating the lids in a state where the pressure is reduced to a predetermined predetermined pressure and then setting the pressure to normal pressure, it becomes possible to allow the adhesive formed on the lid to enter the concave stepped portion with good controllability. There is an advantage that an airtight structure can be easily formed.

In particular, even when the collective substrate is warped or the like, an airtight structure can be reliably formed, and both productivity improvement and cost reduction can be achieved at the same time.

It is explanatory drawing of the hollow package by the manufacturing method of the hollow package of this invention. It is explanatory drawing of the manufacturing method of the hollow package of this invention. It is explanatory drawing of the manufacturing method of the hollow package of this invention. It is explanatory drawing of the manufacturing method of the hollow package of this invention. It is explanatory drawing of the manufacturing method of the hollow package of this invention. It is explanatory drawing of the manufacturing method of the hollow package of this invention. It is explanatory drawing of the manufacturing method of the hollow package of this invention. It is explanatory drawing of the manufacturing method of the hollow package of this invention. It is explanatory drawing of the manufacturing method of the hollow package of this invention. It is explanatory drawing of the conventional manufacturing method of this kind of hollow package.

The hollow package according to the method for manufacturing a hollow package of the present invention is provided with a concave step portion on the upper surface of a wall portion surrounding the chip mounting portion, and an adhesive is contained in the step portion. An adhesive is also formed on the upper surface of the wall portion, and the lid is attached via this adhesive layer. Hereinafter, examples of the present invention will be described in detail according to the manufacturing process thereof.

First, examples of the present invention will be described in detail. FIG. 1 is an explanatory view of a hollow package according to the method for manufacturing a hollow package of the present invention, FIG. 1 (a) is a plan view in a state where the lid and the adhesive layer are removed, and FIG. 1 (b) is FIG. 1 (a). ) Is a cross-sectional view on the XY plane, and FIG. 1 (c) is a side view showing a state in which the lid and the adhesive layer are attached. As shown in FIGS. 1A and 1B, a chip 2 such as a SAW device or a MEMS device is mounted on the chip mounting unit 1. In this embodiment, the chip mounting portion 1 is formed of a lead frame, and the chip mounting portion 1 is formed with hanging pins extending in four directions. A wall portion 3 is formed around the chip mounting portion 1 on which the chip 2 is mounted. On the upper surface of the wall portion 3, step portions 4 communicating with both side surfaces of the wall portion 3 are formed. In the example shown in FIG. 1A, one step portion 4 is formed on each of the four side wall portions 3 formed around the chip mounting portion 1. As an example, the width of the step portion 4 can be about 0.2 mm and the depth can be about 0.05 mm. The chip 2 mounted on the chip mounting unit 1 is connected to the lead 6 by a connecting means such as a wire 5. For example, an epoxy resin is filled between the chip mounting portion 1 and the lead 6 and between the lead 6 and the adjacent lead 6, and the space between the leads is fixed.

The surface side of the chip 2 mounted on the chip mounting portion 1 has a hollow structure, and the lid 7 is mounted so as to face the chip mounting portion 1. The lid 7 has a structure in which the lid 7 is attached to the upper surface of the wall portion 3 via an adhesive layer 8. In this embodiment, as shown in FIGS. 1 (b) and 1 (c), the adhesive layer 8 penetrates into the stepped portion 4 to form an airtight structure.

Stepped portion 4 which is a characteristic structure in the hollow package by the manufacturing method of hollow package of the present invention, when following method for producing a hollow package of the present invention described below, an important constituent.

Next, the method for manufacturing the hollow package of the present invention will be described. FIG. 2A is a partial plan view of the assembly substrate 10 in which the back tape 9 is attached to the back surface, and FIG. 2B shows a cross-sectional view on the XY plane of FIG. 2A. As shown in FIG. 2, the collective substrate 10 has a shape in which a plurality of chip mounting portions 1 and leads 6 described in FIG. 1 are continuous, and an outer peripheral portion 11 is formed around the chip mounting portion 1 and leads 6 and the like.

The collecting substrate 10 uses a lead frame generally used in the manufacturing process of a semiconductor device, and at the same time, resin-seals between the chip mounting portion 1 and the lead 6 and between the lead 6 and the adjacent lead 6. The wall portion 3 and the outer peripheral portion 11 are formed. This sealing resin is produced, for example, by setting a lead frame in a transfer mold mold, pouring the resin into it, and curing it. Specifically, the sealing resin does not flow into the region where the chip mounting portion 1 is planned to be formed, and the wall portion 3 is planned to be formed, between the chip mounting portion 1 and the lead 6, and between the lead 6 and the adjacent lead 6. The transfer mold mold is designed so that the sealing resin flows into the outer peripheral portion 11. Further, in the region where the step portion 4 is to be formed, the male side of the mold is formed in a convex shape, so that the wall portion 3 made of the sealing resin and the wall portion 3 thereof are formed as shown in FIG. 2 after being collectively sealed. A stepped portion 4 notched in a concave shape is formed on the upper surface. As an example, the width of the upper surface of the wall portion 3 is preferably 0.4 mm or more because the lid 7 needs to be sufficiently adhered to the adhesive layer 8. Further, it is desirable that the heights of the wall portion 3 and the outer peripheral portion 11 are 0.15 mm higher than the height of the chip 2. Further, the back tape 9 attached to the back surface of the chip mounting portion 1 and the lead 6 is collectively sealed and then peeled off.

The step portion 4 is formed so as to communicate with both side surfaces of the wall portion 3 and the outer peripheral portion 11. With such a structure, in the manufacturing process described later, when the lid 7 is attached to the outer peripheral portion 11 of the assembly substrate 10 without a gap through the adhesive layer 8 under a reduced pressure atmosphere, each chip mounting portion 1 is attached. The stepped portion 4 on the wall portion 3 communicates with each other, and each space can be maintained in a uniform decompression state. In the example shown in FIG. 2, the stepped portion 4 is formed on the four surfaces constituting the chip mounting portion 1, but it is not always necessary to form the stepped portion 4 on the four surfaces.

Further, the shape of the step portion 4 on the outer peripheral portion 11 is not necessarily limited to the above-mentioned shape, and may have another shape. Specifically, for example, the stepped portion 4 formed on the outer peripheral portion 11 may be formed on the upper surface of the outer peripheral portion 11 so as not to communicate with both side surfaces. With such a structure, when the lid 7 is attached to the outer peripheral portion 11 of the assembly substrate 10 under a reduced pressure atmosphere in the manufacturing process described later, even if the pressure is changed from the reduced pressure atmosphere to normal pressure, the upper surface of the outer peripheral portion 11 is formed. It is possible to prevent the adhesive layer 8 from flowing out from the stepped portion 4 formed in the above. On the other hand, each chip mounting portion 1 is communicated with a step portion 4 on the wall portion 3, and each space can be maintained in a uniform decompression state.

Next, the chip 2 is mounted on the chip mounting portion 1 of the assembly substrate 10, and the electrode formed on the chip 2 by the wire 5 and the lead 6 of the assembly substrate 10 are electrically connected (FIG. 3). In the following description, a cross-sectional view of the collective substrate 10 in a state where three chip mounting portions 1 are connected will be described. At this time, the capillary used in the wire bonder device uses a deep access or the like having a thin tip in order to avoid contact with the wall portion 3 made of the sealing resin, so that the chip is close to the area of the chip mounting portion 1. It can be installed.

Next, a lid 7 is prepared in which the adhesive layer 8 is formed on one side and the dicing sheet 12 is attached to the other side. Further, as the lid 7, a metal film made of an Fe—Ni alloy can be used in addition to an organic-inorganic thin film such as a glass epoxy resin. Further, as the adhesive layer 8, in addition to the epoxy resin-based thermosetting resin, a thermosetting resin can be used, and for example, a phenol resin-based resin, a silicone resin-based resin, or the like may be used. The thickness of the adhesive layer 8 may be sufficient to penetrate into the stepped portion 4, and more preferably about 0.05 mm thicker than the depth of the stepped portion 4. As the dicing sheet 12, a dicing sheet 12 generally used in the manufacturing process of a semiconductor device can be used. For example, a base material made of vinyl chloride (PVC), polyolefin (PO), or the like can be used. Further, the dicing sheet 12 is held in advance by a ring-shaped jig, and then attached to one side of the lid 7. The lid 7 having the above configuration is prepared in advance so as to cover the collecting substrate 10 and not to be smaller than the outer peripheral portion 11, and above the wall portion 3 and the outer peripheral portion 11 via the adhesive layer 8 in the decompression device 13. Place the lid 7 on the. At this time, the assembly substrate 10 is placed on the hot plate 14 (FIG. 4).

Next, the outer peripheral portion 11 and the lid 7 are bonded together. Specifically, first, the air in the decompression device 13 is expelled ^{to create a decompression atmosphere (about 1.0 × 10 4} Pa). Further, as the adhesive of the adhesive layer 8, a resin having low fluidity is selected. As an example, A2029 manufactured by Nagase ChemteX Corporation can be used. At this time, the hot plate 14 is heated to 80 ° C. to heat the assembly substrate 10, the adhesive layer 8, and the whole. When the adhesive layer 8 is heated and softened, the adhesive layer 8 is brought into close contact with the upper surface of the outer peripheral portion 11 while being pressure-bonded from above the dicing sheet 12 using a roller 15, and the adhesive is formed in the step portion 4. Incorporate layer 8. Further, the adhesive layer 8 may use a selected adhesive made of another adhesive. In that case, the temperature of the hot plate 14 may be changed to, for example, 150 ° C. according to the softening temperature of the adhesive used. In this step, since the step portion 4 communicates with both side surfaces on the upper surface of the outer peripheral portion 11, the inside of the decompression device 13 is heated after the collecting substrate 10, the adhesive layer 8 and the whole are heated by the hot plate 14. It may be a decompressed atmosphere.

On the other hand, when the stepped portion 4 on the upper surface of the outer peripheral portion 11 described above is formed halfway without communicating with both side surfaces, the pressure reducing device 13 is first made into a decompression atmosphere, and then the adhesive layer 8 is formed. After the lid 7 is placed on the wall portion 3 and the outer peripheral portion 11 via the inner peripheral portion 11, the adhesive layer 8 may be inserted into the stepped portion 4 and bonded together while being crimped using the roller 15.

After crimping the outer peripheral portion 11 on one side (right side in the drawing) of the assembly substrate 10 using the roller 15, the roller 15 is moved to the left in FIG. 5 and the outer peripheral portion 11 is crimped (FIGS. 5 and 6). ). Further, the outer peripheral portion 11 (four sides) and the lid 7 are bonded together without a gap by crimping to another outer peripheral portion 11 (not shown). At this time, there may be a portion where the adhesive layer 8 does not enter the stepped portion 4 on the upper surface of the wall portion 3 due to the warp of the collecting substrate 10 or the like (FIG. 6). The purpose of this step is to bond the outer peripheral portion 11 and the lid 7 with the adhesive layer 8 in the decompression device 13 to bring the hollow structure portion in the assembly substrate 10 into a decompression state. There is no limitation on the structure of the stepped portion 4 in the portion 11.

Next, the atmosphere is put into the decompression device 13 and the pressure is returned to normal pressure (FIG. 7). At this time, each hollow structure in the assembly substrate 10 is in a reduced pressure state because the outer peripheral portion 11 and the lid 7 are adhered by the adhesive layer 8. Further, since each hollow structure communicates with each other by a step portion 4 on the upper surface of the wall portion 3, the pressure of each hollow structure is the same. When the pressure is returned to normal pressure in such a state, since the outside of the hollow structure is at normal pressure, the lid 7 is pushed toward the hollow structure side due to the pressure difference. In this way, even if the roller 15 is used due to the warp of the collective substrate 10, the stepped portion 4 and the lid 7 formed on the wall portion 3 and the upper surface of the wall portion 3 cannot be brought into close contact with each other by using the adhesive layer 8. Even at this point, since the adhesive layer 8 is in a softened state by heating, the lid 7 and the stepped portion 4 can be adhered to each other by the pressure difference. At this time, the length of the stepped portion 4 formed on the upper surface of the outer peripheral portion 11 may be set so that the adhesive of the adhesive layer 8 is not swept away to the hollow structure side due to the pressure difference from the outside of the package.

Further, when the step portion 4 described above is formed halfway without communicating with both side surfaces of the outer peripheral portion 11, the step portion 4 does not exist on the outer surface of the outer peripheral portion 11, so that the adhesive layer is formed. The adhesive of 8 is not washed away toward the hollow structure side. After that, the assembly substrate 10 is taken out from the decompression device 13 (FIG. 8).

Next, using a dicing device, the dicing saw 16 is rotated and cut while sprinkling water (FIG. 9). That is, with the dicing sheet 12 side facing down, the assembly substrate 10, the outer peripheral portion 11 or the wall portion 3, the adhesive layer 8 and the lid 7 are cut from the opposite side to the dicing sheet 12 using the dicing saw 16. It can be a single-sided hollow package.

Although the examples of the present invention have been described above, it goes without saying that the present invention is not limited thereto. For example, the step portion 4 is provided at one location on the upper surface of each of the wall portion 3 and the outer peripheral portion 11, but two or more locations may be provided. Alternatively, it may be on the corners where they intersect, not on the upper surface of the wall portion 3 or the outer peripheral portion 11. Further, although the shape of the step portion 4 is concave, it may be convex, U-shaped or V-shaped.

1: Chip mounting part,
2: Chip,
3: Wall,
4: Step part,
5: Wire,
6: Lead,
7: Lid,
8: Adhesive layer,
9: Back tape,
10: Assembly board,
11: Outer circumference,
12: Dicing sheet,
13: Decompression device,
14: Hot plate,
15: Roller,
16: Dicing saw.

Claims (2)

Oite method of manufacturing a hollow package for mounting the chip inside the package,
A step of preparing a collective substrate including a plurality of chip mounting portions, a wall portion surrounding each of the chip mounting portions, and a concave step portion communicating with the chip mounting portion adjacent to the upper surface of the wall portion.
The process of mounting the chip on each of the chip mounting portions,
A sheet-shaped lid is placed on the wall portion in a reduced pressure atmosphere via an adhesive layer, and the adhesive layer made of an adhesive is filled between the step portion and the upper surface of the wall portion and the lid. By doing so, the step of bonding the lid and the stepped portion and the upper surface of the wall portion without a gap by the adhesive layer, and
A method for producing a hollow package, which comprises a step of cutting and removing the lid, the wall portion, and a part of the assembly substrate to individualize them using a dicing saw . In the method for manufacturing a hollow package according to claim 1, the step of bonding the lid and the stepped portion and the upper surface of the wall portion without a gap by the adhesive layer is a sheet-like adhesion on the wall portion under a reduced pressure atmosphere. The pressure difference between the pressure of each chip mounting portion and the external pressure of each chip mounting portion as normal pressure after the lid with the agent is placed and the lid is bonded to at least the outer peripheral portion of the assembly substrate without a gap. A method for manufacturing a hollow package, which comprises filling the adhesive layer between a stepped portion and an upper surface of the wall portion surrounded by the outer peripheral portion and the lid.

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