Resin molding device and method for producing resin molded article

Abstract

The present invention provides a resin molding device that makes it possible to finely adjust the interval between a lower platen and an upper platen.　The resin molding device comprises: an upper platen to which an upper mold is fixed; a lower platen to which a lower mold is fixed; a plurality of tie bars which connect the upper platen and the lower platen; a mold clamping mechanism which moves the lower platen up and down; and a position adjustment mechanism which is capable of adjusting, for each tie bar, the position of the upper platen with respect to the tie bars.

Description

Resin molding device and method for manufacturing resin molded product

[0001] The present invention relates to a resin molding apparatus and a method for manufacturing a resin molded product.

[0002] In a resin molding apparatus using a mold clamping mechanism, for example, when the mold thickness changes due to mold replacement, it is necessary to adjust the distance between the movable platen and the fixed platen. Patent Document 1 discloses a mold pressure adjusting device for an injection molding apparatus. This mold pressure adjusting device can adjust the position of the fixed platen (end housing) left and right by synchronously rotating nuts attached to four tie bars with a single drive source (hydraulic motor).

[0003] Japanese Utility Model Publication No. 61-7060

[0004] However, for example, resin molding devices used in semiconductor manufacturing require high-precision products, so there is a demand for technology that allows for more precise adjustment of the gap between the movable platen and the fixed platen.

[0005] The present invention was made in consideration of the above-mentioned circumstances, and the problem it aims to solve is to provide a resin molding apparatus that allows for fine adjustment of the distance between the lower platen and the upper platen, and a method for manufacturing a resin molded product.

[0006] The problem that the present invention aims to solve is as described above, and in order to solve this problem, the resin molding apparatus of the present invention comprises an upper platen to which an upper mold is fixed, a lower platen to which a lower mold is fixed, a plurality of tie bars connecting the upper platen and the lower platen, a mold clamping mechanism that moves the lower platen up and down, and a position adjustment mechanism that can adjust the position of the upper platen relative to the tie bars for each of the tie bars.

[0007] Furthermore, the method for manufacturing a resin molded product according to the present invention is a method for manufacturing a resin molded product using the resin molding apparatus, and includes an adjustment step of adjusting the position of the upper platen relative to the tie bars, a mold clamping step of moving the lower platen relative to the upper platen to clamp the mold after the adjustment step, and a resin molding step of resin molding an object to be molded after the mold clamping step.

[0008] According to the present invention, the distance between the lower platen and the upper platen can be finely adjusted.

[0009] 1 is a schematic plan view showing the overall configuration of a resin molding apparatus according to one embodiment; FIG. 2 is a schematic front view showing the configuration of a molding mechanism; FIG. 3 is a schematic front sectional view showing a molding mold; FIG. 4 is a schematic front sectional view showing the configuration of a position adjustment mechanism (individual adjustment mechanism); (a) A diagram showing how a servo motor is driven; (b) A diagram showing how a fixed platen moves upward; (a) A diagram showing an example of distortion of each tie bar when the mold is clamped; (b) A diagram showing how the position of the fixed platen is adjusted; (a) A diagram showing an example of a clamp position when a predetermined distortion occurs in each tie bar; (b) A diagram showing how the position of the fixed platen is adjusted. A flowchart showing a method for manufacturing a resin molded product according to one embodiment.

[0010] In the following explanation, the directions indicated by arrows U, D, L, R, F, and B in the figure will be defined as upward, downward, leftward, rightward, forward, and backward, respectively.

[0011] <Overall Configuration of Resin Molding Apparatus 1> First, the configuration of the resin molding apparatus 1 will be described using Figure 1. The resin molding apparatus 1 resin-encapsulates electronic elements such as semiconductor chips (hereinafter simply referred to as "chips 2a" (see Figure 3)) to manufacture resin molded products. In particular, this embodiment illustrates a resin molding apparatus 1 that performs resin molding using a transfer molding method. Note that the chips 2a are not shown in any figures other than Figure 3.

[0012] The resin molding apparatus 1 includes, as its components, a supply module 10, a resin molding module 20, and an unloading module 30. Each component is detachable and replaceable with respect to the other components.

[0013] <Supply Module 10> The supply module 10 supplies lead frames 2, which are a type of substrate with chips 2a mounted thereon, and resin tablets T to the resin molding module 20. The lead frames 2 are one embodiment of the molding object according to the present invention. In this embodiment, the lead frames 2 are used as an example of a substrate to be molded, but various other substrates (glass epoxy substrates, ceramic substrates, resin substrates, metal substrates, etc.) can also be used in addition to the lead frames 2. The supply module 10 mainly includes a frame sending unit 11, a frame supply unit 13, a resin material supply mechanism 14, a loader 17, and a control unit 18.

[0014] The frame sending section 11 sends out the lead frames 2 that are not sealed with resin and are housed in an in-magazine unit (not shown) to the frame supplying section 13. The frame supplying section 13 receives the lead frames 2 from the frame sending section 11, aligns the received lead frames 2 appropriately, and passes them to the loader 17.

[0015] The resin material supply mechanism 14 supplies the resin tablets T to a loader 17 (described later). The resin material supply mechanism 14 can align a plurality of resin tablets T and deliver them to the loader 17.

[0016] The loader 17 transports the lead frames 2 and resin tablets T received from the frame supply unit 13 and the resin material supply mechanism 14 to the resin molding module 20. The loader 17 is equipped with a heater plate (not shown) for preheating the lead frames 2. The heater plate is heated by a heating device while the loader 17 is on standby. The heater plate can also heat the lead frames 2 while the loader 17 is transporting the lead frames 2.

[0017] The loader 17 is also provided with a cleaning mechanism 17a for cleaning the molding dies (lower die 160 and upper die 170) described below. The cleaning mechanism 17a may be, for example, a dust collection mechanism capable of sucking up dust adhering to the surfaces of the molding dies. The cleaning mechanism 17a is provided, for example, at the front end of the loader 17.

[0018] The control unit 18 controls the operation of each module of the resin molding apparatus 1. The control unit 18 controls the operations of the supply module 10, the resin molding module 20, and the carry-out module 30. The control unit 18 can also be used to arbitrarily change (adjust) the operation of each module.

[0019] In this embodiment, an example is shown in which the control unit 18 is provided in the supply module 10, but the control unit 18 can also be provided in other modules. It is also possible to provide multiple control units 18. For example, it is possible to provide a control unit 18 for each module or device, and to control the operations of each module individually while linking them together.

[0020] <Resin molding module 20> The resin molding module 20 resin-seals the chip 2a mounted on the lead frame 2. In this embodiment, two resin molding modules 20 are arranged side by side. Note that the number of resin molding modules 20 may be one, or three or more. By using multiple resin molding modules 20 to resin-seal the lead frame 2 in parallel, the manufacturing efficiency of resin molded products can be improved. The resin molding module 20 mainly includes a molding mechanism 100.

[0021] The molding mechanism 100 mainly includes a molding die (a lower die 160 and an upper die 170) and a die clamping mechanism 150 (see FIG. 2).

[0022] The molding dies (lower die 160 and upper die 170) use molten resin material to resin-encapsulate the chip 2a mounted on the lead frame 2. The molding dies include a pair of upper and lower dies, namely, the lower die 160 and the upper die 170 (see FIG. 2, etc.).

[0023] The mold clamping mechanism 150 (see FIG. 2) clamps or opens the molding dies (lower die 160 and upper die 170) by moving the lower die 160 up and down. The specific configuration of the molding mechanism 100 will be described later.

[0024] <Unloading Module 30> The unloading module 30 receives and unloads the resin-sealed lead frame 2 from the resin molding module 20. The unloading module 30 mainly includes an unloader 31 and a substrate accommodating section 32.

[0025] The unloader 31 holds the resin-sealed lead frame 2 and carries it out to the substrate accommodating section 32. The substrate accommodating section 32 accommodates the resin-sealed lead frame 2.

[0026] <Forming Mechanism 100> Next, a specific configuration of the forming mechanism 100 will be described with reference to FIGS. 2 to 4. FIG.

[0027] Fig. 2 is a diagram schematically illustrating the configuration of the molding mechanism 100. Fig. 3 is a diagram schematically illustrating the molding dies (lower die 160 and upper die 170) extracted from the configuration shown in Fig. 2. Fig. 4 is a diagram schematically illustrating the configuration of the position adjustment mechanism 190 (individual adjustment mechanism 200).

[0028] As shown in FIG. 2, the molding mechanism 100 mainly includes a base 110, tie bars 120, a movable platen 130, a fixed platen 140, a mold clamping mechanism 150, molding dies (lower die 160 and upper die 170), a transfer mechanism 180, and a position adjustment mechanism 190.

[0029] The base 110 supports the tie bars 120 and the mold clamping mechanism 150. The base 110 is formed in the shape of a rectangular parallelepiped having an appropriate vertical width.

[0030] The tie bars 120 connect the movable platen 130 and the fixed platen 140. The tie bars 120 are formed in a longitudinal shape with the longitudinal direction facing the up-down direction. In this embodiment, the tie bars 120 are formed in a cylindrical shape. The lower portions of the tie bars 120 are fixed to the base 110. A plurality of tie bars 120 are provided. In this embodiment, four tie bars 120 are provided, one at each of the four corners of the base 110. The number of tie bars 120 is not limited to four, and the number and arrangement of the tie bars 120 can be changed as desired.

[0031] The movable platen 130 has the lower mold 160 fixed thereto and moves the lower mold 160 up and down. The movable platen 130 is one embodiment of a lower platen according to the present invention. The movable platen 130 is formed in a rectangular parallelepiped shape with an appropriate vertical width. The upper and lower middle portions of the tie bars 120 are inserted so as to penetrate the four corners of the movable platen 130 in the vertical direction. This allows the movable platen 130 to move up and down along the tie bars 120. A lower mold chase holder 131 for holding the lower mold 160 is provided on the upper part of the movable platen 130.

[0032] The upper mold 170 is fixed to the fixed platen 140. The fixed platen 140 is one embodiment of the upper platen according to the present invention. The fixed platen 140 is formed in a rectangular parallelepiped shape with an appropriate vertical width. The fixed platen 140 is disposed above the movable platen 130. The upper portions of the tie bars 120 are inserted into through-holes 140a (see FIG. 4) formed at the four corners of the fixed platen 140 so as to penetrate the fixed platen 140 vertically. The fixed platen 140 is fixed to the tie bars 120 via a position adjustment mechanism 190. An upper mold chase holder 141 for holding the upper mold 170 is provided below the fixed platen 140. A pressure adjustment plate 142 for adjusting the vertical position of the upper mold chase holder 141 is disposed between the fixed platen 140 and the upper mold chase holder 141. By appropriately changing the thickness (width in the vertical direction) of the pressure adjustment plate 142, it is possible to adjust the vertical position of the upper die chase holder 141 relative to the fixed platen 140. By adjusting the vertical position of the upper die chase holder 141 using the pressure adjustment plate 142, it is possible to adjust the mold contact and clamping force when the mold is clamped.

[0033] The mold clamping mechanism 150 clamps or opens the forming dies (lower die 160 and upper die 170) by moving the movable platen 130 up and down. The mold clamping mechanism 150 mainly includes a toggle link 151, a lifting member 152, and a ball screw 153.

[0034] The toggle link 151 is a link mechanism that connects the base 110 and the movable platen 130. The toggle link 151 is configured to be able to expand and contract vertically by combining multiple link members. An intermediate portion of the toggle link 151 in the vertical direction is connected to a lifting member 152. The lifting member 152 is fitted into a ball screw 153. The ball screw 153 is disposed with its longitudinal direction facing the vertical direction. The lifting member 152 can be raised and lowered vertically by rotating the ball screw 153 with a drive source (not shown) such as a servo motor. As the lifting member 152 rises and falls vertically, the toggle link 151 is operated, and the movable platen 130 can be moved vertically relative to the base 110.

[0035] 2 and 3 forms the lower part of the forming mold. The lower mold 160 is fixed to the upper part of the movable platen 130. The lower mold 160 mainly includes a pot 161 and a lower mold heater 162.

[0036] The pot 161 shown in FIG. 3 is a portion that accommodates the resin tablet T. The pot 161 is formed so as to penetrate the lower mold 160 from top to bottom. The pot 161 is formed in the left-right center of the lower mold 160. A plurality of pots 161 are formed so as to be lined up front and back (not shown). In this embodiment, the lead frames 2 are arranged on the left and right of the pot 161 of the lower mold 160, which is a so-called two-piece configuration, but the lower mold 160 may be configured so that only one lead frame 2 is arranged, or so that three or more lead frames 2 are arranged on the lower mold 160.

[0037] The lower die heater 162 is provided inside the lower die 160 to heat the lower die 160 when resin molding is performed.

[0038] 2 and 3 forms the upper part of the molding die. The upper die 170 mainly includes a recess 171, a resin flow path 172, and an upper die heater 173.

[0039] 3 is a portion that forms a cavity, which is a space for resin sealing, between the lead frame 2 and the upper mold 170 when the lead frame 2 is placed on the lower mold 160 and the lower mold 160 and upper mold 170 are closed. A chip 2a fixed to the lead frame 2 is housed in the cavity, and the chip 2a is resin-sealed with a resin material supplied to the cavity. The recess 171 is formed by recessing the lower surface of the upper mold 170 upward. The recess 171 is formed in a position and shape that corresponds to the shape of the product (resin molded product), etc.

[0040] The resin flow path 172 is a portion that guides the molten resin tablet T (resin material) to the recess 171 (cavity) when the lead frame 2 is placed on the lower mold 160 and the lower mold 160 and upper mold 170 are closed. The resin flow path 172 is formed by recessing the lower surface of the upper mold 170 upward. The resin flow path 172 is formed so as to connect the pot 161 and the recess 171 (cavity) when the lower mold 160 and upper mold 170 are closed.

[0041] The upper die heater 173 is provided inside the upper die 170 to heat the upper die 170 when resin molding is performed.

[0042] The shapes of the lower mold 160 and the upper mold 170 described in this embodiment are merely examples, and can be changed as desired depending on the shape, number, etc. of the products.

[0043] 2 and 3, the transfer mechanism 180 supplies the resin material to the cavity and mainly includes a plunger 181 and a transfer driver (not shown).

[0044] 3 is used to inject and supply the resin tablet T (resin material) contained in the pot 161 to the cavity. The plunger 181 is arranged in the pot 161 so as to be able to move up and down (raise and lower).

[0045] The transfer drive unit (not shown) is a drive source that moves the plunger 181 in the up and down direction. The transfer drive unit (not shown) can be configured by, for example, a servo motor, an air cylinder, or the like.

[0046] 2 and 4 is used to adjust the position of the fixed platen 140 relative to the tie bars 120 for each tie bar 120. The position adjustment mechanism 190 mainly includes a plurality of individual adjustment mechanisms 200, strain gauges 260, and an adjustment control unit 270.

[0047] The individual adjustment mechanisms 200 are provided on the tie bars 120, respectively, and adjust the position of the stationary platen 140 relative to the provided tie bars 120. In this embodiment, four individual adjustment mechanisms 200 are provided corresponding to the four tie bars 120.

[0048] The configuration of the individual adjustment mechanisms 200 will be described below with reference to Figure 4. Since the four individual adjustment mechanisms 200 have the same configuration, the following description will focus on one of them. The individual adjustment mechanism 200 mainly includes a support member 210, a connecting member 220, a spring 230, an adjustment nut 240, and a changing mechanism 250.

[0049] The support member 210 is for supporting the stationary platen 140 via a spring 230. The support member 210 mainly includes a pair of upper and lower plates (a lower plate 211 and an upper plate 212) and a pillar portion 213.

[0050] The lower plate 211 is formed, for example, in the shape of a rectangular plate. The lower plate 211 is disposed with its plate surface oriented generally horizontally. The center of the lower surface of the lower plate 211 is fixed to the upper end of the tie bar 120. A plurality of through holes 211a are formed in the lower plate 211. For example, one through hole 211a is formed at each of the four corners of the lower plate 211.

[0051] The upper plate 212 is formed, for example, in a shape (rectangular plate) generally similar to that of the lower plate 211. The upper plate 212 is disposed above the lower plate 211 so as to be parallel to the lower plate 211. The upper plate 212 is disposed so as to be located above the connecting member 220. In this way, the upper plate 212 comes into contact with the upper end of the connecting member 220, thereby preventing the connecting member 220 from rising excessively.

[0052] The pillar portion 213 is formed in a pillar shape with its longitudinal direction facing the up-down direction. The lower portion of the pillar portion 213 is fixed to the lower plate 211. The upper portion of the pillar portion 213 is fixed to the upper plate 212. For example, a plurality of pillar portions 213 may be provided. The lower plate 211 and the upper plate 212 are connected by the pillar portions 213.

[0053] The connecting member 220 is used to connect the stationary platen 140 and the support member 210. The connecting member 220 is formed in a columnar shape (for example, a cylindrical shape) with its longitudinal direction facing the up-down direction. A plurality of connecting members 220 (four in this embodiment) are provided at positions corresponding to the through holes 211a of the lower plate 211. The connecting members 220 are arranged so as to pass vertically through the through holes 211a of the lower plate 211. The lower end of the connecting member 220 is fixed to the stationary platen 140. A circular, flat flange portion 221 is formed at the upper end of the connecting member 220. The flange portion 221 is arranged between the lower plate 211 and the upper plate 212.

[0054] The spring 230 is for applying an upward force to the stationary platen 140. The spring 230 is one embodiment of an application member according to the present invention. The spring 230 is formed by a compression coil spring. The spring 230 is disposed between the lower plate 211 and the flange portion 221 of the connecting member 220. This allows the spring 230 to apply a force to the flange portion 221 (connecting member 220) that pushes the flange portion 221 upward.

[0055] The adjusting nut 240 is used to restrict upward movement of the stationary platen 140. The adjusting nut 240 is one embodiment of a restricting member according to the present invention. The diameter of the adjusting nut 240 is formed to be larger than the inner diameter of the through-hole 140a of the stationary platen 140. The adjusting nut 240 is fitted into a male thread (not shown) formed on the upper part of the tie bar 120. By rotating the adjusting nut 240, the adjusting nut 240 can be moved up and down relative to the tie bar 120.

[0056] The changing mechanism 250 is used to change the vertical position of the adjusting nut 240. The changing mechanism 250 mainly includes a servo motor 251 and a transmission unit (a reduction mechanism 252, a drive gear 253, and a driven gear 254) that transmits the power of the servo motor 251.

[0057] The servo motor 251 serves as a drive source for moving the adjusting nut 240. The rotational position and rotational speed of the servo motor 251 are controlled based on an external control signal. The servo motor 251 is disposed to the side of the support member 210.

[0058] The speed reducing mechanism 252 is for reducing the rotation speed of the servo motor 251. The speed reducing mechanism 252 is configured by, for example, a plurality of gears, a housing that houses the gears, etc. The speed reducing mechanism 252 is provided below the servo motor 251.

[0059] The drive gear 253 is rotated by the power output from the reduction mechanism 252. The drive gear 253 is provided below the reduction mechanism 252. The drive gear 253 is connected to an output shaft (not shown) of the reduction mechanism 252, and rotates by the power transmitted from the servo motor 251 via the reduction mechanism 252. The servo motor 251, the reduction mechanism 252, and the drive gear 253 are supported on the upper surface of the stationary platen 140.

[0060] The driven gear 254 is for transmitting the rotation of the drive gear 253 to the adjusting nut 240. The driven gear 254 is formed on the outer peripheral surface of the adjusting nut 240. The driven gear 254 can be formed integrally with the adjusting nut 240, or can be formed as a separate member from the adjusting nut 240. The driven gear 254 is arranged to mesh with the drive gear 253.

[0061] The strain gauges 260 shown in Fig. 2 are used to measure strain occurring in the tie bars 120. The strain gauges 260 are provided on each of the tie bars 120. It is desirable that the strain gauges 260 be provided in positions that are less susceptible to the heat that occurs during resin molding. In this embodiment, an example is shown in which the strain gauges 260 are provided below the tie bars 120 (near the base 110). The strain gauges 260 can measure the strain in the vertical direction of the tie bars 120.

[0062] The adjustment control unit 270 is for controlling the operation of the servo motor 251. The adjustment control unit 270 is mainly composed of an arithmetic processing unit such as a CPU, and storage devices such as RAM and ROM. The storage device of the adjustment control unit 270 stores information and various programs required to control the operation of the servo motor 251. Note that, although the control unit 18 (see FIG. 1) and the adjustment control unit 270 are illustrated separately in this embodiment, it is also possible to configure the adjustment control unit 270 integrally with the control unit 18 (see FIG. 1).

[0063] The adjustment control unit 270 is provided with various input devices (not shown), such as a touch panel, a keyboard, and switches. By using the input devices, various information related to the operation of the servo motor 251 can be input to the adjustment control unit 270. The adjustment control unit 270 is also provided with various display devices (not shown), such as a liquid crystal panel, a touch panel, and lamps. By using the display devices, various information related to the operation of the servo motor 251 can be displayed.

[0064] The adjustment control unit 270 is connected to each strain gauge 260 and can acquire the measurement results of each strain gauge 260. The adjustment control unit 270 is also connected to the servo motor 251 and can send a control signal to the servo motor 251 to control the operation of the servo motor 251.

[0065] The adjustment of the position of the stationary platen 140 using the position adjustment mechanism 190 (individual adjustment mechanism 200) described below can be performed manually by an operator or automatically by the adjustment control unit 270. When the operator manually adjusts the position of the stationary platen 140, the operator can check the measurement results of the strain gauges 260 on a display device and operate the servo motor 251 in accordance with the measurement results. When the adjustment control unit 270 automatically adjusts the position of the stationary platen 140, the adjustment control unit 270 can control the operation of the servo motor 251 based on various measured information (for example, the measurement results of the strain gauges 260), various programs, etc.

[0066] <Operation of Individual Adjustment Mechanism 200> The operation of the individual adjustment mechanism 200 will be described below.

[0067] As shown in Figure 4, the spring 230 pushes the connecting member 220 upward. As a result, the stationary platen 140 is pushed upward along the tie bar 120 via the connecting member 220. The upper surface of the stationary platen 140 comes into contact with the adjusting nut 240, thereby restricting upward movement of the stationary platen 140. In this way, the vertical position of the stationary platen 140 relative to the tie bar 120 can be determined by the vertical position of the adjusting nut 240.

[0068] For example, when moving the fixed platen 140 upward relative to the tie bar 120, as shown in FIG. 5A , the servo motor 251 is driven to move the adjusting nut 240 upward relative to the tie bar 120. By moving the adjusting nut 240 upward, a gap is created between the adjusting nut 240 and the fixed platen 140.

[0069] When a gap occurs between the adjusting nut 240 and the stationary platen 140, the spring 230 pushes the stationary platen 140 upward, as shown in FIG. 5B . The stationary platen 140 comes into contact with the adjusting nut 240, thereby restricting its upward movement. By moving the adjusting nut 240 upward in this manner, the stationary platen 140 can be moved upward relative to the tie bar 120.

[0070] 5A illustrates a state in which a gap has formed between the adjusting nut 240 and the fixed platen 140 in order to explain the operation of the individual adjustment mechanism 200 in stages. However, in reality, the fixed platen 140 also moves upward following the upward movement of the adjusting nut 240. For this reason, almost no gap occurs between the adjusting nut 240 and the fixed platen 140.

[0071] On the other hand, when moving the fixed platen 140 downward relative to the tie bar 120, although not shown in the drawings, the servo motor 251 is driven to move the adjusting nut 240 downward relative to the tie bar 120. This causes the fixed platen 140 to be pushed downward via the adjusting nut 240, thereby moving the fixed platen 140 downward.

[0072] <Adjustment Method Using Position Adjustment Mechanism 190> An example of a method for adjusting the position of the stationary platen 140 using the position adjustment mechanism 190 will be described below.

[0073] First, an example of a method for adjusting the clamping force by adjusting the overall position of the stationary platen 140 using the position adjustment mechanism 190 will be described.

[0074] Generally, a molding mechanism 100 using a toggle link 151 as in this embodiment is designed to clamp the mold near the top dead center of the toggle link 151 (when the toggle link 151 is fully extended) and to obtain the clamping force required for resin molding. However, if the thickness of the molding mold or lead frame 2 is changed, or if changes in the dimensions of each part (e.g., the top dead center of the toggle link 151) occur due to changes in the components over time, the mold clamping position (clamp position) may change, and the required clamping force may not be obtained. Therefore, in this embodiment, the position of the fixed platen 140 can be adjusted by the position adjustment mechanism 190 so that the required clamping force is obtained.

[0075] Specifically, with the lead frame 2 placed in the lower mold 160, the mold clamping mechanism 150 is operated to clamp the mold, just as in actual resin molding. In this state, at least one of the clamping force and the clamping position is measured. The clamping force can be measured using a measuring device such as a load cell. The clamping position can be measured by measuring the rotational position of the servo motor of the mold clamping mechanism 150 or by using various measuring devices.

[0076] Next, the operation of the servo motors 251 of each individual adjustment mechanism 200 is controlled based on the measurement results of the clamping force or clamping position. Specifically, the position of the stationary platen 140 is adjusted up or down to a position where the required clamping force is obtained or to an appropriate clamping position. At this time, the servo motors 251 of each individual adjustment mechanism 200 are all controlled to rotate by the same amount. This allows the stationary platen 140 to move in parallel without tilting its posture. In this way, by adjusting the overall position of the stationary platen 140, the mold clamping position (clamping position) and clamping force can be adjusted. Furthermore, by adjusting the position of the stationary platen 140, mold clamping can be performed near the top dead center of the toggle link 151. This allows the capacity of the drive source (such as a servo motor) of the mold clamping mechanism 150 to be optimized, thereby reducing component costs and component size.

[0077] Next, an example of a method for adjusting the mold contact by adjusting the position of the fixed platen 140 for each tie bar 120 using the position adjustment mechanism 190 will be described. Two types of methods for adjusting the mold contact (a first adjustment method and a second adjustment method) will be described below.

[0078] 6 and 7, in order to distinguish between the four tie bars 120, the symbols A to D will be added to the reference numerals in counterclockwise order in a plan view, starting from the front left tie bar 120. Similarly, the symbols A to D will be added to the reference numerals of the individual adjustment mechanisms 200 corresponding to each of the tie bars 120A to 120D. Furthermore, although specific numerical values ​​such as distortion are exemplified below, these are tentative values ​​for the purpose of explanation, and the present invention does not limit the various numerical values.

[0079] First, the first adjustment method will be described using FIG. 6. The first adjustment method is a method of adjusting the mold contact based on the strain of each tie bar 120 when the mold is clamped with a constant clamping force. Specifically, as shown in FIG. 6(a), the strain (ε) of each tie bar 120 is measured in a state where the mold is clamped with an appropriate clamping force. In FIG. 6, the strains of each tie bar 120A to 120D are indicated as ε(A) to ε(D), respectively.

[0080] In the example shown in Figure 6(a), it can be seen that the distortion of the right front tie bar 120B is relatively large. From this, it can be inferred that the mold contact on the right front side of the mold is strong. Also, in the example shown in Figure 6(a), it can be seen that the distortion of the left rear tie bar 120D is relatively small. From this, it can be inferred that the mold contact on the left rear side of the mold is weak. Therefore, by adjusting the position of the fixed platen 140 relative to each tie bar 120 so that the distortion of each tie bar 120 is uniform, it is possible to achieve uniform mold contact on the mold.

[0081] Specifically, as shown in FIG. 6( b), the individual adjustment mechanism 200B corresponding to the tie bar 120B, which had a relatively large distortion, is controlled to move the stationary platen 140 upward relative to the tie bar 120B. This weakens the mold contact on the right front side of the mold. Furthermore, the individual adjustment mechanism 200D corresponding to the tie bar 120D, which had a relatively small distortion, is controlled to move the stationary platen 140 downward relative to the tie bar 120D. This strengthens the mold contact on the left rear side of the mold.

[0082] In this way, by repeating the measurement of the distortion of each tie bar 120 and the control of the individual adjustment mechanism 200 several times, the position of the fixed platen 140 is adjusted so that the distortion of each tie bar 120 is constant, as shown in Figure 6(b). This makes it possible to adjust the mold contact so that it is uniform.

[0083] Next, the second adjustment method will be described with reference to FIG. 7. The second adjustment method is a method of adjusting the die contact based on the clamp position when the same strain occurs in each tie bar 120. Specifically, as shown in FIG. 7(a), the clamp position when the strain (ε) of each tie bar 120 is 100 is measured. Note that in FIG. 7, the clamp positions when the strain of each tie bar 120A to 120D is 100 are shown as CL POS(A) to CL POS(D), respectively. Note that the clamp position is expressed as the amount of movement of the lower die 160 raised relative to an appropriate position.

[0084] 7A, when the mold clamping mechanism 150 is used to raise the lower mold 160 and press the lower mold 160 against the upper mold 170, a load is applied to each tie bar 120, causing strain in each tie bar 120. When the clamp position is gradually increased (the lower mold 160 is raised), the strain in tie bar 120B first reaches 100 when the clamp position reaches 99.8 mm. When the clamp position is further increased, the strain in tie bar 120A and tie bar 120C also reaches 100 when the clamp position reaches 100 mm. When the clamp position is further increased, the strain in tie bar 120D reaches 100 when the clamp position reaches 100.1 mm.

[0085] In the example shown in FIG. 7( a), it can be seen that the strain of the right front tie bar 120B reached 100 at a relatively early stage (when the clamp position is small). This suggests that the mold contact on the right front side of the mold is strong. In addition, in the example shown in FIG. 7( a), it can be seen that the strain of the left rear tie bar 120D reached 100 at a relatively late stage (when the clamp position is large). This suggests that the mold contact on the left rear side of the mold is weak. Therefore, by adjusting the position of the fixed platen 140 relative to each tie bar 120 so that the same strain is generated in each tie bar 120 at the same timing (same clamp position), it is possible to achieve uniform mold contact on the mold.

[0086] Specifically, as shown in Figure 7(b), individual adjustment mechanism 200B corresponding to tie bar 120B, whose distortion reached 100 at a relatively early stage, is controlled to move stationary platen 140 upward relative to tie bar 120B. This weakens the mold contact on the right front side of the mold. Also, individual adjustment mechanism 200D corresponding to tie bar 120D, whose distortion reached 100 at a relatively late stage, is controlled to move stationary platen 140 downward relative to tie bar 120D. This strengthens the mold contact on the left rear side of the mold.

[0087] In this way, by repeating the measurement of the clamp position when the strain reaches 100 and the control of the individual adjustment mechanism 200 several times, the position of the fixed platen 140 is adjusted so that the strain of each tie bar 120 reaches 100 at the same timing (clamp position), as shown in Figure 7(b). This makes it possible to adjust the mold contact so that it is uniform.

[0088] As described above, in this embodiment, the position of the stationary platen 140 relative to the tie bars 120 can be adjusted for each tie bar 120, allowing for fine adjustment of the position of the stationary platen 140 (the distance between the stationary platen 140 and the movable platen 130). Furthermore, because the position of the stationary platen 140 can be adjusted using the position adjustment mechanism 190, it is possible to omit or simplify the position adjustment of the stationary platen 140 using the pressure adjustment plate 142. This reduces the workload on the worker required to adjust the position of the stationary platen 140.

[0089] <Outline of Operation of Resin Molding Apparatus 1> Next, an outline of the operation of the resin molding apparatus 1 configured as described above (a method for manufacturing a resin molded product using the resin molding apparatus 1) will be described with reference to FIGS. 1 and 8. FIG.

[0090] First, the position of the stationary platen 140 is adjusted as needed (step S11 in FIG. 8 ). Specifically, as described above, the clamping force and mold contact are adjusted using the position adjustment mechanism 190. The position adjustment of the stationary platen 140 in step S11 is performed at an appropriate timing, such as when the molding die is replaced, when resin molding of a different type of lead frame 2 or a different lot number of lead frames 2 is started, or when adjustment is required due to changes in the dimensions of each part caused by changes in the components over time. In other words, if adjustment is not needed, the adjustment in step S11 can be omitted.

[0091] Next, the lead frames 2 and resin tablets T are delivered to the loader 17 (step S12 in FIG. 8). Specifically, in the supply module 10 shown in FIG. 1, the frame delivery unit 11 delivers the lead frames 2 stored in an in-magazine unit (not shown) to the frame supply unit 13. The frame supply unit 13 appropriately aligns the received lead frames 2 and delivers them to the loader 17.

[0092] Furthermore, the resin material supply mechanism 14 delivers to the loader 17 the number of resin tablets T required for one resin molding in the resin molding module 20 .

[0093] Next, the loader 17 is caused to enter the molding die (step S13 in FIG. 8). Specifically, after receiving the lead frame 2 and the resin tablet T, the loader 17 moves to the resin molding module 20 while preheating the lead frame 2. The loader 17 then moves from the rear to the molding die of the molding mechanism 100. Thereafter, the loader 17 places the lead frame 2 on the upper surface of the lower die 160 and stores (sets) the resin tablet T in the pot 161 of the lower die 160 (step S14 in FIG. 8).

[0094] After placing the lead frame 2 on the lower die 160 and storing the resin tablet T in the pot 161, the loader 17 retreats from the molding die (step S15 in FIG. 8).

[0095] Next, the molding die is clamped by the clamping mechanism 150 (step S16 in FIG. 4). Specifically, the clamping mechanism 150 is driven to raise the lower die 160 toward the upper die 170. When the lower die 160 approaches the upper die 170, the lead frame 2 is sandwiched between the lower die 160 and the upper die 170.

[0096] Next, the transfer mechanism 180 injects the resin material into the cavity (step S17 in FIG. 8). Specifically, the resin tablet T stored in the pot 161 is heated and melted by heaters (lower die heater 114 and upper die heater 123) provided in the molding die. The transfer mechanism 180 raises the plunger 181 to inject the melted resin tablet T (resin material) into the cavity.

[0097] After the resin material is injected by the transfer mechanism 180, by waiting until a predetermined time has elapsed, the resin material is hardened and the chip 2a of the lead frame 2 can be resin-sealed.

[0098] Next, the mold is opened by the mold clamping mechanism 150 (step S18 in FIG. 8). Specifically, the mold clamping mechanism 150 is driven to lower the lower mold 160 so that it separates from the upper mold 170. This allows the resin-sealed lead frame 2 to be released from the upper mold 170. Thereafter, the lead frame 2 is carried out from the mold (step S19 in FIG. 8). Specifically, the lead frame 2 is carried out from the mold by the unloader 31 shown in FIG. 1 and accommodated in the substrate accommodation section 32 of the unloading module 30. In this manner, the resin-sealed lead frame 2 (resin molded product) is manufactured.

[0099] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and appropriate modifications are possible within the scope of the technical idea of ​​the invention described in the claims.

[0100] For example, in the above embodiment, an example was shown in which adjustments such as mold contact were made by controlling the position adjustment mechanism 190 based on the strain generated in the tie bars 120, but the present invention is not limited to this. For example, it is also possible to adjust the mold contact by measuring the distance between the movable platen 130 and the fixed platen 140 (for example, the distance at each of the four corners) using various measuring devices such as a dial gauge or a displacement meter, and controlling the position adjustment mechanism 190 so that the two are parallel. Note that it is also possible to control the position adjustment mechanism 190 based on various information that serves as a guide for mold contact, not limited to the strain of the tie bars 120 and the distance between the platens.

[0101] Furthermore, in this embodiment, a toggle link type mold clamping mechanism 150 is exemplified, in which the toggle link 151 is used to lift the lower mold 160 toward the upper mold 170, but the present invention is not limited to this. For example, the present invention can also be applied to a direct-acting axis type mold clamping mechanism that uses a ball screw, a hydraulic (oil) cylinder, or the like to directly lift the lower mold 160 toward the upper mold 170. Furthermore, the drive source of the mold clamping mechanism 150 is not limited to a servo motor, and various drive sources such as hydraulic (oil) pressure, air pressure, etc. can also be used.

[0102] In addition, in this embodiment, the spring 230 formed by a compression coil spring is exemplified as an example of an application member that applies force to the stationary platen 140, but the present invention is not limited to this. For example, various members capable of applying force, such as a tension coil spring, a leaf spring, or a cylinder, can be used as the application member.

[0103] In addition, in this embodiment, the adjusting nut 240 is used as an example of a restricting member that restricts the upward movement of the fixed platen 140, but the present invention is not limited to this. Various members that can change their vertical positions can be used as the restricting member.

[0104] In addition, in this embodiment, the molding mechanism 100 is illustrated as being equipped with the pressure adjustment plate 142, but the present invention is not limited to this. For example, it is also possible to omit the pressure adjustment plate 142 and adjust the mold contact, clamping force, etc. using only the position adjustment mechanism 190.

[0105] Furthermore, the configuration of the position adjustment mechanism 190 (individual adjustment mechanism 200) described in this embodiment is just one example, and the configuration can be changed as desired as long as the position of the fixed platen 140 can be adjusted for each tie bar 120. For example, in this embodiment, an example has been shown in which each individual adjustment mechanism 200 is provided with a drive source (servo motor 251), but it is also possible to configure each individual adjustment mechanism 200 to operate using a common (single) drive source. In this case, for example, by providing a mechanism that switches between enabling and disabling the transmission of power from the drive source to each individual adjustment mechanism 200, the individual adjustment mechanisms 200 can be operated independently of each other.

[0106] Although not specifically described in the above embodiment, resin molding may be performed with a release film provided on the surface of the molding die (for example, the lower surface of the upper die 170).

[0107] Furthermore, in the above embodiment, the molding die configured from the lower die 160 and the upper die 170 has been described as an example, but it is also possible to use a molding die including, for example, an intermediate die.

[0108] In addition, in the above embodiment, a resin molding device 1 using the transfer molding method is used as an example, but the present invention is not limited to this and can also be applied to a resin molding device using the compression molding method.

[0109] <Notes> The resin molding apparatus 1 according to the first aspect of the present disclosure includes a fixed platen 140 (upper platen) to which an upper mold 170 is fixed, a movable platen 130 to which a lower mold 160 is fixed, a plurality of tie bars 120 connecting the fixed platen 140 and the movable platen 130, a mold clamping mechanism 150 that moves the movable platen 130 up and down, and a position adjustment mechanism 190 that can adjust the position of the fixed platen 140 relative to the tie bars 120 for each tie bar 120. According to the resin molding apparatus 1 according to the first aspect of the present disclosure, the distance between the fixed platen 140 and the movable platen 130 can be finely adjusted. This allows fine adjustment of the clamping force, mold contact, etc.

[0110] The position adjustment mechanism 190 on the second side according to the first side includes a plurality of individual adjustment mechanisms 200 that are provided on the plurality of tie bars 120, respectively, and that can adjust the position of the stationary platen 140 relative to the tie bars 120. According to the resin molding apparatus 1 of the second side of the present disclosure, the distance between the stationary platen 140 and the movable platen 130 can be finely adjusted.

[0111] The individual adjustment mechanism 200 of a third aspect according to the second aspect includes a spring 230 (application member) that applies an upward force to the stationary platen 140, an adjustment nut 240 (restriction member) that restricts the upward movement of the stationary platen 140, and a change mechanism 250 that changes the up-down position of the adjustment nut 240. According to the resin molding apparatus 1 of the third aspect of the present disclosure, the position of the stationary platen 140 can be adjusted with a simple configuration.

[0112] The changing mechanism 250 of a fourth aspect according to the third aspect includes a servo motor 251 (drive source), and a transmission unit (a reduction mechanism 252, a drive gear 253, and a driven gear 254) that transmits power of the servo motor 251 to the adjusting nut 240. According to the resin molding apparatus 1 of the fourth aspect of the present disclosure, the position of the fixed platen 140 can be adjusted with a simple configuration.

[0113] The drive source of a fifth aspect according to the fourth aspect is configured by a servo motor 251. According to the resin molding apparatus 1 of the fifth aspect of the present disclosure, the position of the stationary platen 140 can be finely adjusted.

[0114] The transmission unit of a sixth aspect according to the fourth or fifth aspect includes a speed reduction mechanism 252 that can reduce the power of the servo motor 251 and transmit it. According to the resin molding apparatus 1 of the sixth aspect of the present disclosure, the torque of the servo motor 251 can be increased. This allows the stationary platen 140 to be moved more reliably.

[0115] The mold clamping mechanism 150 of a seventh aspect according to any one of the first to sixth aspects is configured using a toggle link system or a linear shaft system. According to the resin molding apparatus 1 of the seventh aspect of the present disclosure, regardless of the system, the distance between the fixed platen 140 and the movable platen 130 can be finely adjusted. Furthermore, particularly with the toggle link system, by adjusting the position of the fixed platen 140, it is possible to adjust the mold clamping to occur near the top dead center of the toggle link 151, thereby optimizing the capacity of the drive source of the mold clamping mechanism 150.

[0116] The resin molding apparatus 1 of an eighth aspect according to any one of the first to seventh aspects includes a strain gauge 260 provided on each of the tie bars 120 and capable of detecting strain in the tie bars 120. According to the resin molding apparatus 1 of the eighth aspect of the present disclosure, the distance between the stationary platen 140 and the movable platen 130 (such as the mold contact state) can be easily estimated. This makes it possible to easily adjust the position of the stationary platen 140.

[0117] A manufacturing method for a resin molded product according to a ninth aspect of the present disclosure is a manufacturing method for a resin molded product using the resin molding apparatus 1 of any one of the first to eighth aspects, and includes: an adjustment step (step S11) of adjusting the position of the stationary platen 140 relative to the tie bars 120; a mold clamping step (step S16) of moving the movable platen 130 relative to the stationary platen 140 to clamp the mold after the adjustment step; and a resin molding step (step S17) of resin molding a lead frame 2 (molding object) after the mold clamping step. According to the manufacturing method for a resin molded product according to the ninth aspect of the present disclosure, the distance between the stationary platen 140 and the movable platen 130 can be finely adjusted. This allows fine adjustment of the clamping force, mold contact, etc.

[0118] REFERENCE SIGNS LIST 1 Resin molding device 100 Molding mechanism 120 Tie bar 130 Movable platen 140 Fixed platen 160 Lower mold 170 Upper mold 190 Position adjustment mechanism 200 Individual adjustment mechanism 230 Spring 240 Adjustment nut 250 Change mechanism 251 Servo motor 252 Reduction mechanism 253 Drive gear 254 Driven gear 260 Strain gauge

Claims

1. An injection molding apparatus comprising: an upper platen to which an upper mold is fixed; a lower platen to which a lower mold is fixed; a plurality of tie bars connecting the upper platen and the lower platen; a clamping mechanism for moving the lower platen vertically; and a position adjusting mechanism for adjusting the position of the upper platen with respect to each of the tie bars.

2. The injection molding apparatus according to claim 1, wherein the position adjusting mechanism includes a plurality of individual adjusting mechanisms provided respectively on the plurality of tie bars and capable of adjusting the position of the upper platen with respect to the tie bars.

3. The injection molding apparatus according to claim 2, wherein each individual adjusting mechanism includes an applying member for applying an upward force to the upper platen, a restricting member for restricting upward movement of the upper platen, and a changing mechanism for changing the vertical position of the restricting member.

4. The injection molding apparatus according to claim 3, wherein the changing mechanism includes a drive source and a transmission unit for transmitting the power of the drive source to the restricting member.

5. The injection molding apparatus according to claim 4, wherein the drive source is constituted by a servo motor.

6. The injection molding apparatus according to claim 4 or 5, wherein the transmission unit includes a speed reducing mechanism capable of reducing and transmitting the power of the drive source.

7. The injection molding apparatus according to any one of claims 1 to 6, wherein the clamping mechanism is constituted by a toggle link method or a direct acting shaft method.

8. The injection molding apparatus according to any one of claims 1 to 7, further comprising a strain gauge provided respectively on the plurality of tie bars and capable of detecting the strain of the tie bars.

9. A method for manufacturing an injection molded article using the injection molding apparatus according to any one of claims 1 to 8, the method including: an adjusting step of adjusting the position of the upper platen with respect to the tie bars; a clamping step of moving the lower platen with respect to the upper platen to perform clamping after the adjusting step; and an injection molding step of injection molding a molding object with resin after the clamping step.

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