JP3003735B2 - Mold device for molding resin-sealed parts of electronic components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold device for molding a resin sealing portion of an electronic component such as a diode.

[0002]

2. Description of the Related Art In an electronic component, for example, an axial type diode 1 as shown in FIG. 5, an element body 2 is resin-sealed with a thermosetting resin, for example, an epoxy resin containing silica. In the diode 1, a pair of wires 3 connected to the element body 2 project coaxially from opposite end surfaces of a substantially cylindrical resin sealing portion 4 in opposite directions. In addition, the concave 5 on the side surface of the resin sealing portion 4 is a protrusion pin mark. Transfer molding is performed in the resin sealing, and a mold device as shown in FIGS. 6 and 7 is used for the transfer molding. Here, this conventional mold apparatus will be described. 11 is the upper mold, 12 is the lower mold, these upper mold 11 and lower mold
Reference numeral 12 denotes a unit that moves up and down with respect to each other to open and close.
Between the upper mold 11 and the lower mold 12, a shot cavity (not shown), a runner 13 communicating with the shot cavity, and a row of Multiple mold cavities 14
And gates 15 for connecting the mold cavities 14 to the runners 13, respectively. The runner 13 and the gate 15 are formed by grooves formed in the upper mold 11. The mold cavity 14 includes substantially semi-cylindrical concave portions 16 and 17 formed on the lower surface of the upper mold 11 and the upper surface of the lower mold 12, respectively. The gate 15 is tapered from the runner 13 toward the mold cavity 14, and forms an obtuse angle with respect to the flow direction of the resin in the runner 13 indicated by an arrow in FIG. It is open to one end surface of the cavity 14. Also, a mold cavity is provided on the lower surface of the upper mold 11 and the upper surface of the lower mold 12.
Wire fitting grooves 18 and 19 are respectively formed so as to penetrate the central axis of 14. Further, for example, a shallow concave portion is formed on the lower surface of the upper mold 11 to form the air vent portions 20 and 21 that allow the mold cavity 14 to communicate with the outside of the mold at the time of mold clamping.
The one air vent portion 20 is open on both sides of the mold cavity 14 adjacent to one end surface of the mold cavity 14 where the gate 15 is opened. The other air vent 21
Is an opening at the other end surface of the mold cavity 14. The upper mold 11 and the lower mold 12 are provided with protrusion pins 22 and 23 for releasing the resin solidified in the molded resin sealing portion 4 and the runner 13, respectively.

When the element body 2 of the diode 1 is sealed with resin, the diode 1 before resin sealing is mounted on the lower mold 12 with the mold open. In this state, the lower half of the horizontal wire 3 of the diode 1 is fitted into the wire fitting groove 19 of the lower mold 12, and the element body 2 is positioned above the concave portion 17 of the lower mold 12. Next, as shown in FIG. 7, the mold is clamped. In this state, a mold cavity 14 is formed, and the element body 2 of the diode 1 is located in the mold cavity 14 and the wire 3 of the diode 1 is The upper half is fitted into the wire fitting groove 18 of the upper mold 11.
Then, the thermosetting resin loaded in the shot cavity is melted and transferred from the shot cavity into the mold cavity 14 via the runner 13 and the gate 15. When the resin is filled in the mold cavity 14 in this manner, the air in the mold cavity 14 flows out of the mold via the slit-shaped air vents 20 and 21 between the upper mold 11 and the lower mold 12. Next, after the resin in the mold cavity 14 and the runner 13 has solidified, the mold is opened. At this time, first, on the upper mold 11 side, by pushing out the pushing pin 22,
The resin that is solidified in the mold cavity 14 and the resin that is solidified in the resin sealing portion 4 and the runner 13 are separated from the upper mold 11. Then, on the side of the lower mold 12, the resin solidified in the resin sealing portion 4 and the runner 13 is pushed out of the lower mold 12 by the protrusion of the protrusion pin 23.
Leave 12 Then, after taking out the resin-sealed diode 1 from the mold together with the resin solidified in the runner 13, a gate break is performed. That is, gate 15
At the tip of the resin, the resin solidified in the runner 13 and the resin sealing portion 4 of the diode 1 are cut.

[0004]

However, the gate 15
Wears as the molding is repeated, and the mold cavity
The tip on the 14 side, etc., begins to curve. And
If such abrasion of the gate 15 proceeds, the gate break will be hindered. For example, in the above-mentioned conventional mold apparatus, in the molding of 50,000 to 100,000 times, due to the wear of the gate 15, at the time of the gate break, cutting is not reliably performed at the tip of the gate 15, and the resin solidified in the gate 15 is formed. May be attached to the resin sealing portion 4 of the diode 1, or the resin sealing portion 4 may be partially missing and attached to the gate 15 side. Then, in such a case, there arises a problem that post-processing is required or the diode 1 itself in which the resin sealing portion 4 is formed does not become a product. On the other hand, in order to minimize the trouble of the gate break due to the wear of the gate 15, the gate 15 may be made as small as possible. However, if the gate 15 is made smaller, the gate 15 is likely to be clogged with foreign matter. When the gate 15 is clogged with foreign matter, an unfilled portion of the resin is generated in the mold cavity 14, and the molded resin sealing portion 4 becomes porous. Therefore, in the conventional mold apparatus having only one gate 15 for one mold cavity 14, the gate 15 must be set to a certain size from the beginning.

If the flow of the resin into the mold cavity 14 is too slow, the resin solidifies before the filling is completed, and
Unfilled resin occurs at 14 while the mold cavity 14
If the resin flows into the resin sealing portion 4 too quickly, air is entrained and bubbles are generated in the resin sealing portion 4. In the conventional mold apparatus, there is only one gate 15 for one mold cavity 14, and the resin is hardly turned around in the part opposite to the wire 3 and the element body 2 in the mold cavity 14. . In order to allow the resin to flow into the mold cavity 14 at a certain speed without generating bubbles, the air vent portions 20 and 21 from the mold cavity 14 are
In addition to the end face opposite the gate 15 of 14, the mold cavity 14
On both sides. However, providing a large number of air vents 20 and 21 is not inherently preferable because traces thereof can be formed in the resin sealing portion 4 of the diode 1 and the number of steps of die processing increases.

Further, the element body 2 of the diode 1
It has a structure in which silicon is stacked in the axial direction and is vulnerable to lateral stress. However, in the conventional mold apparatus, since one gate 15 is located at one end of one mold cavity 14 and is open only on one side of the wire fitting grooves 18 and 19, the gate 15 There is a possibility that a stress is applied to the element main body 2 from the side by the resin flowing into the element main body 2 and this element main body 2 is adversely affected.

SUMMARY OF THE INVENTION The present invention is intended to solve such a problem, and can reduce inconvenience at the time of a gate break due to abrasion of a gate while preventing unfilled resin in a mold cavity. , Resin can flow into the mold cavity at an appropriate speed,
It is an object of the present invention to provide a mold device for molding a resin sealing portion of an electronic component, which can prevent an element body from being adversely affected when a mold cavity is filled with a resin.

[0008]

According to the present invention, in order to achieve the above object, the present invention is used for molding a resin sealing portion of an electronic component in which a wire projects from an end face of a resin sealing portion for sealing an element body. An upper mold and a lower mold that can be opened and closed freely, and a shot cavity, a runner communicating with the shot cavity, a gate communicating with the runner, and a gate opened at an end face between the upper mold and the lower mold. A resin sealing portion of an electronic component forming a mold cavity in which an element body portion of the electronic component is inserted, a wire fitting groove into which a wire of the electronic component is fitted, and an air vent portion communicating the mold cavity outside the mold. In the molding die apparatus, the gate is provided in a pair with a wire fitting groove interposed in one mold cavity, and the air vent portion is provided on an end face of the mold cavity opposite to the gate. It is those that were opened.

[0009]

In the mold apparatus for molding a resin-sealed portion of an electronic component of the present invention, when the element body of the electronic component is resin-sealed, for example, after mounting the electronic component before resin sealing on a lower mold. The upper mold and the lower mold are clamped. In this state, a shot cavity, a runner, a gate, a mold cavity, and an air vent are formed between the upper mold and the lower mold, and the element body of the electronic component enters the mold cavity. The wires of the component are fitted into the wire fitting grooves of the upper and lower dies, respectively. Then, the resin is transferred from the shot cavity to the mold cavity via the runner and the gate. At this time, the resin flows into one mold cavity from a pair of gates that are located across the wire fitting groove and that are open at the end face of the mold cavity.
Uneven stress is not applied to the element body. In addition, the resin flows into the mold cavity from a pair of gates located across the wire fitting groove, so that the air vent portion is opened only on the end surface opposite to the gate of the mold cavity, and the air vent portion is reduced. Nevertheless, the flow of resin can be accelerated without generating bubbles. Furthermore, since there are two gates for one mold cavity,
The wear of these gates progresses slowly. With this,
Even if one of the gates is clogged, resin can flow in from the other gate, so even if the gate is made smaller, no unfilling occurs, and since the gate can be made smaller, the inconvenience at the time of gate break due to wear of the gate is reduced. .

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a mold apparatus for molding a resin sealing portion of an electronic component according to the present invention will be described below with reference to FIGS. The electronic component on which the resin sealing portion 4 is molded is
This is the diode 1 as described above and shown in FIG. 31
Is an upper mold, and 32 is a lower mold. The upper mold 31 and the lower mold 32 move up and down with respect to each other to open and close. The upper mold
31 is a mold plate 33 with a built-in heater not shown
A center block 34 fixed to the center of the lower surface of the mold plate 33 in the left-right direction, and a plurality of chases 35 fixed in a state where the lower surface of the mold plate 33 is abutted on both left and right sides of the center block 34, The lower surface of the mold plate 33 includes an end plate 36 fixed to the end of the chase 35 on the side opposite to the center block 34. The lower mold 32 also includes a mold plate 37 having a heater (not shown) built therein, and a center block 38 fixed to the center of the upper surface of the mold plate 37 in the left-right direction.
And a plurality of chase 39 fixed in a state of being abutted on the left and right sides of the center block 38 on the upper surface of the mold plate 37, and abutted against the end of the chase 39 on the opposite side of the center block 38 on the upper surface of the mold plate 37. It consists of an end plate 40 fixed in a state and the like. With such a configuration, at the time of mold clamping, the center blocks 34 and 38 of the upper mold 31 and the lower mold 32 abut against each other, and the chase 35,
39 are the ones striking each other. That is, the lower surfaces of the center block 34 and the chase 35 of the upper die 31 and the upper surfaces of the center block 38 and the chase 39 of the lower die 32 form parting line surfaces 31a and 32a, respectively. On the upper surface of the center block 38 of the lower mold 32, a concave cull 41 forming a shot cavity is formed, and a runner 42 communicating with the cull 41 is formed. In the upper die 31, a center block
A runner 43 communicating with the runner 42 of the lower mold 32 is formed on a lower surface of the lower mold 32, and a runner 44 communicating with the runner 43 is formed on a lower surface of each chase 35, respectively. A number of first gates 45 and second gates 46 are formed from 44. Further, a plurality of substantially semi-cylindrical concave portions 47 and 48 opening to the parting line surfaces 31a and 32a are formed in the respective chase 35 and 39 of the upper die 31 and the lower die 32 along the runner 44, respectively. The concave portions 47 and 48 form a substantially cylindrical mold cavity 49 communicating with the first gate 45 and the second gate 46 at the time of mold clamping. Further, each chase 3 of the upper die 31 and the lower die 32
The wire fitting grooves 50 and 51 are formed in the parts 5 and 39 and open to the parting line surfaces 31a and 32a and communicate with the concave parts 47 and 48, respectively. The first gate 45 and the second
The gate 46 is tapered from the runner 44 toward the mold cavity 49 and opens at one end surface of each mold cavity 49. A wire fitting groove 50 penetrating through the central axis of each mold cavity 49 is formed. It is located across. In addition,
The first gate 45 forms an obtuse angle with respect to the flow direction of the resin in the runner 44 indicated by the arrow in FIG. 1, while the second gate 46 forms an acute angle with respect to the flow direction of the resin. Further, for example, a shallow concave portion is formed on the lower surface of the chase 35 of the upper mold 31 to form an air vent 52 that allows the mold cavity 49 to communicate with the outside of the mold at the time of mold clamping. The air vent 52 is opened only on the end face of the mold cavity 49 opposite to the gates 45 and 46. Further, a pot 53 forming a shot cavity facing the cull 41 of the lower mold 32 is fixed to the center block 34 and the mold plate 33 of the upper mold 31 in a penetrating state. Further, in the upper die 31, the die plate 33 is formed with a projecting pin insertion slit 61 located above the row of the concave portions 47, and the chase 35 has
A plurality of vertical protrusion pin insertion holes 62 each extending from the protrusion pin insertion slit 61 to each of the concave portions 47 are formed. On the other hand, also in the lower mold 32, the mold plate 37 has
A vertical protruding pin insertion slit 63 is formed below the row of the concave portions 48, and a plurality of vertical protruding pin insertion holes 64 extending from the protruding pin inserting slit 63 to each of the concave portions 48 are formed in the chase 39. Is formed. Further, the mold plates 33 and 37 of the upper mold 31 and the lower mold 32, the center blocks 34 and 38, and the chase 35 and 39 also have vertical protruding pin insertion holes 6 facing the runners 42, 43 and 44.
5, 66 are formed respectively.

In the upper mold 31, a mold plate 33 is provided.
The upper mounting plate 73 is fixed to the upper side via a heat insulating material 71 and a support 72. The upper mounting plate 73 is mounted on the upper platen of the transfer molding machine. Projecting plates 74 and 75 are supported between the mold plate 33 and the upper mounting plate 73 so as to be vertically movable with respect to them. The protruding plates 74 and 75 are urged downward with respect to the mold plate 73 by a spring (not shown). On the protruding plates 74 and 75, a number of product protruding pins 76 and runner protruding pins 77 are fixed so as to protrude downward. Product extension pin 76
Is inserted through the protruding pin insertion slit 61 and the protruding pin insertion hole 62, and the front end thereof is located facing the recess 47. The runner protruding pin 77 is inserted through the protruding pin insertion hole 65, and its tip is located facing the runners 42, 43, 44. Further, the protruding plate 74,
A return pin 78 fixed to 75 penetrates the mold plate 33 slidably. On the other hand, on the upper surface of the mold plate 37 on the lower mold 32 side, a return pin receiver 79 which is in contact with the return pin 78 at the time of mold clamping is fixed. In the lower die 32, a lower mounting plate 83 is fixed below the die plate 37 via a heat insulating material 81 and a support. The lower mounting plate 83 is mounted on a lower platen of a transfer molding machine. Projection plates 84 and 85 are supported between the mold plate 37 and the lower mounting plate 83 so as to be able to move up and down with respect to them. These protruding plates 84, 85
Is urged downward with respect to the mold plate 37 by a spring (not shown). And the protruding plate 8
A number of product protruding pins 86 and runner protruding pins 87 are fixed to 4, 85 so as to protrude upward. The product ejection pin 86 is inserted through the ejection pin insertion slit 63 and the ejection pin insertion hole 64, and the tip thereof faces the recess 48. Also, runner protruding pin
Reference numeral 87 denotes a protrusion which is inserted through the protruding pin insertion hole 66 and whose front end faces the runners 42, 43, 44. Further, return pins 88 fixed to the protruding plates 84 and 85 slidably penetrate the mold plate 37. On the other hand, on the lower surface of the mold plate 33 on the upper mold 31 side, the return pin 88
, A return pin receiver 89 that is in contact with is fixed.

Next, the operation of the above configuration will be described. When the element body 2 of the diode 1 is sealed with a resin, first, the upper die 31 and the lower die 32 are opened, and the diode 1 before resin sealing is lowered using a loading frame (not shown). Mount on mold 32. In this state, the lower half of the horizontal wire 3 of the diode 1 is fitted into the wire fitting groove 51 of the lower mold 32, and the element body 2 of the diode 1 is placed above the concave portion 48 of the lower mold 32. To position. Further, a tablet of a thermosetting resin is loaded into the pot 53. Then, the upper die 31 and the lower die 32 are clamped as shown. In this state, the runner is placed between the upper mold 31 and the lower mold 32.
42, 43, 44, gates 45, 46, and a mold cavity 49 are formed. The element body 2 of the diode 1 enters the mold cavity 49, and the upper half of the wire 3 is connected to the wire fitting groove of the upper mold 31. Mated to 50. Next, the plunger 91 of the transfer molding machine is lowered, and the thermosetting resin in the pot 53 is brought into a molten state by heating by the heaters in the mold plates 33 and 37 and pressing the plunger 91,
By pressing the plunger 91, the runner 42,
It is transferred into the mold cavity 49 via 43 and 44 and gates 45 and 46. At this time, the resin is in one mold cavity 49
In the first, the wire fitting grooves 50 and 51 are interposed.
From the gate 45 and the second gate 46. Then, after the cure time, for example, the lower mold for the upper mold 31
The mold is opened when 32 descends. Accordingly, the upper die 31
In, due to the bias of the spring, the protruding plates 74 and 75 descend with respect to the mold plate 37, and the protruding pins 76 and 77 protrude from the center block and the chase. In this way, by the protrusion of the product protrusion pin 76,
Resin sealing portion 4 made of resin solidified in each mold cavity 49
Are separated from the upper die 31, and the resin solidified in the runners 42, 43, 44 and the cull 41 is separated from the upper die 31 by the protrusion of the runner protrusion pins 77. In the lower mold 32, at the beginning of the mold opening, the protruding plates 84 and 85 are lowered integrally with the mold plate 37. However, when the mold is further opened, a protruding rod (not shown) provided on the transfer molding machine protrudes. The plates 84 and 85 are pressed from below, so that the mold plate is pressed against the bias of the spring.
The protruding plates 84 and 85 rise relatively to 37, and the protruding pins 86 and 87 protrude from the center block 38 and the chase 39. In this way, the protruding product protruding pins 86 separate the resin sealing portions 4 from the lower mold 32, respectively, and the protruding runner protruding pins 87 provide
The resin of the runners 42, 43, 44 and cull 41 is released from the lower mold 42. After completion of the mold opening, the molded diode 1 with the resin sealing portion 4 is taken out of the lower mold 32 together with the loading frame. Thereafter, the mold is clamped for the next molding. At the time of the mold clamping, the lower mold 32 is biased by a spring as the ejecting rod of the transfer molding machine separates from the ejecting plates 84 and 85. Plate 37
The protruding plates 84 and 85 relatively move downward. At the same time, the return pins 88 of the protruding plates 84 and 85 are
By hitting the return pin receiver 89 of 31, the protrusion pins 86 and 87 return to the positions at the time of molding. In the upper die 31, the return pins 78 of the protruding plates 74 and 75 are connected to the lower die 32.
By pressing against the return pin receiver 79 of the mold plate 33, the projecting plate 7
4 and 75 are raised, and the ejection pins 76 and 77 return to the positions at the time of molding.

According to the structure of the above embodiment, a pair of gates 45, 46 opened at one end surface of each mold cavity 49 are provided with the wire fitting grooves 50, 51 interposed therebetween.
When resin flows into the mold cavity 49 from 45 and 46, biased stress is not applied to the element body 2 of the diode 1.
Thereby, the element body 2 is not adversely affected. Also,
Since the resin flows into the mold cavity 49 on both sides of the wire 3 and the element body 2, the resin easily flows around the entire mold cavity 49, and the resin can flow quickly without generating bubbles. The generation of the unfilled portion of the resin in the inside can also be prevented. Further, since the resin easily flows around the entirety of the mold cavity 49, even if the air vent 52 is opened only at the end face of the mold cavity 49 opposite to the gates 45 and 46, it is sufficient. By reducing the number of the air vents 52, the traces of the air vents 52 formed in the resin sealing portion 4 of the diode 1 can be reduced, and the man-hour for die processing can be reduced. Further, since there are two gates 45 and 46 for one mold cavity 49, the progress of wear of the gates 45 and 46 is slowed down. At the same time, even if foreign matter is clogged in one of the gates 45, 46, resin can flow in from the other gates 46, 45.
The generation of the unfilled portion of the resin in the inside can also be prevented. This makes it possible to reduce the size of the gates 45 and 46 themselves. For example, as compared with the case where one gate 15 is provided for one mold cavity 14 as in the related art, gates 45 and 46 are provided.
Can be reduced by half. Since the gates 45, 46 themselves can be made smaller, the inconvenience at the time of gate break due to wear of the gates 45, 46 can be reduced. That is, a part of the resin solidified in the gates 45 and 46 is attached to the resin sealing portion 4 of the diode 1, or a part of the resin sealing portion 4 is chipped and attached to the gates 45 and 46. Can be prevented, and cutting can be reliably performed at the tips of the gates 45 and 46. In addition, the number of moldings before the above-described inconvenience occurs increases.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made. For example,
In the above embodiment, the diode 1 has been described as an example, but the present invention can be applied to electronic components other than the diode.

[0015]

According to the present invention, in a mold apparatus for molding a resin-sealed portion of an electronic component in which a wire projects from an end face of a resin-sealed portion for sealing an element body, a wire is provided for one mold cavity. Since a pair of gates is provided with the fitting groove interposed, and the air vent portion is opened only on the end face opposite to the gate of the mold cavity, even if one gate is clogged with foreign matter,
By allowing the resin to flow from the other gate, it is possible to prevent the generation of an unfilled portion of the resin in the mold cavity. Therefore, the gate itself can be made smaller, and the progress of the wear of the gate itself is slowed down. Inconvenience at the time of a gate break can be reduced, and the number of moldings before the inconvenience occurs can be increased. In addition, the resin can easily flow around the entire cavity of the mold, and despite the small number of air vents, the flow of the resin can be accelerated without generating bubbles, and the occurrence of an unfilled portion of the resin in the mold cavity can be prevented. In addition, since the number of air vents can be reduced, traces of the air vents formed in the resin sealing portion can be reduced, and man-hours for die processing can be reduced. Further, when the resin flows into the mold cavity, a biased stress is not applied to the element main body, and the element main body is not adversely affected.

[Brief description of the drawings]

FIG. 1 is an enlarged bottom view of a part of an upper mold showing one embodiment of a mold device for molding a resin sealing portion of an electronic component of the present invention.

FIG. 2 is a bottom view of a half of the upper die.

FIG. 3 is a cross-sectional view of the same mold cavity portion.

FIG. 4 is a sectional view of a half of the entire mold apparatus.

FIG. 5 is a perspective view of a diode as an electronic component.

FIG. 6 is an enlarged bottom view of a part of an upper mold showing an example of a conventional mold device for molding a resin sealing portion of an electronic component.

FIG. 7 is a cross-sectional view of the same mold cavity portion.

[Description of Signs] 1 Diode (electronic component) 2 Element main body 3 Wire 4 Resin sealing portion 31 Upper die 32 Lower die 41 Cal (shot cavity) 42 Runner 43 Runner 44 Runner 45 First gate (Gate) 46 First Gate 2 (gate) 49 mold cavity 50 wire fitting groove 51 wire fitting groove 52 air vent

Continuation of the front page (56) References JP-A-4-334418 (JP, A) JP-A-63-79640 (JP, U) JP-A-63-98631 (JP, U) JP-A-5-2928 (JP, U) , U) Fully open 1984-9812 (JP, U) Fully open 1987-53127 (JP, U) Fully open 1983-139040 (JP, U) Fully open 1987-114440 (JP, U) (58) Field surveyed (Int.Cl. ⁷ , DB name) B29C 45/26-45/44

Claims (1)

(57) [Claims] 1. An upper part and a lower part which are used for molding a resin sealing part of an electronic component in which a wire protrudes from an end surface of a resin sealing part for sealing an element main body part. Between the lower mold and the shot cavity, a runner communicating with the shot cavity, a gate communicating with the runner, a mold cavity in which the gate is open at an end face and into which the element body of the electronic component enters, and a wire of the electronic component. In a mold apparatus for molding a resin-sealed portion of an electronic component that forms a wire fitting groove into which a mold is fitted and an air vent portion that connects the mold cavity to the outside of the mold, the gate is provided in one mold cavity. A pair of air vent portions are provided with a wire fitting groove interposed therebetween, and the air vent portion is opened only on an end surface of the mold cavity opposite to a gate, wherein a resin sealing portion of an electronic component is formed. Mold equipment.