JP2015119080A - Mold package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for achieving a configuration suitable for making the curing speed of whole resin uniform, while suppressing prolongation of the curing time of resin, when compression molding mold resin in a half-mold package.SOLUTION: A mold package includes a board 10, an electronic component 20 mounted on one side 11 of the board 10, and a mold resin 30 composed of epoxy resin for sealing one side 11 of the board 10 along with the electronic component 20, and the other side 12 of the board 10 is exposed from the mold resin 30. The mold resin 30 is formed by performing compression molding, by using a resin material containing a microcapsule type curing catalyst 50 produced by covering a catalyst 51 for accelerating the curing of epoxy resin in a shell 52 composed of a nonconductive material, and debris 52a of the shell exists in the mold resin 30.

Description

  The present invention relates to a half mold type mold package in which one side of a substrate is sealed with a mold resin and the other side is exposed.

  Conventionally, as this type of mold package, a substrate, an electronic component mounted on one surface of the substrate, a mold resin made of an epoxy resin that is provided on one surface of the substrate and seals the one surface of the substrate together with the electronic component, The one with is proposed. Here, what employ | adopted the structure which exposed the other surface on the opposite side to the one surface in a board | substrate from the said mold resin is called what is called a half mold type.

  Here, the mold resin is usually formed by compression molding for the purpose of collectively sealing multiple substrates. In this case, as described in Patent Document 1, curing of the resin is promoted by including a latent curing catalyst triggered by heat in the resin material to be the mold resin.

Japanese Patent No. 497325

  By the way, the above-described latent catalyst is designed such that the curing reaction proceeds rapidly after reaching a certain temperature. However, in the case of compression molding, the resin material is placed in the lower mold of the upper mold and the lower mold, and the upper and lower molds are matched and heated and pressed with the substrate placed in the upper mold. Thus, the molding resin is molded.

  Therefore, in this case, heat from the lower mold becomes a main heat transfer path to the resin material, and variation in heat reception occurs in the thickness direction of the mold resin. For this reason, with a conventional latent catalyst, the curing rate tends to be non-uniform throughout the resin.

  In this regard, it is also conceivable to design the resin material so that the curing time is increased so that the resin can be cured after the entire resin material is melted. However, in this case, the molding tact time (for example, the time until mold opening) becomes long, leading to deterioration in production efficiency.

  The present invention has been made in view of the above problems, and in the case of compression molding a mold resin in a half mold package, the curing speed is made uniform throughout the resin while suppressing the resin curing time from being prolonged. The object is to realize a configuration suitable for this.

  In order to achieve the above object, the present invention has been created by paying attention to using a microcapsule-type curing catalyst triggered by pressure for compression molding.

  That is, according to the first aspect of the present invention, the substrate (10), the electronic component (20) mounted on the one surface (11) of the substrate, and the one surface of the substrate are sealed together with the electronic component. A mold resin (30) made of an epoxy resin, and the other surface (12) opposite to the one surface of the substrate is exposed from the mold resin, and the mold resin is a catalyst that promotes curing of the epoxy resin. Formed by performing compression molding using a resin material containing a microcapsule-type curing catalyst (50) formed by coating (51) with a shell (52) made of a non-conductive material, The mold resin contains a shell remnant (52a).

  Here, the microcapsule type curing catalyst is mixed with a granular resin material for compression molding, the shell is broken by molding pressure, the curing catalyst oozes out, and curing is promoted. That is, the microcapsule type curing catalyst is a catalyst triggered by pressure. Therefore, the curing rate is made uniform throughout the mold resin without being greatly affected by the variation in heat receiving of the mold resin.

  Therefore, according to the present invention, when the molding resin is compression-molded, it is possible to realize a configuration suitable for making the curing speed uniform over the entire resin while suppressing an increase in the curing time of the resin. .

  Here, as in the invention described in claim 2, in the mold package of claim 1, the shell remnant is such that the portion of the mold resin that is closer to one side of the substrate is opposite to the one side of the substrate. It is preferable that it is biased so as to be larger than the closer portion.

  The portion of the mold resin that is closer to one side of the substrate is farther from the inner surface of the lower mold, that is, the mold on which the resin material is disposed, as compared to the portion that is closer to the first surface 11 of the substrate 10. Is also a small part.

  In that respect, the present invention is formed by molding in a state where a relatively large number of microcapsule-type curing catalysts are contained in the portion near the substrate, so that the curing rate of the portion with low heat reception can be reduced. Effective in speeding up. Therefore, it is preferable in terms of making the curing rate uniform throughout the resin.

  In addition, the code | symbol in the bracket | parenthesis of each means described in the claim and this column is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

It is a schematic sectional drawing which shows the mold package concerning embodiment of this invention. It is a schematic sectional drawing which shows typically the microcapsule type curing catalyst used for the manufacturing method of the mold package shown by FIG. It is process drawing which shows the principal part process in the manufacturing method of the mold package shown by FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, parts that are the same or equivalent to each other are given the same reference numerals in the drawings for the sake of simplicity.

  A mold package according to an embodiment of the present invention will be described with reference to FIG. This mold package S1 is mounted on a vehicle such as an automobile and is applied as a device for driving various electronic devices for the vehicle.

  In broad terms, the mold package S1 of this embodiment is provided on the substrate 10, the electronic component 20 mounted on the one surface 11 of the substrate 10, and the one surface 11 of the substrate 10. And a mold resin 30 to be sealed.

  The substrate 10 has a plate shape in which one plate surface is one surface 11 and the other plate surface opposite to the one surface 11 is the other surface 12, and is formed of a printed circuit board, a ceramic substrate, a lead frame, or the like. The substrate 10 may be a single layer substrate or a multilayer substrate.

  One surface 11 of the substrate 10 is configured as a component mounting surface, that is, a mounting surface, and the electronic component 20 is mounted and fixed to the one surface 11 of the substrate 10 via a die bond material (not shown). The electronic component 20 and the substrate 10 are electrically connected by a bonding wire 40 such as gold or aluminum.

  The electronic component 20 is not particularly limited as long as it is a component that can be mounted on the substrate 10, such as a semiconductor chip such as an IC chip or a transistor element, or a passive element such as a resistor or a capacitor. Further, the electrical connection between the electronic component 20 and the substrate 10 is not limited to the wire bonding shown in FIG. 1, but may be a conductive adhesive or solder, or may be a bump using a flip chip or the like. Good.

  The mold resin 30 seals the one surface 11 and the electronic component 20 on the one surface 11 on the one surface 11 side of the substrate 10, and the other surface 12 side of the substrate 10 is exposed from the mold resin 30. . Thus, the mold package S1 of the present embodiment has a so-called half mold structure.

  The mold resin 30 is made of an epoxy resin and is formed by compression molding. The mold resin 30 is formed in a plate shape having a thickness t on one surface 11 of the substrate 10. Here, the thickness (corresponding to the thickness of the mold resin) t of the mold resin 30 on the one surface 11 of the substrate 10 is, for example, 2 mm or more and 10 mm or less.

  Furthermore, the mold resin 30 is formed by compression molding using a resin material (that is, a mold resin material) containing the microcapsule-type curing catalyst 50 shown in FIG. The microcapsule-type curing catalyst 50 is formed by coating a catalyst 51 as a curing accelerator that accelerates the curing of the epoxy resin constituting the mold resin 30 with a shell 52 made of a non-conductive material.

  Such a microcapsule type curing catalyst 50 is a known one, and various types can be appropriately selected and used as long as they are used as an epoxy resin curing catalyst. For example, as the catalyst 51 that is a curing accelerator, a typical amine-based curing agent as an epoxy resin curing agent, or a heat generating agent that accelerates a curing reaction by increasing the temperature is used.

  The shell 52 is typically a resin, and such a resin is not particularly limited, and examples thereof include epoxy resin, polyester, polyethylene, polystyrene, urethane resin, and phenol resin. Among these, an epoxy resin is preferable from the viewpoint of the stability of the film and the ease of destruction during heating, but the epoxy resin of the shell is made of a material different from the epoxy resin of the mold resin 30.

  The microcapsule-type curing catalyst 50 is configured such that the shell 52 is broken and the internal catalyst 51 comes out due to the pressure applied to the mold resin material during compression molding. Therefore, at the time of compression molding, the catalyst 51 inside the microcapsule-type curing catalyst 50 is mixed with the mold resin material, and the curing of the epoxy resin is promoted by the catalytic effect or heat generation.

  Therefore, in the completed mold resin 30, as shown in FIG. 1, the broken shell 52 is inherent in the mold resin 30 as a shell remnant 52a. Since the shell debris 52a is made of a resin different from the mold resin 30, it can be confirmed, for example, by electron microscope observation or elemental analysis of the cross section of the mold resin 30.

  Further, in the finished mold resin 30, the catalyst 51 may remain in the mold resin 30 even after the epoxy resin curing reaction, but may be consumed by the curing reaction. However, when the catalyst 51 remains in the mold resin 30, the presence or absence can be confirmed by elemental analysis or the like.

  Further, in the present embodiment, as shown in FIG. 1, the shell debris 52 a has a portion closer to one surface 11 of the substrate 10 in the mold resin 30 closer to the opposite side to the one surface 11 of the substrate 10. It is biased and inherent so that there are more parts. That is, in FIG. 1, a portion of the mold resin 30 closer to the interface with the one surface 11 of the substrate 10 has more shell debris 52a than the portion closer to the upper surface of the mold resin 30 in FIG. Has been.

  In the present embodiment, the shell debris 52 a is included only in a portion of the mold resin 30 near the one surface 11 of the substrate 10 and is not present in a portion near the top surface of the mold resin 30. As will be described later, this biased configuration is realized by arranging the microcapsule type curing catalyst 50 in consideration of the heat receiving variation of the molding resin material in the compression molding.

  Next, with reference to FIG. 3, the manufacturing method of mold package S1 of this embodiment is described. First, the substrate 10 and the electronic component 20 are prepared (preparation process).

  And the electronic component 20 is mounted in the one surface 11 of the board | substrate 10 (mounting process). Specifically, the electronic component 20 is fixed to the one surface 11 of the substrate 10 via a die bond material or the like (not shown), and the bonding wire 40 is formed by wire bonding.

  Next, a molding process for forming the mold resin 30 by compression molding is performed. In this step, as shown in FIG. 3, a molding die 100 that performs compression molding by removably matching the upper mold 101 and the lower mold 102 is used.

  Here, the upper mold 101 supports the substrate 10. The lower mold 102 includes a clamp mold 103 that is matched with the upper mold 101 and supports the substrate 10 with the substrate 10 interposed therebetween, and a movable mold 104 that is movable in the vertical direction in FIG. . Each part of the mold 100 is driven by, for example, an actuator or the like.

  In the molding step, the other surface 12 side of the substrate 10 is fixed to the upper die 101 in the upper die 101 and the lower die 102 before matching as shown in FIG. On the other hand, as shown in FIG. 3 (b), a granular mold resin material 30 a to be the mold resin 30 is weighed in an appropriate amount, and this is put into the lower mold 102.

  Next, in the molding step, as shown in FIG. 3C, a microcapsule mold is formed on the surface side of the mold resin material 30a charged in the lower mold 102 (that is, on the surface side in contact with the one surface 11 of the substrate 10). The curing catalyst 50 is charged by coating or the like.

  Thereafter, in the molding process, as shown in FIG. 3D, the upper mold 101 and the lower mold 102 are matched, and in this matched state, the mold resin material 30a is pressurized and heated to be cured, Mold resin 30 is formed.

  Specifically, the upper mold 101 and the clamp mold 103 are supported with the substrate 10 being sandwiched, and the movable mold 104 is moved upward toward the upper mold 101, whereby the mold resin material 30a is brought to the molding pressure. Compress. And the mold resin 30 is formed by hardening the mold resin material 30a in this compression state.

  At this time, as described above, in the microcapsule-type curing catalyst 50, the shell 52 is broken by the molding pressure and the internal catalyst 51 comes out, so that curing of the epoxy resin is promoted. In addition, after the curing is completed, as shown in FIG. 1, the broken shell 52 is inherent in the mold resin 30 as a shell remnant 52 a.

  After forming the mold resin 30 in this manner, the clamp mold 103 and the movable mold 104 are moved downward away from the upper mold 101, and the substrate 10 on which the mold resin 30 is formed is removed from the upper mold 101. The above is the molding process. Thus, the mold package S1 of this embodiment is completed.

  By the way, as described above, the microcapsule-type curing catalyst 50 is mixed with the granular molding resin material 30a for compression molding, the shell 52 is broken by the molding pressure, the catalyst 51 oozes out, and the curing is promoted. It is. That is, the microcapsule type curing catalyst 50 is a catalyst triggered by pressure.

  Therefore, the curing rate is uniform over the entire resin without being significantly affected by the variation in heat receiving of the mold resin material 30a during molding. Specifically, in the molding process, the mold resin material 30a receives heat directly in contact with the lower mold 102, but receives heat from the upper mold 101 through the substrate 10, and thus the main heat transfer of the mold resin material 30a. The path is heat received from the lower mold 102.

  Therefore, the heat receiving variation of the mold resin material 30a is small on the one surface 11 side (that is, the upper mold 101 side) of the substrate 10 and tends to be large on the opposite side to the one surface 11 of the substrate 10 (that is, the lower mold 102 side). Even in this case, the pressure is uniform in the mold 100, and the microcapsule-type curing catalyst 50 of the present embodiment is a pressure trigger. Therefore, the catalyst 50 is not easily affected by variations in heat reception.

  Therefore, according to the present embodiment, when the molding resin 30 is compression-molded, it is possible to realize a configuration suitable for making the curing speed uniform throughout the resin while suppressing the resin curing time from being prolonged. Can do.

  In the present embodiment, as described above with reference to FIG. 1, the shell debris 52 a has a portion of the mold resin 30 closer to the first surface 11 of the substrate 10 closer to the opposite side of the first surface 11 of the substrate 10. It is biased and inherent so that there are more parts.

  As described above, the portion of the mold resin 30 near the one surface 11 is closer to the inner surface of the lower mold 102 on which the mold resin material 30a is disposed than the portion near the one surface 11 opposite to the one surface 11 of the substrate 10. Because it is far away, the heat receiving during molding is also a small part. Therefore, a portion of the mold resin 30 near the one surface 11 tends to have a slower curing speed than a portion near the one surface 11 opposite to the one surface 11 of the substrate 10.

  However, as shown in FIG. 3, the package S1 of the present embodiment is molded in a state where the microcapsule-type curing catalyst 50 is unevenly distributed in a portion of the mold resin material 30a near the one surface 11 of the substrate 10. Since it is comprised by this, the cure rate of a part with small heat receiving can be accelerated. Therefore, it is preferable in terms of making the curing speed uniform throughout the mold resin 30.

  In the present embodiment, the thickness t of the mold resin 30 on the one surface 11 of the substrate 10 is desirably 2 mm or more. According to the inventor's study, when the thickness t of the mold resin 30 is less than 2 mm, the heat receiving variation in the thickness direction of the mold resin 30 in compression molding is small, but when the thickness t is 2 mm or more, the heat receiving variation is large. , Non-uniformity in the curing rate becomes remarkable.

  Therefore, when the thickness t of the mold resin is 2 mm or more, the effect of preventing unevenness of the curing rate due to the heat receiving variation is effectively exhibited by adopting the configuration of the present embodiment. The upper limit of the thickness t of the mold resin 30 is not particularly limited, but is preferably about 10 mm in practice.

  In this embodiment, the pressure trigger type microcapsule type curing catalyst 50 is used in compression molding. In this regard, for example, in the case of conventional transfer molding, since the pressure higher than the molding pressure is applied in the kneading process of the mold resin material, the tableting process of the tablet, etc., the microcapsule type curing catalyst 50 cannot be applied. In the case of transfer molding, pressure is applied by a pot or runner that feeds the resin to the mold, so that the resin hardens first on the gate side, and the gate side tends to be clogged.

  However, in the compression molding of this embodiment, the molding pressure is generated inside the cavity of the mold 100 in which the molding resin material 30a is charged, and the molding pressure is uniformly applied to the entire resin material 30a. Then, as described above, the microcapsule-type curing catalyst 50 is directly injected into the cavity to perform the molding, so that the problem that occurs in the transfer molding does not occur.

(Other embodiments)
The microcapsule-type curing catalyst 50 is the same as that of the above embodiment as long as the catalyst 51 for promoting the curing of the epoxy resin constituting the mold resin 30 is covered with a shell 52 made of a non-conductive material. Other than that.

  In the above embodiment, the shell debris 52a is such that the portion of the mold resin 30 closer to the first surface 11 of the substrate 10 is larger than the portion closer to the opposite side of the first surface 11 of the substrate 10. It was biased and inherent. Specifically, the shell debris 52 a is included only in a portion of the mold resin 30 near the one surface 11 of the substrate 10 and does not exist in a portion near the outer surface of the mold resin 30.

  However, in the case of this biased configuration, the above-described biased arrangement of the shell debris 52a in the mold resin 30 only needs to be realized, and a small number of shell debris 52a also exists in the portion near the outer surface of the mold resin 30. It may be. Further, in addition to the above-described biased configuration, the shell remnants 52 a may be uniformly present throughout the mold resin 30.

  Further, the thickness t of the mold resin 30 on the one surface 11 of the substrate 10 is not limited to 2 mm or more as described above, and the above embodiment can be applied even when it is less than 2 mm with relatively small variation in heat reception. Of course.

  Further, the electronic component 20 mounted on the one surface 11 of the substrate 10 and sealed with the mold resin 30 may not be one, but may be plural.

  Further, the present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope described in the claims. The above embodiments are not irrelevant to each other, and can be combined as appropriate unless the combination is clearly impossible, and the above embodiments are not limited to the illustrated examples. Absent. In each of the above-described embodiments, it is needless to say that elements constituting the embodiment are not necessarily essential unless explicitly stated as essential and clearly considered essential in principle. Yes. Further, in each of the above embodiments, when numerical values such as the number, numerical value, quantity, range, etc. of the constituent elements of the embodiment are mentioned, it is clearly limited to a specific number when clearly indicated as essential and in principle. The number is not limited to the specific number except for the case. Further, in each of the above embodiments, when referring to the shape, positional relationship, etc. of the component, etc., the shape, unless otherwise specified and in principle limited to a specific shape, positional relationship, etc. It is not limited to the positional relationship or the like.

DESCRIPTION OF SYMBOLS 10 Substrate 11 One side of substrate 12 Other side of substrate 20 Electronic component 30 Mold resin 50 Microcapsule type curing catalyst 51 Catalyst 52 Shell 52a Shell debris

Claims (3)

A substrate (10);
An electronic component (20) mounted on one surface (11) of the substrate;
A mold resin (30) made of an epoxy resin provided on one surface of the substrate and sealing the one surface of the substrate together with the electronic component;
The other surface (12) opposite to the one surface of the substrate is exposed from the mold resin,
The mold resin is a resin material containing a microcapsule-type curing catalyst (50) formed by coating a catalyst (51) that promotes curing of an epoxy resin with a shell (52) made of a non-conductive material, It is formed by performing compression molding,
The mold package is characterized in that a debris (52a) of the shell is contained in the mold resin.   The shell debris is biased and contained so that the portion of the mold resin closer to one surface of the substrate is larger than the portion closer to the opposite surface of the substrate. The mold package according to claim 1.   The mold package according to claim 1 or 2, wherein a thickness of the mold resin on one surface of the substrate is 2 mm or more.

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