JP4301991B2 - Resin sealing method for molded products - Google Patents

Description

  The present invention relates to a resin sealing method for a molded product in which the molded product is sealed with a resin in a mold that faces each other.

  Conventionally, an upper mold, a frame-shaped mold that is disposed opposite to the upper mold and has a through hole, and a lower mold that has a compression mold that fits into the through hole and can move forward and backward with respect to the upper mold. , And a device for resin-sealing a molded product on which an electronic component or the like is mounted is widely known.

  This conventionally known resin sealing device fixes the molded product by clamping the peripheral portion of the molded product with an upper mold and a (lower mold) frame-shaped mold, and in this state (lower mold) ) The resin is compression-molded by moving the compression mold relatively to the upper mold side, and the product to be molded is resin-sealed.

  By the way, when the resin surface of the molded product is pulled away from the mold, a considerable peeling load is applied to the molded product and the sealed resin. Therefore, when the molded product is a fragile material or the sealing resin is thin, the peeling load causes destruction of the molded product, destruction of the sealing resin, peeling of the molded product and the sealing resin. Such troubles are likely to occur.

  Therefore, conventionally, after sealing, in a state where the molded product is clamped by the upper mold and the frame-shaped mold, the compression mold is first moved backward to separate the compression mold from the resin surface of the molded product, Thereafter, the product to be molded is separated. This is because it is necessary to perform the most difficult process of separating the resin surface from the mold under a “stable support state” in which the molded product is securely clamped by the upper mold and the frame mold. is there.

  On the other hand, a method of interposing a so-called release film between a sealing resin surface and a mold at the time of molding has been proposed (for example, see Patent Document 1). The release film covers the contact surface of the mold with the resin and prevents the sealing resin from adhering to the contact surface to prevent the mold from being released favorably. A special film material having heat resistance that can withstand heat, releasability easily peelable from both resin and mold, and high stretchability is used.

JP 2002-59453 A

  However, it is uneconomical because the release film needs to be replaced for each molding (sealing), and further, a transport mechanism and a sealing for supplying the release film between the mold and the resin There is also a problem that a transport mechanism for removing the film from the mold surface later is required, and the apparatus becomes more complicated.

  On the other hand, according to a manufacturing method called potting, for example, such a problem at the time of mold release can be avoided, but this method has low molding accuracy and is not necessarily appropriate as a manufacturing method for a precise electronic component.

  The present invention has been made to solve such a conventional problem, and can easily and easily peel the resin surface and the mold surface with a simple configuration. Thus, it is an object of the present invention to provide a resin sealing method for a molded product that can be satisfactorily sealed without being damaged even if the molded product is related to a very fragile substrate.

The present invention relates to a resin sealing method of a molded product in which the molded product is sealed with a resin in a mold that faces each other, and a portion of the molded product that is not resin-sealed is separated from the mold. The first procedure in which only the resin is in contact with a specific mold among the molds, and in this state, the second waits until the resin separates from the specific mold due to molding shrinkage. The above-mentioned problem is solved by including the procedure.

  In the present invention, as a technique for separating (peeling) the sealing resin surface of the molded product and the mold, a release film is not interposed as in the prior art, but molding shrinkage of the resin itself is used. According to the inventor's test, it has been confirmed by this technique that even if the molded article is formed of a very fragile material such as ceramic, it can be separated without any problem.

  The molded resin is heated and compressed at a high temperature and a high pressure, and a molding shrinkage phenomenon that occurs when the resin returns to a normal temperature state occurs uniformly on all resin surfaces in contact with the mold. This shrinkage force appears in the form of internal shearing stress that acts on the surface of the molded resin sealing resin and the mold, so there is no external force (force applied from the outside for peeling) Thus, the resin surface can be self-separated from the mold.

  Conventionally, since the peeling between the resin surface and the mold has been realized by an external peeling force, it has been necessary to perform the peeling in a state where the product to be molded is securely clamped. Therefore, the separation between the molded product (substrate side) and the mold has not been performed prior to the separation between the resin surface of the sealed resin and the mold.

  However, in order to use the phenomenon called molding shrinkage between the mold and the resin surface, the present invention allows only the resin to be separated from the mold by separating the part that is not resin-sealed from the mold. A step (first procedure) for bringing the mold into contact is first executed. The separation between the resin surface of the sealed resin and the mold is performed thereafter, that is, in a state where there is no contact surface with the mold other than the resin surface (second procedure). This reversal of the order can be said to be the greatest feature of the present invention.

  Various variations are conceivable for the present invention. This will be described in detail later.

  Even with a fragile article to be molded with a simple configuration, the resin surface and the mold surface can be reliably and easily separated.

  Hereinafter, an example of an embodiment of the present invention will be described in detail based on the drawings.

  FIG. 1 shows an outline of a resin sealing apparatus to which a resin sealing method according to an example of the embodiment is applied. FIG. 1 schematically shows the outline of the resin sealing device focusing on its function, and does not necessarily match the specific configuration of the actual device.

  The resin sealing device 2 heat-compresses a resin 8 on a ceramic substrate (molded product) 6 on which an electronic component 4 is mounted, and seals the mounting portion of the electronic component 4 with an upper mold. A (first mold) 12 and a lower mold (second mold) 14 facing the upper mold 12 are provided. The lower mold 14 includes a frame-shaped mold 16 and a compression mold 18. The upper mold 12 is fixed in the resin sealing device 2, and the lower mold 14 is configured to move up and down by the lower mold driving unit 15 (with the frame-shaped mold 16 and the compression mold 18).

  The frame-shaped mold 16 is arranged to face the upper mold 12 and includes a through hole 16A. The compression mold 18 can be moved back and forth with respect to the upper mold 12 while being fitted into the through hole 16A. The frame-shaped mold 16 is attached to the compression mold 18 via a spring 20. The spring 20 constantly urges the frame-shaped mold 16 in the direction of the upper mold 12 (upward in FIG. 1). The frame-shaped mold 16 is connected to a pull-down drive unit 24 via a hook 22, and the frame-shaped mold 16 is resisted against the urging force of the spring 20 by driving the pull-down drive unit 24. Pull-down drive is possible. The pull-down drive unit 24 is mechanically connected to the compression mold 18 via the structure 25 and can move up and down in accordance with the vertical movement of the compression mold 18.

  The upper mold 12, the frame-shaped mold 16, and the compression mold 18 are equipped with heaters 32, 34, and 36 for heating the sealing resin 8, respectively.

  In addition to this, the resin sealing device 2 includes a charging mechanism (not shown) for charging the sealing resin 8 onto the compression mold 18. The charged resin 8 is heat-compressed in a molding space 28 surrounded by the compression mold 18, the through-hole 16 </ b> A of the frame-shaped mold 16, and the upper mold 12, and the electronic component 4 portion of the ceramic substrate 6 is formed. Seal. The upper mold 12 is provided with suction means or chucking means (not shown) for temporarily holding the ceramic substrate 6.

  A release promoting material such as a release film is not interposed between the compression mold 18 and the sealing resin 8 to be charged. Therefore, a transport mechanism related to supply / removal of the release film is not provided.

  Next, the resin sealing method according to the present embodiment will be described in detail while explaining the operation of the resin sealing device 2. 2A to 2E are operation explanatory diagrams from molding (sealing) to mold release.

  First, as shown in FIG. 2A, a ceramic substrate (molded product) 6 on which an electronic component 4 is mounted is held on the upper mold 12 by means such as suction or chucking, and then sealed. The resin 8 is put into a molding space 28 formed by the frame-shaped mold 16 and the compression mold 18.

  Next, as shown in FIG. 2B, the lower die 14, that is, the frame-shaped die 16 and the compression die 18 are driven and raised to the upper die 12 side by the lower die driving unit 15, and the ceramic substrate 6 is moved. The upper mold 12 and the frame-shaped mold 16 are clamped.

  When the lower die 14 is further raised in this state, as shown in FIG. 2 (C), the clamping by the compression die 18 proceeds while the spring 20 is compressed, and the resin 8 is heated and compression molded, and the electronic The part 4 is resin-sealed.

  Thereafter, as shown in FIG. 2 (D), after the resin 8 is cured to such an extent that it can be taken out from the molds 12 and 14, the frame-shaped mold 16 is pulled down via the hooks 22 by driving the pull-down drive unit 24. Then, the clamp state with the upper mold 12 is released.

  As shown in FIG. 2 (E), when the entire lower die 14 is further pulled down from the state of FIG. 2 (D), the unsealed portions 6A and 6B of the ceramic substrate 6 become molds (in this embodiment). Is separated from the upper mold 12 and the frame-shaped mold 16), and a state is formed in which only the resin 8 is in contact with a specific mold (in this embodiment, the compression mold 18). The steps from FIG. 2D to FIG. 2E correspond to the first procedure in the present invention.

  In this embodiment, in this state, the resin 8 is molded and contracted by waiting for a preset time, and the resin 8 is separated from the compression mold 18. This is a step corresponding to the second procedure in the present invention. At this time, for example, in order to promote molding shrinkage, the compression mold 16 may be cooled, or cold air may be supplied as necessary. However, when the product to be molded is a fragile member such as a ceramic substrate as in this embodiment, sufficient consideration must be given to the supply amount and temperature, particularly when cold air is supplied. The present invention basically does not require such cooling promotion control. The standby time is, for example, about 5 to 10 seconds, although it depends on the amount of resin and the like.

  This standby is not necessarily intended to do nothing, but other work (for example, movement of a predetermined member including a mold, a predetermined part) in order to shorten the manufacturing cycle time using this standby time. Needless to say, the cleaning may be performed in parallel.

  After separation, the ceramic substrate 6 separated (sealed) from the compression mold 18 is taken out by means such as suction (not shown). At this time, the external force for extraction may be zero or almost zero, and extremely easy extraction is possible.

  The shearing stress acting on the contact surface between the resin 8 and the compression mold 18 generated in the process of waiting for the molding shrinkage of the resin 8 is a so-called internal stress generated inside the resin 8 itself, and the resin is smaller. It can be said that there is no possibility that the resin 8 will be destroyed during this contraction process because of the stress to be achieved. In addition, since no stress is generated in the direction in which the ceramic substrate 6 and the resin 8 are peeled off (vertical direction), there is almost no possibility that the resin 8 is peeled off from the ceramic substrate 6. Further, only the external force in the longitudinal direction accompanying the contraction of the resin 8 is applied to the ceramic substrate 6, and no external force in the vertical direction is applied. Therefore, the possibility that the ceramic substrate 6 is destroyed is extremely low.

  As a result, a yield of almost 100% can be ensured, and productivity can be greatly increased. In addition, even if it is desired to use a ceramic material for the substrate, the thickness or use of the ceramic material has been limited in consideration of the fragility of the ceramic material. The material can be used. This means that the quality of the molded product itself can be improved, and can be said to be an effect of a dimension different from “preventing destruction when taking out the molded product”.

  In the above embodiment, as a resin sealing device for applying the present invention, an upper mold (first mold), a frame-shaped mold having a through-hole disposed opposite to the upper mold, and this Although the thing of the structure provided with the compression die which can be moved forward / backward with respect to an upper mold | type was fitted by the through-hole was employ | adopted, The resin sealing device for applying this invention A specific configuration is not particularly limited to this configuration. For example, a frame-shaped mold and a compression mold may be formed on the upper mold side, and a frame-shaped mold and a compression mold are formed on both the upper mold and the lower mold. It may be. Further, it is not always necessary to use a combination of a frame-shaped mold and a compression mold.

  In the above embodiment, the frame-shaped mold is first retracted to a position where it does not contact the product, and in this state, the upper mold and the lower mold are opened to form a state where the resin is in contact only with the compression mold. Thus, the first procedure is realized, but the specific configuration of the first procedure is not limited to this. For example, the first procedure is realized by first opening the first mold and the second mold, stopping the compression mold at a predetermined position, and continuing to open only the frame-shaped mold. Also good. In short, before peeling the resin surface from the mold (before entering the second procedure waiting for molding shrinkage), as a result, the unsealed part of the molded product is separated from the mold, and only the resin is It suffices if a procedure for making contact with a specific mold among the molds is prepared.

  According to the present invention, the resin surface and the mold are separated from each other almost completely by molding shrinkage, and it is possible to take out the resin-sealed molding object with zero or near zero external force. However, in the present invention, for example, when the mechanical strength of the molded product itself is relatively high, it is not always necessary to wait until it is finally peeled to the maximum by molding shrinkage. It is not forbidden to shift to the separation process by external force in the advanced state. Even in this case, the applied force (peeling force) can be reduced by the amount of molding shrinkage so far, and the risk of breakage can be reduced accordingly. As described above, the time for waiting for molding shrinkage is generally about 5 to 10 seconds. However, mechanical properties such as the amount of sealing resin, substrate material (brittleness), substrate thickness, etc. Alternatively, it may be set appropriately within this range or outside this range in consideration of a comparison between damage caused by the occurrence of defective products and a decrease in productivity due to the extension of the manufacturing cycle time.

  The present invention is applicable when resin molding a molded product on which electronic components or the like are mounted.

Sectional drawing which shows the outline of the resin sealing apparatus to which the resin sealing method which concerns on an example of embodiment of this invention is applied. Sealing process diagram for explaining a resin sealing method executed in the resin sealing device

Explanation of symbols

2 ... Resin sealing device 4 ... Electronic component 6 ... Ceramic substrate (molded product)
DESCRIPTION OF SYMBOLS 8 ... Resin 12 ... Upper mold 14 ... Lower mold 15 ... Lower mold drive part 16 ... Frame-shaped mold 16A ... Through-hole 18 ... Compression mold 20 ... Molding space 22 ... Hook

Claims (5)

In a resin sealing method of a molded product in which the molded product is sealed with resin in a mold that faces each other,
A first procedure in which the resin-sealed portion of the molded article is separated from the mold, and only the resin is in contact with a specific mold of the mold;
In this state, a second procedure of waiting until the resin separates from the specific mold due to molding shrinkage;
The resin sealing method of the to-be-molded product characterized by including this. In claim 1,
As the mold for the relative wrinkle,
A first mold, a frame-shaped mold disposed opposite to the first mold and having a through hole, and a compression that can be moved forward and backward with respect to the first mold by fitting into the through hole A second mold having a mold, and before the first procedure,
A step of fixing the molded product in the mold by clamping a peripheral portion of the molded product with the first mold and the frame-shaped mold of the second mold;
A resin sealing of the molded product, comprising: a step of compressing and molding the resin by moving the compression mold relative to the first mold side and sealing the molded product. Stop method. In claim 2,
The first procedure is:
A sub-procedure for retracting the frame-shaped mold of the second mold to a position where it does not come into contact with the workpiece;
A sub-procedure for opening the first mold and the second mold in this state to form a state in which the resin is in contact only with the compression mold;
The resin sealing method of the to-be-molded product characterized by including this. In claim 2,
The first procedure is:
A sub-procedure for opening the first mold and the second mold;
A sub-procedure for forming a state in which the resin is in contact only with the compression mold by stopping the compression mold of the second mold at a predetermined position and continuing to open only the frame-shaped mold;
The resin sealing method of the to-be-molded product characterized by including this. In a resin sealing method of a molded product in which the molded product is sealed with resin in a mold that faces each other,
As the mold for the relative wrinkle,
A first mold, a frame-shaped mold disposed opposite to the first mold and having a through hole, and a compression that can be moved forward and backward with respect to the first mold by fitting into the through hole A second mold having a mold, and
A sub-procedure for opening the first mold and the second mold, and stopping the compression mold of the second mold at a predetermined position, and continuing to open only the frame-shaped mold, A first procedure including a sub-procedure for forming a state in which the resin is in contact with only the compression mold;
In this state, a second procedure for waiting for the resin to undergo molding shrinkage;
The resin sealing method of the to-be-molded product characterized by including this .

Images