JP2003136563A - Mold for electronic part by sealing in resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently prevent the deformation or cutting of a wire or the voids or the like of a resin molded product from being generated. SOLUTION: An outflow part 8 for flowing a molten resin 10 out of a mold pot 4 is formed at one spot in the mold pot 4 and resin passages 7a and 7b for transferring the molten resin 10 after diverting the resin 10 into two different flow directions from the outflow part 8, are constituted so that the resin transfer distances 9a and 9b of the resin passages 7a and 7b are the same. Thus the molten resin 10 is equally injected into the mold cavities 2(2a) and 2(2b) through the resin passages 7a and 7b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a resin encapsulation molding die for an electronic component for resin encapsulation of a lead frame on which an electronic component such as an IC is mounted.

[0002]

2. Description of the Related Art Conventionally, an electronic component mounted on the lead frame has been sealed and molded with a resin material (cylindrical resin tablet) by a transfer molding method. Using a mold for resin sealing molding of electronic parts consisting of a fixed upper mold and a movable lower mold,
Usually, it is performed as follows.

That is, as shown in FIG. 5, first, a cylindrical resin tablet 53 is supplied into a pot 52 having a circular mold surface shape in the lower mold 51, and an electron is placed at a predetermined position of the lower mold 51. The lead frame 54 on which the components are mounted is supplied and set, and both the molds (51) are clamped to separate the electronic component and the peripheral lead frame 54 from the mold cavity 56 for resin molding (two in the figure). ), And then press the resin material heated and melted in the pot 52 with a resin pressurizing plunger to push the pot 52 into the pot 52.
The molten resin 59 is separately pushed into the mold cavity 56 through the resin passages 58 provided at the two positions of the cull portion 57 on the pot 52 side by pressing the resin distribution cull portion 57 arranged opposite to each other. By injecting, the electronic component and the lead frame 54 around the electronic component are sealed and molded in the resin molded body molded in the mold cavity 56. After the lapse of the time required for the thermosetting of the molten resin, the molds (51) are opened, and the resin molded product (product) is ejected from the molds (51) and released. .

[0004]

However, as shown in FIG. 5, when a cylindrical resin tablet 53 is supplied into the circular pot 52, the resin tablet 53 often contacts the inner wall of the pot 52. Since the supply position of the resin tablet 53 in the pot 52 is biased, the resin tablet 53 is not uniformly heated and melted. For example, as shown in FIG.
The resin tablet 53 is not uniformly heated and melted, and the pot 52 including the cull portion 57 is also provided.
Since there are two outlets of the molten resin from the inside, the molten resin 59 is evenly (at the same timing) in each resin passage 58 from the two outlets of the molten resin provided in the pots 52 and 57 at the same time. Since the resin does not flow out, the transfer distances of the tips of the molten resin 59 flowing out from the pots 52 and 57 in the resin passages 58 do not become the same distance. That is, the molten resin 59 is not evenly injected (for example, the same melt viscosity, the same injection pressure, the same transfer speed, the same timing) into the mold cavities 56 through the resin passages 58. A difference in filling due to the molten resin 59 will occur in the mold cavity 56. Therefore, the quality of the resin moldings molded in the mold cavities 56 varies. For example, the mold cavity 56 described above.
As the pressure of the molten resin 59 injected into the inside increases, the wire for electrically connecting the electronic component and the lead (the lead frame 54) described above is deformed or cut, and the molten resin 59 is not melted. When the pressure is reduced, voids and the like are generated in the resin molded body molded in the mold cavity 56, and a product (resin molded body) of uniform quality is efficiently obtained in the mold cavity 56. I can't. That is, since the molten resin 59 cannot be evenly injected into the mold cavity 56, there is an adverse effect that a product of uniform quality cannot be efficiently obtained.

Therefore, the object of the present invention is to efficiently obtain a product of uniform quality by uniformly injecting the molten resin into the mold cavity.

[0006]

[MEANS FOR SOLVING THE PROBLEMS] A mold for resin-sealing molding of an electronic component according to the present invention for solving the above-mentioned technical problems is provided from a pot for supplying a resin material into a plurality of mold cavities. A mold for resin encapsulation molding of an electronic component, in which molten resin is separately injected through resin passages for resin transfer provided correspondingly in the mold cavities, and the molten resin from the pot to the pot Is provided with an outflow section for outflowing
It is characterized in that the distance of the resin passage from the outflow portion to each of the cavities is the same.

Further, a resin encapsulation molding die for an electronic component according to the present invention for solving the above-mentioned technical problem is divided into an even number of die cavities in two and into the same number of cavities. A set of mold cavities is formed, and two resin passages are separately connected and connected to the outflow passage corresponding to the set of the two mold cavities.

Further, a metal mold for resin molding of an electronic component according to the present invention for solving the above-mentioned technical problem is characterized in that a bottleneck for resin rectification is provided at the outflow portion. To do.

Further, a resin sealing molding die for an electronic component according to the present invention for solving the above-mentioned technical problem has a transfer direction of the outflow portion and a transfer direction of two resin passages. It is characterized in that the angles are formed at right angles.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the mold for resin encapsulation molding according to the present invention includes a pot for supplying a resin material (a portion for supplying molten resin) and a plurality of mold cavities (a resin molding portion). ), A resin passage for transferring resin (a portion for transferring molten resin) provided correspondingly in each of the mold cavities, and an outflow portion for outflowing the molten resin, which serves as one outlet for the molten resin in the pot. Since the distance of the resin passage from the outflow portion to each of the cavities is configured to be the same, the molten resin flowing out from the pot through the outflow portion into the resin passage is The resin is evenly branched and divided in the transfer direction of the resin passage, and then, the resin is evenly and separately transferred into each of the resin passages having the same distance, so that the molten resin is evenly distributed in each of the mold cavities (particularly, , Same pressure, same pressure It can be timing in) and injected into each another. That is, since the molten resin can be evenly injected into each of the mold cavities, it is possible to efficiently prevent the deformation or cutting of the wire or the occurrence of voids or the like in the resin molded body. Therefore, since it is configured as described above, it is possible to efficiently obtain products of uniform quality.

[0011]

Embodiments will be described below with reference to the drawings.

The mold shown in FIG. 1 comprises a fixed upper mold and a movable lower mold 1 facing the upper mold, and both molds (1) have upper and lower molds for resin molding. Cavity 2
And two mold cavities 2 (2
a) and 2 (2b) are provided. Also, the lower mold 1
Is provided with a resin material supply pot 4 for supplying a cylindrical resin tablet 3 (resin material), and a resin pressurizing plunger for pressurizing the resin material heated and melted in the pot 4. There is. Therefore, by supplying and setting the lead frame 5 on which the electronic component is mounted at a predetermined position of the lower mold 1 and clamping the both molds (1), the electronic component and the periphery thereof are set in the mold cavity 2. The lead frame 5 can be fitted and set. In addition, the above-mentioned upper mold is provided with a resin-distributing cull portion 6 which is arranged so as to face the lower-mold pot 4, and is separately connected to each of the mold cavities 2 (2a) and 2 (2b) described above. The resin passage 7 is provided. In the illustrated example, the resin passage 7a is communicatively connected to the mold cavity 2 (2a), and the resin passage 7b is communicatively connected to the mold cavity 2 (2b). The branched molten resin 10 can be separately transferred in the two transfer directions 7a and 7b, that is, in the respective mold cavities 2 (2a) and 2 (2b). . Also,
Between the branch point of the resin passage connecting the resin passage 7a and the resin passage 7b to each other and the pot 4 including the cull portion 6, the molten resin 10 is provided from the side of the pots 4 and 6 to the branch point. An outflow portion 8 (outlet portion) for outflowing the resin is provided so as to communicate with each other. As shown in the figure, the molten resin 10 is transferred from the pots 4 and 6 to the resin passages 7a and 7b.
There is only one outlet where the water flows out. That is, the pot 4
The molten resin 10 that has flowed from the outflow portion 8 on the 6 side to the branch point of the resin passage 7 branches in the resin passage 7 to pass through the resin passage 7a to the mold cavity 2 (2a). Also, the mold cavity 2 described above
The molten resin 10 can be injected into (2b) through the resin passage 7b described above. Therefore, the molten resin 10 flows out into the resin passage 7 (the branching point) from the one outflow portion 8 provided in the pots 4 and 6, so that the two branched resin passages 7a and 7b are provided. The molten resin 10 can be branched / split evenly (at the same melt viscosity, at the same pressure, at the same transfer speed, at the same timing), and the branched molten resin 10 can be distributed in the resin passages 7a and 7b described above. Therefore, it is possible to uniformly transfer (in particular, at the same transfer speed and the same pressure) in the transfer direction.

Further, as shown in FIGS. 1 and 2, the positions at which the outflow portion 8 communicates with the resin passage 7 are connected to the two mold cavities 2 (2a) and 2 (2b). It is configured such that the distances are the same.
In the illustrated example, the distance 9a between the resin inlet of the mold cavity 2 (2a) and the resin outlet of the outflow portion 8 and the resin inlet of the mold cavity 2 (2b) and the resin outlet of the outflow portion 8 are shown. And the distance 9b from the same are the same. That is, since the distances 9a and 9b from the branch point to the mold cavities 2 (2a) and 2 (2b) are set to the same distance, the resin outflow portion 8 to the resin passages 7a are set.・ Molten resin 10 that has branched out into 7b
Are evenly transferred in the respective resin passages 9a and 9b along the transfer direction thereof (in particular, at the same transfer speed), and are evenly transferred into the respective mold cavities 2 (2a) and 2 (2b). In particular, they can be injected at the same pressure and at the same timing, and each of the mold cavities 2 (2a).
It is possible to eliminate the filling difference of the molten resin 10 in (2b). Therefore, it is possible to effectively prevent the deformation or cutting of the wire as described above, or the generation of voids or the like in the resin molded body as described above, and efficiently produce a product of uniform quality in the mold cavity. Obtainable.

Further, as shown in FIGS. 1 and 2, the angle between the transfer direction of the outflow portion 8 (the direction in which the molten resin flows) and the transfer direction of the resin passage 7a, or the transfer of the outflow portion 8 The angle between the direction and the transfer direction of the resin passage 7b is configured to be a right angle with respect to the transfer direction of the outflow portion 8 as the center line of line symmetry. That is, by causing the molten resin 10 to collide with the inner wall of the outlet 8 on the side opposite the resin passage 7 side at a right angle (perpendicularly) from the outlet 8, the molten resin is passed from the branch point to each of the resin passages. It is configured to be able to evenly branch and split in a line-symmetrical manner in the 7a and 7b directions. Therefore, the resin passages 7a, 7a
It is configured such that the molten resin 10 can be evenly branched and branched into the inside of b, and the branched molten resin 10 can be evenly transferred inside the resin passages 7a and 7b.

Further, as shown in FIG. 3, the outflow portion 8 is provided with a resin rectification bottleneck 14, and the bottleneck bottle 14 has a cross-sectional area of the resin passage 7 side outlet whose passage cross-section is the above-mentioned. It is configured to have a smaller cross-sectional area (shown by a flow path diameter 13) (shown by a flow path diameter 12). Further, since the bottleneck 14 is configured to transfer the molten resin 10 from the small cross-sectional area (13) to the large cross-sectional area (12) in the cross-sectional area of the flow path, the cross-sectional area difference causes Since the pressure of the molten resin 10 can be adjusted and decreased, and the transfer speed of the molten resin 10 can be reduced, the flow of the molten resin 10 flowing into the resin passage 7 is rectified and moderated. It can be configured in a kana flow state. Therefore, since the molten resin 10 can be gently collided with the inner wall of the outflow portion 8 on the side opposite to the outlet on the resin passage 7 side in a straightened state, the molten resin 10 is extremely evenly distributed in the resin passages 7a and 7b. Can be branched and diverted to.

In the example shown in FIG. 2, the molten resin 1 flows in the resin passage 7 from the resin outlet (branch point) of the outflow portion 8 in the direction of the mold cavities 2 (2a) and 2 (2b).
0 is shown separately flowing, and the transfer distance 1 in the resin passage 7a with respect to the tip of the molten resin 10 is shown.
1a and the transfer distance 11b in the resin passage 7b are the same.

Further, as shown in the figure, the resin passage 7
Is composed of a runner and a gate 15, and the gate 15 is configured to communicate with the mold cavity 2 described above. Further, as shown in FIG. 4, in the gate 15, the flow direction of the molten resin 10 injected into the mold cavity 2 is a center direction 16 of the mold cavity.
Is configured to be. That is, since the molten resin 10 can be injected into the mold cavity 2 toward the center direction 16, the molten resin 10 can be evenly injected in the mold cavity 2 without deviation. It is configured. Therefore, a resin molding (product) of uniform quality can be efficiently molded in the mold cavity 2.

That is, as shown in FIG. 1, first, the resin tablet 3 is supplied into the lower mold pot 4, and the lead frame 5 having electronic components mounted thereon is supplied and set at a predetermined position of the lower mold 1. At the same time, the two molds (1) are clamped. At this time, the electronic parts and the lead frame 5 around the electronic parts are separated from each other by the mold cavities 2 (2a) and 2 (2).
b) Fitting set inside. Then, the resin material heated and melted in the pot 4 is pressurized by the plunger, so that the molten resin 10 is passed from the pot 4 including the cull portion 6 through the outflow portion 8 including the bottleneck 14 to the resin passage. The molten resin 10 is injected into the resin passage 7, and the molten resin 10 is branched / split at the branch point in the resin passage 7 to separately flow the branched molten resin 10 into the resin passages 7a and 7b. Next, the molten resin 10 is transferred along the transfer direction in each of the resin passages 7a and 7b, so that the molten resin 10 is evenly and separately in each of the mold cavities 2 (2a) and 2 (2b). Molten resin will be injected. After the lapse of the time required to cure the molten resin, the electronic components and the lead frame around the electronic cavities 2 (2a) and 2 (2b) are separated from each other by the mold cavities 2 (2).
(2a) and 2 (2b) are sealed and molded in a resin molded body. That is, by having the above-mentioned configuration, the mold cavities 2 (2a).
Since the molten resin 10 can be evenly injected into the inside of (2b), it is possible to efficiently prevent the deformation or cutting of the wire or the generation of voids or the like in the resin molded body, and to obtain uniform quality. Can be efficiently obtained.

Further, in the above-mentioned embodiment, the structure using two mold cavities 2 is illustrated, but a structure using a plurality of mold cavities can be adopted, for example. That is, in the above-described embodiment, the outflow portion is provided between the pot and the branch point for communicating and connecting the resin passages provided corresponding to the plurality of mold cavities, and the branch point (the outflow portion). ) To the respective mold cavities, the resin passages may have the same distance. Therefore, the molten resin can be made to flow out from the above-mentioned outflow portion, and the molten resin can be evenly and separately injected into the mold cavities through the resin passages.

Further, in the above-mentioned embodiment, the structure using the two mold cavities 2 has been illustrated, but for example, an even number of mold cavities is divided into two and the same number is divided into two mold cavities. It is possible to adopt a configuration in which the resin passages of two paths are arranged corresponding to the mold cavities of the above-mentioned two groups. In this case, as in the case of the above-described embodiment, the respective distances between the above-mentioned mold cavities and the branch points at which the resin passages of the above-mentioned two paths are connected for communication are set to the same distance.

Further, in the above-mentioned embodiment, it is possible to adopt a structure using an odd number of mold cavities. That is,
In the above-described embodiment, an outflow portion is provided between the pot and the branch point for connecting and connecting the resin passages provided corresponding to the odd-numbered mold cavities, and the mold cavities are provided from the branch point. It is possible to adopt a configuration in which the distance of the resin passage to the same is the same.

Further, in the above embodiment, the outflow portion 8
An example is given in which the angle between the transfer direction of the resin and the transfer direction of the two resin passages 7 is set to be a right angle, but the transfer direction of the outflow portion 8 is set as a line symmetrical center line, and the outflow portion 8 is And the transfer directions of the two resin passages (7) are set to the same angle, and the transfer directions of the two resin passages (7) are line symmetrical. be able to. That is, the molten resin 10 that has flowed into the resin passage (7) from the outflow portion 8 is branched and split at the same angle in the line symmetric state in the transfer direction of the two resin passages (7). Become. Therefore, the molten resin 10 can be evenly transferred in the two resin passages (7).

In each of the above-mentioned embodiments, the pot, the cull portion and the plunger constitute a molten resin supply portion, the resin passage 7 constitutes a molten resin transfer portion, and the mold The cavity 2 constitutes a resin molding part.

The present invention is not limited to the above-mentioned embodiments, and within the scope of the gist of the present invention,
It can be arbitrarily and appropriately changed / selected and adopted as needed.

[0025]

According to the present invention, by uniformly injecting the molten resin into the mold cavity, it is possible to efficiently obtain products of uniform quality, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a schematic plan view schematically showing a resin encapsulation molding die for an electronic component according to the present invention, showing a state in which a resin tablet is supplied into a die pot.

FIG. 2 is a schematic plan view schematically showing a mold corresponding to FIG. 1, showing a state in which molten resin has flowed out of the mold pot into a resin passage.

FIG. 3 is a schematic enlarged plan view schematically showing an enlarged main part of the mold corresponding to FIG. 1, in which molten resin has flowed out of the mold pot into the resin passage of the mold. It shows the state.

FIG. 4 is a schematic enlarged plan view schematically showing the main part of the mold corresponding to FIG. 1, in which molten resin has flowed from the resin passage of the mold into the mold cavity. It shows the state.

FIG. 5 is a schematic plan view schematically showing a conventional resin sealing molding die, showing a state in which a resin tablet is supplied into the die pot.

FIG. 6 is a schematic plan view schematically showing a mold corresponding to FIG. 5, showing a state where molten resin has flowed out of the mold pot into a resin passage.

[Explanation of symbols]

1 movable lower mold 2 mold cavity 2a Mold cavity 2b mold cavity 3 resin tablets 4 pots 5 lead frame 6 Cull part 7 resin passage 8 Outflow section 9a Distance of resin passage 9b Resin path distance 10 Molten resin 11a Transfer distance of molten resin 11b Transfer distance of molten resin 12 Cross section of outflow 13 Sectional quality of bottleneck 14 bottleneck 15 gates 16 Center of mold cavity

Claims (4)

[Claims] 1. An electronic component for individually injecting a molten resin from a resin material supply pot into a plurality of mold cavities through resin passages for resin transfer provided correspondingly in the respective mold cavities. A resin encapsulation mold of
An outflow part for outflowing the molten resin from the pot is provided in the pot, and the distances of the resin passages from the outflow part to the cavities are configured to be the same, respectively. Mold for static molding. 2. An even number of mold cavities is divided into two and the same number to form two sets of mold cavities, and two sets of mold cavities are formed in the outflow passage to correspond to the sets of two mold cavities. The metal mold for resin encapsulation molding of an electronic component according to claim 1, wherein resin passages are provided so as to communicate with each other. 3. The resin encapsulation molding die for an electronic component according to claim 1, wherein a bottleneck for resin rectification is provided in the outflow portion. 4. The mold for resin encapsulation molding of an electronic component according to claim 2, wherein an angle between a transfer direction of the outflow portion and a transfer direction of the two resin passages is formed as a right angle.