JP2010274495A - Mold for resin sealing of electronic component and resin sealing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress problems such as cracking of chips mounted on a chip mounting surface and peeling of chips from the chip mounting surface caused by a deformation of a substrate due to the resin pressure of fluid resin. <P>SOLUTION: In the molding mold for resin sealing of an electronic component composed of a lower mold 17 and an upper mold 12, a projection 18 is provided on the mold surface so as not to be planarly overlapped with a plurality of external electrodes 9 of the substrate 1 mounted on the mold surface of the lower mold 17. The projection 18 has substantially the same thickness as the thickness of the plurality of external electrodes 9. The deformation wherein the substrate 1 is formed to be convex to the side of the non-chip mounting surface 8 generated caused by the resin pressure of the fluid resin 14 applied to the substrate 1 in such a state that the lower mold 17 and the upper mold 12 are clamped, is prevented by supporting the substrate 1 with the projection 18. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is for resin sealing of electronic parts used when a substrate on which a semiconductor chip or the like (hereinafter referred to as “chip”) is mounted is fixed to a mold surface of the mold and the chip is resin-sealed. The present invention relates to a mold and a resin sealing method.

  Manufacturing an electronic component by sealing a chip with a resin will be described with reference to FIG. FIG. 1 (1) is a plan view showing a substrate on which a chip is mounted in a process for manufacturing an electronic component, and FIG. 1 (2) is a diagram illustrating a conventional process for manufacturing the electronic component in which a substrate is fixed to a lower mold and a mold is used. It is a fragmentary sectional view which shows the state clamped along the AA line of FIG. 1 (1). In addition, in order to make it easy to understand, any figure included in this application document is schematically omitted or exaggerated as appropriate.

  Conventionally, an electronic component is manufactured by resin-sealing chips such as a memory and a CPU mounted on a substrate as follows. First, one or a plurality of chips 4 are mounted on a die bonding pattern 3 provided on a chip mounting surface 2 of a printed circuit board 1. Next, the chip 4 is resin-sealed using a mold for resin sealing (described later) composed of a pair of molds facing each other. Here, as a base material (base material) of the substrate 1, a ceramic base material such as alumina is used in addition to a resin base material such as glass epoxy.

  As shown in FIG. 1, the bonding pad 5 of the chip 4 and the bonding pad 6 of the substrate 1 are electrically connected by a wire 7. A plurality of external electrodes 9 called pads and lands are provided on the surface of the substrate 1 opposite to the chip mounting surface, in other words, on the chip non-mounting surface 8. The external electrode 9 is provided for the purpose of electrically connecting the electronic component and a device existing outside the electronic component. The external electrode 9 is made of a copper foil having a predetermined thickness (for example, 17 μm thickness, 35 μm thickness, 70 μm thickness, etc.). Furthermore, a solder resist 10 as a protective film is formed so as to open a predetermined region of the external electrode 9 over the entire chip non-mounting surface 8.

  The manner in which the external electrodes 9 are arranged on the chip non-mounting surface 8 varies depending on the specifications of the electronic component. For example, as shown in FIG. 1A, the external electrode 9 may be disposed near the periphery of the chip non-mounting surface 8. In some cases, the external electrodes 9 are uniformly arranged on the chip non-mounting surface 8. Further, when the external electrodes 9 are irregularly arranged on the chip non-mounting surface 8, in other words, the external electrodes 9 may be arranged such that the arrangement density of the external electrodes 9 is large or small. Furthermore, a pattern (not shown) for connecting the external electrodes 9 to each other, a pattern (not shown) for connecting the external electrodes 9 and the bonding pads 6 of the substrate 1 may be provided. Finally, a spherical or columnar protruding electrode (bump) is formed on the external electrode 9.

  As shown in FIG. 1 (2), transfer molding is used as a resin molding method for sealing the chip 4 with resin. And the lower mold | type 11 and the upper mold | type 12 which oppose each other are used as a shaping | molding die for resin sealing. The lower mold 11 and the upper mold 12 together constitute a mold for resin sealing. The lower mold 11 is provided with a recess 13 to which the substrate 1 is fixed. The upper mold 12 is provided with a cavity 15 that is a space to be filled with the fluid resin 14 for resin sealing so as to completely include the chip 4 and the wire 7. Further, the upper mold 12 is provided with a flow path 16 that is a space connected to the cavity 15 and in which the fluid resin 14 flows. A heater (not shown) is provided around the cavity 15 and the flow path 16 of the upper mold 12.

  The steps for resin-sealing the chip 4 are as follows. First, the substrate 1 on which the chip 4 is mounted is placed in the recess 13 of the lower mold 11. The substrate 1 is fixed in the recess 13 by a known means such as adsorption. Next, the lower mold 11 and the upper mold 12 are clamped. Next, a fluid resin 14 made of a thermosetting resin such as an epoxy resin or a silicone resin is injected and filled into the cavity 15 via the flow path 16. Thereafter, the fluid resin 14 is heated by using a heater (not shown) to cure the fluid resin 14 to form a cured resin (not shown). Thereby, a cured resin is formed in the cavity 15, and the chip 4 is resin-sealed with the cured resin. Next, after the lower mold 11 and the upper mold 12 are opened, a molded product including the substrate 1, the chip 4, and the cured resin, that is, a sealed substrate is taken out (see, for example, Patent Document 1).

JP 2004-214430 (9th page, FIG. 2)

  By the way, in recent years, as the demand for thinning electronic components has become stronger, the substrate 1 has been made thinner. As a result, when filling the cavity 16 with the fluid resin 14, a downward force is applied to the substrate 1 due to the resin pressure of the fluid resin 14, and the substrate 1 may be deformed to protrude downward. I came. In particular, when the external electrode 9 is disposed near the periphery of the chip non-mounting surface 8, the deformation of the substrate 1 becomes large. As a result, problems such as the chip 4 mounted on the chip mounting surface 2 breaking and the chip 4 peeling off from the chip mounting surface 2 have occurred. Further, when a ceramic base material is used as the base material of the substrate 1, the substrate 1 itself may be damaged.

  An object of the present invention is to cause problems such as cracking of a chip mounted on a chip mounting surface and peeling of a chip from the chip mounting surface due to deformation of the substrate caused by the resin pressure of the fluid resin.

  Hereinafter, the reference numerals in parentheses in the descriptions of “means for solving the problems” and “effects of the invention” are described for the purpose of facilitating the comparison between the terms in the description and the components shown in the drawings. It is. Further, these symbols and the like do not mean that “the meaning of the terms in the description is limited to the components shown in the drawings”.

  In order to solve the above-described problems, a molding die for resin sealing of an electronic component according to the present invention includes a chip mounting surface (2) on which a chip (4) is mounted, and the opposite of the chip mounting surface (2). A first die (17,) on which a substrate (1) having a chip non-mounting surface (8) comprising a surface and a plurality of external electrodes (9) provided on the chip non-mounting surface (8) is placed. 20), a second mold (12, 19) opposite to the first mold (17, 20), and a space in which the chip (4) is accommodated. The second mold (12, 19) A molding die for resin sealing of an electronic component including a cavity (15) provided so as not to overlap a plurality of external electrodes (9) in a mold surface of the first die (17, 20). And the protrusion (18) is substantially the same as the thickness of the plurality of external electrodes (9). It characterized by having a correct thickness.

  Moreover, the molding die for resin sealing of the electronic component according to the present invention is the molding die described above, wherein the convex portion (18) is other than the convex portion (18) on the mold surface of the first die (17, 20). The portion is formed by being removed by machining by a predetermined amount.

  Moreover, the molding die for resin sealing of the electronic component according to the present invention is the molding die described above, wherein the convex portion (18) is other than the convex portion (18) on the mold surface of the first die (17, 20). The portion is formed by being removed by etching by a predetermined amount.

  Moreover, the molding die for resin sealing of the electronic component according to the present invention is the above-mentioned molding die, wherein the convex portion (18) is formed by plating on the die surface of the first die (17, 20). Features.

  Further, the resin sealing method for an electronic component according to the present invention includes a chip mounting surface (2) on which the chip (4) is mounted and a chip non-mounting surface (8) composed of the opposite surface of the chip mounting surface (2). And a first mold (17, 20) on which a substrate (1) having a plurality of external electrodes (9) provided on the chip non-mounting surface (8) is placed, and the first mold ( 17, 20) and the second mold (12, 19) opposite to each other, and an electron including a cavity (15) that is formed of a space in which the chip (4) is accommodated and is provided in the second mold (12, 19). An electronic component resin sealing method using a molding die for resin sealing of a component, the step of placing a substrate (1) on a mold surface of a first mold (17, 20), and a fluid resin The step of filling the cavity (15) with (14, 21), the first mold (17, 20) and the second mold (1 19), a step of forming a cured resin by curing the fluid resin (14, 21) filled in the cavity (15), and a first die (17, 20). The step of opening the second mold (12, 19) and the step of taking out a molded product including the substrate (1), the chip (4), and the cured resin, and the step of clamping the mold include The substrate (1) is supported by using the projections (18) provided so as not to overlap the plurality of external electrodes (9) on the mold surface of the molds (17, 20). ) Has a thickness substantially equal to the thickness of the plurality of external electrodes (9).

  Moreover, the resin sealing method of the electronic component which concerns on this invention is a part other than the convex part (18) in the type | mold surface of a 1st type | mold (17, 20) in the above-mentioned resin sealing method. Is formed by removing a predetermined amount by machining.

  Moreover, the resin sealing method of the electronic component which concerns on this invention is a part other than the convex part (18) in the type | mold surface of a 1st type | mold (17, 20) in the above-mentioned resin sealing method. Is formed by being removed by etching by a predetermined amount.

  In the resin sealing method for an electronic component according to the present invention, in the above-described resin sealing method, the convex portion (18) is formed by plating on the mold surface of the first mold (17, 20). And

  According to the present invention, the substrate (1) generated due to the resin pressure of the fluid resin (14, 21) being applied to the substrate (1) is convex toward the chip non-mounting surface (8) side. Such deformation can be prevented by the convex portion (18) supporting the substrate (1). Thereby, problems, such as a crack of the chip (4) mounted on the chip mounting surface (2) and peeling of the chip (4) from the chip mounting surface (2), can be prevented.

FIG. 1 (1) is a plan view showing a substrate on which a chip is mounted in the process of manufacturing an electronic component, and FIG. 1 (2) is a diagram illustrating a conventional process for manufacturing the electronic component in which a substrate is fixed to a lower mold and a mold is formed. It is a fragmentary sectional view which shows the state clamped along the AA line of FIG. 1 (1). FIG. 2A is a plan view showing a substrate on which a chip is mounted in the process of manufacturing an electronic component, and FIG. 2B is a diagram showing the substrate is fixed to the lower mold in the resin sealing method for an electronic component according to the first embodiment. It is a fragmentary sectional view which shows the state by which the shaping | molding die was clamped along the BB line of FIG. 2 (1). FIG. 3A is a plan view showing a substrate on which a chip is mounted in the process of manufacturing an electronic component. FIG. 3B is a diagram illustrating a method for fixing a substrate to a lower mold in the resin sealing method for an electronic component according to the first embodiment. It is a fragmentary sectional view which shows the state by which the shaping | molding die was clamped along CC line of FIG. 3 (1). FIG. 4A is a plan view showing a substrate on which a chip is mounted in the process of manufacturing an electronic component, and FIG. 4B is a diagram showing a substrate fixed to the lower mold in the resin sealing method for an electronic component according to the second embodiment. It is a fragmentary sectional view which shows the state by which the shaping | molding die was clamped along the DD line | wire of FIG. 4 (1).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  Embodiment 1 of a mold for resin sealing of an electronic component and a resin sealing method according to the present invention will be described with reference to FIGS. FIG. 2A is a plan view showing a substrate on which a chip is mounted in the process of manufacturing an electronic component, and FIG. 2B is a diagram showing the substrate is fixed to the lower mold in the resin sealing method for an electronic component according to this embodiment. It is a fragmentary sectional view which shows the state by which the shaping | molding die was clamped along the BB line of FIG. 2 (1). FIG. 3A is a plan view showing a substrate on which a chip is mounted in the process of manufacturing an electronic component, and FIG. 3B is a diagram showing the substrate fixed to the lower mold in the resin sealing method for an electronic component according to this embodiment. It is a fragmentary sectional view which shows the state by which the shaping | molding die was clamped along CC line of FIG. 3 (1).

  As shown in FIGS. 2 and 3, in this embodiment, a lower mold 17 and an upper mold 12 are used as molds for resin sealing of electronic components. The mold surface in the recess 13 of the lower mold 17 is provided with a table-like convex portion 18 at the center of the mold surface and a shelf-like convex portion 18 at the periphery of the mold surface. These convex portions 18 are provided substantially corresponding to a portion of the chip non-mounting surface 8 where the external electrode 9 is not disposed in a state where the substrate 1 is disposed in the depression 13 when viewed in plan. Further, the convex portion 18 has a height (substantially equal height) substantially equal to the thickness of the external electrode 9 of the substrate 1. 2 and 3, the shelf-like convex portions 18 are shown at both ends of the recess 13, and the table-like convex portions 18 are shown at portions other than both ends of the recess 13. The convex portion 18 is formed by, for example, machining such as cutting including vibration cutting.

  According to the molding die for resin sealing of an electronic component according to this embodiment, when the fluid resin 14 is filled in the cavity 15, the downward force applied to the substrate 1 by the resin pressure of the fluid resin 14 is applied. , Added to the convex portion 18 through the substrate 1. Thereby, the convex part 18 supports the board | substrate 1 which received downward force. Therefore, the convex portion 18 prevents the substrate 1 from being deformed so as to protrude downward due to the resin pressure of the fluid resin 14 being applied to the substrate 1.

  According to the resin sealing method for an electronic component according to the present embodiment, the substrate 1 that receives the downward force is supported by the convex portion 18 in the step of injecting the fluid resin 14 into the cavity 15. Therefore, it is possible to prevent the protrusion 18 from causing the substrate 1 to protrude downward due to the resin pressure of the fluid resin 14 being applied to the substrate 1. And in the state which prevented the deformation | transformation which the board | substrate 1 becomes convex downward, the fluid resin 14 is hardened and a hardening resin (not shown) is formed, Resin the chip | tip 4 with the hardening resin. It can be sealed.

  As described above, according to the present embodiment, the convex portion 18 prevents deformation of the substrate 1 that protrudes downward due to the resin pressure of the fluid resin 14 being applied to the substrate 1. Can do. As a result, problems such as cracking of the chip 4 mounted on the chip mounting surface 2 and peeling of the chip 4 from the chip mounting surface 2 can be prevented.

  In this embodiment, transfer molding is used as a resin molding method for sealing the chip 4 with resin, in other words, as a method for injecting the fluid resin 14 into the cavity 15. Not only this but injection molding can also be used as a system which injects fluid resin 14 into cavity 15.

  A second embodiment of the present invention will be described below with reference to FIG. FIG. 4A is a plan view showing a substrate on which a chip is mounted in the process of manufacturing the electronic component that is the subject of the present invention. FIG. 4B shows a state where the substrate is fixed to the upper mold and the mold is clamped along the line DD in FIG. 4A in the resin sealing method of the electronic component according to the present embodiment. It is a fragmentary sectional view. In this embodiment, compression molding is used as a resin molding method for sealing the chip 4 with resin.

  As shown in FIG. 4B, in this embodiment, a lower mold 19 and an upper mold 20 are used as molds for resin sealing of electronic components. The substrate 1 is fixed to the mold surface of the upper mold 20 by a known means such as suction. In the present embodiment, on the mold surface of the upper mold 20, the table-like convex portion 18 at the center portion of the mold surface and the shelf-like convex portion 18 at the peripheral portion of the mold surface are both downward in the figure. It is formed so as to protrude. Further, the lower mold 19 is provided with a cavity 15, and the cavity 15 is filled with the fluid resin 21.

  The resin sealing method of the electronic component according to the present embodiment is as follows. First, the substrate 1 is aligned with the mold surface of the upper mold 20 and then fixed.

  Next, the cavity 15 is filled with the fluid resin 21. Here, the following method can be used. The first method is a method in which after a solid resin material is supplied to the cavity 15, the resin material is heated to soften and melt. As the solid resin material, a material having a form such as a sheet, powder, granule, or tablet can be used. The second method is a method of supplying a liquid resin material (liquid resin) at room temperature to the cavity 15 using a dispenser or the like.

  Next, the lower mold 19 and the upper mold 20 are clamped. As a result, the lower mold 19 and the upper mold 20 are clamped in a state where the chip 4 and the wire 7 are immersed in the fluid resin 21. Therefore, upward resin pressure by the fluid resin 21 is applied to the substrate 1. Thereafter, the fluid resin 21 is cured by continuously heating the fluid resin 21.

  Next, the lower mold 19 and the upper mold 20 are opened. Thereafter, a molded product including the substrate 1, the chip 4, and the cured resin (not shown), that is, a sealed substrate is taken out.

  According to the molding die for resin sealing of an electronic component and a resin sealing method according to the present embodiment, the lower die 19 and the upper die 20 are placed in a state where the chip 4 and the wire 7 are immersed in the fluid resin 21. In the mold clamping process, the substrate 1 that receives the upward force due to the resin pressure is supported by the protrusions 18. Therefore, it is possible to prevent the convex portion 18 from deforming the substrate 1 to be upwardly convex due to the resin pressure being applied to the substrate 1. As a result, problems such as cracking of the chip 4 mounted on the chip mounting surface 2 and peeling of the chip 4 from the chip mounting surface 2 can be prevented.

  In the description of the present embodiment, as for the mold used for compression molding, the convex portion 18 at the center has been described in the same manner as the mold used for transfer molding shown in FIG. The mold used for compression molding, in other words, the upper mold 20 has the convex portions 18 located between the external electrodes 9 is the same as the case shown in FIG. is there.

  In each of the embodiments described so far, the case where the external electrode 9 is arranged near the periphery of the chip non-mounting surface 8 has been described as shown in FIG. The present invention is not limited to this, and the present invention can be applied to the case where the external electrodes 9 are uniformly disposed on the chip non-mounting surface 8 and the case where the external electrodes 9 are irregularly disposed on the chip non-mounting surface 8. Can be applied. In addition, even when a pattern for connecting the external electrodes 9, a pattern for connecting the external electrodes 9 and the bonding pads 6 of the substrate 1, and the like are provided on the chip non-mounting surface 8. Can be applied.

  Further, the convex portion 18 is formed by using machining such as cutting. Not only machining but the following well-known methods may be used and the convex part 18 may be formed. The first method is to remove a predetermined portion of the mold surface of the recess 13 in the figure from the lower mold 11 in the state shown in FIG. Is formed as the convex portion 18. Etching can be used as a method for removing the predetermined portion. In this method, a portion to be removed (a portion other than the portion corresponding to the convex portion 18) is exposed using an appropriate mask member. Then, in the exposed portion, the lower mold 11 is removed by an appropriate amount (depth) using etching.

  The second method is a method of forming the convex portion 18 by plating a necessary portion from the lower mold 11 in the state shown in FIG. In this method, a necessary portion, that is, a portion corresponding to the convex portion 18 is exposed using an appropriate mask member. And the convex part 18 is formed in the exposed part by performing the electroforming process which uses metal plating by a well-known method.

  In addition, a photoreactive resist film, a resist ink, etc. can be used as a member for a mask used in both the first method and the second method. Then, a photoreactive resist film or the like is patterned by a photolithography technique.

  According to the first method and the second method described above, the photoreactive resist film or the like is patterned by photolithography. Accordingly, it is possible to remove a predetermined portion from the mold surface by collectively acting on the mold surface, and to perform electroforming on the exposed portion of the mold surface. Therefore, the convex part 18 can be formed in a short time compared with machining. In addition, the convex portion 18 having a complicated shape can be easily formed as compared with machining.

  Further, an example in which one chip 4 is mounted on one substrate 1 has been described. The present invention is not limited to this, and the present invention can also be applied to the case where a plurality of chips 4 are mounted on one substrate 1 and the chips 4 are resin-sealed to produce one electronic component.

  The present invention can also be applied to the case where a plurality of regions are provided on a single substrate 1 and one or a plurality of chips 4 are respectively mounted on these regions. In this case, a configuration in which one substrate 1 after resin sealing corresponds to one electronic component may be employed. Moreover, you may employ | adopt the structure in which the part corresponded to each area | region formed when the one board | substrate 1 was separated into pieces each corresponded to one electronic component. Furthermore, a configuration may be adopted in which portions corresponding to a plurality of regions formed by separating one substrate 1 into pieces are respectively equivalent to one electronic component.

  The chip 4 has been described by taking a semiconductor chip such as a memory and a CPU as an example. Not limited to this, the chip 4 may be another type of semiconductor chip such as a power semiconductor chip, a chip-like element other than a semiconductor, or the like. Furthermore, a light emitting element such as a light emitting diode (LED) or a laser diode can be used as the chip 4. In this case, a resin having translucency is used as the fluid resin 14.

  Further, in order to electrically connect the bonding pad 5 of the chip 4 and the bonding pad 6 of the substrate 1, wire bonding using a wire 7 was used. However, the present invention is not limited to this, and the above-described connection may be performed using flip chip bonding.

  In addition, the present invention is not limited to the above-described embodiments, and may be arbitrarily combined, changed, or selected as necessary without departing from the spirit of the present invention. It can be done.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Chip mounting surface 3 Die bonding pattern 4 Chip 5 Chip bonding pad 6 Substrate bonding pad 7 Wire 8 Chip non-mounting surface 9 External electrode 10 Solder resist 11, 17, 19 Lower mold 12, 20 Upper mold 13 Indentation 14 Flowable resin 15 Cavity 16 Channel 18 Protrusion 21 Flowable resin

Claims (8)

A first substrate on which a chip mounting surface on which a chip is mounted, a chip non-mounting surface composed of a surface opposite to the chip mounting surface, and a plurality of external electrodes provided on the chip non-mounting surface is placed. A mold for resin-sealing an electronic component, comprising: a mold; a second mold opposite to the first mold; and a cavity formed in a space for accommodating the chip. There,
In the mold surface of the first mold, provided with a convex portion provided so as not to planarly overlap the plurality of external electrodes,
The convex part has a thickness substantially equal to the thickness of the plurality of external electrodes, and is a molding die for resin sealing of an electronic component. In the molding die for resin sealing of the electronic component according to claim 1,
The convex part is formed by removing a part other than the convex part on the mold surface of the first mold by a predetermined amount by machining. . In the molding die for resin sealing of the electronic component according to claim 1,
A mold for resin-sealing an electronic component, wherein the projection is formed by removing a portion of the mold surface of the first mold other than the projection by a predetermined amount. In the molding die for resin sealing of the electronic component according to claim 1,
The convex part is formed by plating on the mold surface of the first mold, and is a molding die for resin sealing of an electronic component. A first substrate on which a chip mounting surface on which a chip is mounted, a chip non-mounting surface composed of a surface opposite to the chip mounting surface, and a plurality of external electrodes provided on the chip non-mounting surface is placed. A molding die for resin sealing of an electronic component, comprising: a die; a second die opposite to the first die; and a cavity provided in the second die, the space containing the chip. A resin sealing method for an electronic component to be used,
Placing the substrate on the mold surface of the first mold;
Filling the cavity with a flowable resin;
Clamping the first mold and the second mold;
Forming a cured resin by curing the flowable resin filled in the cavity;
Opening the first mold and the second mold; and
And a step of taking out a molded product including the substrate, the chip, and the cured resin,
In the clamping step, the substrate is supported by using convex portions provided so as not to overlap the plurality of external electrodes on the mold surface of the first mold,
The method according to claim 1, wherein the convex portion has a thickness substantially equal to a thickness of the plurality of external electrodes. In the resin sealing method of the electronic component according to claim 5,
The method of resin sealing an electronic component, wherein the convex portion is formed by removing a portion other than the convex portion on the mold surface of the first mold by a predetermined amount. In the resin sealing method of the electronic component according to claim 5,
The method of resin sealing an electronic component, wherein the convex portion is formed by removing a portion other than the convex portion on the mold surface of the first mold by a predetermined amount. In the resin sealing method of the electronic component according to claim 5,
The method for sealing an electronic component according to claim 1, wherein the convex portion is formed on the mold surface of the first mold by plating.

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