JP7703219B2 - Compression molding device and compression molding method - Google Patents

Description

The present invention relates to a compression molding device and a compression molding method.

A known method for manufacturing a package in which components such as semiconductor elements are resin-sealed is to mold resin onto a workpiece in which components are mounted on a carrier, and to manufacture a package in which the components are resin-sealed. One such resin-sealing method is the compression molding method.

Patent Document 1 discloses a resin molding device that uses a molding die that includes an upper die that holds a workpiece having electronic components mounted on a substrate, and a lower die that has a recess formed therein into which molding resin is supplied via a film, to resin-mold the workpiece and process it into a molded product.

JP 2019-145548 A

However, with conventional technology, there was a risk of the molding resin scattering inside the device when it was supplied to the recess.

The present invention has been made to solve these problems, and provides a compression molding device and a compression molding method that can prevent resin from scattering within the device.

The compression molding device according to one aspect of the present invention includes a heating section that heats granular resin to a semi-molten state, a resin supply section that has an adsorption section and supplies the heated semi-molten resin in a state where it is electrostatically adsorbed to the adsorption section, one die having a recess into which resin is supplied by the resin supply section, and the other die that holds a workpiece having electronic components mounted on a substrate, and a die that seals the workpiece with resin.

This invention can prevent resin from scattering inside the device.

1 is a side view showing a schematic configuration of a resin sealing apparatus according to an embodiment; FIG. 2 is an enlarged cross-sectional view showing a main part of a vibration mechanism. 1A to 1C are diagrams illustrating an example of a resin sealing method according to an embodiment of the present invention. 1A to 1D are diagrams illustrating an example of a resin sealing method according to an embodiment of the present invention.

Below, one embodiment of the resin sealing device 1 is described with reference to the drawings.

As shown in FIG. 1, the resin sealing device 1 includes a resin supply unit 10 and a mold 30. The resin supply unit 10 is an example of a resin supply section.

The resin supply unit 10 includes a stage 11, a resin guard 12, a heater 13, a transport head 14, and a vibration mechanism 20.

The stage 11 is flat and has a frame-shaped resin guard 12 on its upper surface. The area of the upper surface of the stage 11 that is surrounded by the resin guard 12 functions as a supply area 12A to which resin R is supplied. The resin guard 12 defines the outer shape of the supply area 12A by restricting the resin R from scattering outside the supply area 12A. The supply area 12A is slightly smaller in size than the cavity of the mold 30.

The resin R is a granular (including powder) thermosetting resin with a particle size of, for example, 0.5 mm to several mm. Examples of thermosetting resins include, but are not limited to, epoxy-based resins containing fillers. Granular resins include, for example, crushed resins made by kneading molding resin and fillers, compressing them into a predetermined shape, and then crushing them, and cylindrical resins made by kneading the resin and extruding it using a mold with a circular hole, cutting it to a certain length, and molding it into a cylindrical shape. These cylindrical and crushed granular resins tend to scatter in random directions when they fall into the resin guard 12.

The vibration mechanism 20 is provided below the stage 11. The vibration mechanism 20 spreads the resin R supplied to the supply area 12A by vibrating the stage 11 three-dimensionally. The vibration mechanism 20 vibrates the stage 11 three-dimensionally.

The heater 13 is provided on the upper surface of the stage 11 and heats the resin R supplied to the supply area 12A to a semi-molten state. The semi-molten state refers to a state in which at least a portion of the granular resin is fused to each other, and the number of pores that serve as an insulating layer between the particles of the granular resin in the preliminary fused resin is reduced, although pores may remain between the particles of the fused granular resin. In the semi-molten state, the thermal conductivity of the resin can be improved. In addition, the heater 13 heats the granular resin R, which is prone to scattering, to a semi-molten state, and keeps at least a portion of the particles connected, thereby preventing the resin R from scattering. The heating temperature is preferably 60°C to 80°C, but is not limited because the temperature at which the resin becomes semi-molten varies depending on the properties of the resin. The heater 13 is provided on the upper surface of the stage 11 and heats the resin R from below. In addition, after the granular resin is spread on the resin guard 12, the heater may be transported to the space above the resin R to heat it from above. Furthermore, the resin R may be heated from both the upper and lower sides. The resin guard 12 may be removed after the resin R is heated.

The transport head 14 is configured to be movable between the stage 11 and the mold 30. An electrostatic chuck 16 is provided on the underside of the transport head 14. The transport head 14 applies a voltage to the electrode of the electrostatic chuck 16 while the electrostatic chuck 16 is in contact with the resin R located in the supply area 12A, generating a Coulomb force between the electrode and the resin R, thereby adsorbing the semi-molten resin R. When transporting the resin R, it is better to move the resin R after removing the resin guard 12 from the resin R, because the amount of upward movement of the resin R is small. As an example, the resin R may be pushed up and moved upward by using a heater 13 configured to be movable relative to the supply area 12A, or a flat plate installed in the stage 11. As shown by the dashed line in FIG. 1, the transport head 14 moves to the position of the mold 30 while the semi-molten resin R is adsorbed to the electrostatic chuck 16, and then the voltage applied to the electrode of the electrostatic chuck 16 is released to detach the semi-molten resin R from the electrostatic chuck 16, thereby supplying the resin R to the mold 30.

The mold 30 is composed of an upper mold 31 and a lower mold 32. In the illustrated example, a cavity recess 32A (hereinafter, abbreviated as recess 32A) is formed in the lower mold 32. Specifically, the lower mold 32 includes a lower mold plate 33 formed in a flat plate shape, a cavity piece 34 fixed to the lower mold plate 33, and a clamper 36 connected to the lower mold plate 33 via a plurality of springs 35 arranged to surround the cavity piece 34. The clamper 36 is biased in a direction approaching the upper mold 31 based on the elastic force of the spring 35.

The clamper 36 is configured to be slidable relative to the cavity piece 34, but is partially provided with suction holes (not shown) that suck air from the recess 32A. The clamper 36 protrudes further toward the upper mold 31 than the cavity piece 34, and together with the cavity piece 34 forms the recess 32A, which is a space for molding the resin R. The lower mold 32 is covered with a release film F that fits along the inner surface of the recess 32A. The release film F covers the parting line surface of the lower mold 32 through the suction holes that suck the recess 32A and suction holes (not shown) provided on the upper surface of the clamper 36.

The release film F is, for example, a film material that has excellent heat resistance, ease of peeling, flexibility, and extensibility. Examples of such film materials include PTFE (polytetrafluoroethylene), ETFE (polytetrafluoroethylene polymer), PET, FEP, fluorine-impregnated glass cloth, polypropylene, and polyvinylidine chloride.

Semi-molten resin R transported by the transport head 14 is supplied to the recess 32A of the lower mold 32 while covered with a release film F.

The workpiece W is placed on the lower surface of the upper mold 31. The workpiece W has a configuration in which, for example, multiple electronic components are mounted in a matrix on a substrate. Examples of the substrate include a resin substrate, a ceramic substrate, a metal substrate, a carrier plate, a lead frame, a wafer, etc. Examples of the electronic components include a semiconductor chip, a MEMS chip, a passive element, a heat sink, a conductive member, a spacer, etc.

The upper and lower dies of the mold are equipped with heaters, and the mold is heated to approximately 100°C to 200°C. After resin R is supplied into recess 32A, upper die 31 and lower die 32 begin to clamp together, and after the upper surface of clamper 36 and the lower surface of upper die 31 come into contact, spring 35 bends as the resin melts, and the workpiece W is sealed with a specified thickness of resin R.

Figure 2 is an enlarged cross-sectional view showing the main parts of the vibration mechanism 20 provided in the resin supply unit 10. As shown in Figure 2, the vibration mechanism 20 includes a frame 21 formed in a box shape with an opening at the top, a plate 22 formed in a flat shape and covering the opening of the frame 21, at least one vibration support 23 fixed to the underside of the plate 22, and at least one actuator 24 arranged on each vibration support 23.

In the illustrated example, the plate 22 is formed in a roughly rectangular flat plate shape, and vibration supports 23 are arranged at the four corners of the plate 22. Each actuator 24 is arranged between one of the vibration supports 23 and the frame 21, connecting the two. The actuator 24 is, for example, a voice coil motor, and one of the built-in coil bobbin and yoke moves slightly relative to the other. Vibrations can be applied to the vibration support 23 by the reciprocating motion of the coil bobbin etc. in the movement direction specific to each motor.

The actuator 24 is not limited to a voice coil motor, and may be another type of vibrator. An actuator 24 is disposed on each vibration support 23 to vibrate the vibration support 23 in the vertical Z direction. In the illustrated example, the vibration support 23 is formed into a substantially rectangular parallelepiped, one end of the vibration support 23 is connected to the underside of the plate 22, and the other end opposite the one end is connected to the actuator 24.

In the illustrated example, in addition to the actuator 24Z in the vertical direction Z, actuators 24X and 24Y are further arranged to vibrate the vibration support 23 in the horizontal directions X and Y. An example of the X direction is the left-right direction as seen by the operator of the resin sealing device 1, and an example of the Y direction is the front-back direction as seen by the operator. The vibration mechanism 20 can generate vibrations in three axes, the X axis, the Y axis, and the Z axis, which are perpendicular to each other, at the installation location of the vibration support 23, so that the supply area 12A placed on the plate 22 can be vibrated three-dimensionally. In this structure, the vibration mechanism 20 is separately provided under the stage 11, but the stage 11 may also serve as the vibration mechanism 20. As an example, the plate 22 of the vibration mechanism 20 may also serve as the heater 13, or the heater 13 may be provided on top of the plate 22.

Figure 3 is a diagram showing a schematic diagram of an example of a resin sealing method using the resin sealing device 1.

As shown in FIG. 3, in the resin sealing method according to this embodiment, for example, a resin guard 12, which is a rectangular frame-shaped metal member, is placed on the upper surface of the plate 22 of the vibration mechanism 20 (step S1).

A predetermined amount of granular or other resin R is supplied to a predetermined position in the supply area 12A within the frame of the resin guard 12 (step S2). When vibration is applied using the vibration mechanism 20, the resin R rolls and spreads quickly within the supply area 12A.

The spread resin R is then evenly spread to every corner of the supply area 12A by vertical vibration, smoothing the supplied resin R (step S3). The smoothed resin R is then heated to make the resin R semi-molten (step S4). After the resin R is heated, the resin guard 12 is removed from the resin R. The semi-molten resin R is then supplied to the mold 30, and the resin R is molded within the mold 30 to resin-seal the workpiece W.

Next, we will explain the flow of the resin sealing process using the resin sealing device 1 according to this embodiment.

First, as shown in FIG. 4(a), the resin sealing device 1 brings the transport head 14 close to the resin R that is in a semi-molten state in the supply area 12A of the stage 11 in FIG. 3(d).

Next, as shown in FIG. 4(b), the resin sealing device 1 applies a voltage to the electrodes of the electrostatic chuck 16 while the electrostatic chuck 16 is in contact with the resin R supplied to the supply area 12A, thereby electrostatically adsorbing the semi-molten resin R to the electrostatic chuck 16.

Next, as shown in FIG. 4(c), the resin sealing device 1 transports the transport head 14 to the mold 30 while the semi-molten resin R is electrostatically adsorbed to the electrostatic chuck 16. Then, the resin sealing device 1 moves the transport head 14 to a position where the electrostatic chuck 16 faces the recess 32A of the lower mold 32 in the vertical direction.

Next, as shown in FIG. 4(d), the resin sealing device 1 supplies the resin R detached from the electrostatic chuck 16 to the recess 32A of the lower die 32 by removing the voltage applied to the electrode of the electrostatic chuck 16 while supplying the release film F to the recess 32A of the lower die 32. The timing of supplying the release film F to the recess 32A of the lower die 32 may be any timing prior to the timing of detaching the resin R from the electrostatic chuck 16. As described above, the release film F is covered in the shape of the recess by the suction holes on the top surface of the clamper 36 and the suction holes between the clamper 36 and the cavity piece 34.

Then, the resin sealing device 1 clamps the upper die 31 and the lower die 32 together and molds the resin R inside the die 30, thereby sealing the workpiece W with the resin R.

As described above, according to this embodiment, the transport head 14 has an electrostatic chuck 16, and supplies the heated semi-molten resin R to the mold 30 while it is electrostatically adsorbed to the electrostatic chuck 16. This makes it possible to prevent the resin R from scattering inside the resin sealing device 1, compared to when the transport head 14 supplies the resin R to the mold 30 without heating it in advance.

The above embodiment can also be embodied in the following different forms.
In the above embodiment, the resin sealing apparatus 1 may smooth the granular resin R by pressing the granular resin R from above with a plate or the like before heating.

- In the above embodiment, the resin sealing device 1 may omit the resin processing section that smoothes the granular resin R before heating.

- In the above embodiment, the electrostatic chuck was used to adsorb semi-molten resin to the underside of the cavity recess of a compression molding device that has a movable lower mold with a cavity recess, and transport the resin therein. However, the electrostatic chuck may be used to heat the resin in the cavity recess of a compression molding device that has a movable upper mold with a cavity recess to prevent misalignment, and the semi-molten resin may be placed on the electrostatic chuck for transport.

The above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. The elements of the embodiments, as well as their arrangements, materials, conditions, shapes, sizes, etc., are not limited to those exemplified, and may be modified as appropriate. Furthermore, configurations shown in different embodiments may be partially substituted or combined.

1...resin sealing device, 10...resin supply unit, 11...stage, 12...resin guard, 13...heater, 14...transport head, 16...electrostatic chuck, 20...vibration mechanism, 30...mold, 31...upper mold, 32...lower mold, 32A...cavity recess, 33...lower mold plate, 34...cavity piece, spring...35, 36...clamper, R...resin, W...workpiece.

Claims (4)

a resin guard for holding the granular resin supplied to the stage;
a vibration unit that vibrates the granular resin held by the resin guard to smooth it ;
a heating section that heats the granular resin held by the resin guard and smoothed to bring at least a portion of the granular resin into a semi-molten state in which voids remain between particles of the granular resin;
a resin conveying section having an adsorption section and conveying the heated semi-molten resin in a state where the resin is electrostatically adsorbed to the adsorption section;
a mold including one mold having a recess into which the semi-molten resin is carried by the resin transport unit, and a mold including another mold for holding a workpiece having an electronic component mounted on a substrate, the mold being configured to resin-seal the workpiece;
Equipped with
Compression molding equipment. A film supply unit that supplies a film to the recess,
The resin conveying unit conveys and supplies the semi -molten resin to the recess of the one of the molds to which the film has been supplied by the film supplying unit.
The compression molding apparatus of claim 1 . The resin guard is removable,
The resin guard is removed from the stage when the semi-molten resin is being transported.
The compression molding apparatus according to claim 1 or 2. Holding the granular resin supplied to the stage with a resin guard;
vibrating the granular resin held by the resin guard to smooth it ;
heating the granular resin held by the resin guard and smoothed to a semi-molten state in which at least a portion of the granular resin is fused to each other and voids are left between the particles of the granular resin;
transporting the heated semi-molten resin by electrostatic adsorption;
sealing the workpiece with resin using a mold including one mold having a recess into which the semi-molten resin is supplied and another mold for holding a workpiece having an electronic component mounted on a substrate;
having
Compression molding method.

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