JP2992982B2 - 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. 3, an element body 2 is sealed with a thermosetting resin, for example, an epoxy resin. The diode 1 has a pair of wires 3 connected to the element body 2 and a resin sealing portion 4 having a substantially cylindrical shape.
Coaxially project from each other in opposite directions. In addition, the concave 5 on the side surface of the resin sealing portion 4 is a protrusion pin mark. In the resin sealing, transfer molding is performed, and a mold device as shown in FIGS. 4 to 8 is used for the transfer molding. Here, this conventional mold apparatus will be described. Numeral 11 denotes an upper die, and numeral 12 denotes a lower die. The upper die 11 and the lower die 12 move up and down with respect to each other to open and close. The upper mold 11 includes a mold plate 13 having a heater (not shown) built therein, a center block 14 fixed to the center of the lower surface of the mold plate 13 in the left-right direction, and left and right of the center block 14 on the lower surface of the mold plate 13. A plurality of chase 15 fixed in a state of being abutted on both sides, and a chase on the lower surface of the mold plate 13
15 and an end plate 16 fixed in a state of being abutted against the end on the side opposite to the center block 14. The lower mold 12 also includes a mold plate 17 having a heater (not shown) built-in, a center block 18 fixed to the center of the upper surface of the mold plate 17 in the left-right direction, and a mold plate 17.
A plurality of chase 19 fixed in a state of being abutted on the left and right sides of the center block 18 on the upper surface of the
It comprises an end plate 20 fixed in a state of being abutted on the 18 side end. With such a configuration, at the time of mold clamping, the center blocks 14,
18 hit each other and chase 15, 19 hit each other. That is, the center block of the upper die 11
Lower surface of 14 and chase 15 and center block of lower mold 12
The upper surfaces of 18 and chase 19 form parting line surfaces 11a and 12a, respectively. A concave cull 21 is formed on the upper surface of the center block 18 of the lower die 12, and a runner 22 communicating with the cull 21 is formed. In the upper die 11, a runner 23 communicating with the runner 22 of the lower die 12 is formed on the lower surface of the center block 18, and a runner 23 communicating with the runner 23 is formed on the lower surface of each chase 15. 24 are formed, and a large number of gates 25 are formed from the runner 24. Further, the upper mold 11 and the lower mold
Each of the 12 chases 15, 19 has its parting line surface
A plurality of substantially semi-cylindrical shapes opening to 11a and 12a,
Recesses 26 and 27 each having a shape obtained by cutting a cylinder into two using a horizontal plane including the center axis thereof as a cutting surface are formed along the runner 24. A substantially cylindrical mold cavity 28 communicating therewith is formed. The concave portion
Each of the cross-sectional shapes orthogonal to the axial direction of 26 and 27 is a complete semicircular shape. Also, conventionally, a grain is formed on the surface of the resin sealing portion 4 by subjecting the inner surfaces of the concave portions 26 and 27 of the upper mold 11 and the lower mold 12 to graining. In the mold device, the concave portion 26 of the upper mold 11 and the lower mold
The roughness of the grain was the same in the twelve concave portions 27. In addition,
The roughness of the grain formed by electric discharge machining is usually 10μ
m, it takes time to process, but 4-5 μm
It is also possible to make the degree. The chase 15, 19 of the upper mold 11 and the lower mold 12 are formed with wire fitting grooves 29, 30 which open to the parting line surfaces 11a, 12a and communicate with the recesses 26, 27, respectively. . Further, for example, a shallow concave portion is formed on the lower surface of the chase 15 of the upper mold 11 to form air vent portions 31 and 32 for communicating the mold cavity 28 outside the mold at the time of mold clamping. A pot 33 is fixed to the center block 14 and the mold plate 17 of the upper mold 11 so as to face the cull 21 of the lower mold 12 in a penetrating state.
Further, in the upper mold 11, the mold plate 13 has a concave portion.
A protruding pin insertion slit 41 is formed above the row of 26, and a plurality of vertical protruding pin insertion holes 42 are formed in the chase 15 from the protruding pin insertion slit 41 to the respective recesses 26. I have. On the other hand, the lower mold 12
Also, in the mold plate 17, a vertical protruding pin insertion slit 43 is formed above the row of the concave portions 27, and a plurality of chase 19 extending from the protruding pin A vertical protruding pin insertion hole 44 is formed. Further, the projecting pin insertion holes 45, 46, which are perpendicular to the runners 22, 23, 24, are also provided on the mold plates 13, 17 of the upper mold 11 and the lower mold 12 and the center blocks 14, 18 and the chase 15, 19. Are formed respectively.

In the upper mold 11, a mold plate 13 is provided.
An upper mounting plate 53 is fixed to the upper side through a heat insulating material 51 and a support 52. The upper mounting plate 53 is mounted on the upper platen of the transfer molding machine. Projecting plates 54 and 55 are supported between the mold plate 13 and the upper mounting plate 53 so as to be vertically movable with respect to these. The protruding plates 54 and 55 are urged downward with respect to the mold plate 13 by a spring (not shown). On the protruding plates 54 and 55, a number of product protruding pins 56 and runner protruding pins 57 are fixed so as to protrude downward. Product extension pin 56
The protruding pin is inserted through the protruding pin insertion slit 41 and the protruding pin insertion hole, and the front end is positioned facing the concave portion. The runner protruding pin 57 is inserted through the protruding pin insertion hole 45, and has a front end facing the runners 22, 23, and 24. Further, the protruding plate 54,
A return pin 58 fixed to 55 penetrates the mold plate 13 slidably. On the other hand, on the upper surface of the mold plate 17 on the lower mold 12 side, a return pin receiver 59 that is in contact with the return pin 58 at the time of mold clamping is fixed. In the lower die 12, a lower mounting plate 63 is fixed below the die plate 17 via a heat insulating material 61 and a support 62. The lower mounting plate 63 is mounted on a lower platen of a transfer molding machine. Projection plates 64 and 65 are supported between the mold plate 17 and the lower mounting plate 63 so as to be able to move up and down with respect to them. This protruding plate 64, 65
Is urged downward (or away from) the mold plate 17 by a spring (not shown). On the protruding plates 64 and 65, a number of product protruding pins 66 and runner protruding pins 67 are fixed so as to protrude upward. The product ejection pin 66 is inserted through the ejection pin insertion slit 43 and the ejection pin insertion hole 44, and has a tip facing the recess 27. Also,
The runner protruding pin 67 is inserted through the protruding pin insertion hole 46, and its tip is located facing the runners 22, 23, 24. Further, return pins 68 fixed to the protruding plates 64 and 65 slidably penetrate the mold plate 17. On the other hand, on the lower surface of the mold plate 13 on the upper mold 11 side, a return pin receiver 69 which is in contact with the return pin 68 at the time of mold clamping is fixed.

Next, the operation of the above configuration will be described. At the time of molding, first, with the mold opened, the diode 1 before resin sealing is mounted on the lower mold 12 using a loading frame (not shown). In this state,
The lower half of the horizontal wire 3 of the diode 1 is the lower mold
Fits into 12 wire fitting grooves 30. Also, a tablet of a thermosetting resin is loaded into the pot 33. Then, the mold is clamped as shown. In this state, the upper half of the wire 3 is fitted into the wire fitting groove 29 of the upper mold 11 and the element body 2 of the diode 1 is placed in the mold cavity 28 formed between the upper mold 11 and the lower mold 12. To position. Next, the plunger 71 of the transfer molding machine is lowered. The thermosetting resin in the pot 33 is brought into a molten state by the heating of the heaters in the mold plates 13 and 17 and the pressing of the plunger 71. Runner from Cal 21 by pressing
It flows into the mold cavity 28 via 22, 23, 24 and the gate 25. FIG. 8A shows a state in which the resin is filled in the mold cavity 28 in the mold-clamped state. Thereafter, for example, the lower mold 12 is lowered with respect to the upper mold 11 to open the mold. Along with this, in the upper die 11, the protruding plates 54, 55 are lowered with respect to the die plate 17 by the bias of the spring, and as shown in FIG.
Project from the center block 14 and the chase 15.
In this way, the protruding product protruding pins 56 release the resin sealing portions 4, which are resins solidified in the mold cavities 28, from the upper mold 11, respectively, and protrude the runner protruding pins 57 to form the runner 22. , 23,24
And the resin solidified in the cal 21 is released from the upper mold 11.
In the lower mold 12, at the beginning of the mold opening, the protruding plates 64 and 65 are lowered integrally with the mold plate 17, but when the mold is further opened, a protruding rod (not shown) provided on the transfer molding machine protrudes. The plates 64, 65 are pressed from below, whereby the protruding plates 64, 65 rise relatively to the mold plate 17 against the bias of the spring,
As shown in FIG. 8C, the projecting pins 66 and 67 project from the center block 18 and the chase 19. In this manner, the resin sealing portion 4 is released from the lower mold 12 by the protrusion of the product protrusion pin 66, and the runners 22, 23, and 23 are formed by the protrusion of the runner protrusion pin 67.
The resin in the portions 24 and 21 is released from the lower mold 12. After completion of the mold opening, the molded diode 1 with the resin sealing portion 4 is taken out of the lower mold 12 together with the loading frame. After that, the mold is clamped for the next molding. At the time of mold clamping, in the lower mold 12, as the ejection rod of the transfer molding machine separates from the ejection plates 64, 65,
The protruding plates 64 and 65 are lowered relative to the mold plate 17 by the bias of the spring. At the same time, the return pins 68 of the protruding plates 64 and 65 abut against the return pin receiver 69 of the upper die 11, so that the protruding pins 66 and 67 return to the positions at the time of molding. In the upper die 11, the return pins 58 of the protruding plates 54, 55 abut against the return pin receiver 59 of the lower die 12, so that the protruding plates 54, 55 are pressed against the die plate 13 against the bias of the spring. Rises, and the ejection pins 56 and 57 return to the positions at the time of molding.

[0005]

As described above, in the conventional mold device for molding the resin sealing portion 4 of the diode 1 as an electronic component, the molded diode 1 of the resin sealing portion 4 is taken out. At this time, before the diode 1 is pushed out from the lower mold 12 by the push-out pins 66, the diode 1 is surely released from the upper mold 11 and the diode 1 is moved to the lower mold 12.
The upper mold 11 also has a mold cavity 28
However, since the protruding pins 56 are provided, the following problems arise. First, the number of diodes 1 in one mold device is very large, for example, 320, but providing such a large number of protruding pins 56 is necessary from the viewpoint of material, processing and assembly. Causes cost increase. For example, epoxy resin is easy to flow in a molten state and has high adhesiveness.
Outer peripheral surfaces of 56, 57, 66, 67 and protruding pin insertion holes 42, 44,
The gap between the peripheral surfaces of 45 and 46 must be as small as 5 μm in diameter or as small as about 2 to 3 μm in clearance on one side. It is very difficult. Also, the protruding pins 56, 57, 66,
The bite amount of the tip of 67 into the resin sealing portion 4 is 0 to 0.05.
mm. If the biting amount is larger than that, it has an adverse effect on the element body 2, while if the biting amount is less than 0, a protrusion is formed in the resin sealing portion 4, which is not preferable. Thus, the protruding pin 5
The height of 6, 57, 66, 67 also requires a high degree of precision control, but the protruding pins 56, 5 that require such precision control.
The large number of 7, 66, 67 is disadvantageous in manufacturing. Also, since the ejection pins 56, 57, 66, and 67 tend to cause malfunction of the mold apparatus, a large number of ejection pins 56, 5
The presence of 7, 66, 67 is also disadvantageous in ensuring good operability of the mold apparatus. In addition, protruding pins 56 and 5
7, 66 and 67 also cause burrs.

Therefore, as shown in FIG. 9, the product projecting pin 56 on the upper die 11 side is eliminated, and the product projecting pin 66 is
It is conceivable to provide it only on the lower mold 12 which is necessary for taking out the product, that is, the diode 1. However, if there is no product protrusion pin 56 on the upper mold 11 side, there is a possibility that the resin sealing portion 4 to be stopped on the lower mold 12 side may adhere to the upper mold 11 side when the mold is opened. And the resin sealing part 4 is an upper mold
If you follow the 11 side, you will not be able to take out products etc. properly. In fact, as described above, in the conventional mold apparatus, the concave portion 26 of the upper mold 11 forming the mold cavity 28 and the lower mold
The cross-sectional shape of the concave portion 27 of the 12, that is, the cross-sectional shape orthogonal to the axial direction of the concave portions 26 and 27 are both half of a perfect circle, and the concave portion 26 of the upper die 11 and the concave portion 27 of the lower die 12 And the upper mold 11 and the upper mold 12 have substantially the same resistance to release of the resin sealing portion 4.
If there is no protrusion by the protrusion pins 56 and 57 from the side,
At the time of opening the mold, as shown in FIG.
Is easily attached to the upper mold 11 side.

On the other hand, although it is not a mold apparatus for molding a resin-sealed portion of an electronic component, Japanese Utility Model Application Laid-Open No. 58-128013 discloses a movable mold of a fixed mold and a movable mold that can be opened and closed. It is described that a molding surface of a molding die is subjected to a satin finish to prevent a molded product from sticking to a fixed molding die when the mold is opened. However, grain affects the design and workability of the molded product,
Improper setting of the roughness of the grain causes deterioration of the releasability, so it is actually important to set the roughness of the grain.

The present invention is intended to solve such a problem, and it is possible to eliminate the product protruding pin on the upper mold side and to prevent the resin sealing portion from being attached to the upper mold side when the mold is opened. It is an object of the present invention to provide a mold device for molding a resin-sealed portion of an electronic component, which can be surely prevented and can balance workability, designability, and releasability.

[0009]

In order to achieve the above object, the present invention comprises an upper die and a lower die which can be freely opened and closed, and the upper die and the lower die have a substantially semi-cylindrical opening to the parting line surface thereof. Forming a concave portion of each shape and forming an embossment on the inner surface of these concave portions, and forming a substantially cylindrical mold cavity when closing the mold by the concave portions of the upper die and the lower die. In the mold apparatus, a protrusion pin for releasing the resin sealing portion molded in the mold cavity is provided only in the lower mold among the upper mold and the lower mold, and the roughness of the grain of the concave portion of the upper mold is 5 to 5. 6
μm, and the roughness of the grain of the concave portion of the lower die was 10 to 15 μm.

[0010]

In the mold apparatus for molding a resin-sealed portion of an electronic component according to the present invention, when the upper mold and the lower mold are clamped, the recesses of the upper mold and the lower mold overlap to form a substantially cylindrical mold. A cavity is formed. By filling the mold cavity with a resin, a resin sealing portion of the electronic component is molded. After that, the upper mold and the lower mold are opened, and the resin-sealed electronic component is taken out. The roughness of the concave of the upper mold is 5 to 6 μm, whereas the concave of the lower mold is 5 μm. Due to the roughness of the grain being 10 to 15 μm, the resistance of the resin sealing part to the release from the mold at the beginning of mold opening is smaller on the upper mold side than on the lower mold side. Even if there is no, the resin sealing portion securely stops at the lower mold side without sticking to the upper mold side. After that, it is pushed up by the ejection pin on the lower mold,
The resin sealing part separates from the lower mold. 5 to 6 μm or
The grain roughness of 10 to 15 μm is preferable from the viewpoint of workability and design in electric discharge machining of the grain, in addition to releasability.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a mold device for molding a resin sealing portion of an electronic component according to the present invention will be described below with reference to FIGS. The mold apparatus of the present embodiment has the same configuration as the mold apparatus shown in FIGS. 4 to 7 described above, and therefore, the same parts are denoted by the same reference numerals and the description thereof will be omitted. Are omitted, and in the following description, FIGS.
The code attached to is quoted. The mold apparatus of the present embodiment is a lower mold
On the 12 side, a product protruding pin 66 for releasing the resin sealing portion 4 of the diode 1 is provided, while on the upper die 11 side, there is provided a product protrusion pin 66 for releasing the resin sealing portion 4 of the diode 1. No protruding pins are provided. In addition, on the upper mold 11 side,
A runner protruding pin 57 is provided. Also, upper mold
A substantially semi-cylindrical concave portion 7 formed in the lower mold 11 and the lower mold 12, respectively, to form a substantially cylindrical mold cavity 76 at the time of mold clamping.
Grains 79 and 80 are formed on the inner surfaces of 7 and 78, respectively. These embosses 79 and 80 are formed by electric discharge machining or the like. The roughness of the grain 79 of the recess 77 of the upper mold 11 is 5 to 6 μm, and the roughness of the grain 80 of the recess 78 of the lower mold 12 is 10 to 15 μm.
μm, and the texture 79 of the concave portion 77 of the upper die 11 is
The grain is smaller than 80.

Next, the operation of the above configuration will be described. When the element body 2 of the diode 1 is sealed with resin, the diode 1 before resin sealing is first mounted on the lower mold 12 using a loading frame in a mold open state. Then, as shown in FIG. 1 and FIG.
The mold 11 is clamped to the lower mold 12, and in this clamped state, the recess 77 of the upper mold 11 and the recess 78 of the lower mold 12 overlap to form a substantially cylindrical mold cavity 76. Then, the resin is filled into the mold cavity 76 to form the resin sealing portion 4. Thereafter, the upper mold 11 and the lower mold 12 are opened.
As shown in (b), the resin sealing portion 4 is separated from the upper mold 11. This is because the texture 79 of the recess 77 of the upper mold 11 is
This is because the resistance to the release of the resin sealing portion 4 is smaller on the upper mold 11 side than on the lower mold 12 side. When the mold further opens, as shown in FIG. 2C, the product protruding pin 66 relatively rises with respect to the chase 19 on the lower mold 12 side, and the resin protruding pin 66 is formed by the product protruding pin 66. 4 is pushed up and separated from the lower mold 12. After that, the diode 1, runner 22,
Take out the resin at parts 23, 24 and 21.

According to the structure of the above embodiment, the mold cavity is provided.
Of the recesses 77, 78 forming the
Since 79 is finer than the grain 80 of the concave portion 78 of the lower mold 12, even if there is no product ejecting pin for releasing the resin sealing portion 4 on the upper mold 11 side, resin molding is performed at the beginning of mold opening. The part 4 can be reliably prevented from sticking to the upper mold 11 side, and the resin sealing part 4 can be securely stopped to the lower mold 12 side. Eliminating the protruding pins on the upper mold 11 side can reduce manufacturing costs and also reduce malfunctions. Also, the grain 79 of 5 to 6 μm or 10 to 15 μm is used.
The roughness of 80 is preferable from the viewpoints of workability and design in electric discharge machining of the grain 79, 80, in addition to mold releasability.

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 device for molding a resin sealing portion of an electronic component, the projecting pins for releasing the resin sealing portion formed by the substantially cylindrical mold cavity are formed in the upper die and the lower die. Of the molds, only the lower mold is provided, and among the recesses forming the mold cavity, the roughness of the upper mold recess is 5 to 6 μm, and the roughness of the lower mold recess is 10 to 15 μm.
m, when the mold is opened, the resistance of the resin sealing portion to the mold release is smaller on the upper mold side than on the lower mold side,
Even though there is no protrusion pin on the upper mold side for releasing the resin sealing part, the resin sealing part can be reliably prevented from sticking to the upper mold side, and the resin sealing part can be securely lowered. Can be stopped on the mold side. By eliminating the protrusion pin on the upper die side, it is possible to reduce the cost and to reduce malfunctions. In addition, the above 5 to 6 μm and 10 to
By setting the roughness of 15 μm, the workability, design, and releasability in grain discharge machining can be balanced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a mold cavity portion showing an embodiment of a mold device for molding a resin sealing portion of an electronic component of the present invention;
A portion is shown enlarged.

FIG. 2 is a cross-sectional view of a mold cavity showing an operation when the mold is opened.

FIG. 3 is a perspective view of a diode as an electronic component.

FIG. 4 is a cross-sectional view showing an example of a conventional mold device for molding a resin sealing portion of an electronic component.

FIG. 5 is a bottom view of a part of the upper die.

FIG. 6 is an enlarged bottom view of a part of the upper die.

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

FIG. 8 is a cross-sectional view of the same mold cavity portion.

FIG. 9 is a cross-sectional view of a mold cavity showing a mold apparatus in which a product ejecting pin is eliminated from an upper mold.

[Explanation of symbols]

 1 Diode (Electronic parts) 11 Upper die 11a Parting line surface 12 Lower die 12a Parting line surface 76 Die cavity 77 Depression 78 Depression 79 Surface 80 Surface

Continuation of the front page (51) Int.Cl. ⁶ identification code FI // B29K 105: 20 B29L 31:34 (58) Field surveyed (Int.Cl. ⁶ , DB name) B29C 45/00-45/84 H01L 21/56

Claims (1)

(57) [Claims] An upper mold and a lower mold that can be opened and closed are provided. Each of the upper mold and the lower mold has a substantially semi-cylindrical concave portion that opens to the parting line surface, and a crimp is formed on the inner surface of the concave portion. In a mold apparatus for molding a resin-sealed portion which forms a substantially cylindrical mold cavity at the time of mold clamping by the concave portions of the upper mold and the lower mold, the resin-sealed portion molded by the mold cavity is released. Protruding pins are provided only on the lower mold of the upper mold and the lower mold, and the roughness of the grain of the concave of the upper mold is 5 to 6 μm, and the roughness of the grain of the concave of the lower mold is 10 to 15 μm. Characteristic mold device for molding resin sealing part of electronic parts.