Compression molding method

Abstract

The present invention provides a compression molding method that can prevent the generation of voids even when the workpiece has a narrow section, thereby preventing molding defects caused by voids. [Solution] The compression molding method according to the present invention comprises: a resin preparation step of preparing a sheet-like resin of a predetermined shape as the sealing resin R; a workpiece holding step of holding a workpiece W, in which the sheet-like resin R is placed on an electronic component Wb, in a predetermined position inside the sealing mold 202; a first mold closing step of closing the sealing mold 202 so that the first mold 204 and the second mold 206 come into contact and seal the inside of the sealing mold 202; a depressurization step of reducing the pressure inside the sealing mold 202 after the first mold closing step; and a second mold closing step of further closing the sealing mold 202 after the depressurization step, or while the depressurization step is being carried out, to seal the workpiece W with the sheet-like resin R and process it into a molded product Wp.

Description

Technical Field

[0001] The present invention relates to a compression molding method.

Background Art

[0002] As an example of a resin sealing method for sealing a work having electronic components with a sealing resin and processing it into a molded product, a method using a compression molding method is known.

[0003] The compression molding method is a technique for resin sealing by supplying a predetermined amount of sealing resin to a sealing region (cavity) provided in a sealing mold configured to include a first mold (for example, an upper mold) and a second mold (for example, a lower mold), placing a work in the sealing region, and clamping with the lower mold and the upper mold. As an example, when using a sealing mold provided with a cavity in the upper mold, a technique of supplying the sealing resin all at once to the center position on the work and molding is known (see Patent Document 1: Japanese Patent Application Laid-Open No. 2017-209903).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the conventional compression molding exemplified in Patent Document 1, a liquid resin is used as the sealing resin, and a step of discharging a predetermined amount onto a work on which electronic components are mounted on a base material is provided.

[0006] Conventionally, when sealing a work with a sealing resin and processing it into a molded product, air or the like contained in the work or the sealing resin or taken in during the process remains as so-called voids without escaping, causing molding defects, which has been a problem.

Means for Solving the Problems

[0007] In response to the above-mentioned problems, the inventors conducted diligent research and found that, until now, liquid resins were thought to have excellent filling properties, easily penetrate into narrow spaces (for example, the space between flip-chip mounted electronic components and the substrate), and thus suppress the generation of voids. However, it was discovered that in reality, when liquid resin is dispensed onto a workpiece, it can trap air in narrow spaces and seal the surrounding area, which can actually become a cause of void generation.

[0008] The present invention has been made in view of the above circumstances, and aims to provide a compression molding method that can prevent the generation of voids even when the workpiece has a narrow portion, and can prevent the generation of molding defects caused by voids.

[0009] The present invention solves the above problem by a solution described below as one embodiment.

[0010] A compression molding method according to one embodiment is a compression molding method for processing a workpiece on which electronic components are mounted on a substrate into a molded product by sealing it with a sealing resin using a sealing mold comprising a first mold and a second mold, wherein the method comprises: a resin preparation step of preparing a sheet-like resin of a predetermined shape as the sealing resin; a workpiece holding step of holding the workpiece, on which the sheet-like resin is placed with the electronic components, in a predetermined position within the sealing mold; a first mold closing step of closing the sealing mold so that the first mold and the second mold come into contact and the inside of the sealing mold is sealed; a depressurization step of reducing the pressure inside the sealing mold after the first mold closing step; and a second mold closing step of further closing the sealing mold after the depressurization step, or while the depressurization step is being carried out, to seal the workpiece with the sheet-like resin and process it into a molded product.

[0011] According to this method, even with workpieces that have particularly narrow sections, it is possible to prevent air from remaining in the workpiece, improve the filling properties of the sealing resin, and prevent the formation of voids.

[0012] Furthermore, it is preferable that the first mold closing step is a step in which the first mold and the second mold come into contact to seal the inside of the sealing mold, and the sealing mold is closed while remaining at a position where no pressing force is applied to the workpiece.

[0013] Furthermore, it is preferable to further include a resin melting step, after the first mold closing step and before the second mold closing step, in which the sheet-like resin is melted in the heated sealing mold while the depressurization step is performed, and the melting step is allowed to enter at least part or all of the space formed between the electronic components.

[0014] Furthermore, it is preferable that the workpiece holding step includes the step of placing the sheet-like resin on the electronic components of the workpiece outside the sealing mold, then transporting the workpiece into the sealing mold and holding it in a predetermined position, or transporting the workpiece into the sealing mold and holding it in a predetermined position, and then placing the sheet-like resin on the electronic components of the workpiece inside the sealing mold.

[0015] Furthermore, it is preferable to use a workpiece that has a space between the substrate and the electronic component.

[0016] Furthermore, it is preferable that the sheet-like resin used has an adhesive surface, and that the workpiece holding step includes a step of adhering the sheet-like resin to the electronic components of the workpiece. [Effects of the Invention]

[0017] According to the present invention, void formation can be prevented even when the workpiece has a narrow section. Therefore, the occurrence of molding defects caused by voids can be prevented. [Brief explanation of the drawing]

[0018] [Figure 1] Figure 1 is a plan view showing an example of a compression molding apparatus used when implementing the compression molding method according to this embodiment. [Figure 2] Figure 2 is a side view showing an example of the press device of the compression molding device in FIG. 1. [Figure 3] Figure 3 is an explanatory diagram of the compression molding method according to an embodiment of the present invention. [Figure 4] Figure 4 is an explanatory diagram following FIG. 3. [Figure 5] Figure 5 is an explanatory diagram following FIG. 4. [Figure 6] Figure 6 is an explanatory diagram following FIG. 5. [Figure 7] Figure 7 is an explanatory diagram following FIG. 6. [Figure 8] Figure 8 is an explanatory diagram following FIG. 7. [Figure 9] Figure 9 is an explanatory diagram following FIG. 8.

Embodiments for Carrying Out the Invention

[0019] (Compression Molding Device) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view (schematic view) showing an example of a compression molding device 1 used when implementing the compression molding method according to the present embodiment. For the sake of convenience of explanation, in the figure, the left - right direction (X - direction), front - rear direction (Y - direction), and up - down direction (Z - direction) in the compression molding device 1 are indicated by arrows. Also, in all the drawings for explaining each embodiment, members having the same function are denoted by the same reference numerals, and repeated explanations may be omitted.

[0020] The compression molding apparatus 1 is an apparatus that uses a sealing mold 202 equipped with a first mold (for example, an upper mold 204) and a second mold (for example, a lower mold 206) to resin-seal (compression-molded) a workpiece (product to be molded) W. Hereinafter, the compression molding apparatus 1 will be described using an example where the workpiece W is held by a workpiece holding section 205 provided on either the upper mold 204 or the lower mold 206, and the cavity 208 (including a portion of the mold surface) provided on the other is covered with a release film F. A clamping operation is performed by closing the molds of the upper mold 204 and the lower mold 206, and the workpiece W is resin-sealed (compression-molded) using a sealing resin R. However, the apparatus is not limited to this configuration, and a release film is not mandatory.

[0021] First, the workpiece W to be molded has a configuration in which electronic components Wb are mounted on a base material Wa. Examples of base material Wa include rectangular or circular plate-shaped members such as resin substrates, ceramic substrates, metal substrates, carrier plates, lead frames, and wafers. On the other hand, examples of electronic components Wb include coil sheets, semiconductor chips, MEMS chips, passive elements, heat sinks, conductive members, and spacers. The workpiece W has a configuration in which these electronic components Wb are mounted on the base material Wa (flip-chip mounting, wire bonding mounting, etc.). As an example, the top surface of the electronic component Wb (the surface opposite to the base material Wa) is configured as a flat plane within the same plane, but this is not limited to this. Also, the number of electronic components Wb constituting one workpiece W is not particularly limited and can be set to one or more.

[0022] A thermosetting resin (for example, an epoxy resin containing a filler) is used as the sealing resin R. However, the configuration is not limited to this. In this embodiment, a sheet-like resin is used as the sealing resin R. This sealing resin R is formed in a sheet-like shape (for example, about 50 to 500 μm thick) with a predetermined shape (set according to the configuration of the workpiece W and molded product Wp) having tackiness (adhesion) on its surface (both sides, or at least one side that is in close contact with the workpiece W). In order to prevent the sheet-like resins R from sticking together, a protective film (not shown) is attached to the surface (both sides or one side).

[0023] Furthermore, as the release film F, film materials with excellent heat resistance, ease of peeling, flexibility, and stretchability, such as PTFE (polytetrafluoroethylene), ETFE (polytetrafluoroethylene polymer), PET, FEP, fluorine-impregnated glass cloth, polypropylene, and polyvinylidine chloride are preferably used.

[0024] Next, an overview of the compression molding apparatus 1 according to this embodiment will be described. As shown in Figure 1, the compression molding apparatus 1 mainly comprises a transport unit 100A that primarily transports the workpiece W and the molded product Wp, a workpiece supply unit 100B that primarily supplies the workpiece W, a resin supply unit 100C that primarily supplies the resin, a press unit 100D that primarily processes the workpiece W into a molded product Wp by resin sealing, a post-cure unit 100E that primarily performs post-curing of the molded product Wp after resin sealing, a molded product storage unit 100F that primarily stores the molded product Wp after post-curing, and a control unit 100G that primarily controls each mechanism and each process.

[0025] In this embodiment, the transport unit 100A is positioned in the center of the apparatus, and each unit is arranged to surround the transport unit 100A. Specifically, the work supply unit 100B, resin supply unit 100C, and molded product storage unit 100F are positioned in front of the transport unit 100A. The press unit 100D is positioned behind the transport unit 100A. The post-cure unit 100E is positioned to the right and front right of the transport unit 100A. The control unit 100G is positioned to the rear right of the transport unit 100A. However, the configuration is not limited to this.

[0026] Furthermore, the compression molding apparatus 1 can be modified by changing the configuration of its units. For example, the configuration shown in Figure 1 is an example where two press units 100D are arranged, but it is also possible to arrange only one press unit 100D, or three or more press units 100D, etc. It is also possible to arrange other units in addition (none of which are shown).

[0027] (Transport unit) First, let's describe the transport unit 100A provided by the compression molding apparatus 1.

[0028] The transport unit 100A is equipped with a transport device 102 for transporting workpieces W and molded products Wp. For example, the transport device 102 is configured to include a guide rail 104, a base portion 106 that reciprocates along the guide rail 104 in a predetermined direction (for example, left and right), and a holding and moving mechanism 108 (for example, a multi-joint robot) fixed to the base portion 106 for holding and moving workpieces W and molded products Wp. This allows for the holding of workpieces W and molded products Wp, transport between units, and loading and unloading into and from each mechanism.

[0029] (Work supply unit) Next, we will describe the workpiece supply unit 100B provided by the compression molding apparatus 1.

[0030] The work supply unit 100B is equipped with a work stocker 110 used to store workpieces W. For example, the work stocker 110 may be a known stack magazine, slit magazine, etc., and is capable of storing multiple workpieces W at once. These multiple workpieces W are then dispensed one by one by a holding and moving mechanism 108. In this embodiment, the workpieces W dispensed by the holding and moving mechanism 108 are placed on a stage 312 provided in the resin supply unit 100C, which will be described later.

[0031] (Resin supply unit) Next, the resin supply unit 100C provided in the compression molding apparatus 1 will be described. In this resin supply unit 100C, sealing resin R is supplied (loaded) onto the workpiece W that has been transported from the workpiece supply unit 100B by the transport device 102.

[0032] The resin supply unit 100C includes a resin stocker 310 used to store the sealing resin (in this embodiment, a sheet-like resin) R. For example, the resin stocker 310 contains multiple sheets of sealing resin (sheet-like resin) R, which are removed one by one by a removal device (not shown) and mounted on a workpiece W placed on the stage 312. This removal device is equipped with a mechanism for peeling off the protective film from the surface of the sheet-like resin R (the side on which the workpiece W is mounted).

[0033] (Press Unit) Next, the press unit 100D provided in the compression molding apparatus 1 will be described. In this press unit 100D, resin sealing is performed on the workpiece W (with sealing resin R mounted) that has been transported from the resin supply unit 100C by the transport device 102.

[0034] The press unit 100D includes a sealing die 202 having a pair of dies that open and close (for example, a set of multiple die blocks, die plates, die pillars, and other components made of alloy tool steel). It also includes a press device 250 that drives the sealing die 202 to open and close to seal the workpiece W with resin. Furthermore, it includes a transport loader 280 for loading and unloading the workpiece W and molded product Wp to and from the sealing die 202 (however, the transport loader 280 may be omitted, and loading and unloading may be performed directly by the aforementioned holding and moving mechanism 108).

[0035] Here, as shown in Figure 2, the press device 250 is configured to include a pair of platens 254 and 256, a plurality of tie bars 252 on which the pair of platens 254 and 256 are mounted, and a drive device for moving (raising and lowering) the platen 256. Specifically, the drive device is configured to include a drive source (e.g., an electric motor) 260 and a drive transmission mechanism (e.g., a ball screw or a toggle link mechanism) 262 (however, it is not limited to this). In this embodiment, the upper platen 254 in the vertical direction is set as a fixed platen (a platen fixed to the tie bar 252), and the lower platen 256 is set as a movable platen (a platen that is slidably held by the tie bar 252 and moves up and down). However, it is not limited to this, and the top and bottom may be reversed, that is, 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 (none of which are shown).

[0036] On the other hand, the sealing die 202 is a pair of dies disposed between the pair of platens 254 and 256 in the press device 250, and comprises a first die (in this embodiment, the upper die 204 which is on the upper side in the vertical direction) and a second die (in this embodiment, the lower die 206 which is on the lower side in the vertical direction). That is, the upper die 204 is assembled to the upper platen (in this embodiment, the fixed platen 254), and the lower die 206 is assembled to the lower platen (in this embodiment, the movable platen 256). The die closes and opens as the upper die 204 and the lower die 206 move closer to and further apart from each other (the vertical direction (up and down direction) is the die opening and closing direction).

[0037] Next, the upper mold 204 of the sealing mold 202 will be described in detail. As shown in Figure 3, the upper mold 204 includes a first chase 210, a cavity piece 226 held by it, a first clamper 228, and the like. A cavity 208 is provided on the lower surface of the upper mold 204 (the surface on the lower mold 206 side).

[0038] The first clamper 228 is configured in an annular shape to surround the cavity piece 226 and is assembled to move up and down while floating apart from the lower surface of the first chase 210 (or a support plate not shown) via a first clamper spring 224 (for example, a biasing member exemplified by a coil spring) (however, it is not limited to this assembly structure). The cavity piece 226 constitutes the back (bottom) of the cavity 208, and the first clamper 228 constitutes the side of the cavity 208. The shape and number of cavities 208 provided in one upper die 204 are appropriately set according to the shape and number of workpieces W, etc. (one or more).

[0039] Here, the press device 250 is provided with a film supply unit 212 that supplies a release film F to cover the mold surface 204a (a predetermined area) including the inner surface of the cavity 208 in the upper die 204. For example, the release film F is in the form of a roll, but it may also be in the form of strips.

[0040] Furthermore, the upper mold 204 is provided with suction passages (holes, grooves, etc.) that communicate with a suction device, such as at the first clamper 228 and at the boundary between the first clamper 228 and the cavity die 226 (not shown). This allows the release film F supplied from the film supply unit 212 to be adsorbed and held on the mold surface 204a, including the inner surface of the cavity 208.

[0041] Furthermore, in this embodiment, an upper mold heating mechanism (not shown) is provided for heating the upper mold 204 to a predetermined temperature. This upper mold heating mechanism includes a heater (e.g., an electric heating wire heater), a temperature sensor, a power supply, etc., and the heating is controlled by the control unit 150. As an example, the heater is built into the first chase 210 and heats the upper mold 204 to a predetermined temperature (e.g., 100°C to 300°C).

[0042] Next, the lower mold 206 of the sealing mold 202 will be described in detail. As shown in Figure 3, the lower mold 206 includes a second chase 240, a plate 242 held by it, a second clamper 238, and the like.

[0043] The second clamper 238 is configured in an annular shape to surround the plate 242 and is assembled to move vertically while floating apart from the upper surface of the second chase 240 (or a support plate not shown) via a second clamper spring 234 (for example, a biasing member exemplified by a coil spring) (however, it is not limited to this assembly structure).

[0044] Furthermore, the lower mold 206 is provided with a workpiece holding section 205 that holds (including placing) the sealing resin R and workpiece W in a predetermined position on the upper surface of the plate 242. Here, a suction passage (hole, groove, etc.) communicating with a suction device is provided on the upper surface of the plate 242 (not shown). This allows the workpiece W to be held by suction to the workpiece holding section 205 provided on the upper surface of the plate 242.

[0045] Furthermore, the lower mold 206 is provided with suction passages (holes, grooves, etc.) that communicate with a suction device in the second clamper 238, plate 242, etc. (not shown). In addition, sealing members (for example, O-rings made of elastomer) 244, 246 are provided at the boundary between the second clamper 238 and plate 242, and on the upper surface of the second clamper 238 that contacts the first clamper 228 of the upper mold 204 with the release film F interposed therebetween. This allows the internal space to be depressurized when the sealing mold 202 is sealed.

[0046] In this embodiment, a lower mold heating mechanism (not shown) is provided to heat the lower mold 206 to a predetermined temperature. This lower mold heating mechanism includes a heater (e.g., an electric heating element), a temperature sensor, a power supply, etc., and the heating is controlled by the control unit 150. As an example, the heater is built into the second chase 240 and heats the lower mold 206 to a predetermined temperature (e.g., 100°C to 300°C).

[0047] (Post-cure unit) Next, the post-cure unit 100E provided in the compression molding apparatus 1 will be described. In this post-cure unit 100E, post-curing is performed on the molded product Wp that has been transported from the press unit 100D by the transport device 102.

[0048] The post-cure unit 100E includes one or more ovens (post-cure ovens) 400, each having multiple heating chambers 402 that hold the molded product Wp, which is transported by the conveying device 102, inside and perform post-curing by heating it to a set temperature. Alternatively, the system may be configured without the post-cure unit 100E (not shown).

[0049] (Molded product storage unit) Next, the molded product storage unit 100F of the compression molding apparatus 1 will be described. In this molded product storage unit 100F, the molded product Wp that has been transported from the post-cure unit 100E by the transport device 102 is stored.

[0050] The molded product storage unit 100F is equipped with a molded product stocker 112 used for storing molded products Wp. For example, a known stack magazine, slit magazine, etc., can be used for the molded product stocker 112, and it is capable of storing multiple molded products Wp at once. These multiple molded products Wp are loaded one by one by a holding and moving mechanism 108.

[0051] (Control unit) Next, the control unit 100G provided in the compression molding apparatus 1 will be described. This control unit 100G is configured to include an operation unit 152 in which the operator inputs the operating conditions of the compression molding apparatus 1, and a control unit 150 that controls the operation of each mechanism in the compression molding apparatus 1 in accordance with the operating conditions input by the operator and pre-stored operating conditions. Note that the operation unit 152 is not limited to being located within the control unit 100G, but may be located in another unit or in an adjacent location.

[0052] (Compression molding method) Next, the steps of the compression molding method according to this embodiment, which is carried out using the compression molding apparatus 1 described above, will be explained. Here, Figures 4 to 9 are explanatory diagrams of each step, and are shown as front cross-sectional views in the same direction as Figure 3.

[0053] First, a preparation process is carried out. The preparation process consists of the following steps: A heating process (upper mold heating process) is carried out in which the upper mold 204 is heated to a predetermined temperature (for example, 100°C to 300°C) using the upper mold heating mechanism. A heating process (lower mold heating process) is carried out in which the lower mold 206 is heated to a predetermined temperature (for example, 100°C to 300°C) using the lower mold heating mechanism. A film supply process is also carried out in which a new release film F is supplied by operating the film supply unit 212 and adsorbed so as to cover a predetermined area of ​​the mold surface 204a, including the inner surface of the cavity 208 in the upper mold 204.

[0054] Before, during, or in parallel with the above preparation process, a resin preparation process is carried out to prepare a sheet-like resin R as the sealing resin R. As an example, one sheet of sealing resin (sheet-like resin) R is taken from the resin stocker 310, and the protective film is peeled off the surface of the sheet-like resin R (the side on which the workpiece W is mounted).

[0055] After the preparation step and the resin preparation step, a workpiece holding step is performed to hold the workpiece W, in which the sheet-like resin R is placed on the electronic component Wb, in a predetermined position within the sealing mold 202 (see Figure 4).

[0056] As an example of the workpiece holding process according to this embodiment, a sheet-like resin R is placed on the electronic component Wb of the workpiece W outside the sealing mold 202 (here, on the stage 312 of the resin supply unit 100C). At this time, the surface of the sheet-like resin R (with the protective film removed) has tackiness (adhesion), so the sheet-like resin R adheres to the upper surface of the electronic component Wb of the workpiece W. Next, the workpiece W is transported into the sealing mold 202 by a transport device (for example, a holding and moving mechanism 108, a transport loader 280, etc.) and held in a predetermined position (workpiece holding section 205).

[0057] As another example of the workpiece holding process, the workpiece W may be transported into the sealing mold 202 by a transport device (e.g., a holding and moving mechanism 108, a transport loader 280, etc.) and held in a predetermined position (workpiece holding section 205). Then, the sheet-like resin R may be transported into the sealing mold 202 by a transport device (e.g., a holding and moving mechanism 108, a transport loader 280, etc.), and the sheet-like resin R may be placed on the electronic component Wb of the workpiece W inside the sealing mold 202.

[0058] After all of the above steps have been completed, a resin sealing step is performed in which the workpiece W is sealed with a sealing resin (sheet-like resin) R to form a molded product Wp. The resin sealing step according to this embodiment comprises the following steps.

[0059] First, the first mold closing process is performed (see Figure 5). Specifically, the upper mold 204 and the lower mold 206 come into contact with each other to seal the inside of the sealing mold 202 (i.e., it becomes a closed space except for the suction passage), and the sealing mold 202 is closed only to a position where no pressing force acts on the workpiece W (i.e., the lower surface of the cavity piece 226 does not come into contact with the sheet-like resin R mounted on the workpiece W). Here, "the upper mold 204 and the lower mold 206 come into contact" means that, with the release film F interposed, the lower surface of the first clamper 228 of the upper mold 204 and the upper surface of the second clamper 238 of the lower mold 206 (including the case where only the sealing member 244 provided on the upper surface comes into contact) come into contact (tightly adhere without gaps).

[0060] Next, a depressurization step is performed to reduce the pressure inside the sealing mold 202, which is a sealed space (i.e., the space in which the workpiece W, including the cavity 208, is held). This solves the aforementioned problem, namely, the problem that when liquid resin is used in conventional compression molding methods, air can be trapped around the electronic component Wb of the workpiece W to be sealed (especially in narrow areas such as between the electronic component Wb and the substrate Wa, or between electronic components Wb themselves), which can cause voids to form.

[0061] More specifically, with the sheet-like resin R placed on the electronic component Wb of the workpiece W, a process of reducing the pressure inside the sealing mold 202 can be carried out. At this time, the narrow parts of the workpiece W can be made to be completely uncovered by the sheet-like resin R (excluding the parts in contact between the electronic component Wb and the sheet-like resin R). Therefore, the pressure reduction effect can be applied to all narrow parts.

[0062] Next, after the first mold closing process and before the second mold closing process described later, a resin melting process is carried out in which the sheet-like resin R is melted in the heated sealing mold 202 while a depressurization process is performed and the melted resin enters the space of the workpiece W. As an example, the sealing mold 202 is further closed from the position where the upper mold 204 and the lower mold 206 are in contact after the first mold closing process described above. At this time, the first clamper 228 descends and clamps the base material Wa of the workpiece W (the second clamper spring 234 is set to have a smaller biasing force than the first clamper spring 224 in order to perform this operation). Also, the cavity piece 226 descends relatively within the cavity 208 and comes into contact with the sheet resin R via the film F (see Figure 6). Therefore, by stopping the closing operation of the sealing mold 202 and maintaining that state for a set time, the sheet-like resin R melts inside the heated sealing mold 202 and enters the space (part or all) of the workpiece W (see Figure 7). This "space" is at least the space formed between electronic components Wb, and may also include the space formed between the substrate Wa and the electronic components Wb. With this configuration, the sheet-like resin R can be melted and enter the space of the workpiece W under reduced pressure. Therefore, compared to the conventional process in which liquid resin (and granular resin) is supplied onto the workpiece W before being transported into the sealing mold 202 (i.e., under no reduced pressure), it is possible to prevent air from being trapped in the space of the workpiece W.

[0063] In the resin melting process, as shown in the example above, the cavity piece 226 is in contact with the sheet resin R via the film F. However, in other cases, the process may be carried out with the cavity piece 226 not in contact with the sheet resin R via the film F (for example, in the position after the first mold closing process) (not shown).

[0064] Next, after the resin melting process, the second mold closing process is performed either by stopping the depressurization process or while the depressurization process is being carried out (see Figure 6). Specifically, the sealing mold 202 is further closed from the position after the resin melting process described above. That is, the cavity piece 226 is further lowered relative to the cavity 208, heating and pressurizing the sealing resin (sheet-like resin) R onto the workpiece W. As a result, the sealing resin R is heat-cured, and the workpiece W is resin-sealed (compression-molded), forming the molded product Wp (see Figure 8). Next, the sealing mold 202 is opened, and a mold opening process is performed to separate the molded product Wp from the used release film F so that the molded product Wp can be removed (see Figure 9).

[0065] Thus, by performing the aforementioned depressurization process, the sealing resin (sheet-like resin) R can be heated and pressurized while the depressurization is applied to all narrow parts of the workpiece W to be sealed. Therefore, it is possible to prevent the trapping of air in narrow parts, which was a problem with liquid resins, and improve resin filling performance, thereby preventing the generation of voids during resin sealing (compression molding) and, consequently, molding defects in the molded product Wp. As a prime example of a narrow part to be sealed, the space between the flip-chip mounted electronic component Wb and the substrate Wa has particularly poor resin filling performance and is prone to air retention, making the series of steps according to this embodiment an extremely effective solution.

[0066] Next, a molded product unloading process is performed in which the molded product Wp is unloaded from the sealing mold 202 by a conveying device (here, a conveying loader 280, but a holding and moving mechanism 108 may also be used) and transported to the post-cure unit 100E.

[0067] After post-curing of the molded product Wp in the post-cure unit 100E, the molded product Wp is transported to the molded product storage unit 100F and then stored in the molded product stocker 112.

[0068] After the molded product unloading process, or concurrently therewith, the film supply unit 212 is activated to discharge the used release film F from the sealing mold 202 and to feed a new release film F into the sealing mold 202 and set it in place in a film supply process.

[0069] The above outlines the main steps of the compression molding method performed using the compression molding apparatus 1. However, the above order of steps is merely an example, and the order can be changed or the steps performed in parallel as long as there are no obstacles.

[0070] As explained above, according to the present invention, void formation can be prevented even if the workpiece has a narrow section. Therefore, the occurrence of molding defects caused by voids can be prevented.

[0071] Furthermore, the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the scope of the invention. For example, although the description was given using a configuration in which the first type is the upper type and the second type is the lower type, it can also be applied to a configuration in which the first type is the lower type and the second type is the upper type. [Explanation of Symbols]

[0072] 1. Compression molding apparatus (resin encapsulation apparatus) 202 Sealing mold 204 Upper mold (1st mold) 206 Lower type (Type 2) 250 Pressing device F Release Film R Sealing resin Double job Wp molded product

Claims

1. A compression molding method for processing a workpiece on which electronic components are mounted on a base material into a molded product by sealing it with a sealing resin using a sealing mold comprising a first type and a second type, The aforementioned sealing resin is prepared in a resin preparation step of preparing a sheet-like resin of a predetermined shape, A workpiece holding step of holding the workpiece, in which the sheet-like resin is placed on the electronic component, in a predetermined position within the sealing mold, A first mold closing step is performed to close the sealing mold, in which the first mold and the second mold come into contact to seal the inside of the sealing mold, After the first mold closing step, a depressurization step is performed to reduce the pressure inside the sealing mold, The process includes a second mold closing step, performed after or while the aforementioned depressurization step is being carried out, in which the sealing mold is closed to seal the workpiece with the sheet-like resin and process it into a molded product. A compression molding method characterized by the following.

2. The first mold closing step is a step in which the first mold and the second mold come into contact to seal the inside of the sealing mold, and the sealing mold is closed by stopping at a position where no pressing force is applied to the workpiece. The compression molding method according to claim 1, characterized by the above.

3. The process further includes a resin melting step, performed after the first mold closing step and before the second mold closing step, in which the sheet-like resin is melted in the heated sealing mold while the depressurization step is carried out, and the melting step is allowed to enter at least part or all of the space formed between the electronic components. A compression molding method according to claim 1 or claim 2, characterized by the above.

4. The workpiece holding step is, After placing the sheet-like resin on the electronic components of the workpiece outside the sealing mold, the workpiece is brought into the sealing mold and held in a predetermined position. or, A step of transporting the workpiece into the sealing mold and holding it in a predetermined position, and then placing the sheet-like resin on the electronic components of the workpiece within the sealing mold, Having A compression molding method according to claim 1 or claim 2, characterized by the above.

5. As the workpiece, a workpiece having a space between the substrate and the electronic component is used. A compression molding method according to claim 1 or claim 2, characterized by the above.

6. As the aforementioned sheet-like resin, a sheet-like resin having an adhesive surface is used. The workpiece holding step includes a step of adhering the sheet-like resin to the electronic components of the workpiece. The compression molding method according to claim 5, characterized by the above.

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