JP2009064804A - Electronic apparatus and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure mechanical connection between a semiconductor chip and a substrate while preventing the generation of a short circuit caused by a bump portion protruded from a concavity of the substrate without previously providing the bump and a conductive adhesive in the concavity of the substrate in an electronic apparatus constituted by providing en electrode in the concavity formed on one surface of a substrate, introducing the bump of the semiconductor chip into the concavity, and connecting the bump with a substrate electrode. <P>SOLUTION: In an electronic apparatus, a concavity 21 whose bottom is constituted by a substrate electrode 40 is provided on one surface 20a of a substrate 20, a bump 30 is introduced into the concavity 21 and made to come into direct contact with the substrate electrode 40, an electric insulative adhesive 50 is arranged on a portion other than the concavity 21 of a portion between the substrate 20 and a semiconductor chip 10, the semiconductor chip 10 and the substrate 20 are adhered to each other, and a nonadhesive arrangement portion 60 which is a region in which the adhesive 50 is not arranged on an opening edge of the concavity 21 and a region for housing a protruded portion from the concavity 21 of the bump 30 is provided between the substrate 20 and the semiconductor chip 10. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an electronic device in which an electronic component and a substrate are joined via bumps, and a method for manufacturing such an electronic device.

  Conventionally, as this type of electronic device, an electronic device such as an electronic component, a resistor, a capacitor, or the like is generally mounted on a substrate such as a glass substrate or a ceramic substrate via bumps.

  Such an electronic device is prepared by preparing an electronic component having a plurality of bumps made of solder, copper, etc. on one side and a substrate having a plurality of electrodes formed on the one side corresponding to the bumps. The bump is bonded to the substrate electrode by making one surface of the component and one surface of the substrate face each other and contacting the bump and the substrate electrode while heating the bump.

  Here, conventionally, when aligning a plurality of bumps and a plurality of substrate electrodes corresponding to the bumps, it is very difficult to position the spherical bump tip in contact with the planar surface of the substrate electrode. Met.

  Therefore, bump misalignment and separation failure occur during operation and transportation, and bump height difference between multiple bumps occurs due to bump size variation, board warpage and twisting, etc. As a result, a connection failure occurred between the bump and the substrate electrode.

In order to solve such a problem, as described in Patent Document 1 and Patent Document 2, a method has been proposed in which the electrode of the substrate is formed into an uneven shape and a bump is fitted into the recessed portion. Here, in Patent Document 1, after a conductive adhesive is disposed in advance in the recess, a method of fitting a bump therein is adopted. In Patent Document 2, a bump on the substrate side is provided in the recess in advance. And a bump on the electronic component side are employed.
JP-A-10-313170 Japanese Unexamined Patent Publication No. 07-335992

  However, as described in Patent Document 1 and Patent Document 2, in the method in which the bump of the electronic component is inserted into the recess of the substrate, for example, when the volume of the bump is larger than the volume of the recess, the bump is removed from the recess. There is a risk that it will protrude and cause a short circuit between the electrodes.

  In addition, since the connection between the electronic component and the substrate is only a bump connection, the difference in thermal stress between the electronic component and the substrate is directly transmitted to the base of the bump, causing a crack at the base of the bump, resulting in a connection life. Causes problems such as lowering. In this case, it is conceivable to provide an underfill between the electronic component and the substrate. However, an arrangement step for that purpose is required, which may increase the manufacturing cost.

  In addition, in Patent Document 1, a conductive adhesive is disposed in advance in the recesses of the substrate before bonding, and in Patent Document 2, a bump is formed in advance. In these cases, the conductive adhesive is disposed. And a bump forming step is required, which may increase the manufacturing cost.

  The present invention has been made in view of the above problems, and an electronic device is provided in which an electrode is provided in a recess formed on one surface of a substrate and a bump of an electronic component enters the recess to be connected to the electrode. In order to ensure the mechanical bondability between the electronic component and the substrate without providing bumps or conductive adhesive in the recesses of the substrate in advance and preventing the occurrence of short circuits due to the bumps protruding from the recesses of the substrate. The purpose is to do.

  In order to achieve the above object, the present invention provides a bump (30) on one surface (20a) of a substrate (20), which is recessed from the one surface (20a) and whose bottom is constituted by an electrode (40). ) Enters the recess (21) and is in direct contact with the electrode (40), and is joined to the electrode (40), and one surface (20a) of the substrate (20) and one surface (10a) of the electronic component (10) An electrical insulating adhesive (50) is disposed in a region other than the region where the recess (21) is located, and the electronic component (10) and the substrate (20) are disposed through the adhesive (50). In addition, the adhesive (50) is not disposed on the opening edge of the recess (21) between the one surface (20a) of the substrate (20) and the one surface (10a) of the electronic component (10). The part of the bump (30) that protrudes from the recess (21) Non adhesive disposed portion which is a region for storing that was provided (60), the first feature.

  According to this, even when the bump (30) is bonded, even if the heated bump (30) is deformed and protrudes from the recess (21), the protruding portion is within the range of the non-adhesive arrangement portion (60). It is possible to prevent the adhesive (50) from adhering to the adhesive region and the adjacent recess (21), that is, the adjacent electrode (40). Further, the bump (30) and the electrode (40) of the substrate (20) are in direct contact, but the bump (30) and the electrode (40) are bonded to the substrate (20) by the adhesive (50). The contact with the electrode (40) is also ensured, and the stress applied to the bump (30) is relaxed.

  Therefore, according to the present invention, bumps that protrude from the recesses (21) of the substrate (20) without previously providing bumps or conductive adhesive in the recesses (21) of the substrate (20) in advance are provided. While preventing the occurrence of a short circuit due to the portion (30), it is possible to ensure the mechanical bondability between the electronic component (10) and the substrate (20).

  Here, the bump (30) may have a spherical shape made of solder, and the recess (21) may have a polygonal opening.

  In this way, when the bump (30) enters the recess (21), a gap is formed between the spherical bump (30) and the corner of the recess (21), and the gap is a thermally deformed bump. Since it becomes the space which accommodates the excess part of (30), it is preferable.

  The present invention can also be regarded as a method for manufacturing an electronic device. That is, in the manufacturing method of the present invention, first, as the substrate (20), a substrate that is recessed from the one surface (20a) and has a recess (21) whose bottom is constituted by the electrode (40) is prepared, and before the bonding step. An electrically insulating adhesive (50) is disposed in a portion other than the portion where the recess (21) is located in at least one of the one surface (20a) of the substrate (20) and the one surface (10a) of the electronic component (10). In addition, an adhesive (50) is formed on the opening edge of the recess (21) between the one surface (20a) of the substrate (20) after being bonded by the adhesive (50) and the one surface (10a) of the electronic component (10). The adhesive (50) is placed so that there is a non-adhesive placement part (60), which is a region where () is not placed.

  Next, in the bonding step, the bump (30) and the electrode (40) are bonded by bringing the bump (30) into the recess (21) and directly contacting the electrode (40) while heating the bump (30). In addition, the electronic component (10) and the substrate (20) are bonded via the adhesive (50), and a portion of the bump (30) that protrudes from the recess (21) by the heating is a non-adhesive. It is made to position in the range of an arrangement | positioning part (60). This manufacturing method is the second feature of the present invention.

  According to this manufacturing method, even if the heated bump (30) is deformed and protrudes from the concave portion (21) when the bump (30) is bonded, the protruding portion is not attached to the non-adhesive placement portion (60). It stays within the range, and it is possible to prevent the adhesive (50) from entering the adhesive region and the adjacent recess (21), that is, the adjacent electrode (40). Further, the bump (30) and the electrode (40) of the substrate (20) are in direct contact, but the bump (30) and the electrode (40) are bonded to the substrate (20) by the adhesive (50). The contact with the electrode (40) is also ensured, and the stress applied to the bump (30) is relaxed.

  Therefore, according to the manufacturing method of the present invention, the bump (21) of the substrate (20) is not provided in advance in the recess (21) of the substrate (20), and the recess (21) of the substrate (20). It is possible to ensure the mechanical bondability between the electronic component (10) and the substrate (20) while preventing the occurrence of a short circuit due to the protruding bump (30).

  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.

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

(First embodiment)
FIG. 1 is a diagram illustrating a main part of an electronic device according to a first embodiment of the present invention, where (a) is a schematic sectional view of the main part, and (b) is a main part shown in (a). It is the upper view schematic plan view of the said principal part when cut | disconnected by the AA dashed-dotted line in (a).

  In FIG. 1, (a) is a schematic cross-sectional view along the dot-dash line BB in (b). Further, in FIG. 1B, for the purpose of identification, hatching is applied to bumps 30 described later, and point hatching is applied to non-adhesive placement portions 60 described later for convenience.

  This electronic device generally includes an electronic component 10 having a plurality of bumps 30 on one surface 10a side, and a substrate 20 having a plurality of electrodes 40 formed on positions corresponding to the bumps 30 on one surface 20a side, The bump 30 is bonded to the electrode 40 in a state where the bump 30 and the electrode 40 are in contact with each other while the one surface 10a of the electronic component 10 and the one surface 20a of the substrate 20 are opposed to each other.

  The electronic component 10 is not particularly limited as long as the electronic component 10 has the bump 30 on the one surface 10a that is the surface facing the substrate 20, but in the present embodiment, the electronic component 10 is the semiconductor chip 10 made of a silicon semiconductor. The semiconductor chip 10 is, for example, a general IC chip, and is formed by a semiconductor process.

  A plurality of chip electrodes 11 to which bumps 30 are connected are provided on one surface 10a of the semiconductor chip 10. The chip electrode 11 is used for electrical connection between the semiconductor chip 10 and the outside. For example, Ti / Ni is used as a base and the surface is made of Au. The planar shape of the chip electrode 11 is a circular shape similar to the shape of the bump 30 shown in FIG.

  The bump 30 is made of a conductive material that is deformed by heat applied during bonding to the electrode 40. Here, as a typical example, the bump 30 is a solder bump made of a solder material such as Pb-free solder or eutectic solder. The bump 30 has a spherical shape whose outer shape is a spherical surface, and is provided on the chip electrode 11 by a method such as a solder ball or printing.

  The substrate 20 is an insulating multilayer substrate 20 formed by laminating a plurality of electrically insulating layers. Specifically, there may be mentioned one in which a plurality of insulating layers such as ceramics such as alumina, glass epoxy, or resin are laminated and the electrode 40 is provided between each layer. Hereinafter, the electrode 40 of the substrate 20 is referred to as a substrate electrode 40 so as to be distinguished from the chip electrode 11. Further, FIG. 1A shows a surface layer 2a on one surface 20a of the substrate 20 and an inner layer 2b which is a base thereof.

  A concave portion 21 is provided in a position corresponding to the bump 30 of the semiconductor chip 10 on one surface 20 a of the substrate 20 facing the one surface 10 a of the semiconductor chip 10. The recess 21 is recessed from the one surface 20 a of the substrate 20, and the bottom thereof is constituted by the substrate electrode 40.

  Specifically, the surface layer on the one surface 20 a side of the substrate 20 is punched by pressing or laser processing, and this is used as the recess 21. In other words, the recess 21 is a portion where the surface layer on the one surface 20a side of the substrate 20 is removed to form a hole, and the depth of the recess 21 is the thickness of the surface layer 2a located on the outermost surface on the one surface 20a side of the substrate. Substantially equivalent. The recess 21 preferably has a polygonal opening. Here, as shown in FIG. 1B, the opening of the recess 21 has a square shape.

  Here, the bottom portion of the recess 21 is configured by the substrate electrode 40 means that the bottom surface of the recess 21 is the surface of the substrate electrode 40. The substrate electrode 40 is an electrode of a general multilayer substrate. Here, as shown in FIG. 1A, the substrate electrode 40 is formed from the opening side of the recess 21 by the first electrode 41, The second electrode 42 is laminated.

  The first electrode 41 and the second electrode 42 are made of, for example, an Au film and a Cu film formed by plating, respectively. That is, in this embodiment, the surface of the substrate electrode 40 that forms the bottom surface of the recess 21 is the first electrode 41 of the substrate electrode 40 and is made of Au that has excellent wettability with respect to the solder that forms the bump 30. Is.

  The bumps 30 of the semiconductor chip 10 are joined to the substrate electrode 40 in a state of entering the recess 21 of the substrate 20 and in direct contact with the substrate electrode 40. Here, the bump 30 made of solder is in direct contact with the first electrode 41 made of gold having excellent solder wettability. Thereby, the semiconductor chip 10 and the substrate electrode 40 are electrically connected via the bumps 30.

  Further, in the present electronic device, as shown in FIG. 1, an adhesive 50 is disposed in a portion other than the portion where the recess 21 is located between the one surface 20 a of the substrate 20 and the one surface 10 a of the semiconductor chip 10. ing.

  The adhesive 50 is made of a thermosetting resin that is electrically insulating and is cured by heat. Specifically, the adhesive 50 is made of an epoxy resin, and is applied by printing or the like and applied with heat to be cured. The semiconductor chip 10 and the substrate 20 are bonded via the adhesive 50.

  Further, as shown in FIG. 1, in the present embodiment, a region 60 where the adhesive 50 is not disposed at the opening edge of the recess 21 is provided between the one surface 20 a of the substrate 20 and the one surface 10 a of the semiconductor chip 10. It has been. This region 60 is configured as a non-adhesive placement portion 60 that is a region for storing a portion of the bump 30 that protrudes from the recess 21.

  In other words, the non-adhesive placement portion 60 is located outside the opening of the recess 21 starting from the outer peripheral end of the opening of the recess 21 between the one surface 10a of the semiconductor chip 10 after bonding and the one surface 20a of the substrate 20. This is a region that extends to the end of the adhesive 50 located in the area. Here, as shown in FIG. 1B, the non-adhesive placement portion 60 is a rectangular frame-like region that is located outside the recess 21 having a square opening shape and surrounds the recess 21.

  The width C of the non-adhesive placement part 60 is represented by the dimension C in FIG. That is, due to the presence of the non-adhesive placement portion 60, the opening of the recess 21 and the adhesive 50 are in a positional relationship that is separated by a distance of the width C through the non-adhesive placement portion 60.

  More specifically, the non-adhesive placement portion 60 is located outside the opening of the recess 21 between the one surface 10a of the semiconductor chip 10 and the one surface 20a of the substrate 20 after being bonded, and the semiconductor chip 10. This is a portion corresponding to a region surrounded and partitioned by the one surface 10 a, the one surface 20 a of the substrate 20, and the end surface of the adhesive 50.

  The non-adhesive placement portion 60 accommodates a portion of the bump 30 that protrudes from the recess 21. In the present electronic device, the size of the bump 30 is designed so that the entire recess 30 can be inserted into the recess 21. However, the bump 30 may not protrude into the recess 21 due to manufacturing variations. It can happen.

  FIG. 1 shows a case where such a bump 30 protrudes. For example, the right side of FIG. 1A, the upper right and lower left bumps 30 of FIG. 1B have the same size as the recesses 21, but the left side of FIG. 1A and the upper left side of FIG. 1B. In the lower right bump 30, protrusion from the recess 21 occurs. In the present embodiment, as shown in FIG. 1, the protruding portion of the bump 30 where the protrusion has occurred is located within the range of the non-adhesive arrangement portion 60.

  Next, a method for manufacturing the electronic device of this embodiment will be described. In the present manufacturing method, the semiconductor chip 10 and the substrate 20 are opposed to each other through the bumps 30 and the bumps 30 and the substrate electrodes 40 are brought into contact with each other while the bumps 30 are heated to be deformed. Here, the deformation due to heating of the bumps 30 is plastic deformation, and may be deformed after passing through a molten state.

  FIG. 2 is a process diagram illustrating a bonding process of the semiconductor chip 10 and the substrate 20 via the bumps 30 in the present manufacturing method, and shows a cross section of each workpiece.

  First, bumps 30 are formed on the one surface 10a of the semiconductor chip 10 with respect to the chip electrode 11 by a method such as solder balls or printing. On the other hand, the substrate 20 having the substrate electrode 40 formed at a position corresponding to the bump 30 on the one surface 20a is prepared. Such a board | substrate 20 is manufactured by forming the recessed part 21 with an above described press etc. in the manufacturing process of a general multilayer substrate.

  Next, the adhesive 50 is disposed by printing or the like as described above on a portion of the surface 20a of the substrate 20 other than the portion where the recess 21 is located (adhesive placement step). Here, the portion other than the portion where the concave portion 21 is located on the one surface 20a of the substrate 20 is a convex portion protruding from the bottom of the concave portion 21, that is, the substrate electrode 40, as shown in FIG. This convex part is comprised by the surface layer 2a of the one surface 20a side in the board | substrate 20 as a multilayer board | substrate.

  Here, in this adhesive placement step, the adhesive 50 is not placed on the opening edge of the recess 21 between the one surface 20a of the substrate 20 after being bonded by the adhesive 50 and the one surface 10a of the semiconductor chip 10. The adhesive 50 is arranged so that the non-adhesive arrangement part 60 exists. This can be easily performed by using, for example, a printing mask that does not have the adhesive 50 applied to the non-adhesive placement portion 60.

  Next, in the bonding step, as shown in FIG. 2A, after one surface 10a of the semiconductor chip 10 and one surface 20a of the substrate 20 are made to face each other, as shown in FIG. 10 is lowered toward the substrate 20 to cause the bump 30 to enter the recess 21, and the bump 30 and the substrate electrode 40 are directly contacted and the semiconductor chip 10 and the substrate 20 are bonded via the adhesive 50.

  The entry of the bump 30 into the recess 21, the contact of the bump 30 to the substrate electrode 40 and the adhesion by the adhesive 50 are performed by pressing the semiconductor chip 10 and pressing it against the substrate 20 and heating the bump 30 and the adhesive 50. Do. The bumps 30 and the adhesive 50 are specifically heated by heating the workpiece using an oven or a heater.

  This heating increases the temperature in a multistage manner, for example, from 100 ° C to 300 ° C. As a result, the adhesive 50 is cured by heat and the semiconductor chip 10 and the substrate 20 are bonded together, and the bumps 30 are deformed by heat and contacted and bonded to the substrate electrode 40.

  Here, the non-adhesive placement part 60 becomes a space sealed by the semiconductor chip 10, the substrate 20, and the adhesive 50 by the adhesion of the adhesive 50. Further, most of the bumps 30 have a size equal to or smaller than the opening of the recess 21, and these heated bumps 30 enter the recess 21 and contact the substrate electrode 40 to be deformed by the pressing force.

  On the other hand, when the initial bump size is larger than the opening of the recess 21, the bump 30 is deformed by heat and enters the recess 21, contacts the substrate electrode 40, and is further pressed and deformed. Thereby, the contact area by the direct contact of the bump 30 and the substrate electrode 40 is ensured, and both 30 and 40 are electrically joined.

  As a specific example, in the present embodiment, the adhesive 50 is made of an epoxy resin and is thermally cured at about 150 ° C., for example. Further, the bump 30 is made of solder, and is reflowed at about 200 ° C. to 300 ° C. by the heating to be in a molten state. In this state, the bump 30 enters the recess 21 and directly contacts the substrate electrode 40. .

  In this joining step, as described above, there is a possibility that the bumps 30 that do not fully enter the recesses 21 due to manufacturing variations or the like may protrude from the recesses 21 due to thermal deformation. The bump 30 on the right side in FIG. 2B has an appropriate size with respect to the concave portion 21 and is exactly the entire size, but the bump 30 on the left side protrudes from the concave portion 21.

  In the bonding process in the present manufacturing method, the protruding portion of the bump 30 is located within the range of the non-adhesive placement portion 60. This is because the non-adhesive placement portion 60 is sealed and partitioned by the substrate 20, the semiconductor chip 10, and the adhesive 50 as described above by bonding the substrate 20 and the semiconductor chip 10 with the adhesive 50. This is because it becomes a space and the progress of the protruding portion of the bump 30 is kept in the space.

  Thus, along with the end of the bonding process, the bumps 30 of the semiconductor chip 10 and the substrate electrodes 40 of the substrate 20 are electrically connected, and one surface 10a of the semiconductor chip 10 and one surface of the substrate 20 are formed at portions other than the recesses 21. 20a is mechanically joined to the adhesive 50 to complete the electronic device of this embodiment.

  By the way, according to the present embodiment, the concave portion 21 whose bottom portion is constituted by the substrate electrode 40 is provided on the one surface 20a of the substrate 20, and the bump 30 is inserted into the concave portion 21 so as to be in direct contact with the substrate electrode 40. Bonded to the substrate electrode 40. Therefore, compared with the case where the substrate electrode is provided on one surface of the flat substrate, the positioning of the bump 30 and the substrate electrode 40 in the bonding step can be performed with high accuracy.

  Further, the bump 30 and the substrate electrode 40 are in direct contact, and the electrical connection between the bump 30 and the substrate electrode 40 is realized without providing a conductive adhesive or bump in the concave portion of the substrate as in the conventional case. ing.

  And since the semiconductor chip 10 and the board | substrate 20 are adhere | attached with the adhesive agent 50, even if the bump 30 and the board | substrate electrode 40 are a mere direct contact, both 30 and 40 leave | separate by the adhesive force of the adhesive agent 50. The state where they are pressed against each other is ensured, and the electrical connection by contact is ensured.

  Further, the bonding with the adhesive 50 increases the bonding area between the semiconductor chip 10 and the substrate 20 as compared with the conventional bonding of only the bump portion, so that the stress applied to the bump 30 due to the thermal history during use is reduced. In addition, the connection life of the bump 30 can be improved.

  In addition, by adopting a bonding form using the adhesive 50, even when the semiconductor chip 10 is mounted on the back surface of the substrate 20, it is possible to prevent chip dropping before reflow. Furthermore, by mechanically bonding the semiconductor chip 10 and the substrate 20 with the adhesive 50, a reinforcing material such as underfill is not necessary.

  In addition, according to the present embodiment, the non-adhesive placement portion 60 is provided between the one surface 20 a of the substrate 20 and the one surface 10 a of the semiconductor chip 10 to accommodate the bump 30 protruding from the recess 21. Yes.

  According to this, even when the heated bump 30 is deformed and protrudes from the concave portion 21 during the bonding step of the manufacturing method, the protruding portion remains within the range of the non-adhesive arrangement portion 60 and is caused by the adhesive 50. It is possible to prevent intrusion into the adhesion region or the adjacent recess 21, that is, the adjacent substrate electrode 40.

  The effect of this non-adhesive arrangement | positioning part 60 is demonstrated more concretely using FIG. FIG. 3 is a schematic cross-sectional view showing a main part of an electronic device that does not have the non-adhesive placement portion 60 in the electronic device shown in FIG. 1 as a comparative example. In this comparative example, the adhesive 50 is provided in contact with the opening of the recess 21 between the substrate 20 and the semiconductor chip 10.

  In this case, when the bump 30 protrudes during the bonding process, the portion of the bump 30 protruding from the recess 21 penetrates to the area where the adhesive 50 is disposed, as shown in FIG. It enters between the chip 10. Then, a gap as shown in FIG. 3 is generated between the semiconductor chip 10 and the substrate 20.

  If there is a gap between the semiconductor chip 10 and the substrate 20, solder balls or foreign matters floating in the cleaning liquid may be caught between the chip and the substrate in a subsequent process such as cleaning. Since the bonding area is reduced by the adhesive 50, the reliability is lowered.

  However, according to the present embodiment, because the bump protruding portion absorbs the non-adhesive arrangement portion 60, there is no gap between the semiconductor chip 10 and the substrate 20 in the bonding region by the adhesive 50. Such a problem can be avoided and reliability can be improved.

  Further, the absorption effect of the bump protruding portion by the non-adhesive arrangement portion 60 will be described more specifically with reference to FIGS. FIG. 4 is a diagram showing a contact state with the substrate electrode 40 when the height variation of the bump 30 occurs, and FIG. 5 is a contact state with the substrate electrode 40 when the depth of the recess is shallower than the minimum bump height. FIG.

  The effect by the non-adhesive arrangement portion 60 is also exhibited when height variation occurs between the plurality of bumps 30. In the case of the comparative example of FIG. 3 described above, the allowable amount of protrusion of the bump 30 is strictly limited, and it is necessary to reduce the variation in the volume of the bump 30 with respect to the volume of the recess 21 as much as possible. In contrast, according to the present embodiment, the amount of variation can be increased, which is advantageous in manufacturing.

  For example, as shown in FIG. 4A, in the plurality of bumps 30, the height between the bumps 30 (bump height) varies due to manufacturing variations and the like, resulting in a bump height difference. On the other hand, the depth of the recess 21 (the recess depth) substantially corresponds to the thickness of the surface layer 2a of the substrate 20, and the variation is small compared to the bump height.

  When the bump height varies in this way, as shown in FIG. 4B, there is a possibility that a low bump 30 may come out of contact with the bottom of the recess 21, that is, the substrate electrode 40.

  Therefore, in the present embodiment, priority is given to the contact between the substrate electrode 40 and the bump 30 and the recess depth is set shallower than the minimum bump height. Here, the minimum bump height is obtained by conducting trial processing in advance and performing statistical processing such as a standard deviation on the bump height.

  In this case, as shown in FIG. 5, the bump 30 having the smallest bump height contacts the substrate electrode 40 as shown in FIG. 5. FIG. 5A shows a case where the volume of the concave portion 21 is set to be larger than the maximum volume of the plurality of bumps 30. In this case, the protrusion of the bump 30 to the non-adhesive arrangement portion 60 is not caused. Does not happen.

  On the other hand, FIG. 5B shows a case where the volume of the recess 21 is set smaller than the maximum volume of the plurality of bumps 30. In this case, although the bump 30 protrudes to the non-adhesive arrangement portion 60, the protruding bump 30 remains within the non-adhesive arrangement portion 60, so there is no problem.

  As described above, in this embodiment, if the depth of the recess is set to be shallower than the minimum bump height, the bump 30 and the substrate electrode 40 can be absorbed by the non-adhesive placement portion 60 due to the absorption effect of the protruding portion of the bump 30. The electrical connection by contact can be reliably performed.

  That is, in the case where there is no non-adhesive placement portion 60, it is necessary to strictly control the variation in the size of the bumps 30, but in the case of this embodiment, the variation width is increased due to the presence of the non-adhesive placement portion 60. This is expected to have the advantage of improving the manufacturing yield.

  As described above, according to the electronic device and the method for manufacturing the electronic device of the present embodiment, the bump 20 or the conductive adhesive as in the related art is not provided in advance in the recess 21 of the substrate 20 and the substrate 20 While preventing the occurrence of a short circuit due to the portion of the bump 30 protruding from the recess 21, it is possible to ensure the mechanical bondability between the semiconductor chip 10 and the substrate 20 and the electrical connection between the bump 30 and the substrate electrode 40.

  Here, although it does not limit about the principal part dimension of the electronic device for implement | achieving the effect of this embodiment mentioned above appropriately, one specific example is described. FIG. 6 is a diagram showing dimensions of each part in a state before the semiconductor chip 10 and the substrate 20 are joined in the electronic device shown in FIG.

  In FIG. 6, dimension M: diameter M of chip electrode 11, dimension P: arrangement pitch P of chip electrode 11, dimension H: bump height H, dimension D: thickness D of adhesive 50, dimension N: recess depth N, dimension L: width M of the recess 21. Here, the recess 21 is a square, and the width L of the recess 21 is the length of one side of the square. Further, the dimension C is the width C of the non-adhesive placement portion 60 described also in FIG.

  In the dimensions thus defined, for example, the diameter M of the chip electrodes 11 is about φ230 μm, the arrangement pitch P of the chip electrodes 11 is about 370 μm, the bump height H is about 115 μm, and the thickness D of the adhesive 50 is about 20 ˜30 μm, concave portion depth N: about 100 μm, concave portion 21 width M: 230 μm, non-adhesive placement portion 60 width C: 10-20 μm.

  Further, in the present embodiment, as described above, the bump 30 has a spherical shape made of solder, and the concave portion 21 has a polygonal opening.

  In this way, the concave portion 21 has a corner portion with respect to the spherical bump 30, and when the bump 30 enters the concave portion 21, a gap is formed between the bump 30 and the corner portion of the concave portion 21 ( (See FIG. 1 (b) above). This gap is a space for storing an excess portion of the thermally deformed bump 30, which is preferable in preventing the bump 30 from protruding from the recess 21.

  As described above, in the present embodiment, the surface of the substrate electrode 40 that contacts the bump 30 is configured as the first electrode 41 made of gold having excellent solder wettability. Thereby, the wettability with the solder bump 30 becomes good, and the joining becomes easy without flux. Therefore, there is no flux residue and the concern about bump corrosion is significantly reduced.

(Second Embodiment)
FIG. 7 is a schematic cross-sectional view showing the main part of the bonding step in the method for manufacturing an electronic device according to the second embodiment of the present invention, in which the semiconductor chip 10 and the substrate 20 are opposed to each other after the adhesive placement step. Is shown.

  In the first embodiment, the example in which the adhesive 50 is disposed on the substrate 20 side has been described. However, in the manufacturing method of the present embodiment, the adhesive 50 is disposed on the semiconductor chip 10 side as an electronic component in the adhesive disposing step. Deploy.

  In this case, the adhesive 50 is disposed by dispensing, printing, or the like on a portion of the one surface 10a of the semiconductor chip 10 other than the portion where the recess 21 is located. Here, the portion other than the portion where the concave portion 21 is located in the one surface 10 a of the semiconductor chip 10 is a portion other than the portion facing the concave portion 21 of the substrate 20 in the one surface 10 a of the semiconductor chip 10.

  Of course, also in this case, the bonding is performed so that the non-adhesive placement portion 60 exists at the opening edge of the recess 21 between the one surface 20a of the substrate 20 after the bonding with the adhesive 50 and the one surface 10a of the semiconductor chip 10. Agent 50 is placed.

  Thereafter, also in the present embodiment, an electronic device similar to that shown in FIG. 1 is manufactured by performing the same bonding step. And also by the manufacturing method of this embodiment, it is possible to obtain the same effect as the said 1st Embodiment.

(Third embodiment)
FIG. 8 is a schematic cross-sectional view showing the main part of the bonding step in the method for manufacturing an electronic device according to the third embodiment of the present invention, in a state where the semiconductor chip 10 and the substrate 20 are opposed to each other after the adhesive placement step. Is shown.

  In the manufacturing method of the present embodiment, in the adhesive placement step, a portion other than the portion where the recess 21 is located in the one surface 10a of the semiconductor chip 10 and a portion other than the portion where the recess 21 is located in the one surface 20a of the substrate 20. The adhesive 50 is disposed on both.

  In this case, the semiconductor chip 10 and the semiconductor chip 10 and the non-adhesive arrangement portion 60 exist at the opening edge of the recess 21 between the one surface 20a of the substrate 20 after being bonded by the adhesive 50 and the one surface 10a of the semiconductor chip 10. Adhesives 50 are disposed on both sides of the substrate 20.

  Thereafter, also in the present embodiment, an electronic device similar to that shown in FIG. 1 is manufactured by performing the same bonding step. Also, the manufacturing method of the present embodiment can provide the same effects as those of the first embodiment.

  In the present embodiment, as the adhesive 50, a two-component curable material that cures by mixing a curing agent and a main agent may be used. In this case, for example, the curing agent may be provided separately on the semiconductor chip 10 side and the main agent may be provided on the substrate 20 side.

(Fourth embodiment)
FIG. 9 is a schematic cross-sectional view showing the main part of the bonding step in the method for manufacturing an electronic device according to the fourth embodiment of the present invention, in which the semiconductor chip 10 and the substrate 20 are opposed to each other after the adhesive placement step. Is shown.

  In the manufacturing method of the present embodiment, the adhesive 50 is disposed in a portion of the one surface 10a of the semiconductor chip 10 other than the portion where the recess 21 is located in the adhesive placement step. Also, the adhesive 50 is disposed.

  That is, as shown in FIG. 9, the adhesive 50 is arranged so that the bumps 30 are covered with the adhesive 50 while the non-adhesive arrangement portion 60 is formed on the one surface 10 a of the semiconductor chip 10. In this case, the adhesion between the bumps 30 and the substrate 20 can be improved and the displacement of the bumps 30 can be reduced.

  However, in this case, the bump 30 breaks through the adhesive 50 by a pressing force when the semiconductor chip 10 is mounted on the substrate 20 in the bonding step. As a result, the bump 30 and the substrate electrode 40 are in direct contact, and the both 30 and 40 are electrically connected. Further, the side surfaces of the bumps 30 and the side surfaces of the recesses 21 are bonded by the adhesive 50.

  Moreover, as a manufacturing method of this embodiment, when the adhesive 50 is arrange | positioned in site | parts other than the site | part in which the recessed part 21 is located among the one surfaces 20a of the board | substrate 20 in the adhesive agent arrangement | positioning process, the non-adhesive arrangement | positioning part 60. Further, the adhesive 50 may be disposed also on the inner surface of the recess 21 while forming.

  In this case, the adhesive 50 is disposed on the inner surface of the concave portion 21, but the bumps 30 are caused by the pressing force in the joining step in the same manner as the placement of the adhesive 50 on the semiconductor chip 10 side shown in FIG. 9. What is necessary is just to electrically connect both 30 and 40 by breaking through the adhesive agent 50. The same effect as in the case of FIG. 9 can be expected.

  Thus, in this embodiment, although it is necessary for the bump 30 to pierce the adhesive 50 in the bonding process, the bonding process substantially similar to that in the above-described embodiment is performed, as shown in FIG. An electronic device similar to the above can be manufactured. And it is possible to acquire the effect similar to the said 1st Embodiment.

(Fifth embodiment)
FIG. 10 is a schematic cross-sectional view showing the main part of the bonding step in the method for manufacturing an electronic device according to the fifth embodiment of the present invention, in which the semiconductor chip 10 and the substrate 20 are opposed to each other after the adhesive placement step. Is shown.

  The present embodiment is different from the first embodiment in that the side surface of the recess 21 is a tapered surface that expands from the bottom of the recess 21 toward the opening. Thereby, the position of the bump 30 can be accurately determined with respect to the concave portion 21 of the substrate 20. In addition, it is obvious that the tapered recess 21 can be applied to the second to fourth embodiments.

(Sixth embodiment)
FIG. 11: is a schematic sectional drawing which shows the principal part of the joining process in the manufacturing method of the electronic device which concerns on 6th Embodiment of this invention, and the state which made the semiconductor chip 10 and the board | substrate 20 face each other after an adhesive agent placement process Is shown.

  In the present embodiment, the side surface of the recess 21 is a tapered surface, but the inclination direction is opposite to that of the fifth embodiment, and the tapered surface extends from the opening of the recess 21 toward the bottom. In this case, it is expected that the volume of the concave portion 21 increases and the shape variation of the bump 30 can be easily absorbed. It is obvious that the concave portion 21 having the tapered shape is also applicable in the second to fourth embodiments.

(Other embodiments)
The bump 30 may be a bump made of Cu, Au, or the like other than the solder described above. In these cases, the bumps 30 are provided on the chip electrode 11 by plating, wire bonding, sputtering, vapor deposition, or the like. The number of bumps 30 and the arrangement form can be appropriately changed.

  Further, the substrate 20 may be any substrate as long as the concave portion 21 whose bottom portion is the substrate electrode 40 is provided on the one surface 20a that is the surface facing the electronic component 10, and may be a single layer substrate other than the multilayer substrate described above. May be. In the case of a single-layer substrate, for example, a configuration may be employed in which a concave portion is provided on one surface, a substrate electrode is provided on the bottom, and this substrate electrode is routed to the other surface side of the substrate through a through hole or the like.

  Further, in the above embodiment, when the bump 30 has a spherical shape made of solder, the concave portion 21 is thermally deformed to the corner portion of the concave portion 21 by making the shape of the opening portion polygonal. A storage space for an excess portion of the bump is formed, but the polygon may be a rectangle, a triangle, a pentagon, a hexagon, or the like other than the square.

  Further, the substrate electrode 40 constituting the bottom of the concave portion 21 may not be formed by laminating the first electrode 41 made of Au and the second electrode 42 made of Cu as in the above-described embodiment, One layer may be used. As such a thing, you may consist of conductor pastes, such as W (tungsten) and Mo (molybdenum), for example.

It is a figure which shows the principal part of the electronic device which concerns on 1st Embodiment of this invention, (a) is a schematic sectional drawing of the said principal part, (b) was cut | disconnected by the AA dashed-dotted line in (a). It is a top schematic plan view of the relevant part at the time. It is process drawing which shows the joining process in the manufacturing method of the electronic device which concerns on 1st Embodiment. It is a schematic sectional drawing which shows the principal part of the electronic device which does not have a non-adhesive arrangement | positioning part as a comparative example. It is a figure which shows the contact state to the board | substrate electrode when the height variation of bump arises. It is a figure which shows the contact state to the board | substrate electrode at the time of making a recessed part depth shallower than the minimum bump height. It is a figure which shows the dimension of each part in the state before joining of a semiconductor chip and a board | substrate in the electronic device shown in the said FIG. It is a schematic sectional drawing which shows the principal part of the joining process in the manufacturing method of the electronic device which concerns on 2nd Embodiment of this invention. It is a schematic sectional drawing which shows the principal part of the joining process in the manufacturing method of the electronic device which concerns on 3rd Embodiment of this invention. It is a schematic sectional drawing which shows the principal part of the joining process in the manufacturing method of the electronic device which concerns on 4th Embodiment of this invention. It is a schematic sectional drawing which shows the principal part of the joining process in the manufacturing method of the electronic device which concerns on 5th Embodiment of this invention. It is a schematic sectional drawing which shows the principal part of the joining process in the manufacturing method of the electronic device which concerns on 6th Embodiment of this invention.

Explanation of symbols

10 ... Semiconductor chip as an electronic component, 10a ... One side of the semiconductor chip,
20 ... Substrate, 20a ... One surface of the substrate, 21 ... Recess, 30 ... Bump, 40 ... Substrate electrode,
50 ... Adhesive, 60 ... Non-adhesive placement part.

Claims (3)

An electronic component (10) having a bump (30) on one side (10a),
A substrate (20) having an electrode (40) formed at a position corresponding to the bump (30) on one surface (20a) side;
With the one surface (10a) of the electronic component (10) and the one surface (20a) of the substrate (20) facing each other, the bump (30) and the electrode (40) are in contact with each other. 30) in an electronic device joined to said electrode (40),
The one surface (20a) of the substrate (20) is provided with a recess (21) which is recessed from the one surface (20a) and whose bottom is constituted by the electrode (40).
The bump (30) is joined to the electrode (40) in a state of entering the recess (21) and in direct contact with the electrode (40),
An electrically insulating adhesive between the one surface (20a) of the substrate (20) and the one surface (10a) of the electronic component (10) other than the region where the concave portion (21) is located. (50) is disposed, and the electronic component (10) and the substrate (20) are bonded via the adhesive (50),
Further, the adhesive (50) is disposed at the opening edge of the recess (21) between the one surface (20a) of the substrate (20) and the one surface (10a) of the electronic component (10). A non-adhesive arrangement portion (60), which is a region that is not formed and is a region for accommodating a portion of the bump (30) that protrudes from the recess (21), is provided. The electronic device according to claim 1, wherein the bump (30) has a spherical shape made of solder, and the concave portion (21) has a polygonal opening. An electronic component (10) having a bump (30) on one side (10a) side, and a substrate (20) having an electrode (40) formed at a position corresponding to the bump (30) on the one side (20a) side. After preparing
The one surface (10a) of the electronic component (10) and the one surface (20a) of the substrate (20) are opposed to each other, and the bump (30) and the electrode (40) are heated while heating the bump (30). In the method of manufacturing an electronic device comprising a bonding step of bonding the bump (30) to the electrode (40) by contacting
As the substrate (20), a substrate that has a recess (21) that is recessed from the one surface (20a) and whose bottom is formed by the electrode (40) is prepared.
Before the joining step, in at least one of the one surface (20a) of the substrate (20) and the one surface (10a) of the electronic component (10) other than the portion where the concave portion (21) is located, While placing an electrically insulating adhesive (50),
The arrangement of the adhesive (50) is between the one surface (20a) of the substrate (20) after being bonded by the adhesive (50) and the one surface (10a) of the electronic component (10). The non-adhesive placement portion (60), which is a region where the adhesive (50) is not placed at the opening edge of the recess (21), is performed,
Next, in the bonding step, the bump (30) and the bump (30) are brought into direct contact with the electrode (40) while the bump (30) is heated while the bump (30) is heated. Bonding with the electrode (40) and bonding the electronic component (10) and the substrate (20) via the adhesive (50),
Furthermore, the part which protrudes from the said recessed part (21) by the said heating among the said bump (30) is located in the range of the said non-adhesive arrangement | positioning part (60), The manufacturing method of the electronic device characterized by the above-mentioned .

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