JPH0521877Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is applicable to resin encapsulation molding for molding electronic components such as ICs, diodes, and capacitors with thermosetting resin materials. It concerns the improvement of molds.

[Conventional technology]

A mold for sealing and molding electronic components with thermosetting resin material consists of a single large pot and multiple cavities, and long runners and gates for transferring molten resin material. A type of communication between the two via passages is known.

In this type of mold, based on the configuration of the mold having the above-mentioned aspects, and due to changes in the viscosity of the molten resin material during resin molding, resin sealing with high quality and high reliability is achieved. There is a disadvantage that it is not possible to mold a fixed molded product.

That is, the resin material melted at the pot part is transferred under pressure from the runner part to the cavity part under the pressure of the plunger, and is transferred through the gate part to the terminal end side furthest from the cavity on the starting end side near the pot position. The cavities are sequentially injected under pressure and filled. However, at this time, the molten resin material sequentially filled into the cavity on the starting end side stops flowing one after another, so the gate on the starting end side The parts harden one after another until it is no longer possible to apply sufficient plunger pressure inside those cavities. Therefore, due to the inability to obtain a sufficient predetermined resin pressure, voids are likely to be formed in the resin-sealed molded body, particularly within the cavity on the starting end side. Furthermore, due to the above-mentioned curing of the gate of the cavity on the starting end side, the flow velocity of the molten resin material transferred under pressure to the end side increases, and the molten resin material on the end side is subjected to the heating action of the mold. Due to increased viscosity, etc.
Particularly, in the cavity on the terminal side into which the high-viscosity molten resin material is injected, there is a disadvantage that the bonding wire on the semiconductor lead frame is easily deformed or broken.

As a mold that eliminates the above-mentioned disadvantages, for example, a required plurality of small pot groups and a predetermined plurality of cavity groups are arranged in parallel, and each of the pots is arranged at a predetermined position in the vicinity thereof. A mold for resin sealing molding that adopts the so-called multi-pot plunger method, in which a predetermined plurality of cavities are communicated with each other through passages for transferring molten resin material of the same length (short and equal length). is proposed.

In this multi-pot plunger type mold, the elongated runner part of the conventional mold is substantially omitted, so the resin material melted in the pot part is melted by the pressing force of the plunger. The molten resin material is immediately injected under pressure and filled into a predetermined cavity near the pot portion through a passageway for transferring molten resin material of equal length consisting of short runners and gates, or of equal length consisting only of gates. Therefore, the conventional disadvantages as described above can be eliminated.

[Problem that the invention attempts to solve]

By the way, when using a multi-pot plunger type mold, if the number of cavities communicating with any pot section is less than a predetermined plurality, for example, for one pot section, In a configuration in which a predetermined plurality of cavities (for example, four cavities each) are arranged in parallel on both sides, the number of cavities communicating with any one of the pots is greater than the predetermined plurality on both sides. For example, when three cavities are arranged in parallel, the following problems occur in terms of resin molding.

That is, as shown in FIGS. 4 and 5, each cavity 2 formed on the mold surface 1 is arranged in a straight line corresponding to the number and each position of electronic components mounted on a straight semiconductor lead frame 3. It is customary to arrange them in a shape. Therefore, for example, as shown in FIG. 4, three minority cavities 2 ₁ to 2 ₃ and 2 4 to 2, which are smaller than the predetermined plurality described above, are placed on both sides of one pot portion ₄ . ₆ are arranged in parallel, each molten resin material transfer passage 5 ₁ to 5 ₃ , 5 ₄ provided between the pot portion and each minority cavity.
~5 There will be a difference in the length of ₆ .
As a result, there are differences in the resin molding conditions when the molten resin material in the pot is injected into each of the minority cavities under pressure, making it impossible to mold a uniform resin-sealed molded product. There is.

_Moreover , in order to make this under _the same resin molding conditions, for _{example ,} as shown in FIG. must be configured so that the
Therefore, in this case, there are problems in that designing and manufacturing the mold is troublesome and time-consuming, and furthermore, the overall yield of the molded resin material decreases because the transfer path becomes long. There is a problem.

A similar problem also occurs in the case of a configuration in which the above-mentioned few cavities are disposed only on one side of one pot.

The present invention employs the above-mentioned multi-pot plunger type mold for resin sealing, and when the number of cavities communicating with any of the pots is less than a predetermined number. In this case, substantially the same mold can be used in both the predetermined plurality of cavities and the small number of cavities, without requiring any trouble in designing and manufacturing the mold, and without reducing the overall yield of the molded resin material. It is an object of the present invention to provide a mold for resin sealing molding that can inject a molten resin material under pressure under resin molding conditions.

Another object of the present invention is to easily detect and detect the pressing force (resin pressure) of the plunger against the molten resin material in the cavity in the above-mentioned resin sealing mold.

[Means for solving problems]

The mold for resin encapsulation of electronic components according to the present invention is designed to solve the conventional problems as described above.
A required plurality of pot groups and a required plurality of cavity groups are arranged in parallel, and each pot portion and a prescribed plurality of cavities arranged at predetermined positions in the vicinity thereof are made of molten resin material of the same length. In a mold for resin-sealing an electronic component, the number of cavities communicating with each of the pot portions through the transfer passages is smaller than the predetermined plurality described above. , forming a resin reservoir of a desired shape at a lateral position of any of the pots, and communicating the pot and the resin reservoir via a molten resin material introduction passage of a desired length; The total filling volume of resin material in the resin reservoir and the molten resin material introduction passage, and the resin in the minority cavity in any of the above pot parts and the molten resin material transfer passage that communicates the minority cavity with the pot part. It is characterized in that it is formed and constructed so that the total filling capacity of the material is approximately equal.

Further, the mold for resin-sealing electronic components according to the present invention is formed so that the total filling volume of the resin material in the minority cavity described above is approximately equal to the total filling volume of the resin material in the resin reservoir, and , formed so that the total filling volume of the resin material in the transfer passage that communicates the minority cavity and the pot portion is approximately equal to the total filling volume of the resin material in the introduction passage that communicates the resin reservoir portion and the pot portion. It is characterized by the fact that

Moreover, the mold for resin-sealing electronic components according to the present invention has the length of the transfer passage that communicates the above-mentioned minority cavity and the pot part, and the length of the introduction passage that communicates the resin reservoir part and the pot part. This is characterized in that the two sides are formed to have approximately the same length.

Moreover, the mold for resin-sealing electronic components according to the present invention has the shape of the transfer passage that communicates the above-mentioned minority cavity and the pot portion, and the shape of the introduction passage that communicates the resin reservoir portion and the pot portion. are characterized in that they are formed into substantially the same shape.

Furthermore, the mold for resin-sealing electronic components according to the present invention is characterized in that the above-mentioned resin reservoir is provided with a resin pressure detection means for detecting the pressure applied to the resin material in the cavity. That is.

[Effect]

According to the configuration of the present invention, resin sealing molding in each of the predetermined plurality of cavities is performed under the same resin sealing molding conditions.

In addition, for resin sealing molding in a small number of cavities that are less than a predetermined number, a resin reservoir and a molten resin material introduction passage corresponding to the missing cavity and molten resin material transfer passage are provided. As a result, resin sealing molding is performed under substantially the same resin sealing molding conditions as in the case of resin sealing molding in each of the predetermined plurality of cavities.

〔Example〕

Next, the present invention will be explained based on the embodiment shown in FIGS. 1 and 2.

Each of the figures shows a mold surface 11 of an upper mold (or lower mold) in a mold for resin-sealing electronic components.

Cull portions 12 are formed on the mold surface in correspondence with respective positions of a required plurality of pot groups (not shown) arranged linearly on the other mold surface side.

These cull portions 12 are joined at the same positions as the above-mentioned pots when both the upper and lower molds are clamped, and constitute a part of the pot that is the supply section for the resin material, and are heated and melted within the pot. It is provided as a branch point for sending out the resin material to each cavity side (therefore, hereinafter, the cull part and the pot part will be described as synonymous).

Further, on both sides of the cull portion 12, a required plurality of cavity groups 14 are formed in parallel in correspondence with the number and positions of electronic components to be mounted on the linear semiconductor lead frame 13. It is arranged.

Further, the cavity group 14 includes a predetermined plurality (two) of cavities 14 ₁ to 14 ₂ and 14 ₃ to 14 ₄ on both sides of one cull portion 12 .
It is configured by arranging them respectively. Further, the cull portion and the predetermined plurality of cavities are short and equal length passages 15 ₁ to 15 ₂ and 15 ₃ for transferring molten resin material.
~15 ₄ are connected to each other.

In addition, in the cull part 12 ₁ disposed at one end,
A small number of cavities 14 5 and 14 6 smaller than the predetermined plurality, that is, one small number of cavities 14 ₅ and 14 ₆ are arranged on both sides of the cavity. Further, the cull portion 12 ₁ and the minority cavities 14 ₅ , 14 ₆ communicate with each other via molten resin material transfer passages 15 ₅ , 15 ₆ that are the same short length as the transfer passage 15 ₁ and the like and have equal lengths. has been done.

Also, the lateral position of the cull portion 12 ₁ that communicates with the minority cavities 14 ₅ and 14 ₆ , for example, as shown in the figure, the minority cavities that do not overlap with both semiconductor lead frames 13 set on the mold surface 11, respectively. A resin reservoir 16 formed in a desired shape and depth is provided in between, and the resin reservoir 16 and the cull portion ₁₂₁ are connected to each other for introduction of molten resin material of a required length. They are communicated via passages 17 and 18.

The resin reservoir 16 corresponds to the extra cavities 14 _{2 and 14 4 in the predetermined plurality of cavities 14 1 to 14 2} and 14 ₃ to 14 ₄ described above. Also,
The introduction passages 17 and 18 are the transfer passage 1 which communicates the above-described plurality of predetermined cavities with the cull portion 12.
This corresponds to the extra passages 15 ₂ and 15 ₄ in 5 ₁ to 15 ₄ . Furthermore, the resin reservoir 16 and the introduction passages 17, 18 are such that the total volume of the resin material filled therein is equal to the resin filled in the minority cavities 14 ₅ , 14 ₆ and the transfer passages 15 ₅ , 15 ₆ . It is configured to be approximately the same as the total capacity of the material.

In addition, the resin reservoir 16 is equipped with a pressure sensor and other suitable resins for detecting the resin pressure in the cavity using the pressing force of the plunger applied to the molten resin material introduced into the resin reservoir. A pressure detection means 19 is provided.

Incidentally, similar cavities (not shown) are provided on the other side of the mold surface corresponding to the arrangement positions of the cavities 14 ₁ to 14 ₆ formed on the mold surface 11 side. In addition, each transfer passage 15 ₁ formed on the mold surface 11 side is provided on the other mold surface.
~15 It is customary to not provide a transfer passage similar to ₆ , but if necessary, it is also possible to adopt a configuration in which the transfer passage is arranged oppositely on the mold surface on the other side. In this case, introduction passages similar to the introduction passages 17 and 18 may be provided facing each other on the mold surface on the other side.

Next, a case will be described in which resin encapsulation molding of an electronic component is performed using a mold having the above configuration.

First, the semiconductor lead frame 13 is set at a predetermined position on the mold surface 11, and both the upper and lower molds are clamped. At this time, the electronic components on the lead frame are fitted into the cavities provided opposite to each other on both dies.

In the above state, each pot part (cull part 12, 1
By supplying the same amount of resin material (resin tablets) to ₂₁ ) and heating and melting it, and pressurizing it with a plunger, the molten resin material is transferred from the cull portions 12, ₁₂₁ . Aisle 15 ₁ ~
15 ₆ into each cavity 14 ₁ to 14 ₆ .

At this time, the injection and filling operation of the molten resin material in the minority cavities 14 ₅ and 14 ₆ is performed under substantially the same resin molding conditions as the injection and filling operation in the predetermined plurality of cavities 14 ₁ to 14 ₂ and 14 ₃ to 14 ₄ . become.

That is, in the cull portion 12 ₁ , compared to other cull portions 12, due to its structure, the cavities 14 ₂ ,
14 ₄ section and transfer passages 15 ₂ and 15 ₄ sections are missing, but in their place, a resin reservoir 16 of the same capacity and the same number of molten resin material introduction passages 17 and 18 of the same capacity are provided. Since the cull part 12 ₁ is also configured to have a structure in which the other cull parts 12 and
This is because they have substantially the same configuration.

In addition, in the resin reservoir 16 and the molten resin material introduction passages 17 and 18, the cavities 14 ₂ ,
Since the molten resin material to be injected is filled into the 14 ₄ section and the transfer passages 15 ₂ and 15 ₄ sections, it is possible to prevent the filled resin material from adhering to both semiconductor lead frames 13. .

Furthermore, when the resin reservoir section 16 is provided with the resin pressure detection means 19, the resin pressure caused by the plunger can be easily and reliably detected.

As mentioned above, this resin pressure can be equated with the resin pressure within each cavity 14 ₁ to 14 ₆ , so
The resin pressure inside each cavity can be easily detected, and
This can be done reliably and has the advantage that, for example, the detection signal from the resin pressure detection means 19 can be used as a control signal for the fluid pressure for operating the plunger.

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

For example, in FIG. 3, a predetermined plurality of pieces (for example, four pieces each) are placed on both sides of one cull.
This shows the case where two cavities are arranged respectively.
In addition, two minority cavities 21 smaller than the predetermined plurality are provided in the cull portion 20 disposed at one end thereof.
22, 23 to 24 are respectively arranged, and the cull portion and the minority cavity are communicated through passages 25 and 26 for transferring molten resin material having substantially equal length, respectively, and further, the above-mentioned A resin reservoir 27 of a desired shape and depth is formed at a side position of the cull 20, and molten resin material introduction passages 28, 29 of a predetermined length are formed between the resin reservoir 27 and the cull 20. It is constructed by communicating with each other through the

However, the only difference is that the predetermined plurality of cavities is four and the small number of cavities is two, and that a passage for transporting the molten resin material is provided corresponding to this configuration, and the other configurations are the same as the previous one. Substantially the same as the example. Therefore, with the configuration of this embodiment, substantially the same operations and effects as those of the previous embodiment described above can be obtained.

Furthermore, in each of the embodiments described above, transfer passages 15 ₅ , 15 6 , which communicate the respective minority cavities 14 ₅ , 14 ₆ , 21 to 22, 23 to 24 and each pot portion (cull portions 12 ₁ and ₂₀ ), The length and shape of 25 and 26 are determined by the introduction passage 17, which communicates the resin reservoir portions 16 and 27 with the pot portions (cull portions 12 ₁ and 20).
They may be formed to have substantially the same length and shape as 18, 28, and 29.

Furthermore, the introduction passages 17, 18, 28, and 29
It is preferable that the number of the transfer passages 15 ₅ , 15 ₆ , 25 , 26 is the same as that of the transfer passages 15 5 , 15 6 , 25 , 26 . However, the state in which the molten resin material is injected into each cavity through the transfer passages and the state in which the molten resin material is introduced into the resin reservoirs 16 , 27 through the introduction passages are different.
Therefore, for example, as shown in FIG. 4, a single introduction passage 30 that satisfies this set condition may be provided.

In these cases, the time for injecting the molten resin material into each cavity and the manner in which the molten resin is injected are all the same, which has the effect of making it possible to equalize the resin molding conditions with higher precision.

[Effect of idea]

According to the configuration of the present invention, a multi-pot plunger type resin sealing mold is adopted, and,
Even if the number of cavities communicating with any of the pot parts is less than a predetermined number, it is possible to eliminate the need for designing and manufacturing the mold, and to make the entire molded resin material. The molten resin material can be pressurized and injected into both the predetermined plurality of cavities and the small number of cavities under substantially the same resin molding conditions without reducing the yield. Therefore, it is possible to reliably solve the conventional problems as described above, and also to provide a mold capable of molding a resin-sealed molded product with high quality and high reliability.

Further, according to the configuration of the present invention, excellent practical effects such as being able to easily and reliably detect the resin pressure in the cavity of the above-mentioned resin sealing mold are achieved. be.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view showing the main part of the mold surface of the resin-sealing mold according to the present invention. FIG. 2 is a partially cutaway plan view showing an enlarged view of the main part of the mold surface of the mold. FIG. 3 is a partially cutaway plan view of the main part of the die surface showing another embodiment of the present invention. FIG. 4 is a plan view of the main part of the mold surface showing another example of the structure of the introduction passage. FIG. 5 and FIG. 6 are both partially cutaway plan views of the main parts of the mold surface for explaining problems with conventional molds. Explanation of symbols, 12...Cull part (pot part), 1
2 ₁ ... Cull part (pot part) 14 ₁ - 14 ₂ ... Predetermined plural cavities, 14 ₃ - 14 ₄ ... ... Predetermined plural cavities, 14 ₅ ... Minority cavities, 14 ₆ ...
Minority cavity, 15 ₁ to 15 ₆ ...transfer passage,
16...Resin reservoir, 17, 18...Introduction passage, 1
9...Resin pressure detection means, 20...Cull part (pot part), 21-22...Minority cavity, 23-2
4...Minority cavity, 25, 26...Transfer passage, 27...Resin reservoir, 28, 29...Introduction passage, 30...Introduction passage.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A plurality of pot groups and a plurality of cavity groups arranged in parallel, and a plurality of pots arranged at predetermined positions in the vicinity of each pot portion. The cavities are communicated with each other via passages for transferring molten resin material of the same length, and the number of cavities communicated with any of the pot portions is smaller than the predetermined plurality described above. In a mold for resin-sealing electronic components, a resin reservoir of a desired shape is formed at a side position of one of the pots, and the pot and the resin reservoir are filled with molten resin of a required length. The total filling volume of the resin material in the resin reservoir and the molten resin material introduction passage, and the inside of the minority cavity in any of the above pot parts and the minority cavity and the pot part are communicated through the material introduction passage. 1. A mold for resin-sealing an electronic component, characterized in that the mold is formed so that the total filling volume of the resin material in the molten resin material transfer passage to be communicated is approximately equal to the total filling volume of the resin material. (2) Resin in a transfer passage that is formed so that the total amount of resin material filling in the minority cavity is approximately equal to the total amount of resin material filling in the resin reservoir, and that communicates the minority cavity with the pot portion. The electronic component according to claim (1), characterized in that the total filling volume of the resin material is formed so as to be approximately equal to the total filling volume of the resin material in the introduction passage that communicates the resin reservoir section and the pot section. Mold for resin sealing. (3) Claim characterized in that the length of the transfer passage that communicates the minority cavity and the pot section and the length of the introduction passage that communicates the resin reservoir section and the pot section are formed to be approximately the same length ( A mold for resin-sealing the electronic components described in 1). (4) Claim (1) characterized in that the shape of the transfer passage that communicates the minority cavity and the pot portion and the shape of the introduction passage that communicates the resin reservoir portion and the pot portion are substantially the same. A mold for resin encapsulation of electronic components described in . (5) Claims (1) to (4) characterized in that the resin reservoir is provided with a resin pressure detection means for detecting pressure applied to the resin material within the cavity.
A mold for resin encapsulation of electronic components described in .