JPH0621122A - Method and metal mold for resin sealing molding of electronic component - Google Patents

Abstract

(57) [Summary] [Purpose] Improving the releasability of the cured resin in the cull part 1,
As a result, the overall resin molding cycle time is shortened and high-efficiency production is achieved. [Composition] A plurality of required resin pressure distribution projections (3, 4) having inclined surfaces 5 are provided on the surface 2 of the cull portion 1 of the resin encapsulation molding die of the electronic component 16, The protrusion (3, 4)
By heating (melting) the resin tablet 8 while pressing (pressurizing) it, the pressing force of the plunger 9 applied to the resin tablet 8 is dispersed through each of the protrusions (3, 4) and the surface of the cull portion is dispersed. The degree of pressure bonding of the cured resin to 2 is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, ICs and LSs.
The present invention relates to an improved resin encapsulation molding method and a metal mold for encapsulating electronic components such as I, diodes, and capacitors with a resin, and particularly to a method for improving productivity by shortening a resin molding cycle time.

[0002]

2. Description of the Related Art A transfer molding method has been conventionally used for sealing and molding an electronic component with a thermosetting resin material such as an epoxy resin. This method is, for example, as shown in FIG. It is usually carried out as follows using a resin molding die. That is, the upper mold 12 and the lower mold 13 in the resin molding die are heated to the resin molding temperature by the heating means 20 in advance. Next, the lead frame 15 on which the electronic component 16 is mounted is fitted and set at a predetermined position of the recess 19 provided on the die surface of the lower die 13, and the resin tablet 8 is placed on the lower die.
Supply in 13 pots 10. Next, the upper and lower molds (12, 13) are clamped together, and the electronic component 16 and the lead frame 15 around it are
Are fitted and set in the upper and lower cavities (17, 17) opposite to the mold surfaces of both molds. Further, the resin tablet 8 in the pot 10 is heated by the heating means 20, and is pressed (pressurized) by the plunger 9 against the cull portion surface 2 to be heated and melted. Through the resin passage 18 (runner and gate), the resin is injected and filled into both upper and lower cavities (17, 17), and the electronic components 16 in the both cavities (17, 17) and the lead frame 15 around it are inserted in both cavities (17, 17). Molded resin molding (not shown) that is molded according to the shape of the cavity (17, 17)
Seal inside. Next, after resin curing, both upper and lower molds (1
(2.13) is opened, and at the same time as this, the cavities (17.
The resin-sealed molded body in 17) and the cured resin in the lead frame 15 and the resin passage 18 may be released from the mold.

[0003]

By the way, the above-mentioned pot
The resin tablet 8 in 10 is the heating means as described above.
The heating effect of 20 and the surface of the cull part 2 by the plunger 9
However, since the cull portion-cured resin after resin molding is strongly pressed against the surface 2 of the cull portion by the pressing force of the plunger described above, the cull portion-cured resin is cured. It has become very difficult to release the resin from the mold, and this has been considered to be a factor in which the overall resin molding cycle time must be set long.

In order to easily release the cull portion curable resin from the mold, for example, it is conceivable to lower the pressing force of the plunger 9 to lower the pressure bonding degree of the cull portion curable resin to the cull portion surface 2. In this case, there is a serious problem that a predetermined pressurizing force (resin pressure) against the resin and a pressure transfer action of the molten resin material cannot be obtained, and therefore a predetermined resin molding condition cannot be satisfied.

Therefore, according to the present invention, a predetermined resin molding condition can be satisfied, and the degree of pressure bonding of the cured resin to the surface of the cull portion is reduced to improve the releasability of the cured resin of the cull portion. An object of the present invention is to provide a resin encapsulation molding method and a die for an electronic component, which can achieve high-efficiency production by shortening the overall resin molding cycle time.

[0006]

In order to solve the above-mentioned technical problems, a resin encapsulation molding method for an electronic component according to the present invention comprises a resin tablet, a pot of a mold, and a cull portion opposed to the pot. Of the resin tablet is heated by heating, and the resin tablet is pressed by a plunger to be melted, and the molten resin material is pressure-transferred from the space section into the cavity and set in the cavity. In the resin encapsulation molding method for an electronic component, the resin tablet encapsulation molding is performed by the plunger, wherein the step of pressing the resin tablet by the plunger has a plurality of inclined surfaces provided with the resin tablet on the surface of the cull portion. By heating and melting while pressing against the individual projections, the pressure of the plunger applied to the resin tablet is dispersed through the projections, and the cured resin on the surface of the cull portion is dispersed. Wherein the reducing compression degree.

The mold for resin sealing molding of electronic parts according to the present invention includes a fixed mold, a movable mold opposite to the fixed mold,
A pot provided on one side of both molds, a cull portion provided on the other mold corresponding to the position of the pot, and a heating means for heating a resin tablet supplied to a space formed by the pot and the cull portion. A means for pressurizing the resin tablet in the space, and a resin passage for pressurizing and transferring the molten resin material in the space heated and melted by the heating means and the pressurizing means of the resin tablet into the cavities of the molds A mold for resin encapsulation molding of an electronic component, comprising: a plurality of required projections for dispersing resin pressure force, which has an inclined surface on the surface of the cull portion for heating and melting while pressing a resin tablet. It is characterized in that the body is arranged.

Further, the mold for resin encapsulation molding of electronic parts according to the present invention comprises a plurality of required large projections having an inclined surface on the surface of the cull portion for heating and melting while pressing the resin tablet. It is characterized in that the body and the satin-finished surface are arranged.

Further, the resin encapsulation molding die for an electronic component according to the present invention is characterized in that a desired matte surface is formed on the inclined surface of the above-mentioned projection.

Further, the resin encapsulation molding die of the electronic component according to the present invention is constructed by setting the sectional inclination angle of the inclined surface formed on the above-mentioned projection in the range of 30 degrees to 80 degrees. Characterize.

The resin encapsulation molding die for an electronic component according to the present invention is characterized in that the surface of the cull portion is subjected to a surface treatment for improving releasability.

Further, the resin encapsulation molding die for an electronic component according to the present invention is constructed by disposing a plurality of required projections having an inclined surface at the tip of the plunger of the resin pressing means. It is characterized by having done.

Further, in the resin encapsulation molding die of the electronic component according to the present invention, the top dead center at the time of resin pressurization of the above-mentioned plunger tip is set so as to be located below the chamfered portion of the pot. In addition, the cull portion is provided so as to project on the chamfered portion side of the pot.

[0014]

[Function] The pressure of the plunger applied to the resin tablet is dispersed through the inclined surface of the protrusion provided in the cull portion to reduce the degree of pressure bonding of the cured resin to the surface of the cull portion, thereby curing the cull portion. The mold releasability of the resin can be improved.

Further, the combined use of the projection and the matte surface and the surface treatment of the cull portion for improving the releasability further improve the releasability of the curl cured resin. be able to.

[0016]

The present invention will be described in detail below with reference to the drawings of the embodiments. FIG. 1 and FIG. 2 are enlarged views of the cull portion 1 in the resin encapsulation molding die of the electronic component.
Shows a state where one end surface of the resin tablet 8 is joined to the cull portion surface 2, and FIG. 2 shows an initial state in which the resin tablet 8 is pressed (pressurized) on the cull portion surface 2 while heating. ing.

On the surface 2 of the cull portion, a satin-finished surface (rough-finished surface) 7 is formed, and a plurality of required projections 3 having an inclined surface 5 and having a conical shape or a polygonal pyramid shape are formed. It is arranged regularly or irregularly.

When the resin tablet 8 supplied into the mold pot (10) is pressed by the plunger (9), one end surface of the resin tablet 8 has the protrusion in the cull portion 1 as shown in FIG. Join with the tip of the body 3. Then, when the resin tablet 8 is further pressed by the plunger (9), as shown in FIG. 2, the resin tablet 8 is softened by the heating action of the heating means (20), and is softened between the projections 3. It is press-fitted to reach the surface 2 of the cull portion and is heat-cured after a lapse of a predetermined time. The resin hardened in the cull portion 1 has a pressing force dispersed by the projections 3 provided on the surface 2 of the cull portion, and the degree of pressure bonding is reduced.

Next, this will be described in detail with reference to the principle diagram shown in FIG. When the heated resin tablet 8 is pressed against the protrusion 3, the pressing force A applied in the moving direction of the plunger 9 is mechanically 2 at the inclined surface 5 of the protrusion 3.
Will be dispersed in the direction. That is, the pressing force A is
Dispersed into one dispersing force (component force) B that acts perpendicularly (right angle) to the inclined surface 5 of the protrusion 3 and the other dispersing force C that acts along the inclined surface 5 of the protrusion 3. It will be. In other words, the pressure force of the cured resin on the surface 2 of the cull part is
It does not correspond to the pressing force A applied in the moving direction of the plunger 9 described above, but corresponds to the dispersing force B · C. However, since the inclined surface 5 has a draft angle of the cured resin, it is considered that the cured resin pressure bonding force corresponds to the dispersion force B in a substantial sense. Therefore, the pressure-bonding force of the cured resin on the surface 2 of the cull portion is greatly reduced. As a result, the degree of pressure-bonding of the cured resin on the surface 2 of the cull portion is reduced, and the releasability of the cured resin is greatly increased. Will be improved. Therefore, without changing the pressing force of the plunger 9 against the resin tablet 8,
Since the degree of pressure-bonding of the cured resin to the cull portion surface 2 can be substantially reduced, predetermined resin molding conditions can be satisfied, and the mold release property of the cull portion cured resin can be improved.

The surface 2 of the cull portion has a satin-finished surface 7
It is also possible to adopt a configuration in which only a large number of the above-mentioned projections 3 are provided without providing the above.

The sectional inclination angle θ (see FIG. 3) of the inclined surface 5 of the projection 3 may be set to an angle between 30 degrees and 80 degrees, for example. An appropriate angle can be selected in consideration of the properties of the mold material and the resin material and the like. According to the experiment, good releasability is obtained when the cross-section inclination angle θ is set to an angle between 30 degrees and 80 degrees, and as a result, compared with the conventional method, the overall mold release property is improved. We were able to reduce the resin molding cycle time by about 20%.

A desired matte surface 6 may be formed on the inclined surface 5 of the protrusion 3. In this case, since the satin surface 6 can synergistically enhance the above-described dispersion effect of the pressing force, the degree of pressure bonding of the cured resin to the cull portion surface 2 can be further reduced to improve the releasability of the cured resin. It can be further improved.

Further, a structure may be adopted in which large and small projections (not shown) are arranged on the surface 2 of the cull portion, and further, a desired matte surface is formed on the inclined surfaces of these projections. You may do it. In this case, when the heated resin tablet is pressed, the pressing force is first dispersed on the inclined surface of the large protrusion, and then the pressing force is secondarily dispersed on the inclined surface of the small protrusion. As a result, the degree of pressure bonding of the cured resin to the cull portion surface 2 can be further reduced, and the releasability of the cured resin can be further improved.
Further, when the matte surface is formed on both the large and small projections, it is possible to synergistically enhance the dispersion effect of the pressing force.

Further, as shown in FIG. 4, it is possible to adopt a structure in which only the large-sized protrusion 4 is provided on the surface 2 of the cull portion, and further, the inclined surface 5 of the large-sized protrusion is used. It is also possible to form the required satin surface 6. In this case, when the pressing force is dispersed on the inclined surface 5 of the large protrusion 4, the dispersing effect of the pressing force can be synergistically increased substantially at the satin surface 6 of the inclined surface. Is.

Further, as shown in FIG. 5, a protrusion 3 similar to that described above may be provided at the tip portion 11 of the plunger 9, and the surface of the protrusion 3 may be described above. You may make it provide the same satin surface. in this case,
The tip end surface of the plunger 9 also has the same pressing force dispersion effect as described above, and the effect of reducing the pressure bonding degree of the cull portion curing resin and improving the releasing property based on this, and further, the plunger itself. There is an advantage that durability can be improved. Reference numeral 18 in the figure indicates a resin passage.

The surface 2 of the cull portion can be easily released from the resin that cures in the cull portion. For example, by subjecting the surface of the cull portion to surface treatment such as nickel plating, the resin for curing the cull portion can be obtained. The releasability may be improved.

FIG. 6 shows an example of improvement of the cull structure of the die. That is, as shown in FIG. 7, when a chamfer 10a for facilitating the loading of the resin tablet 8 is formed at the upper edge portion of the mold pot 10, the chamfered portion and the plunger are formed at the time of resin molding. The residual resin in the space between 9 and 9 will be cured. Since the residual cured resin in the chamfered portion has a very small thickness, the residual cured resin remains in the pot 10 while being adhered to the chamfered portion at the time of releasing the cull portion cured resin. There is an adverse effect that it adversely affects the resin molding process. To eliminate this harmful effect,
For example, it is conceivable that the top dead center of the plunger tip portion 11 when the resin is pressed is set to a position lower than the chamfer 10a so that the chamfered portion is formed thicker. However, this portion is an unnecessary portion that cannot be used as a product, and there is a drawback that waste of the resin material occurs. Therefore, in order to solve these problems, as shown in FIG.
The top dead center at the time of resin pressurization of 11 is set to be a position lower than the chamfer 10a, and the cull portion 1 may be provided so as to project on the chamfer 10a side (parting line side) of the pot. In this case, there is an advantage that not only the chamfered portion can be formed thicker but also the resin material is not wasted.

The present invention is not limited to the above-described embodiments, and other methods and configurations can be arbitrarily and appropriately changed and selected as necessary without departing from the spirit of the present invention. Can be adopted as

[0029]

According to the present invention, not only the predetermined resin molding conditions can be satisfied, but also the degree of pressure bonding of the cured resin to the surface of the cull portion can be reduced and the releasability of the cured resin of the cull portion can be improved. Therefore, it has an excellent practical effect that it can provide a resin encapsulation molding method and a mold for an electronic component that can shorten the overall resin molding cycle time and achieve high-efficiency production.

[Brief description of drawings]

FIG. 1 is an enlarged vertical sectional end view showing a portion of a cull portion in a resin encapsulation molding die for an electronic component, showing a state where one end surface of a resin tablet is joined to the surface of the cull portion. There is.

FIG. 2 is a partially enlarged vertical sectional end view of a cull portion corresponding to FIG. 1, showing an initial state in which a resin tablet is pressed against the surface of the cull portion.

FIG. 3 is a partially enlarged vertical sectional end view of a cull portion corresponding to FIG. 1, and is an explanatory view of a heating and melting action of a resin tablet.

FIG. 4 is a partially enlarged vertical sectional end view of a cull portion in another embodiment, showing an initial state in which a resin tablet is pressed against the surface of the cull portion.

FIG. 5 is a partially cutaway vertical sectional view of a main part of a mold according to another embodiment.

FIG. 6 is a partially cutaway vertical sectional view of a mold main part in another embodiment.

FIG. 7 is a partially cutaway vertical cross-sectional view of a main part of a mold showing another configuration example of the mold for resin sealing molding of an electronic component.

FIG. 8 is a partially cutaway vertical sectional view of a main part of a mold showing a conventional configuration example of a mold for resin sealing molding of an electronic component, showing the mold open state.

[Explanation of symbols] 1 Cull portion 2 Cull portion surface 3 Projection body 4 Large projection body 5 Inclined surface 6 Pear ground 7 Pear ground 8 Resin tablet 9 Plunger 10 Pot 10a Chamfer 11 Plunger tip 12 Upper mold 13 Lower mold 14 Ejector Pin 15 Lead frame 16 Electronic component 17 Cavity 18 Resin passage 19 Recess 20 Heating means A Pressing force B Dispersing force C Dispersing force θ Cross section inclination angle

Claims (8)

[Claims] 1. A resin tablet is supplied to a space portion consisting of a pot of a mold and a cull portion opposite to the pot to heat the resin tablet, and the resin tablet is pressurized by a plunger to be melted, A resin encapsulation molding method for an electronic component, wherein the molten resin material is pressure-transferred from the space into the cavity and the electronic component set in the cavity is resin-encapsulated. The pressing step heats and melts the resin tablet while pressing the resin tablet against a plurality of required projections having inclined surfaces provided on the surface of the cull portion, thereby increasing the pressure applied by the plunger to the resin tablet. A resin encapsulation molding method for an electronic component, characterized in that the degree of pressure bonding of the cured resin to the surface of the cull portion is reduced by dispersing the resin through the protrusions. 2. A fixed die, a movable die opposed to the fixed die, a pot provided on one side of the two dies, and a cull portion provided on the other die corresponding to the position of the pot. A heating means for the resin tablet supplied to the space portion comprising the pot and the cull portion, a means for pressurizing the resin tablet in the space portion, the heating and melting means for heating the resin tablet A mold for resin encapsulation molding of an electronic component, comprising a resin passage for pressurizing and transferring a molten resin material in a space into the cavities of both molds, wherein a resin tablet is pressed against the surface of the cull part. A mold for resin encapsulation molding of an electronic component, characterized in that a plurality of required projections for resin pressure distribution having an inclined surface to be heated and melted are arranged. 3. A plurality of required large projections having an inclined surface for heating and melting while pressing a resin tablet and a satin surface are arranged on the surface of the cull portion. Item 3. A resin encapsulation molding die for an electronic component according to Item 2. 4. The mold for resin encapsulation molding of an electronic component according to claim 2 or 3, wherein a desired matt surface is formed on an inclined surface of the protrusion. 5. The resin encapsulation for an electronic component according to claim 2, wherein the inclined surface formed on the protrusion is set to have a sectional inclination angle within a range of 30 degrees to 80 degrees. Mold for static molding. 6. The mold for resin encapsulation molding of an electronic component according to claim 2, wherein the surface of the cull part is subjected to a surface treatment for improving releasability. 7. The resin encapsulation of an electronic component according to claim 2, wherein a plurality of required projections each having an inclined surface are arranged at the tip of the plunger of the resin pressing means. Mold for molding. 8. A structure in which the top dead center at the time of resin pressurization of the plunger tip portion is set to a position lower than the chamfered portion of the pot, and the cull portion is projectingly provided on the chamfered portion side of the pot. The mold for resin encapsulation molding of an electronic component according to claim 2, characterized in that.