JPH11198170A - Manufacture of resin molded body with frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the manufacturing method of a resin molded body with a frame, with which the development of thin fins can be structurally mulled without impairing the merit of an outsert molding. SOLUTION: In the manufacturing method of a resin molded body with a frame by forming a resin part 15 so as to cover the lead parts of the frame 10 excluding the surfaces of the end parts of the lead parts abutting against a supporting surface at an outsert molding, which is executed by arranging the lead parts of the metal 10 to a mold cavity so as to abuttingly support the end parts set in these lead parts with the supporting surface provided in the cavity, a mold 22, which is provided opposite to the supporting surface and has a projected part, between which and the supporting surface the end parts of the lead parts are pinched, is used in order to form a resin part 16 excluding the front and rear surfaces of the lead parts at a first process and a mold 23, in the cavity of which the resin part 11 formed at the first process is arranged so as to make it possible to fill a raw material in a hollow part 16a corresponding to the projected part of the resin part 16 is used in order to realize a second process, resulting in executing an outsert molding by filling the hollow part 16a with the raw material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an injection molding method.
In particular, the present invention relates to a method for manufacturing a resin molded body with a frame using an outsert method.

[0002]

2. Description of the Related Art For parts and assemblies such as electric and precision instruments,
As shown in FIG. 6, a metal frame 30 has a plurality of lead portions 30a, and as shown in the cross section of the main part in FIGS. Some are covered with a box-shaped non-conductive portion 31 except for the surface.
The manufacturing method in such a case is roughly divided into the following two methods. In the first manufacturing method, as shown in FIG. 7A, an upper and lower half ceramic member or the like is used as the non-conductive portion 31, and the adhesive 32 It is a method of integrating by. In the second manufacturing method, as shown in FIG. 7B, the resin portion 33 is formed by outsert molding except for the surface of the end portion 30b at the lead portion 30a. In the first manufacturing method, a plurality of steps such as member production, adhesive application, sticking, and adhesive curing are required. For this reason, in terms of mass production, there is a problem in terms of manufacturing time and cost, and it is difficult to say that it is an optimal manufacturing method. The second manufacturing method has been proposed in order to solve the above-mentioned problem, and has advantages such as omitting assembly as in the first manufacturing method and facilitating automation.

FIG. 8 shows a cross section of a main part of a conventional mold used in the second manufacturing method. In this mold structure, the cavity 35 formed by the upper and lower molds 34A and 34B has a holding surface 36 therein, the corresponding portion of the lead 30a is arranged in the cavity 35, and the end 30b of the lead 30a is held by the holding surface. 36, the gate portion 3 is provided in the cavity 35.
From 7 the raw material heated and melted is filled. By this outsert molding, the resin portion 33 is formed so as to cover the corresponding portion of the lead portion 30a except for the surface of the end portion 30b that has been in contact with the holding surface 36. Therefore, in this manufacturing method, a resin molded body with a frame as shown in FIG. 6 can be manufactured in one step.

[0004]

However, the above-mentioned conventional manufacturing method using outsert molding has the following problems. Since the resin molded body with the frame forms the resin part 33 so as to cover the corresponding part of the lead part 30a except for the surface of the end part 30b, the cavity structure of the mold is conventionally used as shown in FIG.
A method of supporting the end portion 30b from one holding surface 36 as shown in FIG. In this support structure, the end 30b is deformed by the molding pressure during molding in the cavity 35, and a fine gap is generated between the end 30b and the holding surface 36 due to the deformation, and the resin material flows into the gap. To cure. The inflow and hardened material remains as thin burrs 38. Such thin burrs 38 are formed, for example, in the lead portion 30a.
Is more likely to occur as the thickness of the layer becomes smaller. For this reason, conventionally, when the surface of the end portion 30b becomes an electrical contact portion, it is necessary to remove burrs by blast processing or the like.
The process is complicated and the man-hour is increased.

As a countermeasure against the above, as shown in FIG. 9, a suction hole 39 communicating with the holding surface 36 supporting the end 30b is provided in the lower mold 34B, and the lower die 34B is supported on the holding surface 36 through the suction hole 39. A method of strongly adsorbing the end portion 30b to the holding surface 36 by a vacuum suction method has been considered. However, in this measure, when the length of the end 30b is short or narrow, the effective hole diameter of the suction hole 39 is restricted. For this reason, practically, there are problems that the suction force cannot be sufficiently imparted, the mold structure becomes complicated, and the maintainability is low, and there are very few practical examples.

SUMMARY OF THE INVENTION The present invention has been developed to solve the above-mentioned problem, and has as its object to provide a frame capable of structurally eliminating the occurrence of the thin burrs without deteriorating the advantages of outsert molding. It is an object of the present invention to realize a method of manufacturing a resin molded body with a resin. Still other objects will be sequentially clarified in the contents described below.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention, a portion of a metal frame is disposed in a cavity of a mold, and an end set in the portion of the frame is provided in the cavity. Forming a resin portion so as to cover a portion of the frame except for one surface of the end portion by outsert molding by abutting the holding surface, and forming the resin portion by a frame by outsert molding. As an example, a resin is provided so as to face the holding surface, and has a convex portion that sandwiches the end between the holding surface and the resin portion. The resin portion is formed excluding the front and back surfaces of the end. A first step of forming a part, and a mold in which the resin part formed in the first step is arranged in a cavity, and the mold can be filled with the raw material in a cavity corresponding to the convex part of the resin part. Use the cavity in front It is obtained so as to go through the second step of outsert molding so as to fill the raw material.

[0008] According to the above structure, in the first step, in order to clamp the end of the frame between the holding surface and the convex portion in the cavity, only the clamping force is set mechanically. The deformation of the end portion due to such a molding pressure and the occurrence of thin burrs resulting from the deformation can be structurally eliminated. The resin part molded in the first step has a cavity corresponding to the convex part with respect to the final resin part as a product, and the resin is filled in the cavity in the second step. Become. The method of the present invention is based on the premise that the number of steps is two compared to the conventional outsert molding. However, it is possible to reduce the manufacturing cost and at the same time greatly improve the quality and reliability for the following reasons. Is what you do.

That is, in a mass production line of injection molding, usually, a frame and the like to be used are set in a mold by an automatic supply system by a robot, and molding automation is almost completely established. For this reason, as a first point, the method of the present invention adds the second step. However, as compared with the above-described deburring step by blasting or the like, the time required for transferring or molding parts or molded articles can be reduced. It is easy, and from this point, it is possible to shorten the manufacturing time as a whole. Second, the conventional deburring operation is difficult to completely automate and lacks quality stability. On the other hand, since the method of the present invention employs outsert molding in both the first and second steps, the method is easily automated with an existing molding apparatus and is easily stabilized in quality. Third,
In the conventional outsert molding, the end is deformed, and if this is also corrected, an additional step other than the deburring step must be added, which complicates the manufacturing process and increases the cost. On the other hand, in the method of the present invention, assert molding is performed in a state where the end is sandwiched from above and below, there is no possibility that the end is deformed by the molding pressure.

The above-described method of the present invention does not require a step of manufacturing a single member such as a ceramic member as compared with the method of FIG. And enables a significant reduction in manufacturing time and cost.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Although this embodiment is a specific example, various technically preferable limitations are added thereto, but the embodiment does not limit the scope of the present invention.

FIG. 1 shows the outline of the method of the present invention. 2A and 2B show a resin molded body with a frame manufactured by the method of the present invention, wherein FIG. 2A is a perspective view as viewed from the front side, and FIG. FIG. 2C is a perspective view, and FIG. 2C is a cross-sectional view particularly illustrating a resin portion structure formed in the present invention. 3 (a) and 3 (b) show the state before and after the molding in the first step in a mold section, and FIGS. 4 (a) and 4 (b) show the state before and after the molding in the second step in a mold section. Is shown. FIGS. 5A and 5B schematically show the used frame and the mold holding range with respect to the used frame. Hereinafter, the technical features and advantages of the method of the present invention will be clarified with reference to these drawings.

According to the method of the present invention, as shown in FIG. 1, a first step and a second step are carried out to produce a resin molded article 1 with a frame as illustrated in FIG.
The frame used is a lead frame 10 obtained by pressing a metal plate as shown in FIG. The lead frame 10 has a rectangular outer frame 11 and a plurality of (in this example, 11 on one side, a total of 22) lead portions 12 extending inward from opposing sides of the outer frame 11.
At four corners of the outer frame 11, positioning holes 11a are provided. A box-shaped resin portion is provided integrally with each lead portion 12 by outsert molding, which will be described later, and the end portion becomes an inner lead portion 12a with one surface exposed. A predetermined interval is set between the inner lead portions 12a on both sides. FIG. 5 (b) shows a range sandwiched by a mold in the outsert molding. The holding range 13 is located at a position before the end of the lead portion 12, and the outer shape of the resin portion 15 is determined by this. The holding range 14 corresponds to the inner lead portion 12a.

The first step is outsert molding of the lead frame 10, and a mold shown in FIG. 3 is used. The second step is to perform outsert molding of the one formed in the first step, and a mold shown in FIG. 4 is used. Here, as schematically shown in FIG. 1, in the production line, an injection molding machine 20 in the first step and an injection molding machine 21 in the second step are installed with a space therebetween. In this production line, for example, a belt-type conveying means or the like is provided on a side portion of each of the injection molding machines 20 and 21, and a transfer robot is arranged between the conveying means and each of the injection molding machines 20 and 21. Then, the lead frame 10 sent by the conveying means is set in the mold 22 of the injection molding machine 20, and the primary molded product 1A manufactured in the first step is transferred from the mold 22 to the conveying means. Design of an automatic transfer system such as setting the primary molded product 1A in the mold 23 of the injection molding machine 21 or transferring the finished product of the second step, that is, the target resin molded article 1 with a frame from the mold 23 to the conveying means. It has become. In addition, each injection molding machine 2
Except for the molds 22 and 23, the molds 0 and 21 are provided with a molded product take-out mechanism, a cooling mechanism, and the like, like the existing ones.

(First Step) In this step, the following molding procedure is performed. First, the lead frame 10 is set on the mold 22. This mold 22 is, as shown in FIG.
A and a lower mold 22B as main components and a cavity 24 formed in a mold clamped state. The lower die 22B is provided with a holding surface 28 for supporting the inner lead portion 12a in a protruding state. The upper mold 22A is provided with a convex portion 29 that faces the holding surface 28 and that holds the inner lead portion 12a between the holding surface 28 and the holding surface 28. And
In the set of the lead frame 10, as shown in FIG.
Is opened, and the lead frame 10 is set in the mold. At this time, the entire lead frame 10 is positioned and arranged with high accuracy using the hole 11a of the outer frame 11.

Next, a mold clamping operation is performed. FIG. 3A shows the vicinity of the cavity 24 when the mold is clamped. In the mold clamping state, the lead frame 10 is sandwiched between the two holding ranges 13 and 14 in FIG. 5B, and in this case, the setting of the holding pressure or the holding force in each of the holding ranges 13 and 14 is not performed. In other words, in this embodiment, the holding range 13 outside the cavity 24 (this is outside the resin molding range and the inner lead portion 12a
With respect to the outer lead portion, and the holding range 14 (which corresponds to the holding surface 28 and the projection 2
9 (corresponding to the clamping portion by 9) has a stronger clamping force. Further, the inner lead portion 12a sandwiched between the holding surface 28 and the convex portion 29 is set so as to be narrowed down to a range where conduction is required, thereby contributing to increasing the surface pressure of the sandwiched portion.

Next, in a mold clamping state, a molten resin as a raw material is injected into the cavity 24 from the gate 26. The gate 24 is set at the position shown in FIG. The molten resin flows from the gate portion 26 to fill the cavity 24, and the cavity 24 is removed except for the clamping range 14, that is, the portion clamped by the holding surface 28 and the projection 29.
Is filled. FIG. 3B shows the resin portion 16 of the primary molded product 1A formed in the first step in this manner. Thereafter, the primary molded product 1A is released from the mold and transferred to a secondary process. A cavity 16a having a size corresponding to the protrusion 29 is formed at a position corresponding to the protrusion 29 in the resin portion 16 of the primary molded product 1A (see FIG. 1).

(Second Step) In this step, the following molding procedure is performed. First, the primary molded product 1A is set in the mold 23. As shown in FIG. 4, the mold 23 mainly includes an upper mold 23A and a lower mold 23B, and has a cavity 25 formed in a mold clamped state. This cavity 25 is shown in FIG.
As shown in (a), when the resin part 16 of the primary molded article 1A is inserted, a space 25a corresponding to the hollow part 16a is formed. The lower die 23B is provided with a holding surface 28a that supports the inner lead portion 12a in a protruding state. The upper die 23A is provided with a gate 27 facing the holding surface 28a and communicating with the space 25a. The gate 27 is located at the position shown in FIG. In the setting of the primary molded product 1A, as shown in FIG. 1, the mold 23 is opened and the primary molded product 1A is set in the mold. Are positioned using the holes 11a of the outer frame 11, and are also positioned by the outer shape of the resin portion 16 fitted into the cavity 25 in a mold-clamped state.

Next, a mold clamping operation is performed. FIG. 4A shows the vicinity of the cavity 24 when the mold is clamped. In the mold-clamped state, the lead frame 10 is sandwiched in the sandwiching range 13 shown in FIG.
Are fitted in the cavity 25. Therefore, the inner lead portion 12a is supported from one side by the holding surface 28a, but is fixed immovably due to the presence of the resin portion 16 in the cavity 25.

Next, in a mold clamping state, a molten resin as a raw material is injected into the cavity 25 from the gate portion 27. The molten resin flows from the gate 27 to the space 25 a of the cavity 25.
To fill the space 25a. At the time of filling, the inner lead portion 12a is fixed in an immobile state as described above, and the resin portion 16 serves as a wall, so that the molten resin does not flow into the opposite side of the gate, that is, the support surface side of the inner lead portion 12a. FIG. 4B shows the resin part 17 of the secondary molding formed in the second step in this manner. Thereafter, the molded product, that is, the resin molded body with frame 1 is released from the mold and transferred to the next step or the like.

In the above-described manufacturing method, in the first step, the resin portion 1 is held in a state where the inner lead portion 12a of the lead frame 10 is sandwiched between the holding surface 28 and the convex portion 29.
6 is formed, the resin is buried in the cavity 16a formed in the resin portion 16 in the second step, so that the deformation of the inner lead portion due to the molding pressure and the thin flash caused by the deformation as in the conventional manufacturing method. Can be eliminated. In addition, this structure requires two steps for the conventional outsert molding. However, by performing continuous molding on the production line, the quality and quality can be relatively easily reduced without increasing the production time. Reliability and can be improved. Alternatively, molding with one mold by a two-color molding method is also possible.

It should be noted that the method of the present invention is not limited to the molded resin article 1 with a frame as the object to be molded, but can be applied to various parts and assemblies as long as the technical element described in claim 1 is provided. is there. The dies 22 and 23 used are also designed based on this form according to the specific form of the framed resin body to be molded.

[0023]

As described above, according to the present invention, the following effects can be obtained. In the first aspect, since the end of the frame is sandwiched between the holding surface and the projection in the cavity of the first step, the deformation of the end due to the conventional molding pressure and the deformation are caused. The occurrence of thin burrs can be eliminated structurally. The resin is buried in the cavity corresponding to the convex portion in the second step. However, compared to the conventional deburring operation, the resin can be stabilized more easily and in quality, and the reliability can be improved. According to the second aspect, since the inner lead portion is formed with high precision without being deformed, the conduction in the inner lead portion can be maintained satisfactorily, and a more excellent quality can be provided. Claims 3 and 4, for example, are not restricted in terms of the form of the frame as compared with the conventional countermeasure as shown in FIG. 9, and can be applied to various forms of resin molded articles with frames.

[Brief description of the drawings]

FIG. 1 is an explanatory process chart showing an outline of a production method of the present invention.

FIG. 2 is a view for clarifying the appearance of the resin molded article with a frame manufactured by the method of the present invention and the structure of the main part thereof.

FIG. 3 is a cross-sectional view of a used mold showing a first step of the method of the present invention before and after molding.

FIG. 4 is a cross-sectional view of a used mold showing a second step of the method of the present invention before and after molding.

FIG. 5 is a diagram showing a frame used in the method of the present invention and a holding range in a first step thereof.

6A and 6B are a top view and a perspective view from the front and back of a conventional product to which the present invention is applied.

FIG. 7 is a sectional view of a main part showing two structural examples of the conventional product.

FIG. 8 is a sectional view showing a conventional mold for outsert molding before and after molding.

FIG. 9 is a sectional view showing an improved example of the conventional mold before and after molding.

[Explanation of symbols]

 1 is a resin molded body with a frame 10 is a lead frame (metal frame) 11 is an outer frame 12 is a lead part (part) 12a is an inner lead part (end part) 15 is a resin part 16 is a resin formed in the first step The portion 16a is a hollow portion 17 is a resin portion formed in the second step 20 and 21 is an injection molding machine used in the first and second steps 22 and 23 are dies 22A and 22B of each injection molding machine in the first step 23A and 23B are mold structures in the second step (upper and lower molds) 24 and 25 are cavities 26 and 27 in each mold 26 and 27 are gate portions 28 and 28a in each mold 29 is convex

Claims (4)

[Claims] 1. A part of a metal frame is disposed in a cavity of a mold, and an end set in the part of the frame is supported by a holding surface provided in the cavity. A method for manufacturing a resin molded body with a frame, wherein a resin portion is formed so as to cover a portion of the frame except for one surface of the end portion, wherein the mold is provided to face the holding surface, A first step of performing an outsert molding so as to form the resin portion except for the front and back surfaces of the end portion using a portion having a convex portion for sandwiching the portion between the holding portion and the holding surface; Outsert molding in which the resin portion formed in the first step is arranged in a cavity and a material that can be filled with the raw material in a hollow portion corresponding to the convex portion of the resin portion is used to fill the hollow portion with the raw material. Second step Method for producing a framed resin molded body characterized by undergoing and. 2. The frame is a lead frame,
The method according to claim 1, wherein an end of the portion is an inner lead portion electrically connected. 3. The method according to claim 1, wherein at least one of the width and the length of the end portion is 5 mm or less. 4. The method for producing a resin molded article with a frame according to claim 1, wherein the resin portion has a substantially box shape projecting from the front and back of the portion.