JP2009302284A - Resin sealing method and resin sealing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To discourage the time required for weighing resin and preforming from affecting the cycle time of a device. <P>SOLUTION: In the resin sealing method, a plurality of semiconductor chips 152 arrayed at different positions in plane are arranged in a single cavity 106. A preforming resin is supplied in the cavity 106 and then compression-molded. An aggregation 162 comprises resin pieces 160 which are combined in plane to be a preforming resin. There are a step of preparing in advance the aggregation 162 of resin pieces 160 where at least two kinds of capacities are ready, and a step in which a particular resin piece group 164 is selectively extracted from the aggregation 162 of resin pieces 160 having been prepared according to a predetermined information, and are combined in plane and temporarily placed. The resin piece group 164 having been temporarily placed is supplied to the cavity 106 while the combination is maintained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technical field of a resin sealing device that compresses and seals a molded product (a substrate, a lead frame, etc.) on which a semiconductor chip is mounted with a resin.

  Conventionally, as shown in FIG. 4, a plurality of semiconductor chips 15 arranged in different planes on the substrate 14 are arranged in one cavity 5, and a resin 17 is poured into the cavity 5. A resin sealing device 1 for compression molding is known (see Patent Document 1). This resin sealing apparatus 1 is premised on a production method in which several tens of semiconductor chips are arranged in a matrix on a large substrate and dicing into each package after collective sealing (MAP sealing).

  In the case of compression molding, the size of the molded product after resin sealing (particularly the size in the thickness direction) depends on the amount of resin supplied into the cavity. For this reason, when the resin is supplied, the required amount is strictly measured and supplied after detecting the number of semiconductor chips mounted on the substrate, the stacking height, and the like.

  For example, when a semiconductor chip stacking failure is confirmed in the upstream process, the semiconductor chip may not be mounted on the substrate, or the stacking of the semiconductor chip may be terminated halfway. This is because the amount of resin required for the entire cavity can vary.

JP 2004-174801 A

  Even if the amount of the resin is adjusted and the resin is supplied into the cavity, in the conventional method, a “resin flow” occurs during compression, which may cause a bonding wire (gold wire) to be cut or short-circuited. This is because even when the required amount of resin 17 is accurately supplied to the cavity 5, the amount is only that the total amount of “as a whole cavity” is the same, and when the cavity 5 is partitioned. This is probably because the optimum amount of resin is not supplied for each section. In other words, since all the semiconductor chips are mounted in a certain section, the amount of resin required for the entire cavity is supplied even though the amount of resin required is small compared to other sections. On the other hand, despite the relatively large amount of resin required because the semiconductor chip is missing, the resin corresponding to the amount equally divided by the whole cavity is supplied, This is because the resin 17 flows from the excessive section A (see FIG. 5) to the section B where the resin is insufficient due to compression.

  In order to solve such problems, the applicant arranges a plurality of semiconductor chips arranged at different positions in a plane in one cavity, supplies resin into the cavity, and compresses and molds the resin. The cavity is virtually divided into predetermined sections in a plan view of the cavity, and the resin is divided and managed so as to correspond to the predetermined sections, and the resin amount of the divided and managed resin Has been proposed (Japanese Patent Application No. 2007-152452: not known at the time of filing this application). In other words, the proposed invention virtually divides the cavity in plan view into several sections and supplies the necessary resin for each section, thereby suppressing the resin flow during compression.

  However, when receiving the information (predetermined parameters) of the stacking state of the semiconductor chip and weighing the resin for each section and further pre-molding, it takes a considerable amount of time for the weighing and pre-molding, The cycle time will be affected.

  Accordingly, the present invention has been made to solve such problems, and provides a resin sealing method and a resin sealing device that reduce the influence of the time required for resin weighing and preforming on the cycle time of the device. The task is to do.

  The present invention relates to a resin sealing method in which a plurality of semiconductor chips arranged at different positions in a plane are arranged in one cavity, and a preformed resin is supplied into the cavity, followed by compression molding. A set of resin pieces for preliminarily forming the resin by combining them in advance, a step of preparing in advance a set of resin pieces having at least two types of capacities, and the prepared resin pieces A specific resin piece group is selectively extracted from a set of pieces according to predetermined information, combined in a plane, and temporarily placed, and the temporarily placed resin piece group is maintained in its combination relationship. The above-mentioned problem is solved by passing the step of supplying the preform as the preformed resin to the cavity.

  In other words, instead of weighing and pre-molding the resin after receiving the semiconductor chip stacking information, the pre-molded resin is prepared in advance as a “collection of resin pieces having different capacities” and the semiconductor chip stacking information is prepared. After receiving, a specific resin piece is selected and extracted from the set of resin pieces, and at the same time, a planar combination is rearranged in a puzzle to form a “resin piece group”. This is a method in which a group is put into a cavity as a preformed resin. That is, no resin weighing or pre-molding is required after receiving the semiconductor chip stacking information. As a result, the preformed resin can be quickly supplied to the cavity, and at the same time, it is possible to prevent the resin flow during compression by a planar combination of resin pieces having different capacities.

  If each of the set of resin pieces is constituted by a rectangular parallelepiped having two sides that are common and one side is changed according to the capacity, the size of each resin piece (for example, other than the thickness) can be reduced. In addition to handling with a single resin piece, it is possible to standardize handling as a group of resin pieces (for example, carrying work by a loader).

  In addition, if each of the resin pieces supplied into the cavity has a one-to-one correspondence with the semiconductor chip, a plurality of stacked semiconductor chips existing on the substrate Accordingly, since the resin piece having the optimum capacity (with the optimum resin amount) can be supplied to the optimum position, the resin flow during compression can be suppressed to the maximum.

  Further, if the resin piece group is temporarily placed so that the flow direction of the resin at the time of compression is along the wiring direction of the wire connected to the semiconductor chip, and supplied to the cavity while maintaining its positional relationship, Even if a resin flow occurs, the possibility that an excessive force acts on the wire is reduced, and it is possible to prevent the wire from being disconnected or short-circuited.

  From a different viewpoint, the present invention is a resin sealing in which a plurality of semiconductor chips arranged at different positions in a plane are arranged in one cavity, and a preformed resin is supplied into the cavity, followed by compression molding. The apparatus is a set of resin pieces that become the pre-molded resin by combining in a planar manner, and is in accordance with predetermined information from a set of resin pieces with at least two kinds of capacities. An alignment mechanism for selectively extracting a specific group of resin pieces and combining them in a plane, a temporary placement section for temporarily placing the resin piece groups extracted by the alignment mechanism, and the temporarily placed resin pieces It is also possible to grasp as a resin sealing device comprising a supply mechanism for supplying the group as the preformed resin to the cavity while maintaining the combination relationship.

  By applying the present invention, it is possible to quickly supply the preformed resin into the cavity while preventing the resin flow during compression.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a diagram schematically showing the flow of development of a set of resin pieces, temporary placement of a group of resin pieces, and insertion of the group of resin pieces into a cavity. FIG. 2 is a diagram showing a first example of the positional relationship between the semiconductor chip and the resin piece (group). FIG. 3 is a diagram showing a second example of the positional relationship between the semiconductor chip and the resin piece (group).

<Configuration of resin sealing device>
The resin sealing device 100 includes an upper mold 102 and a lower mold 104 on which a compression sealing process is performed. A press mechanism (not shown) is connected to the molds 102 and 104, and can be brought into contact with and separated from each other at a predetermined timing. As a result, the substrate (molded product) 150 can be clamped by the upper mold 102 and the lower mold 104. The lower mold 104 is mainly composed of a frame-shaped mold 104A having a through-hole 104B and a compression mold 104C disposed so as to be able to advance and retreat in the through-hole 104B. The surface (the upper mold 102 side surface) of the compression mold 104 </ b> C is set at a recessed position with respect to the surface of the frame mold 104 </ b> A (the upper mold 102 side surface), and the recess forms the cavity 106.

  An adsorption mechanism (substrate holding mechanism) (not shown) is provided on the surface of the upper mold 102 (surface on the lower mold 104 side), and the substrate 150 can be adsorbed and held on the surface of the upper mold 102 by the adsorption mechanism. Has been.

  A plurality of semiconductor chips 152 are arranged and mounted on the substrate 150 in a matrix, that is, at different positions in a plan view. The plurality of semiconductor chips 152 are all accommodated in one cavity 106 formed on the surface of the lower mold 104. The cavity 106 is virtually partitioned into eight sections (sections A to H) in a plan view. In this embodiment, the section is a section that substantially corresponds to the mounting position of each semiconductor chip 152 mounted on the substrate 150 (see FIG. 2). In this embodiment, the example in which the semiconductor chip 152 is mounted on the substrate 150 has been described. However, the same applies to the case where the semiconductor chip 152 is mounted on the lead frame.

  In addition, the resin sealing device 100 according to the present embodiment is provided with a preforming portion 140, an alignment mechanism 130, and a temporary placement portion 120.

  The preforming part 140 literally has a role of pre-molding (pre-molding, pre-molding, tableting) a resin to be put into the molds 102 and 104 into a predetermined shape. Here, for example, a predetermined amount of powdery, granular, liquid, or other resin is heated and compressed in a preforming mold to produce a plate-shaped (sheet-shaped) preformed resin. The most characteristic part of the preforming portion 140 is that the preforming resin to be put into the cavity 106 is not preformed as a single plate-like (sheet-like) resin as a whole, and is divided into a plurality of parts. The point is that the resin piece 160 is preformed. That is, by combining a plurality (8 in the present embodiment) of the resin pieces 160 in a plane (in a puzzle), a (complete) preformed resin to be put into the cavity 106 is formed.

  In addition, the preforming unit 140 preliminarily forms and prepares resin pieces 160 having a plurality of types of capacities (resin amounts) without relying on information on the stacked state of the semiconductor chips 152 (collection of resin pieces). . More specifically, since most of the semiconductor chips 152 mounted on the substrate 150 are normally stacked, resin pieces having a capacity (resin amount) corresponding to the normally stacked semiconductor chips 152. A relatively large number of 160 are prepared as standard products. At the same time, the resin piece 160 having a capacity (resin amount) corresponding to a case where the stacked state of the semiconductor chip 152 is abnormal (when not stacked at all, or only partially stacked) is used as a non-standard product. A small amount is prepared. Note that the preforming unit 140 is also provided with a measurement mechanism that measures the actual capacity (resin amount) of the pre-molded resin piece 160 afterwards.

  The alignment mechanism 130 is configured by a suction part 132 attached to an XY stage. The suction part 132 selectively extracts a specific resin piece 160 from the resin piece set 162 deployed and arranged on the development stage 136, holds it, and conveys it to the temporary placement part 120 ( Alignment). A plurality of resin pieces 160 selected and extracted by the alignment mechanism 130 and temporarily placed in the temporary placement portion 120 form a “resin piece group 164”. In addition, the alignment mechanism 130 is configured to be able to receive information on the stacked state of the semiconductor chips 152 mounted on the substrate 150 (for example, from the previous process).

  Although not shown, a supply mechanism (for example, having eight suction pads 8 that can supply the resin piece group 164 temporarily placed in the temporary placement section 120 to the cavity 106 while maintaining the combined relationship. One resin piece 160 (that is, a supply mechanism capable of adsorbing and holding the resin piece group 164 at a time) is provided.

<Operation of resin sealing device>
The preforming unit 140 prepares the resin pieces 160 in advance as a “collection of resin pieces”. For example, several patterns of resin pieces 160 having different capacities (resin amounts) are preliminarily molded (at least two patterns of “standard product” and “non-standard product” are necessary, and if necessary, further “non-standard product”. Are pre-formed as a plurality of patterns), and a set 162 of these resin pieces is developed on the development stage 136. Each pre-molded individual resin piece 160 has its actual capacity (resin amount) measured by the measurement mechanism, and is placed and deployed to a predetermined position on the deployment stage 136 according to the measurement result. .

  On the other hand, the substrate 150 is supplied to the surface of the upper die 102 by a substrate supply mechanism (not shown) with the molds (the upper die 102 and the lower die 104) open. The substrate 150 is sucked and held by a suction mechanism provided on the surface of the upper mold 102. Before the substrate 150 is supplied to the upper mold 102, the number and position of the semiconductor chips 152 mounted on the substrate 150 as parameters (predetermined information) (position information of the semiconductor chips) Is detected. The detection may be detected by image processing, for example, or when a higher-level production information system (for example, CIM) including the resin sealing device 100 is constructed, information on the system may be used. Is possible. Further, since the volume of each semiconductor chip is known, the volume of the entire semiconductor chip 152 mounted on the substrate 150 can be obtained based on the information on the number of stacked layers (stacked height). As a result, it is possible to calculate the amount of resin (total amount) to be put into the cavity 106.

  Further, in the present embodiment, since the cavity 106 is virtually partitioned, it is possible to simultaneously grasp the amount of resin required for each partition.

  The information for each section (information on the required resin amount for each section) is transmitted to the alignment mechanism 130. The alignment mechanism 130 that has received the information selects an optimal amount of resin pieces 160 for each section from the set of resin pieces 162 developed on the development stage 136 based on the information, and temporarily places the temporary placement unit 120. (In this embodiment, eight resin pieces 160 are temporarily placed on the temporary placement portion 120 to form a resin piece group 164).

  The positional relationship and the respective capacities of the individual resin pieces 160 in the aligned resin piece group 164 completely correspond to the positional relationship and the number of stacked layers of the semiconductor chips 152 mounted on the substrate 150. For example, referring to FIG. 1, when there are eight semiconductor chips 152 to be originally mounted on the substrate 150, only one of the semiconductor chips 152 is not stacked at all (semiconductor chip defect portion 154). If so, the so-called “non-standard product β” resin piece 160 corresponds to the position corresponding to the semiconductor chip defect portion 154, and the so-called “standard product α” resin piece 160 corresponds to the other position. To do.

  Thereafter, the resin piece group 164 (eight resin pieces 160) temporarily placed on the temporary placement unit 120 is supplied (introduced) to the cavity 106 by the supply mechanism while maintaining the positional relationship.

  Thus, in the resin sealing device 100, after receiving the stacking information of the semiconductor chip 152, the resin is not measured and preformed, but the preformed resin is preliminarily “collected 162 of resin pieces 160 having different capacities”. After receiving the stacking information of the semiconductor chip 152, a specific resin piece 160 is selected and extracted from the set 162 of the resin pieces 160, and at the same time, planar combinations are arranged in a puzzle. Instead, a “resin piece group 164” is formed, and the resin piece group 164 is put into the cavity 106 as a preformed resin. That is, since it is not necessary to measure the resin and further perform preforming after receiving the stacking information of the semiconductor chip 152, the preformed resin (resin piece group 164: eight resin pieces 160) can be quickly transferred to the cavity 106. Can be supplied to. At the same time, since an optimal volume (resin amount) of resin is supplied for each section, it is possible to prevent the resin flow during compression to the maximum.

  Each of the resin pieces 160 included in the set 162 of the resin pieces 160 described above is formed of a rectangular parallelepiped having two sides that are common and one side changes according to the capacity. That is, only the thickness differs depending on the capacity, and the vertical size and the horizontal size (width × length) are all common. As a result, the resin pieces 160 can be aligned by the alignment mechanism 130, and handling when the resin piece group 164 is supplied from the temporary placement unit 120 to the cavity 106 by the supply mechanism can be made uniform.

  Further, in the above, the individual resin piece 160 constituting the resin piece group 164 supplied into the cavity 106 has a one-to-one correspondence with the semiconductor chip 152 mounted on the substrate 150. . With such a correspondence, the resin piece 160 having the optimum capacity (the optimum resin amount) can be supplied to the optimum position according to the stacked state of each of the semiconductor chips 152 existing on the substrate 150. The resin flow can be suppressed to the maximum. However, such a “one-to-one correspondence” is not indispensable, and it is of course possible to change the correspondence as necessary. For example, it is good also as the correspondence which considered the flow direction of the resin at the time of compression. More specifically, if the resin pieces 160 are arranged so that the resin flow during compression is along the wiring direction of a wire (bonding wire: gold wire) connected to the semiconductor chip 152, the resin flow is temporarily generated during compression. Even in such a case, the possibility that an excessive force acts on the wire is reduced, and it becomes possible to prevent the wire from being disconnected or short-circuited. For example, as shown in FIG. 3, when wires wired from the semiconductor chip 152 exist only in the left-right direction of the semiconductor chip 152 (left-right direction in FIG. 3: the longitudinal direction of the substrate 150), they are positioned up and down. The configuration may be such that one resin piece 160 is associated with the semiconductor chip 152 (semiconductor chips positioned in the sections A and E, semiconductor chips positioned in the sections B and F).

  In such a state, the upper mold 102 and the lower mold 104 are closed and compression-molded, so that the resin does not flow greatly beyond the sections A to H. Even if a resin flow occurs, it is theoretically small in each compartment. The size, number, and shape of the sections are not particularly limited, and an optimum design can be freely made. The optimum value may be set based on a trade-off relationship between prevention of resin flow at the time of compression by finely setting the compartments and faster resin supply by setting the compartments large.

  In the above-described embodiment, the preforming part 140 is configured as a part of the resin sealing device 100. For example, the preforming part 140 is configured to be independent, and the resin is formed by a tray or a cassette. Pieces 160 may be supplied.

  Further, when the resin is a so-called “plate-shaped preformed resin” in which the resin is preformed as in the present embodiment, the preformed resin is supplied into the cavity 106 as resin pieces 160 divided into a plurality of parts. Therefore, the possibility of air being entrained under the resin when placed in the cavity 106 can be reduced.

  The present invention can be widely applied to a resin sealing apparatus that compresses and seals a molded product such as a substrate or a lead frame on which a semiconductor chip is mounted with a resin.

A diagram schematically showing the flow of the development of a collection of resin pieces, temporary placement of resin pieces, and loading of resin pieces into a cavity The figure which showed the 1st example of the positional relationship of a semiconductor chip and a resin piece (group) The figure which showed the 2nd example of the positional relationship of a semiconductor chip and a resin piece (group) Schematic configuration diagram of a resin sealing device 1 described in Patent Document 1 The figure which showed the example of MAP sealing typically

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Resin sealing apparatus 102 ... Upper mold 104 ... Lower mold 104A ... Frame-shaped mold 104B ... Through-hole 104C ... Compression mold 106 ... Cavity 120 ... Temporary placing part 130 ... Alignment mechanism 132 ... Adsorption part 136 ... Deployment stage 140 ... Preliminary molding part 150 ... Substrate 152 ... Semiconductor chip 154 ... Semiconductor chip defect part 160 ... Resin pieces 162 ... A collection of resin pieces 164 ... Resin pieces group

Claims (5)

A resin sealing method in which a plurality of semiconductor chips arranged at different positions in a plane are arranged in one cavity, and a preformed resin is supplied into the cavity and then compression molded,
A set of resin pieces for making the preformed resin by combining in a planar manner, and preparing in advance a set of resin pieces with at least two kinds of capacities aligned;
A step of selectively extracting a specific group of resin pieces according to predetermined information from the set of prepared resin pieces, combining them in a plane, and temporarily placing;
Supplying the temporarily placed resin piece group to the cavity as the preformed resin while maintaining the combination relationship. In claim 1,
A resin sealing method, wherein each one of the set of resin pieces is constituted by a rectangular parallelepiped having two sides in common and one side changing according to a capacity. In claim 1 or 2,
A resin sealing method, wherein each of the resin piece groups supplied into the cavity has a one-to-one correspondence with the semiconductor chip. In any one of Claims 1 thru | or 3,
The resin piece group is temporarily placed so that the flow direction of the resin during compression is along the wiring direction of the wire connected to the semiconductor chip, and the positional relationship is maintained, and the resin is supplied to the cavity. Resin sealing method. A resin sealing device in which a plurality of semiconductor chips arranged at different positions in a plane are arranged in one cavity, and a preformed resin is supplied into the cavity and then compression molded,
A specific resin piece according to predetermined information from a set of resin pieces that become the pre-molded resin by combining in a planar manner and have at least two types of capacity. An alignment mechanism for selectively extracting groups and combining them in a plane;
A temporary placement section for temporarily placing the resin piece group extracted by the alignment mechanism;
A resin sealing device, comprising: a supply mechanism that supplies the temporarily placed resin piece group to the cavity as the preformed resin while maintaining the combination.

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