JPH07314491A - Transfer molds - Google Patents

Abstract

PURPOSE:To facilitate the attachment and detachment of a cassette and to effectively close molds at the time of molding in the molds in which the cassettes are detachably mounted at mold bases. CONSTITUTION:Cassettes 34, 74 for forming a cavity can be longitudinally inserted into or removed from mold bases 33, 73 to be mounted in a molding machine in a lower mold 31 and an upper mold 32 to be vertically switched. A retaining block 102 made of a material having a large thermal expansion coefficient is provided in the base 33 of the mold 31, and an interposing plate 103 having high hardness is provided at the block 102. A post 105 in which a protruding plate 55 is vertically movably passed is interposed between the plate 103 and the chase 50 of the cassette 34. At the time of molding, the block 102 is expanded by heating with a heater 45 disposed at the base 33 to retain the chase 50 upward. Thus, the block 102 is shrunk in the state that the temperatures of the molds are lowered so as not to retain the chase 50, and hence the cassette 34 can be easily replaced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer molding die apparatus used for resin encapsulation of an IC with, for example, a thermosetting resin.

[0002]

2. Description of the Related Art Conventionally, in the resin encapsulation of an electronic component such as an IC with a thermosetting resin, when a product is switched, a transfer molding machine is used to replace the entire die. However, replacing the entire mold is costly and the replacement work is troublesome.

Further, conventionally, a cassette mold apparatus has been known for the purpose of dealing with small-lot production of a wide variety of products. The cassette mold device is a cassette unit that forms a product-shaped cavity with respect to the mold base that is attached to the platen of the molding machine. Only the cassette unit remains attached to the molding machine. Are replaceable.

FIG. 4 and FIG. 5 show an example of a conventional cassette mold apparatus, and show a lower mold of upper and lower molds which can be opened and closed. In the figure, 1 is a lower platen of the molding machine, 2 is a mold base that is removably mounted on the lower platen 1, and 3 is a cassette part that is removably mounted on the mold base 2. The mold base 2 is fixed with receiving blocks 6 having step portions 5 on both left and right sides of a substrate 4, and pressing plates 7 are fixed on the receiving blocks 6 by bolts 8. Thus, the T groove 9 in the front-rear direction is formed between the step portion 5 of the receiving block 6 and the pressing plate 7. A stopper plate 10 is fixed on the back side between the receiving blocks 6, and a fixing plate 11 is detachably fixed on the front side between the receiving blocks 6. On the other hand, the cassette portion 3 has the T groove 9
There are ridges 12 slidably fitted to the lower parts of the left and right side surfaces.

Then, in order to attach the cassette portion 3 to the mold base portion 2, the cassette portion 3 is slid rearward with respect to the mold base portion 2, and the ridge 12 thereof is fitted into the T groove 9 of the mold base portion 2. Abut the cassette part 3 on the stopper plate 10. Then, the fixing plate 11 is fixed and the cassette portion 3 is pressed from the front. Also,
The cassette part 3 can be removed from the mold base part 2 by the reverse procedure.

[0006]

However, in the above-mentioned conventional mold device, there is a risk that the closed state of the lower cassette portion and the upper cassette portion becomes insufficient. That is, in order to insert and remove the cassette portion 3 into and from the die base portion 2, a slight gap is required between the two, but in the direction orthogonal to the die opening / closing direction, the positioning for fitting the lower die and the upper die together. Even if the lower mold and the upper mold can be mutually regulated in position by providing the block, it is impossible to surely regulate the position in the mold opening / closing direction, that is, in the vertical direction. If the lower mold and the upper mold are not sufficiently closed, burrs are likely to occur in the product on both parting lines.

The present invention is intended to solve such a problem and has a simple structure in a transfer molding die in which a cassette portion can be freely inserted into and removed from a die base portion in a direction intersecting with a die opening / closing direction. It is a first object of the present invention to ensure that the mold closed state can be ensured at the time of molding without taking time and labor for the attachment / detachment work. The second is to further enhance the reliability of the position regulation of the cassette section.
The purpose of. Further, in the case where the cassette part is composed of a chase part forming a cavity and a protruding plate movable with respect to the chase part, it is necessary to surely regulate the position of the chase part despite the protruding plate. The purpose is 3.

[0008]

In order to achieve the above-mentioned object, the invention of claim 1 is provided with a pair of molds which are opened and closed with each other, and a thermosetting property which forms a cavity between the molds closed. In the mold equipment for resin transfer molding,
Each of the two mold bodies includes a mold base portion which has a heater built therein and is attached to a molding machine, and a cassette portion which is detachable from the mold base portion and forms the cavity. And a pressing unit that is actuated by heating and presses the cassette unit toward the other mold body in the mold opening / closing direction between the mold base and the cassette unit. It is provided.

According to a second aspect of the present invention, in the transfer molding die device according to the first aspect of the present invention, in order to achieve the second object, the pressing means is provided on the die base portion. The block is made of a material having a coefficient of thermal expansion larger than that of other portions, and this block is connected to the side of the cassette portion opposite to the cavity.

According to a third aspect of the present invention, in the transfer molding die device according to the second aspect of the present invention, in order to achieve the third object, the cassette section forms a cavity and a chase section. A protrusion plate movably provided on the anti-cavity side of the portion, and an intervening plate having a hardness higher than that of the block is provided on the entire surface of the block of the pressing means on the side of the cassette, and the interposing plate and the chase portion. And a post penetrating the protruding plate so as to be movable therethrough.

According to a fourth aspect of the present invention, there is provided the transfer molding die device according to any one of the first to third aspects,
It is used for resin sealing of electronic parts.

[0012]

In the transfer molding die apparatus of the present invention, a thermosetting resin is filled in a cavity formed between a pair of closed molds, and the filled resin is heated by a heater or the like. After curing, the mold is opened and the product is taken out. When switching the product to be molded, the cassette part forming the cavity with respect to the mold base may be exchanged while the mold base of the mold body is attached to the molding machine.
At the time of this replacement, with the temperature of the mold lowered, after removing the cassette part from the mold base in the direction intersecting the mold opening / closing direction,
Insert the new cassette part into the mold base in the opposite direction. At this time, since the temperature of the mold body is low, the pressing means does not press the cassette part, and the cassette part can be easily inserted and removed. On the other hand, during molding,
By the heating of the heater on the mold base, the pressing means is activated to press the cassette part toward the other mold body in the mold opening / closing direction. As a result, the position of the cassette portion is reliably regulated with respect to the mold base portion, and the mold closed state of both mold bodies is also ensured.

Further, in the transfer molding die device according to the second aspect of the present invention, the coefficient of thermal expansion of the block forming the holding means connected to the side opposite to the cavity of the cassette portion provided in the die base portion has a coefficient of thermal expansion other than that of the die base portion. Therefore, when the mold temperature is low, due to the contraction of the block, the block does not press the cassette portion. On the other hand, when the mold temperature is high, the block presses the cassette portion due to the expansion of the block.

Further, in the transfer molding die apparatus of the third aspect of the present invention, when the die temperature is high, the block expands and presses the chase portion of the cassette portion through the intervening plate and the post. The post movably penetrates the ejector plate, so that expansion and contraction of the block do not interfere with the ejector plate. The post is thin to some extent, but since a high-hardness intervening plate that covers the entire surface of the cassette portion side is interposed between the post and the block, the post is prevented from biting into the block. .

Further, in the transfer molding die device according to the fourth aspect of the present invention, the electronic component is resin-sealed.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the transfer molding die apparatus of the present invention will be described below with reference to FIGS. The mold apparatus of this embodiment is used as an automatic resin sealing apparatus for electric parts such as ICs made of thermosetting resin such as epoxy resin.

1 and 2, 21 is a tie bar of the transfer molding machine, 22 is a lower platen, and 23 is an upper platen. The upper platen 23 is fixed to the upper end of the tie bar 21. The lower platen 22 is located below the upper platen 23, is supported by the tie bar 21 so as to be vertically movable, and is driven by a hydraulic cylinder or the like. That is, the rod that moves up and down in this hydraulic cylinder
24 is connected to the lower side of the lower platen 22.

On the upper side of the lower platen 22, a lower mold 31 which is a mold body is detachably attached, and
An upper mold 32, which is a mold, is detachably attached to the lower side of 23. The lower mold 31 and the upper mold 32 open and close as the lower platen 22 moves up and down, and although not shown, a plurality of mold cavities, a plurality of shot cavities, and a plurality of shot cavities communicated with the mold cavity when they are closed. It forms a runner and a gate.

The lower die 31 comprises a die base portion 33 attached to the lower platen 22, and a cassette portion 34 detachably attached to the die base portion 33 to form the cavity, runner, gate and the like. The mold base 33 includes a mounting plate 35 mounted on the lower platen 22, and a receiving plate 36 fixed on the mounting plate 35.
The receiving blocks 37 are fixed to the left and right sides of the upper portion 36. An upward step surface 38 is formed on the facing surface of these receiving blocks 37. Further, a pressing plate 39 is fixed on each of the receiving blocks 37 by a bolt 40, and a T groove 41 in the front-rear direction is formed between the step surface 38 of the receiving block 37 and the pressing plate 39. Further, a stopper plate 42 is fixed to the back side between both receiving blocks 37, and a fixing plate 43 is detachably fixed to the front side between both receiving blocks 37. Further, a heater 45 is built in the receiving block 37 and the like, and a heat insulating plate 46 is provided on the side surface of the mold base 33. The lower platen of the molding machine
A clamp for fixing the mounting plate 35 on the 22.
47 are attached by bolts 48, and a block 49 that regulates the position of the attachment plate 35 on two sides is fixed.

On the other hand, the cassette section 34 has a chase section 50.
, A chase frame plate 51, a center block 52 and a chase block 53 embedded and fixed in the chase frame plate 51 are provided.
52 and chase block 53 form the shot cavity, runner, gate and mold cavity on the top surface. Then, on the lower portions of the left and right side surfaces of the chase frame plate 51, there are formed ridges 54 which are slidably fitted in the T-grooves 41 of the mold base 33 in the front-rear direction. A protruding plate 55 is supported below the chase portion 50 so as to be vertically movable. The ejection plate 55 is driven by a spring (not shown) or the like as a drive source and moves up and down in conjunction with opening and closing of the mold. A protrusion pin (not shown) fixed to the protrusion plate 55 vertically penetrates the chase frame plate 51 and the chase block 53. Further, a plurality of pots 56 are fixed by vertically penetrating the center block 52 and the chase frame plate 51. These pots 56 forming a shot cavity penetrate the protruding plate 55 slidably.

A plunger 57 is vertically movably fitted in the pot 56. This plunger
57 also penetrates through holes 58 formed in the mold base 33. On the other hand, below the lower platen 22 of the transfer molding machine, there is a hydraulic cylinder for operating the plunger 57.
61 is provided, and a vertically moving piston rod 62 of the hydraulic cylinder 61 is detachably connected to the lower end of the plunger 57 via a one-touch coupler 63.

The upper mold 32 is substantially vertically symmetrical with the lower mold 31 except that there is no pot. That is, the mold base 73 attached to the upper platen 23, and the cavity detachably attached to the mold base 73,
And a cassette portion 74 forming a runner and a gate. The mold base 73 is also attached to the upper platen 23 by a clamp (not shown), the mounting plate 75, the receiving plate 76, the receiving block 77, the step surface 78 thereof, the pressing plate 79, the bolt 80, the T groove 81, Stopper plate,
It has a fixed plate, a heater 85 and a heat insulating plate 86. Further, the cassette portion 74 includes a chase portion 90, a chase frame plate 91 which forms the chase portion 90, a center block 92, a chase block 93,
It has a ridge 94 and a protruding plate 95.

Positioning blocks 96, 97, 98, 99 are fixed to the upper side of the chase frame plate 51 of the lower mold 31 and the lower side of the chase frame plate 91 of the upper mold 32, respectively. Then, the positioning blocks 96 and 97 of the lower mold 31 and the positioning blocks 98 and 99 of the upper mold 32 are fitted in concave and convex as shown in FIG. 3, and the cassette part 34 of the lower mold 31 and the cassette part of the upper mold 32 are joined. The positions of 74 and 74 are restricted relative to each other in the front-rear direction and the left-right direction.

The die base 33 of the lower die 31 is provided with a holding means 101 for holding the cassette portion 34 upward as the die temperature rises. This holding means 10
1, a pressing block 102 made of a material having a large coefficient of thermal expansion is provided on the receiving plate 36 between both receiving blocks 37, and an interposing plate 103 is fixed on the entire upper surface of the pressing block 102. There is. The pressing block 102 and the interposition plate 103 are supported by the receiving plate 36 by the bolts 104, but a slight vertical movement is allowed with respect to the receiving plate 36. On the other hand, a plurality of posts 105 are fixed to the lower surface of the chase frame plate 91. These posts 105
The through hole 106 formed in the protruding plate 55 is vertically movably penetrated, and the lower end surface thereof abuts the upper surface of the intervening plate 103. The pressing block 102 is made of copper or stainless steel (SUS304) or the like, and is the other part of the die base 33 made of steel or the like, especially the receiving block.
Larger coefficient of thermal expansion than 37. The intervening plate 103 and the post 105 are made of steel or the like and have a higher hardness than the pressing block 102.

Next, the operation of the above configuration will be described. When the electronic parts are sealed with resin, an insert such as a lead frame is placed on the lower mold 31 by a transfer device (not shown) with the mold open, and the pot 56
A thermosetting resin tablet is loaded therein. Then,
The lower platen 22 rises and the mold is closed. At this time, the positioning blocks 96 and 97 of the lower die 31 and the positioning blocks 98 and 99 of the upper die 32 are fitted to each other, and the cassette portion 34 of the lower die 31
And the cassette portion 74 of the upper mold 32 are positionally regulated in the front-rear direction and the left-right direction. In this mold closed state, the plunger 57 rises, but the thermosetting oil in the form of a tablet becomes a liquid state by the pressurization and heating by the plunger 57, and the runner between the pot 56 and the lower mold 31 and the upper mold 32 is run. And through the gate into the mold cavity. The thermosetting resin filled in these mold cavities is cured by heating by the heaters 45 and 85 and curing time. In this way, the resin sealing portion is molded on the electronic component main body portion. The mold temperature is 180 by heating with the heaters 45 and 85.
It will be about °. Next, the lower platen 22 is lowered to open the mold, and at this time, the hardened resin in the resin sealing portion or the runner is released by the operation of the ejection plates 55 and 95.
Further, the resin cured in these products or in the runner is taken out by the carrying device.

When the product for molding the resin sealing portion is switched, the mold bases 33 and 73 of the lower mold 31 and the upper mold 32 are kept attached to the platens 22 and 23 of the molding machine, and the mold bases 33 and 73 are fixed to the mold bases 33 and 73. The cassette parts 34 and 74 may be exchanged. It should be noted that this exchange is performed with the chase frame plates 51, 91 and the projecting plates 55, 95 as a set, and particularly in the lower die 31, the pot 56 is also exchanged. During this replacement, the fixing plate 43 is removed, and the cassette parts 34, 74 are pulled out forward from the mold base parts 33, 73 while the temperature of the mold is lowered. At this time, especially the lower mold
At 31, the plunger 57 is left out of the pot 56. Then, install the new cassette parts 34, 74 into the mold base 33,
After inserting it into 73, attach the fixing plate 43. In the cassette parts 34 and 74, the protrusions 54 and 94 of the chase frame plates 51 and 91 are fitted in the T grooves 41 and 81 of the mold base parts 33 and 73.

By the way, when the mold temperature is low, the pressing block 10 is pressed more than the receiving block 37 of the mold base 33.
Due to the larger contraction of 2
The interposition plate 103 descends relative to 37. In this state, a slight gap is formed between the interposition plate 103 and the post 105, and the pressing block 102 does not press the chase portion 50. Therefore, the cassette unit 34 can be easily attached to and detached from the mold base 33. On the other hand, when the die temperature is high due to the heating of the heater 45, the holding block 102 expands more than the receiving block 37, so that the interposing plate is relatively positioned with respect to the receiving block 37.
103 is rising. In this state, the interposition plate 102 hits the post 105, and the chase portion 50 is pressed upward. Therefore, at the time of molding in which the heater 45 heats the chase portion 50 of the cassette portion 34 with respect to the die base portion 33.
Is surely regulated in the vertical direction,
The mold closed state of the chase part 50 of the lower mold 31 and the chase part 90 of the upper mold 32 is also ensured. As a result, the lower mold 31 and the upper mold 32
It is also possible to reliably prevent burrs from being produced on the parting line with.

Thus, according to the configuration of the above embodiment,
In the lower die 31, a pressing means 10 that operates by a temperature change
1 is used, the pressing means 101 presses the cassette portion 34 upward during molding, and the pressing means 101 does not press the cassette portion 34 when replacing the cassette portion 34. While facilitating replacement, the position of the cassette portion 34 can be reliably regulated during molding. Further, in the upper mold 31 having no pressing means, the cassette portion 74 can be easily replaced. Especially, in the automatic resin sealing device for electric parts, the transfer molding machine is often housed in the case and the molding machine can be operated only from the front side. That is, since the cassette parts 34 and 74 can be inserted and removed and the fixing plate 43 can be attached and detached only on the front side of the molding machine, the replacement work of the cassette parts 34 and 74 does not take time and can be replaced promptly.

A pressing block 102 made of a material having a coefficient of thermal expansion larger than that of the receiving block 37 of the die base 33 is used as the pressing means 101 of the cassette part 34, and the chase of the cassette part 34 is caused by the thermal expansion of the pressing block 102. Part 50
Since the pressing means 101 is pressed down, it is possible to operate the pressing means 101 by using the heater 45 which is necessary for molding.
No special wiring is required and the configuration can be simplified. At the same time, the pressing means 101 utilizing the thermal expansion of the solid makes it possible to simplify the configuration, ensure reliable operation, and further improve the reliability of the position regulation of the chase portion 50.

Further, although there is a protruding plate 55 between the chase portion 50 to be pressed and the pressing block 102, a post penetrating the protruding plate 55 in a vertically movable manner.
Since 105 is interposed between the chase portion 50 and the pressing block 102, expansion and contraction of the pressing block 102 do not interfere with the protruding plate 55, and despite the existence of the protruding plate 55, the chase portion 50 Position can be reliably controlled. Although the post 105 has to be thin to some extent, this post 105 and the pressing block 102
Since a large high hardness interposition plate 103 is interposed between
The position of the chase portion 50 can be reliably regulated without the post 105 biting into the soft holding block 102.

The present invention is not limited to the above embodiment, and various modifications can be made. For example,
In the above embodiment, the pressing block 102 made of a material having a large coefficient of thermal expansion is provided on the die base 33, but the pressing block made of a material having a large coefficient of thermal expansion may be provided on the cassette portion. However, when the pressing block 102 is provided on the mold base 33 as in the above-described embodiment, the cassette unit 34 can be made smaller and lighter, and the replacement thereof can be facilitated.

Further, in the above embodiment, the pressing means for the cassette portion 34 is provided only in the lower die 31, but the pressing means for the cassette portion 74 may be provided in the upper die 32 as well. The pressing means of the upper die 32 may have a configuration that is substantially vertically symmetrical with the pressing means 101 of the lower die 31, and presses down the chase portion 90 of the cassette portion 74.

Further, the pressing means for pressing the cassette portion is not limited to the one utilizing the thermal expansion of the solid, but may be the one utilizing the thermal expansion of the fluid.

In the above embodiment, the lower mold 31 has a pot.
Chase frame plates 51, 91 and protruding plate 55, including 56
A cassette unit 3 in which 95 sets are attached to and detached from the mold bases 33 and 73.
4, 74, but the way to divide the mold base and the cassette is not limited to that. For example, the plunger may be replaced together with the cassette part, or if possible, the pot may be shared by a plurality of types of cassette parts.

Further, the present invention can be applied not only to a mold device for resin-sealing an electronic component, but also to other transfer mold devices.

[0036]

According to the first aspect of the present invention, the thermosetting is such that the cassette portion forming the cavity can be inserted into and removed from the die base portion having a built-in heater and attached to the molding machine in a direction intersecting the die opening / closing direction. In the mold device for transfer molding of a resinous resin, a pressing means is provided between the mold base and the cassette to press the cassette in the mold opening / closing direction toward the other mold. The cassette part can be easily attached to and detached from the mold base while the temperature of the body is lowered, while the pressing means presses the cassette part as the temperature rises due to the heating of the heater during molding. The position of the mold can be reliably regulated in the mold opening / closing direction, and the mold closed state of the lower mold and the upper mold can be ensured. Therefore, it is possible to prevent burrs from being produced in the products on both parting lines. Moreover, the structure of the pressing means is simple.

According to the invention of claim 2, the pressing means is
The block is made of a material that has a coefficient of thermal expansion larger than that of the other parts of the mold base, and this block is connected to the side opposite the cavity of the cassette. It can be made reliable, and the reliability of the cassette position regulation can be further enhanced. Moreover, since the block is provided not on the cassette side but on the mold base side, the cassette section to be replaced can be made smaller and lighter.

According to the invention of claim 3, the cassette portion comprises
While the chase portion forming the cavity and the protruding plate are provided, an intervening plate having a hardness higher than that of the block is provided on the entire surface of the pressing means block on the cassette portion side. Since the post that movably penetrates the protrusion plate is provided between the two, the position of the chase portion can be reliably regulated despite the presence of the protrusion plate.

The pressing of the cassette portion by such pressing means is also suitable for a transfer molding die device for resin sealing of electronic parts, as in the invention of claim 4.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a transfer molding die device of the present invention.

FIG. 2 is a plan view of the upper and lower mold sides.

FIG. 3 is a sectional view near the positioning block of the same.

FIG. 4 is a front view showing an example of a conventional mold device.

FIG. 5 is a plan view of the same.

[Explanation of symbols]

 31 Lower mold (mold) 32 Upper mold (mold) 33 Mold base 34 Cassette part 45 Heater 50 Chase part 55 Ejection plate 73 Mold base 74 Cassette part 85 Heater 101 Holding means 102 Holding block 103 Interposing plate 105 Post

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area // B29K 101: 10 B29L 31:34

Claims (4)

[Claims] 1. A transfer molding die apparatus of a thermosetting resin, comprising a pair of mold bodies that are opened and closed with each other, and a cavity is formed between the mold bodies that have been closed. It comprises a mold base that is built in and attached to the molding machine, and a cassette part that is detachable from the mold base and forms the cavity. The cassette part is inserted into the mold base from a direction intersecting the mold opening / closing direction. The transfer molding is detachable, and is provided between the die base portion and the cassette portion with pressing means that is actuated by heating and presses the cassette portion toward the other die body in the die opening / closing direction. Mold equipment. 2. The pressing means comprises a block made of a material which is provided on the mold base and has a coefficient of thermal expansion larger than that of the other parts of the mold base, and the block is connected to the side opposite to the cavity of the cassette part. The transfer molding die device according to claim 1. 3. The cassette portion includes a chase portion forming a cavity, and a protruding plate movably provided on the side opposite to the cavity of the chase portion, and the entire surface of the pressing means on the cassette portion side is provided with the chase portion. The transfer molding die according to claim 2, wherein an interposition plate having a hardness higher than that of the block is provided, and a post movably penetrating the protruding plate is provided between the interposition plate and the chase portion. apparatus. 4. The transfer molding die device according to claim 1, which is used for resin sealing of electronic parts.