JP2024139398A - Encapsulating resin for use in compression molding, and forming method and forming device thereof - Google Patents

Abstract

To provide a compression molding device and a sealing resin capable of realizing a compression molding method capable of preventing the occurrence of molding defects, and a method and device for forming the same.SOLUTION: A method for forming a sealing resin according to the present invention is a method for forming a sealing resin R to be used in compression molding of a workpiece W having a configuration in which an electronic component Wb is mounted on a substrate Wa, and includes a forming step of forming a frame-shaped or lattice-shaped sealing resin R having through holes Rh, the forming step includes a step of setting and forming the position and shape of the through hole Rh such that the electronic component Wb of the workpiece W is accommodated in the through hole Rh and the upper surfaces Wbf of the electronic component Wb is exposed.SELECTED DRAWING: Figure 15

Description

The present invention relates to a sealing resin used in compression molding, as well as a method and device for forming the same.

One example of a resin sealing device and resin sealing method that uses a compression molding method to seal a workpiece having electronic components mounted on a substrate with sealing resin and process it into a molded product.

The compression molding method is a technique in which a predetermined amount of sealing resin is supplied to a sealing area (cavity) provided in a sealing mold comprising an upper mold and a lower mold, a workpiece is placed in the sealing area, and the upper and lower molds are clamped to seal the workpiece with resin. As an example, when a sealing mold having a cavity in the upper mold is used, a technique is known in which the sealing resin is supplied all at once to the center position on the workpiece and molded. On the other hand, when a sealing mold having a cavity in the lower mold is used, a technique is known in which a release film (hereinafter sometimes simply referred to as "film") that covers the mold surface including the cavity and the sealing resin are supplied and molded (Patent Document 1: JP 2019-145550 A).

JP 2019-145550 A

For example, when resin-sealing a strip-type wire-connected electronic component (semiconductor chip) as a workpiece, the compression molding method in which a cavity is provided in the upper die has the problem that resin sealing is difficult because the wire portion of the workpiece held in the lower die comes into contact with the sealing resin previously supplied to the cavity or the sealing resin supplied onto the workpiece and deforms. For this reason, a compression molding method in which the workpiece is held in the upper die, a cavity is provided in the lower die, and sealing resin (granular resin, as an example) is supplied into the cavity has generally been adopted.

However, in a configuration in which a workpiece is held in the upper mold and a cavity is provided in the lower mold, when the workpiece is thin or large, it is difficult to hold it in the upper mold and it is likely to fall. In addition, although the sealing resin is usually supplied into the cavity of the lower mold through a film, when attempting to form a thick molded product with a thickness (here, the thickness of the resin part after molding) exceeding 1 mm, the molding stroke becomes large, and there is a problem that the film is likely to be caught in the molded product, resulting in molding defects. Furthermore, when granular resin is used as the sealing resin, in addition to the problem of the film being easily caught, dust being generated, and the problem of difficult handling, there is a problem that it is difficult to supply (spread) the sealing resin evenly to the entire area in the cavity provided in the lower mold, and uneven winding is likely to occur. In addition, there is a problem that the air contained in the gaps between the particles when the sealing resin is spread and the gas components due to degassing from the sealing resin when melted are not released and remain in the molded product, resulting in molding defects. In particular, in the case of workpieces in which electronic components are mounted via wire connections, there is a risk of wire flow (deformation or breakage of the wire) due to the flow of resin inside the cavity during resin sealing.

On the other hand, when forming a molded product in which electronic components such as heat sinks are exposed, regardless of the arrangement of the cavities, the challenge is to prevent molding defects such as a specific part of the electronic component, such as the top surface of a heat sink (i.e., the cooling surface), not being exposed as designed.

The present invention has been made in consideration of the above circumstances, and aims to provide a sealing resin that is easy to handle and is particularly suitable for forming molded products in which the top surfaces of electronic components mounted on a workpiece are exposed, and that can realize a compression molding device and compression molding method that can prevent molding defects caused by resin flow, uneven winding, residual gas, and dust generation during molding, and can form molded products with large thickness dimensions, as well as a molding method and molding device for the sealing resin.

The present invention solves the above problems by the solution described below as one embodiment.

The sealing resin according to one embodiment is a sealing resin used in compression molding of a workpiece, and is required to be formed in a frame or lattice shape with through holes. For example, a workpiece having a configuration in which electronic components are mounted on a substrate is used as the workpiece. In that case, it is preferable that the resin is formed in a shape having through holes that accommodate the electronic components and expose the top surfaces of the electronic components when placed on the substrate.

In one embodiment, the method for forming a sealing resin is a method for forming a sealing resin used in compression molding of a workpiece having a configuration in which electronic components are mounted on a substrate, and includes a forming step of forming the sealing resin in a frame or lattice shape having through holes, and the forming step includes a step of setting and forming the positions and shapes of the through holes so that the electronic components of the workpiece are housed in the through holes and the top surfaces of the electronic components are exposed.

The forming step preferably includes a step of tableting a base resin to form the sealing resin. It is also preferable that a powder resin is used as the base resin.

By using the sealing resin according to the present invention, it is possible to realize a compression molding device and compression molding method that can prevent molding defects caused by resin flow, uneven winding, residual gas, and dust generation during molding, in particular molding defects where the top surface of electronic components mounted on the workpiece is not exposed, and form molded products with large thickness dimensions. In addition, handling is easier than with granular resins, especially when supplying and setting.

FIG. 2 is a plan view showing an example of a compression molding device in which a sealing resin according to an embodiment of the present invention is used 1A to 1C are explanatory diagrams illustrating an example of a compression molding method using a sealing resin according to an embodiment of the present invention. FIG. 3 is an explanatory diagram continuing from FIG. 2 . 4A is an explanatory view following FIG. 3, and FIG. 4B is an explanatory view following FIG. 4A, both of which are enlarged views of the portion IV in FIG. FIG. 4B is an explanatory diagram following FIG. 4B. FIG. 6 is an explanatory diagram following FIG. 5 . 5A to 5C are explanatory diagrams illustrating another example of a compression molding method using a sealing resin according to an embodiment of the present invention FIG. 8 is an explanatory diagram following FIG. 7 . FIG. 9 is an explanatory diagram following FIG. 8 . 1 is a side view illustrating an example of an apparatus for forming a sealing resin according to an embodiment of the present invention. FIG. 11 is a side cross-sectional view showing an example of a tableting die of the forming apparatus shown in FIG. 5A to 5C are explanatory diagrams of a method for forming a sealing resin according to an embodiment of the present invention. FIG. 13 is an explanatory diagram following FIG. 12. FIG. 14 is an explanatory diagram following FIG. 13. FIG. 2 is a perspective view illustrating an example of a sealing resin according to an embodiment of the present invention. 1 is a perspective view showing an example of a workpiece to be resin-sealed with a sealing resin according to an embodiment of the present invention; 1 is a perspective view showing an example of a molded product that is resin-sealed with a sealing resin according to an embodiment of the

(Compression molding device and compression molding method)
The sealing resin R according to the embodiment of the present invention is a sealing resin R used for compression molding of a workpiece W. First, an outline of a compression molding apparatus 1 and a compression molding method for resin sealing (compression molding) a workpiece W using the sealing resin R will be described. Here, FIG. 1 is a plan view (schematic view) showing an example of the compression molding apparatus 1.

The workpiece W to be sealed has a structure in which electronic components Wb are mounted on a substrate Wa. More specifically, examples of the substrate Wa include plate-shaped members such as resin substrates, ceramic substrates, metal substrates, carrier plates, lead frames, and wafers. Examples of the electronic components Wb include semiconductor chips, MEMS chips, passive elements, heat sinks, conductive members, spacers, and the like. The shape of the substrate Wa is rectangular (striped), square, circular, and the like. The number of electronic components Wb mounted on one substrate Wa is set to one or more (for example, in a matrix).

Examples of methods for mounting electronic components Wb on the substrate Wa include wire bonding and flip chip mounting. Alternatively, in the case of a configuration in which the substrate (glass or metal carrier plate) Wa is peeled off from the molded product Wp after resin sealing, the electronic components Wb can be attached using a thermally peelable adhesive tape or an ultraviolet-curable resin that is cured by exposure to ultraviolet light.

As examples of film F, film materials with excellent heat resistance, ease of peeling, flexibility, and extensibility, such as PTFE (polytetrafluoroethylene), ETFE (polytetrafluoroethylene polymer), PET, FEP, fluorine-impregnated glass cloth, polypropylene, polyvinylidine chloride, etc. are preferably used. Film F is also used when forming sealing resin R in forming device 100 described below.

As shown in FIG. 1, the compression molding device 1 mainly comprises a supply unit 10A for supplying the workpiece W, a press unit 10B for sealing the workpiece W with resin and processing it into a molded product Wp, and a storage unit 10C for storing the molded product Wp. As an example, the supply unit 10A, press unit 10B, and storage unit 10C are arranged in this order along the X direction in FIG. 1. However, the above configuration is not limited to this, and the equipment configuration within the unit, the number of units (particularly the number of press units), the arrangement order of the units, etc. can be changed. It is also possible to have a configuration that includes units other than those described above (all not shown).

In addition, the compression molding device 1 has a guide rail 20 that is linearly provided between each unit, and a transport device (first loader) 22 that transports the workpiece W and the sealing resin R, and a transport device (second loader) 24 that transports the molded product Wp (which may be used to transport the sealing resin R) are provided so as to be movable between predetermined units along the guide rail 20. However, the configuration is not limited to the above, and a configuration may be provided with a common (single) transport device (loader) that transports the workpiece W, the sealing resin R, and the molded product Wp (not shown). Furthermore, the transport device may be configured to include a robot hand or the like instead of a loader.

In addition, the compression molding device 1 has a control unit 30 that controls the operation of each mechanism in each unit, which is located in the supply unit 10A (it may also be configured to be located in another unit).

The press unit 10B is equipped with a pair of sealing dies that are opened and closed by the press device 250. As an example, the sealing dies may be configured such that a cavity is provided in the upper die (sealing die 202), or as another example, may be configured such that a cavity is provided in the lower die (sealing die 302). The press device 250 is also provided with a film supply section 211 that supplies film F to cover the die surface 204a (predetermined area) including the inner surface of the cavity 208 in the upper die 204. As an example, the film F is in a roll shape, but it may also be in a strip shape.

As an example, the steps of a compression molding method performed using a compression molding apparatus 1 equipped with a sealing mold 202 will be described with reference to Figures 2 to 6. In this embodiment, an example will be described in which a molded product Wp is formed in which a predetermined portion Wbf of an electronic component Wb such as a heat sink (specifically, the upper surface (referring to the surface opposite the substrate Wa), i.e., the cooling surface) of the heat sink is exposed. Note that, for simplicity of explanation, the electronic component Wb on the substrate Wa is treated as a single component, but it may be made up of multiple laminated components.

First, a preparation process (sealing preparation process) is carried out. Specifically, a process is carried out in which the upper mold 204 and the lower mold 206 are adjusted to a predetermined temperature (e.g., 100°C to 300°C) and heated. In addition, a process is carried out in which the film supply unit 211 is operated to supply new film F and adsorb it to cover a predetermined area of the mold surface 204a, including the inner surface of the cavity 208 in the upper mold 204.

After the preparation process, a workpiece holding process is performed in which the workpiece W is held by the workpiece holding portion 205 of the lower die 206. Specifically, the workpiece W supplied from the supply magazine 12 is held by the first loader 22 and carried into the sealing die 202, where it is held by the workpiece holding portion 205 of the lower plate 242 (die surface 206a) (see FIG. 2).

After the workpiece holding step, a resin placing step is performed in which the sealing resin R is placed on the workpiece W held by the workpiece holding section 205 (see FIG. 3). Specifically, the sealing resin R formed in the sealing resin forming device (sometimes simply referred to as the "forming device") 100 described below is held by the first loader 22 (or another conveying device may be used) and carried into the sealing mold 202, and placed on the workpiece W held by the workpiece holding section 205. When forming a molded product Wp in which the top surface Wbf of the electronic component Wb is exposed, the workpiece W and the sealing resin R are aligned with each other and placed so that the electronic component Wb is accommodated in the through hole Rh (described in detail later) of the sealing resin R.

Alternatively, as another example of the resin placing process, the sealing resin R formed in the forming device 100 may be placed on the workpiece W before the above-mentioned workpiece holding process. In this case, the workpiece holding process is a process in which the workpiece W with the sealing resin R placed thereon is held by the workpiece holding section 205. That is, the first loader 22 holds the workpiece W with the sealing resin R placed thereon, carries it into the sealing die 202, and holds it in the workpiece holding section 205. This has the advantage of carrying out the workpiece W and sealing resin R in the sealing die 202 in one go, rather than separately.

Next, a resin sealing process is performed in which the workpiece W is sealed with sealing resin R and processed into a molded product Wp. Specifically, the sealing mold 202 is closed, and the cavity piece 226 is lowered relatively within the cavity 208 surrounded by the clamper 228, to perform a mold closing process in which the sealing resin R is heated and pressurized against the workpiece W.

When forming a molded product Wp in which the top surface Wbf of the electronic component Wb is exposed, it is preferable that the sealing mold 202 (in this case, the upper mold 204) has the following configuration. Specifically, the cavity piece 226 is provided with a movable piece 236 that abuts against the entire top surface Wbf of the electronic component Wb and is movable up and down. The movable piece 236 is supported in a state in which it is biased toward the lower mold 206 by a movable piece spring 234 via a pushing pin 232. As an example, the movable piece 236 is set to have an outer shape that is a predetermined dimension larger than the outer shape of the electronic component Wb in a plan view.

The mold closing process performed using the sealing mold 202 having this configuration is as follows. Specifically, the upper mold 204 and the lower mold 206 are moved closer to each other. At this time, the clamper 228 first comes into contact with the base material Wa of the work W and clamps the work W (see FIG. 4A). Next (or at the same time), the movable piece 236 comes into contact with the upper surface Wbf of the electronic component Wb of the work W, covering the entire upper surface Wbf (see FIG. 4B). Next, the lower surface of the cavity piece 226 (the area where the movable piece 236 is not provided) comes into contact with the sealing resin R placed on the base material Wa of the work W and further pressurizes it. This mold closing process causes the sealing resin R to thermally harden and complete the resin sealing (compression molding) (see FIG. 5).

As a step following the mold closing step, the sealing mold 202 is opened and the molded product Wp is separated from the used film F so that the molded product Wp can be removed (see FIG. 6). In this embodiment, as described above, resin sealing is performed with the movable piece 236 covering the upper surface Wbf (entire surface) of the electronic component Wb of the workpiece W, so that the molded product Wp is formed with the upper surface Wbf (entire surface) exposed. As a modified example, it is also possible to set a partial area as the exposed portion instead of the entire upper surface Wbf of the electronic component Wb (not shown).

Next, the molded product Wp is removed from the sealing mold 202 by the second loader 24, and a molded product removal process is carried out to transport it to the storage unit 10C. As an example, the transported molded product Wp is stored in the storage magazine 14. In addition, after or in parallel with the molded product removal process, a process is carried out in which the film supply unit 211 is operated to send out the used film F from the sealing mold 202 and send a new film F into the sealing mold 202 and set it there.

The above are the main steps of the compression molding method performed using the compression molding device 1 when equipped with the sealing mold 202. However, the above order of steps is only an example, and the order of steps can be changed or steps can be performed in parallel as long as there are no problems.

As another example, the steps of a compression molding method performed using a compression molding apparatus 1 equipped with a sealing mold 302 will be described with reference to Figures 7 to 9. In this case, the press device 250 is provided with a film supply section 311 that supplies film F to cover the mold surface 306a (predetermined area) including the inner surface of the cavity 308 in the lower mold 306. As an example, the film F is in a roll shape, but it may also be in a strip shape.

First, a preparation process (sealing preparation process) is carried out. Specifically, a process is carried out in which the upper die 304 and the lower die 306 are adjusted to a predetermined temperature (e.g., 100°C to 300°C) and heated. In addition, a process is carried out in which the film supply unit 311 is operated to supply new film F and adsorb it so as to cover a predetermined area of the die surface 306a, including the inner surface of the cavity 308 in the lower die 306.

After the preparation process, a workpiece holding process is performed in which the workpiece W is held by the workpiece holding portion 305 of the upper die 304. Specifically, the workpiece W supplied from the supply magazine 12 is held by the first loader 22 and carried into the sealing die 302, where it is held by the workpiece holding portion 305 of the upper plate 342 (die surface 304a).

After the workpiece holding process, the resin holding process is performed (it may be performed before or in parallel with the workpiece holding process). The resin holding process includes the following steps. The sealing resin R is held in the cavity 308 of the lower die 306 (see FIG. 7). Specifically, the sealing resin R formed in the forming device 100 is held by the first loader 22 (or another conveying device) and carried into the sealing mold 302, and accommodated in the cavity 308 (specifically, placed on the upper surface of the cavity piece 326). When forming a molded product Wp in which the upper surface Wbf of the electronic component Wb is exposed, the workpiece W and the sealing resin R are aligned with each other and held so that the electronic component Wb is accommodated in the through hole Rh (details will be described later) of the sealing resin R.

Next, a resin sealing process is performed in which the workpiece W is sealed with sealing resin R and processed into a molded product Wp. Specifically, the sealing mold 302 is closed, and the cavity piece 326 is raised relatively within the cavity 308 surrounded by the clamper 328 to perform a mold closing process in which the sealing resin R is heated and pressurized against the workpiece W. This causes the sealing resin R to thermally harden, completing the resin sealing (compression molding) (see FIG. 8).

In this example (when the sealing mold 302 is provided), the cavity piece 326 of the lower mold 306 may be provided with a movable piece 336, a push pin 332, and a movable piece spring 334 configured in the same manner as in the previous example (when the sealing mold 202 is provided). This allows the upper surface Wbf of the workpiece W (electronic component Wb) that abuts against the movable piece 236 to be formed as an exposed surface.

As a process following the mold closing process, the sealing mold 302 is opened and the molded product Wp is separated from the used film F so that the molded product Wp can be removed (see FIG. 9). Next, the molded product unloading process is carried out in which the second loader 24 unloads the molded product Wp from the sealing mold 302 and transports it to the storage unit 10C. As an example, the transported molded product Wp is stored in the storage magazine 14. In addition, after or in parallel with the molded product unloading process, the film supply unit 311 is operated to send out the used film F from the sealing mold 302 and send a new film F into the sealing mold 302 and set it there.

The above are the main steps of the compression molding method performed using the compression molding device 1 when equipped with the sealing mold 302. However, the above order of steps is only an example, and the order of steps can be changed or steps can be performed in parallel as long as there are no problems.

(Sealing resin forming device)
Next, the forming device 100 for forming the sealing resin R used in the compression molding device 1 and the compression molding method will be described with reference to Figs. 10 and 11. The forming device 100 processes the base resin Rm to form the sealing resin R. Here, Fig. 10 is a side view (schematic view) showing an example of the forming device 100. The forming device 100 may be provided either inside or outside the compression molding device 1.

In this embodiment, a thermosetting resin (such as, but not limited to, an epoxy resin containing a filler) is used as the base resin Rm and the sealing resin R formed from the base resin Rm. The sealing resin R is formed as a solid or semi-solid resin having a predetermined shape (details will be described later) that corresponds to the shape of the workpiece W. Usually, one piece constitutes the "whole" of the required amount of sealing (one time per workpiece W), but it may be configured so that several pieces (e.g., about two or three pieces) are divided to constitute the "whole" of the required amount of sealing. In addition, the above-mentioned "semi-solid" does not mean a completely solid state, but a state in which it is melted to the so-called B stage. In addition, a powder resin (form) that is a thermosetting resin (property) is preferably used for the base resin Rm (details will be described later). However, it is not limited to this, and a granular resin, a crushed resin, a solid resin, a liquid resin, or a resin that is a combination of a plurality of them may be used.

As shown in FIG. 10, the forming device 100 is equipped with a tableting die 102 having a pair of dies that are opened and closed (for example, a combination of multiple die blocks, die plates, die pillars, etc., made of alloy tool steel, and other components). It also has a press device 150 that drives the tableting die 102 to open and close. It also has a control calculation unit 170 that controls the operation of each mechanism. Here, FIG. 11 is a side cross-sectional view (schematic diagram) showing an example of the tableting die 102.

As shown in FIG. 10, the press device 150 is configured with a pair of platens 154, 156, a plurality of tie bars 152 on which the pair of platens 154, 156 are supported, and a drive device for moving (raising and lowering) the platen 156. Specifically, the drive device is configured with a drive source (e.g., an electric motor) 160 and a drive transmission mechanism (e.g., a ball screw or a toggle link mechanism) 162 (however, this is not limited to this). In this embodiment, the upper platen 154 in the vertical direction is set as a fixed platen (a platen fixed to the tie bars 152), and the lower platen 156 is set as a movable platen (a platen slidably held by the tie bars 152 and raised and lowered). However, this is not limited to this, and the platens may be set upside down, i.e., the upper side may be set as a movable platen and the lower side as a fixed platen, or both the upper and lower sides may be set as movable platens (neither is shown).

On the other hand, as shown in FIG. 11, the tableting die 102 is provided with an upper die 104 on the upper side in the vertical direction and a lower die 106 on the lower side as a pair of dies arranged between the pair of platens 154, 156 in the press device 150. The upper die 104 is assembled to the upper platen (in this embodiment, the fixed platen 154), and the lower die 106 is assembled to the lower platen (in this embodiment, the movable platen 156). The upper die 104 and the lower die 106 approach and move away from each other to close and open the die (the vertical direction (up and down direction) is the die opening and closing direction). In the tableting die 102 according to this embodiment, the upper die 104 constitutes a so-called "pestle die", and the lower die 106 constitutes a so-called "mortar die".

Next, the lower die 106 of the tableting die 102 will be described in detail. As shown in FIG. 11, the lower die 106 is equipped with a lower die chase 110, a cavity piece 126 held by it, a clamper 128, etc. The lower die chase 110 is fixed to the upper surface of the support plate 114 via a support pillar 112. A cavity 108 is provided on the upper surface of the lower die 106 (the surface facing the upper die 104). A predetermined amount of base resin Rm is accommodated in this cavity 108.

The lower die 106 according to the present embodiment has the following configuration for pressing a predetermined amount of base resin Rm contained in the cavity 108 to form (tablet) the sealing resin R having a predetermined shape corresponding to the shape of the workpiece W (details of the forming method will be described later). Specifically, in the cavity piece 126 (within the area of the cavity piece 126 in a plan view), a movable piece 136 is provided that can abut against a tableting plate 142 of the upper die 104 described later and can move up and down. The movable piece 136 is supported in a state in which it is biased toward the upper die 104 by the movable piece spring 134 via the push pin 132. As an example, the movable piece 136 is set to have an outer shape that is a predetermined dimension larger than the outer shape of the electronic component Wb in a plan view. In the lower mold 106 having the above configuration, a predetermined amount of base resin Rm is accommodated in the recessed portion 138 between the movable pieces 136 (note that the base resin Rm may first be sprayed over the entire cavity 108, including the top surface of the movable pieces 136, and then swept off with a squeegee or the like so that it is finally accommodated in the recessed portion 138).

The clamper 128 is configured in an annular shape to surround the cavity piece 126, and is assembled to be movable up and down while being spaced (floating) from the upper surface of the support plate 114 via the push pin 122 and the clamper spring 124 (a biasing member such as a coil spring, for example) (however, this assembly structure is not limited). The cavity piece 126 forms the inner part (bottom part) of the cavity 108, and the clamper 128 forms the side part of the cavity 108. The shape and number of cavities 108 provided in one lower mold 106 are set appropriately (one or multiple).

Here, the press device 150 is provided with a lower die film supply section 111 that supplies film F to cover the die surface 106a (predetermined area) including the inner surface of the cavity 108 in the lower die 106. As an example, the film F is in a roll shape, but it may also be in a strip shape.

In addition, the lower mold 106 is provided with suction paths (holes, grooves, etc.) (not shown) that communicate with a suction device on the upper surface of the clamper 128 and at the boundary between the clamper 128 and the cavity piece 126. This allows the film F supplied from the lower mold film supply unit 111 to be adsorbed and held on the mold surface 106a, including the inner surface of the cavity 108.

In this embodiment, a lower die heating mechanism (not shown) is provided to heat the lower die 106 to a predetermined temperature. This lower die heating mechanism includes a heater (e.g., an electric wire heater), a temperature sensor, a power source, etc., and heating is controlled by the control unit 30. As an example, the heater is built into the lower die chase 110 and is configured to apply heat to the entire lower die 106 and the base resin Rm contained in the cavity 108. At this time, the lower die 106 is heated to a predetermined temperature (e.g., 50°C to 80°C) at which the base resin Rm does not thermally harden (mainly harden).

Next, the upper die 104 of the tableting die 102 will be described in detail. As shown in FIG. 11, the upper die 104 is provided with a tableting plate 142 that presses a predetermined amount of base resin Rm contained in the cavity 108 of the lower die 106 to form (tablet) the sealing resin R having a predetermined shape corresponding to the shape of the workpiece W (details of the forming method will be described later). The tableting plate 142 is held (fixed) by the upper die chase 140. In this embodiment, a convex portion 144 that can abut against the movable piece 136 of the lower die 106 described above is provided on the lower surface (the surface on the lower die 106 side) of the tableting plate 142. As an example, the convex portion 144 is set so that it abuts against the upper surfaces of all the movable pieces 136 in a plan view and has an outer shape that can cover all the concave portions 138, and is erected at a predetermined height (set according to the forming thickness of the sealing resin R) on the lower surface of the tableting plate 142.

Here, the press device 150 is provided with an upper die film supply section 113 that supplies a film F to cover the die surface 104a (predetermined area) of the upper die 104. As an example, the film F is in a roll shape, but it may also be in a strip shape.

The upper die 104 also has suction passages (holes, grooves, etc.) (not shown) in the tableting plate 142, etc., that communicate with a suction device. This allows the film F supplied from the upper die film supply unit 113 to be adsorbed and held on the die surface 104a.

In addition, in this embodiment, an upper mold heating mechanism (not shown) is provided that heats the upper mold 104 to a predetermined temperature. This upper mold heating mechanism includes a heater (e.g., an electric wire heater), a temperature sensor, a power source, etc., and heating is controlled by the control unit 30. As an example, the heater is built into the upper mold chase 140 and is configured to apply heat to the entire upper mold 104. At this time, the upper mold 104 is heated to a predetermined temperature (e.g., 50°C to 80°C) at which the base resin Rm held (contained) in the lower mold 106 does not thermally cure (mainly cure).

(Method of forming sealing resin)
Next, there will be described steps of the method for forming the sealing resin according to the present embodiment, which is carried out using the above-mentioned forming apparatus 100. Here, Fig. 12 to Fig. 14 are explanatory views of each step, and are illustrated as side cross-sectional views in the same direction as Fig. 11.

First, a preparation step (tabletting preparation step) is performed. The preparation step includes the following steps. A lower mold heating step is performed in which the lower mold 106 is heated to a predetermined temperature (a temperature at which the base resin Rm and the sealing resin R do not fully cure, for example, 50°C to 80°C) by the lower mold heating mechanism. In addition, an upper mold heating step is performed in which the upper mold 104 is heated to a predetermined temperature (a temperature at which the base resin Rm and the sealing resin R do not fully cure, for example, 50°C to 80°C) by the upper mold heating mechanism. In addition, a lower mold film supply step is performed in which the lower mold film supply unit 111 is operated to supply a new film F and adsorb it to cover a predetermined area of the mold surface 106a including the inner surface of the cavity 108 in the lower mold 106. In addition, an upper mold film supply step is performed in which the upper mold film supply unit 113 is operated to supply a new film F and adsorb it to cover a predetermined area of the mold surface 104a of the upper mold 104.

After the preparation process, a forming process is carried out to form the sealing resin R in a "predetermined shape" (details will be described later). As an example, a tableting process is provided in which the base resin Rm is tableted to form the sealing resin R into a solid or semi-solid resin having a predetermined overall shape that corresponds to the shape of the workpiece W. As another example of the forming process, a forming method that does not involve tableting may be adopted.

Specifically, the tableting process involves placing a "predetermined amount" (details to be described later) of base resin Rm into the cavity 108 of the lower die 106 using a dispenser (not shown) or the like (see FIG. 12). As described above, the base resin Rm is placed in the recessed portion 138 between the movable pieces 136 without resting on the upper surface of the movable pieces 136 (note that the base resin Rm may first be sprayed over the entire cavity 108 including the upper surface of the movable pieces 136, and then swept off with a squeegee or the like, before finally being placed in the recessed portion 138).

Next, the press device 150 is operated to close the tableting die 102 that has been heated to the above-mentioned predetermined temperature (see FIG. 13). At this time, the cavity piece 126 rises relatively within the cavity 108, and the base resin Rm is tableted (sandwiched and pressurized) between the cavity piece 126 and the tableting plate 142.

More specifically, first the clamper 128 and the tableting plate 142 (outer part than the convex part 144) come into contact. Then (or at the same time), the upper surface of the movable piece 136 comes into contact with the lower surface of the convex part 144 of the tableting plate 142, so that the entire upper surface of the movable piece 136 is covered. Next, the base resin Rm is tableted (sandwiched and pressed) between the upper surface of the cavity piece 126 (the area of the concave part 138) and the lower surface of the convex part 144 of the tableting plate 142 (the area facing the concave part 138). This forms a solid or semi-solid sealing resin R that has a "predetermined shape" and is not thermally cured (mainly cured). Specifically, the "predetermined shape" is a frame-like or lattice-like shape that is approximately plate-like and has through holes Rh penetrating the plate surface. In this embodiment, the base resin Rm around the movable piece 136 of the lower die 106 (concave portion 138) is formed as the main body portion Ra of the sealing resin R by the above-mentioned forming process (tabletting process in this case), and the position of the movable piece 136 is formed as a through hole Rh. Note that although the movable piece 136 is provided on the cavity piece 126, it may also be provided on the tableting plate 142 (not shown).

An example of the configuration (shape) of the sealing resin R formed in the above process is shown in Figure 15. Specifically, this is an example of a lattice-shaped sealing resin R in which a number of through holes Rh are arranged side by side in a plate-shaped main body portion Ra (however, this is not limited to this). The sealing resin R may be configured so that one piece of the sealing resin R constitutes the "whole" (in this case, lattice-shaped) amount required for sealing (one application per workpiece W), or it may be configured so that a group (connected) of multiple pieces (e.g., two or three pieces) constitutes the "whole" (in this case, lattice-shaped) amount required for sealing.

The above-mentioned sealing resin R (see FIG. 15) can be particularly suitably used for compression molding of a workpiece W (see FIG. 16) in which a heat sink or the like is mounted as an electronic component Wb on a substrate Wa. Specifically, by using the above-mentioned sealing resin R, it is possible to reliably form a configuration in which the upper surface Wbf of the electronic component Wb (heat sink or the like) is exposed in the molded product Wp (see FIG. 17) after resin sealing (after compression molding).

Therefore, in the above-mentioned forming process, it is important to set the position and shape of the through hole Rh in the sealing resin R so that the electronic component Wb of the workpiece W to be sealed is accommodated in the through hole Rh and the top surface Wbf of the electronic component Wb is exposed.

It is important that the above tableting process is carried out at a temperature at which the base resin Rm does not thermally harden (fully harden) (the lower die 106 and the upper die 104 are heated to a temperature at which the base resin Rm does not thermally harden (fully harden)) so that the encapsulating resin R formed can be thermally hardened (fully hardened) in the subsequent resin encapsulating process (a process of the compression molding method). As described above, the "temperature at which the base resin Rm does not thermally harden (fully harden)" depends on the material of the base resin Rm, but is specifically about 50°C to 80°C (about 70°C in this embodiment).

Next, the resin amount setting process for setting the "predetermined amount" of the base resin Rm will be described. As an example of the resin amount setting process, for each workpiece W to be sealed, the number of electronic components Wb mounted on one substrate Wa (the number of mounted or missing components, which may also include measuring the height or weight of the electronic components Wb) is measured by a measuring mechanism or the like (not shown), and the total volume of the electronic components Wb is subtracted from the volume of the cavities 208, 308 of the sealing molds 202, 302 to calculate the amount of resin (in grams) required for resin sealing (compression molding) and set the "predetermined amount". Alternatively, as another example of the resin amount setting process, multiple types of fixed amounts corresponding to the types of workpieces W to be sealed are prepared, and the control calculation unit 170 or the operator selects one of the fixed amounts that is optimal according to the type of workpiece W to set the "predetermined amount". In the case of a fixed amount, it is important that the amount of resin is not insufficient during resin sealing (compression molding). Regardless of the setting, an appropriate amount of base resin Rm can be supplied according to the type of workpiece W. As a result, the appropriate amount of sealing resin R can be accurately formed for each workpiece W. Therefore, molding defects caused by a shortage of the amount of resin required during resin sealing can be prevented. In addition, waste caused by supplying an amount of resin that is greater than necessary can be prevented. In particular, when forming a molded product Wp on which an electronic component Wb, such as a heat sink, is mounted, molding defects can be prevented in which a predetermined portion of the electronic component Wb, (for example, the upper surface, i.e., the cooling surface, of the heat sink) Wbf, is not exposed.

It is also preferable to use a powder resin as the base resin Rm. This allows the "predetermined amount" of resin to be adjusted and supplied with extremely high precision compared to when granular or crushed resin is used. However, it is not limited to powder resin.

After the tableting process, the tableting die 102 is opened and the sealing resin R is separated from the used film F to enable removal of the sealing resin R (see FIG. 14). In this embodiment, the above-mentioned lower die film supply process and upper die film supply process are provided, so that the film F is placed on both the die surface 106a of the lower die 106 and the die surface 104a of the upper die 104, making it easier to release the sealing resin R formed by tableting and preventing damage caused by resin adhesion to the die.

After or in parallel with the mold opening process, the lower mold film supply unit 111 and the upper mold film supply unit 113 are operated to send out the used film F from inside the tableting mold 102 and to send and set a new film F into the tableting mold 102, thereby carrying out a film supply process (lower mold film supply process, upper mold film supply process).

The above process order is just one example, and the order can be changed or the steps can be carried out in parallel as long as no problems are encountered.

As explained above, the sealing resin according to the present invention can be suitably applied to compression molding apparatuses and compression molding methods having a cavity in either the upper mold or the lower mold.

In addition, by using the sealing resin according to the present invention, a compression molding apparatus and a compression molding method that achieve the following effects can be realized. Specifically, the compression molding apparatus and the compression molding method can prevent molding defects caused by resin flow, uneven winding, residual gas, and dust generation during molding. In particular, when a heat sink or the like is mounted as an electronic component, molding defects in which a specific portion of the electronic component (for example, the upper surface of the heat sink, i.e., the cooling surface) is not exposed in the molded product can be prevented. In addition, it is possible to form not only thin molded products (thickness dimension less than 1 mm) but also thick molded products (thickness dimension 1 mm or more). The upper limit of the thickness dimension depends on various setting conditions, but it is considered that it is possible to form up to about 10 mm. In addition, handling during supply and setting is made easier.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the present invention. In particular, a heat sink is given as an example of an electronic component, but this is not limiting. Also, although a case where the entire top surface of an electronic component is the exposed portion is given as an example, this is not limiting.

Reference Signs List 1 Compression molding device 100 Molding resin forming device 102 Tableting mold 138 Concave portion 144 Convex portion 202, 302 Molding mold 236, 336 Movable piece Rm Base resin R Molding resin Ra Main body Rh Through hole W Work Wa Substrate Wb Electronic component

Claims (7)

A method for forming a sealing resin used in compression molding of a workpiece having a configuration in which an electronic component is mounted on a substrate, comprising the steps of:
forming the sealing resin in a frame or lattice shape having through holes;
The method for forming a sealing resin is characterized in that the forming process includes a step of setting and forming the position and shape of the through hole so that the electronic component of the work is accommodated in the through hole and the top surface of the electronic component is exposed. 2. The method for forming an encapsulating resin according to claim 1, wherein the forming step includes a step of forming the encapsulating resin by tableting a base resin. 3. The method for forming a sealing resin according to claim 2, wherein a powder resin is used as the base resin. A forming apparatus for tableting a base resin to form an encapsulating resin to be used in compression molding of a workpiece, comprising:
An apparatus for forming an encapsulating resin, comprising: a tableting die that accommodates the base resin and tablets the encapsulating resin into a frame-like or lattice-like shape having through holes corresponding to the shape of the workpiece. A sealing resin used in compression molding of a workpiece,
A sealing resin formed in a frame or lattice shape having through holes. A sealing resin used in compression molding of a workpiece having a configuration in which an electronic component is mounted on a substrate,
The sealing resin is formed in a shape having a through hole that houses the electronic component and exposes an upper surface of the electronic component when the electronic component is placed on the base material. 7. The sealing resin according to claim 6, wherein the sealing resin is formed in a frame-like or lattice-like shape having the through holes.

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