JP2009043770A - Semiconductor package and manufacturing method of semiconductor package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor package in which substrate damage in bonding substrates can be prevented and connection electrodes can be reliably electrically connected. <P>SOLUTION: In the semiconductor package in which the electrodes of both substrates are electrically connected via shock-absorbing bump electrodes made of a soft member having conductivity, sensor substrate electrodes 5 are formed on a sensor substrate 2 of one side as connection electrodes for connection between the sensor substrate 2 and a lid substrate 1 of the other side, connecting cavities 7 are drilled at a position abutting on the sensor substrate electrodes 5 in bonding on the bonding surface of the lid substrate 1, and shock-absorbing bump electrodes 4 made of a soft member having conductivity are further provided on the tip of a lid substrate penetrating wiring 8 as an electrode disposed in the connecting cavities 7. The bump electrodes 4 are deformed in bonding the lid substrate 1 to the sensor substrate 2, and closely contacts to the sensor substrate electrodes 5, the lid substrate penetrating wiring 8 and the inner wall of the connecting cavities 7. Further, the connecting cavities 7 are each formed in a stress releasing shape for releasing stress in bonding (e.g. frusto-conical, bell, or earthenware mortar). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor package and a semiconductor package manufacturing method.

Conventionally, as a technique for forming a semiconductor package in which a plurality of semiconductor substrates are three-dimensionally joined, as described in Japanese Patent Application Laid-Open No. 2005-340389 “Semiconductor Device and Method for Manufacturing the Same” shown in Patent Document 1, A spherical bump electrode is provided at the tip of the electrode formed in the through-hole formed in the peripheral portion of the substrate, and further, a connection for connecting to the bump electrode provided on the counterpart substrate By providing electrodes, a technique has been developed in which the substrates are joined to each other and electrically connected in a short TAT (Turn Around Time).
Japanese Patent Laid-Open No. 2005-340389

  However, in the conventional technique described in Patent Document 1 and the like, since the spherical bump electrode that is electrically connected to the connection electrode on the counterpart substrate is formed of a metal material such as gold, There is a problem that the substrate is destroyed due to the stress from the bump electrode applied to the electrode joint when the contact electrode is pressed and electrically connected.

  In particular, when manufacturing a semiconductor package having a relatively wide hollow structure between a plurality of connection electrodes provided on the periphery of a substrate, such as a sensor, the height of the bump electrode contacting the connection electrode is more If high accuracy is required and the bump height is exceeded, a considerable amount of stress will be applied to the electrode joint, that is, the bump electrode side substrate and the connection electrode side substrate at the time of bonding. Will cause. On the other hand, if the height is lower than the predetermined bump height, the contact resistance between the bump electrode and the connection electrode is increased, and in the worst case, the electrical connection cannot be made.

  Further, when the bump electrode is short, the stress generated when the bump electrode is pressed to the connection electrode side is increased, and there is a problem that the substrate is easily broken.

  The present invention has been made in view of the above problems, and a semiconductor package and a method for manufacturing a semiconductor package that can prevent a substrate from being damaged due to a stress from a bump electrode and can be securely connected electrically. The purpose is to provide.

  In order to solve the above-described problems, the present invention includes a connection electrode for connection to the other substrate on the bonding surface of one substrate, and the connection surface of the bonding surface of the other substrate is in contact with the connection electrode at the time of bonding. A connecting bump and a soft bump electrode that is electrically connected to an electrode disposed in the connecting cavity, and the shape of the connecting cavity has a stress at the time of joining two substrates. It is characterized by a stress relaxation shape that relaxes.

  According to the semiconductor package and the semiconductor package manufacturing method of the present invention, a soft bump electrode is disposed on the other substrate at the same position as the connection electrode on one of the two substrates to be bonded. The connecting cavity is formed with a stress relaxation shape that enlarges the contact area with the bump electrode and relaxes the stress at the time of bonding when the two substrates are bonded. A bump electrode having a large diameter can be arranged inside the connection cavity, and furthermore, the stress relaxation shape of the connection cavity can relieve stress on the substrate during bonding, thereby preventing the substrate from being destroyed. In addition, the electrodes of both substrates can be reliably connected electrically.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a semiconductor package and a semiconductor package manufacturing method according to the present invention will be described below in detail with reference to the drawings.

(Outline of the present invention)
Prior to the description of the embodiments of the present invention, an outline of the features of the present invention will be described first.

  The present invention relates to a semiconductor package having a structure in which a plurality of substrates are bonded, and a connection electrode for electrically connecting to the other substrate on a bonding surface at the periphery of one substrate on which a semiconductor circuit is formed. (For example, a flat connection electrode) is provided, and on the other substrate, a through electrode that penetrates the through hole is formed as an electrode for leading upward of the semiconductor package at a position that contacts the connection electrode at the time of bonding. Furthermore, a spherical bump electrode for a buffer made of a soft member (soft metal, conductive resin, etc.) is formed at the tip of the through electrode, and the bump electrode is pressed against the connection electrode when both substrates are joined. When this is done, the contact area between the bump electrode and the connection electrode is enlarged to make a good electrical connection state, and at the same time, the contact area between the bump electrode and the substrate is enlarged to In which stress relaxation shapes which are capable of alleviating such a plate stress (frustoconical bowl shape, bell shape, etc.) and structure in which a connection cavity consists to.

  With such a structure, when the bump electrode is pressed and electrically connected to the connection electrode, for example, a flat plate electrode, the stress is distributed along the stress relaxation shape of the connection cavity. Thus, the stress applied to the substrate can be relaxed, and it is possible to prevent the substrate from being destroyed.

  In the following description of the embodiments, a semiconductor package for an infrared sensor is taken as an example, and one substrate on which, for example, a plate electrode is formed as a connection electrode is a semiconductor substrate that forms a semiconductor element such as an infrared sensor, that is, a sensor substrate The case where the other substrate on which the through electrode is formed is a lid substrate that forms a lid for collecting infrared light to the semiconductor element such as the infrared sensor will be described.

  However, the present invention is not limited to such a semiconductor package for an infrared sensor, and may be a semiconductor package configured by bonding two semiconductor substrates together. It may be a case where a single substrate is joined.

(First embodiment)
First, the structure of the first embodiment of the semiconductor package of the present invention will be described with reference to FIG. FIG. 1 is a structural diagram showing an overview structure of a first embodiment of a semiconductor package of the present invention, and FIG. 1A is a bird's eye view showing an overview of an entire semiconductor package for an infrared sensor. b) is a top view when a sensor substrate forming a semiconductor package for an infrared sensor is viewed from above.

  As shown in FIG. 1A, the semiconductor package 30 has a structure in which a lid substrate 1 serving as a lid (infrared light incident window) is bonded to a sensor substrate 2 on which an infrared sensor is formed. ing. In the periphery of the lid substrate 1, a through electrode, that is, a lid substrate through wiring 8 for electrical connection with the sensor circuit of the sensor substrate 2 from the upper surface of the semiconductor package 30 is provided at a predetermined position. And formed in a through hole penetrating from the joint surface with the sensor substrate 2 side to the upper surface on the opposite side.

  As shown in FIG. 1B, at least one sensor 6 that receives infrared light is arranged in an n × n matrix at the center of the sensor substrate 2, and the sensor substrate 2, a plate-like connection electrode electrically connected to the sensor 6, that is, the sensor substrate electrode 5, at a position corresponding to the arrangement position of the lid substrate through-wiring 8 of the lid substrate 1, A predetermined number of connection electrodes for connecting to the lid substrate through-wiring 8 (electrode penetrating the lid substrate 1) on the lid substrate 1 side are provided and bonded to the lid substrate 1 as shown in FIG. In this state, the sensor substrate electrode 5 and the lid substrate through wiring 8 are aligned and arranged so that they can be electrically connected.

  A predetermined number of sensors 6 are arranged on the upper surface side of the sensor substrate 2, that is, on the bonding surface facing the lid substrate 1 when bonded to the lid substrate 1, and are necessary for driving each sensor 6. This circuit is electrically connected to a simple circuit (not shown) and the sensor substrate electrode 5. FIG. 1B shows an example in which the sensors 6 are arranged in an n × n matrix, but the arrangement of the sensors 6 is not limited to such a case. It may be arranged in a plurality of rows (array), or may be arranged radially or concentrically.

  Next, an example of a cross-sectional structure of the semiconductor package 30 shown in FIG. 1 will be described with reference to FIG. FIG. 2 is a cross-sectional view showing a first embodiment of the cross-sectional structure of the semiconductor package of the present invention, and shows the cross-sectional structure in the cross section taken along the one-dot chain line A of FIGS. 1 (a) and 1 (b). Yes. In FIG. 2, in order to avoid complication, the repeated portions of the plurality of sensors 6 as shown in FIG. 1B are omitted and shown, and as shown in FIG. A state in which the bonding surface of the lid substrate 1 is bonded to the upper surface, that is, the bonding surface of the sensor substrate 2 is shown.

  The semiconductor package 30 is formed by joining the sensor substrate 2 and the lid substrate 1, and the sidewall 9 having a height higher than that of the central portion is formed on the outer peripheral edge of the lid substrate 1. A hollow structure corresponding to the height of the sidewall 9 is formed above the sensor 6 in the center of the substrate 2. That is, the semiconductor package 30 has a structure in which the sensor 6 disposed in the center portion of the sensor substrate 2 is enclosed by the window portion in the center of the lid substrate 1 and the sidewall 9 on the outer peripheral edge, and is provided inside. In addition to protecting the sensor 6 and the like, it is possible to maintain an atmosphere necessary for driving the sensor 6 with good airtightness.

  For example, when the sensor 6 arranged at the center of the sensor substrate 2 is a thermal infrared detection sensor or a gyro sensor as described above, the sensor 6 at the center of the sensor substrate 2 As an internal atmosphere of the hollow structure formed above, a rare gas or vacuum is sealed.

  As described above, in the peripheral portion on the bonding surface side of the lid substrate 1, a substantially cylindrical shape (or a truncated cone shape) is formed at a position where the flat substrate connection electrode, that is, the sensor substrate electrode 5 comes into contact with the sensor substrate 2. Penetrating electrodes, i.e., lid substrate penetrating wires 8 are provided. Here, as shown in FIG. 2, a spherical bump electrode 4 for buffering is below the height of the side wall 9 at the tip of the lid substrate through-wire 8 that forms the joint with the sensor substrate electrode 5. The bump electrode 4 first contacts the sensor substrate electrode 5 when bonded to the bonding surface of the sensor substrate electrode 5.

  The bump electrode 4 is made of a soft member having good conductivity and plasticity, and is formed using, for example, a soft metal (such as indium) or a conductive resin. As described above, the bump electrode 4 made of a soft member is spherical before the lid substrate 1 and the sensor substrate 2 are joined, but when the lid substrate 1 and the sensor substrate 2 are joined, the bump electrode 4 made of a soft member is By being pressed on the sensor substrate electrode 5, it deforms according to the shape of the flat sensor substrate electrode 5, enlarges the contact area of both, reduces the electrical contact resistance, and is excellent in conductivity. A simple connection state.

  Further, the lid substrate 1 has a stress applied to the lid substrate 1 at the time of bonding on the lower surface side peripheral portion of the through hole forming the cover substrate through wiring 8, that is, the peripheral portion of the joint surface side through hole facing the sensor substrate 2. As an example of a stress relaxation shape that relaxes, a connection cavity 7 having a truncated cone shape is provided, and a spherical bump electrode 4 is arranged in a space inside the connection cavity 7 so that the lower side of the bump electrode 4 Is projected from the space in the connection cavity 7. The bump electrode 4 made of a soft member is pressed at the top of the bump electrode 4 by the electrode disposed in the connection cavity 7, that is, the tip of the lid substrate through wiring 8 when the lid substrate 1 and the sensor substrate 2 are joined. When the bump electrodes 4 are brought into close contact with each other, the lower portion of the bump electrode 4 is pressed onto the sensor substrate electrode 5 to be deformed according to the shape of the flat sensor substrate electrode 5, while the side portion of the bump electrode 4 is also connected to the connection cavity. 7 is pressed against the inner wall surface and held in a deformed state following the shape of the frustoconical connection cavity 7.

  As a result, when the lid substrate 1 and the sensor substrate 2 are joined, the bump electrode 4 made of a soft material having plasticity can be connected to the sensor substrate electrode 5 in a state where the electrical contact resistance is further reduced. A series of good electrical connection states of the cover substrate through wiring 8, the bump electrode 4, and the sensor substrate electrode 5 can be formed, and at the same time, the contact area between the bump electrode 4 and the frustoconical connection cavity 7 is reduced. Since it expands, it is also possible to reduce the concentrated stress on the lid substrate 1 and to prevent the lid substrate 1 from being broken when the lid substrate 1 and the sensor substrate 2 are joined.

  With the electrical connection structure as described above, it is possible to form the semiconductor package 30 having a junction structure in which input / output of electrical signals to the sensor 6 from the outside is performed from the upper surface side of the package.

  Furthermore, when the lid substrate 1 and the sensor substrate 2 are joined, the bump electrode 4 having plasticity is deformed, and the bump electrode 4 is disposed in the space of the connection cavity 7, thereby having a larger diameter. The bump electrode 4 can be provided, and when the lid substrate 1 and the sensor substrate 2 are joined, the side of the bump electrode 4 is pressed against the frustoconical inner wall surface of the connection cavity 7, By deforming along the frustoconical shape, the stress is dispersed and the stress applied to the lid substrate 1 can be relieved, so that the substrate is not broken at the time of bonding and a good electrical connection state is achieved. It is possible to form.

(Manufacturing method of the first embodiment)
Next, the manufacturing process of the semiconductor package 30 shown in FIGS. 1 and 2 will be described with reference to FIGS. FIG. 3 is a process diagram for explaining a manufacturing process in the first embodiment of the method for manufacturing a semiconductor package of the present invention. The cover substrate 1 has a cover substrate through wiring 8, a bump electrode 4, a connection cavity 7, and the like. The process up to the formation of the sensor substrate 2 and bonding to the sensor substrate 2 is shown. In FIG. 3, as in the case of FIG. 2, the repeated portion of the central portion where the sensor 6 of the semiconductor package 30 is disposed is omitted in the drawing.

  Here, as the material of the lid substrate 1, if the sensor 6 is an infrared sensor that detects infrared light, the material of the material that transmits infrared light is transmitted. If the sensor 6 is a visible sensor that detects visible light, visible light is transmitted. Select the material to be used. Further, if the sensor 6 detects a mechanical quantity such as a gyro sensor, a material can be selected in a wider range.

  First, in the first step shown in FIG. 3A, in order to form the lid substrate 1, a flat plate material made of the above-described material is prepared.

  Next, in the second step shown in FIG. 3B, a predetermined portion of the peripheral portion of the lid substrate 1 is vertically moved using a laser 42 focused in a needle shape by an optical system (not shown). A plurality of penetrating through holes are formed (FIG. 3B illustrates only two left and right portions). At this time, digging is performed while rotating the center line of the laser 42 left and right so that the through hole has a desired inner diameter (FIG. 3B shows a case where laser processing is performed from the lower surface of the lid substrate 1. ) In addition, the through hole may have a substantially cylindrical shape, but in this embodiment, the solder material used as the lid substrate through wiring 8 in a later step is easily formed in the through hole as shown in FIG. The shape of the truncated cone is such that the inner diameter gradually decreases from the lower surface side toward the upper surface side.

  In the third step shown in FIG. 3C, the surface of the lid substrate 1 and the inner wall surface of the through hole are made of Cu (copper), Ni (nickel) or the like by an electroless plating method. A metal layer 43 having good adhesion is attached.

  In the fourth step shown in FIG. 3D, the upper and lower surfaces of the lid substrate 1 are ground and polished to leave the metal layer 43 only on the inner wall surface of the through hole. In addition to removing the excess metal layer formed in step 1, the surface of the polished state necessary for the bonding step (surface activated bonding step) described later is finished.

  Thereafter, in the fifth step shown in FIG. 3 (e), by rotating the cylindrical grinding tool 40 having the abrasive grains fixed on the surface thereof while pressing against the upper surface of the lid substrate 1, The center portion of the upper surface of the lid substrate 1 is cut by a predetermined thickness so as to leave the sidewall 9 at the outer peripheral edge of the lid substrate 1.

  Furthermore, in the sixth step shown in FIG. 3 (f), the grinding tool 40 is rotated with respect to the central axis of the through hole while rotating the grinding tool 40, for example, within a range of 45 degrees to 60 degrees. The cavity 7 for connection is produced by pressing against the peripheral edge portion (edge portion) of the through hole at an inclined angle and cutting in the direction of the central axis of the through hole. As a result, a connection cavity 7 having a truncated cone shape is formed as a stress relaxation shape at the peripheral edge portion of the through hole on the upper surface of the lid substrate 1.

  Next, in the seventh step shown in FIG. 3G, the lower surface of the connecting cavity 7 (the diameter of the truncated cone shape is narrower) from the lower surface of the lid substrate 1 on which the connecting cavity 7 is formed in FIG. Surface) is immersed in a melted solder bath to fill the inside of the through hole with a solder material, and then pulled out from the solder bath and cooled. At this time, the solder material is attached only to the inside of the through hole in which the metal layer 43 having good adhesion to the solder is formed. In this way, a through electrode made of a conductive solder material, that is, the lid substrate through wiring 8 is formed in a form filling the through hole.

  In the next eighth step shown in FIG. 3H, a spherical bump electrode 4 made of a soft metal such as indium is mounted inside the connection cavity 7. By making the bump electrode 4 spherical, the mounting property to the connecting cavity 7 having a truncated cone shape can be improved. The material of the bump electrode 4 is not limited to a metal, but may be any material as long as it is a soft material having plasticity and good conductivity, and may be, for example, a conductive resin. Further, the diameter of the bump electrode 4 is larger than the height of the frustoconical connection cavity 7, and the upper part of the spherical bump electrode 4 is a sidewall 9 formed on the outer peripheral edge of the lid substrate 1. It is mounted in the connection cavity 7 in a state of protruding partly upward from the upper surface.

  In the ninth step shown in FIG. 3I, the sensor substrate 2 on which the sensor 6 and the sensor substrate electrode 5 are formed in advance by a manufacturing process (not shown) is formed on the surface on which the sensor 6 and the sensor substrate electrode 5 are formed. The lid substrate 1 and the sensor substrate 2 are bonded by a surface activated bonding method by pressing from the upper side of the lid substrate 1 with the (bonding surface) facing downward. The sensor substrate 2 is made of silicon as a base material, and in the step (not shown) of forming the sensor 6 or the flat connection electrode, that is, the sensor substrate electrode 5 on the bonding surface of the sensor substrate 2, semiconductor technology or MEMS is used. The sensor 6 and the sensor substrate electrode 5 are formed in advance by a processing technique. The center position of the sensor substrate electrode 5 of the sensor substrate 2 is arranged at a position on the same line as the central axis of the cover substrate through-wire 8 in a state after the cover substrate 1 and the sensor substrate 2 are joined.

  Note that the surface activated bonding method is a method of irradiating the surface of a substrate to be bonded with an ion beam or the like in a vacuum to remove surface contaminants and expose atomic bonds. This is a technique in which the surfaces on which the surface is exposed are brought into contact with each other in a vacuum and bonded. Since this surface activated bonding method does not require heating at the time of bonding, even if the lid substrate 1 and the sensor substrate 2 are made of different materials, thermal distortion occurs at room temperature. It can join without.

  Furthermore, since this surface activated bonding method is performed in a vacuum, it is necessary to keep the inside of the semiconductor package 30 in a vacuum. This is the most effective bonding method when forming a thermal infrared sensor, a gyro sensor, or the like. Become a method.

  In the next tenth step shown in FIG. 3 (j), the lid substrate 1 and the sensor substrate 2 are bonded by the surface activated bonding method in the ninth step, so that the soft bump electrode 4 having plasticity is formed. , Pressed by the tip of the lid substrate through-wiring 8 made of solder material, deformed into a close contact with each other, electrically connected to the lid substrate through-wiring 8, and the sensor substrate electrode on the sensor substrate 2 side 5 is pressed along the surface of the sensor substrate electrode 5 and deformed along the shape of the flat sensor substrate electrode 5 so as to be electrically connected to the sensor substrate electrode 5 in an electrically good state.

  Further, when the lid substrate 1 and the sensor substrate 2 are joined, the shape of the bump electrode 4 is deformed, resulting in stress, but the side of the bump electrode 4 is connected to the connection cavity 7 on the lid substrate 1 side. Is also pressed and deformed according to the shape of the connecting cavity 7 having a truncated cone shape, so that the stress toward the lid substrate 1 is dispersed, and the stress on the lid substrate 1 at the time of bonding is relieved. Can do.

  Furthermore, by installing the bump electrode 4 in the space of the connection cavity 7 having a truncated cone shape, the bump electrode 4 having a large diameter can be disposed, and the stress applied to the lid substrate 1 can be further relaxed and bonded. It is possible to manufacture the semiconductor package 30 that is electrically connected reliably while preventing the substrate from being damaged.

  Note that the sealing resin may be formed on at least the lower surface of the through hole in which the cover substrate through wiring 8 is formed in the lower surface on the cover substrate 1 side in FIG. By forming the sealing resin, the sealing performance inside the semiconductor package 30 can be further improved.

(Second Embodiment)
Next, the structure of the second embodiment of the semiconductor package of the present invention will be described with reference to FIG. The general structure of the semiconductor package 30A of the present embodiment is the same as the structure diagram of FIG. 1 shown in the first embodiment. FIG. 4 is a cross-sectional view showing a second embodiment of the cross-sectional structure of the semiconductor package of the present invention, showing the cross-sectional structure in the cross section taken along the one-dot chain line A of FIGS. 1 (a) and 1 (b). Yes.

  As shown in the cross-sectional view of FIG. 4, unlike the semiconductor package 30 shown in FIG. 2 of the first embodiment, the semiconductor package 30A has a lid substrate on the inner wall surface of the connection cavity 7 on the lid substrate 1A side. The intracavity electrode 3 is newly formed as an electrically conductive layer with the through wiring 8. The intracavity electrode 3 is electrically connected to the lid substrate through wiring 8.

  That is, in the semiconductor package 30A of the present embodiment, the cavity inner electrode 3 electrically connected to the lid substrate through wiring 8 serving as a through electrode is formed on the inner wall surface of the connection cavity 7 as an electrically conductive layer. Therefore, when the lid substrate 1A and the sensor substrate 2 are joined, the electrical connection area of the bump electrode 4 to the lid substrate through wire 8 can be increased by the intracavity electrode 3, so that the lid substrate through wire 8; A series of electrical connection states between the bump electrode 4 and the sensor substrate electrode 5 can be improved more reliably.

(Manufacturing method of the second embodiment)
Next, the manufacturing process of the semiconductor package 30A shown in FIG. 4 will be described with reference to FIG. FIG. 5 is a process diagram for explaining a manufacturing process in the second embodiment of the semiconductor package manufacturing method of the present invention. The lid substrate through wiring 8, the bump electrode 4, the connection cavity 7, The process from forming the in-cavity electrode 3 and the like to bonding to the sensor substrate 2 is shown.

  However, in the manufacturing method of the present embodiment, a through hole is formed in the lid substrate 1A, a frustoconical connection cavity 7 is formed in the peripheral portion of the through hole, and a lid made of a solder material is formed inside the through hole. Each process until the through-substrate wiring 8 is formed is common to the first process in FIG. 3A shown in the first embodiment to the seventh process in FIG. The description will be omitted, and the eighth to thirteenth steps after the lid substrate through-wire 8 is formed in the through hole will be described with reference to FIGS. 5 (h) to 5 (m).

  In FIG. 5 as well, as in the case of FIG. 3, the repeated portion of the central portion where the sensor 6 of the semiconductor package 30A is arranged is omitted.

  In the eighth step shown in (h) of FIG. 5, the photo process is performed so that only the inner wall surface portion of the connection cavity 7 and the front end surface of the cover substrate through-wire 8 are opened as an evaporation mask on the upper surface of the cover substrate 1A. The resist layer 41 is formed by patterning with a resist.

  Next, in the ninth step shown in FIG. 5I, aluminum, gold, or the like is formed on the resist layer 41 formed on the lid substrate 1A, on the inner wall surface of the connection cavity 7, and on the front end surface of the lid substrate through wiring 8. A conductive metal material 44 made of is deposited.

  Thereafter, in the tenth step shown in FIG. 5J, the resist layer 41 is peeled off with an organic solvent, and the metal formed only on the inner wall surface portion of the connection cavity 7 and the front end surface of the lid substrate through-wire 8 The material 44 is realized as the in-cavity electrode 3 of the electrically conductive layer with the lid substrate through wiring 8. As a result, the in-cavity electrode 3 formed on the inner wall surface of the connection cavity 7 is formed in a state of being electrically connected to the lid substrate through wiring 8.

  In the eleventh step shown in FIG. 5 (k), as in FIG. 3 (h) shown in the manufacturing method of the first embodiment, a soft metal such as indium is used as a material inside the connection cavity 7. The spherical bump electrode 4 is mounted. Also in the present embodiment, as in the case of the first embodiment, the material of the bump electrode 4 is not limited to a metal, and any material may be used as long as it is a soft material having plasticity and good conductivity. For example, a conductive resin may be used. Further, the diameter of the bump electrode 4 is larger than the height of the frustoconical connection cavity 7, and the upper part of the spherical bump electrode 4 is a side wall 9 formed on the outer peripheral edge of the lid substrate 1. It is mounted in the connection cavity 7 in a state of protruding partially above the upper surface.

  In the twelfth step shown in FIG. 5L, the sensor substrate 2 on which the sensor 6 and the sensor substrate electrode 5 are formed is formed as in FIG. 3I shown in the manufacturing method of the first embodiment. In the state where the formation surface (joint surface) of the sensor 6 and the sensor substrate electrode 5 is directed downward, the lid substrate 1A and the sensor substrate 2 are pressed by the surface activated joining method by pressing from the upper side of the lid substrate 1A. Join. As in the first embodiment, the center position of the sensor substrate electrode 5 of the sensor substrate 2 is collinear with the central axis of the lid substrate through-wire 8 in the state after the lid substrate 1A and the sensor substrate 2 are joined. It is arranged at the position.

  In the thirteenth step shown in FIG. 5M, the lid substrate 1 and the sensor substrate 2 are bonded to each other by the surface activated bonding method in the twelfth step, which is the same as in the case of the first embodiment. In addition, the soft bump electrode 4 having plasticity is pressed against the in-cavity electrode 3 formed at the tip of the lid substrate through-wiring 8 made of a solder material, and deformed into a state in which they are in close contact with each other. 3 is electrically connected to the lid substrate through-wire 8 via 3 and pressed against the surface of the sensor substrate electrode 5 on the sensor substrate 2 side to deform along the shape of the flat connection electrode, that is, the sensor substrate electrode 5. Thus, the sensor substrate electrode 5 is also electrically connected in a good state.

  Further, the side portion of the bump electrode 4 is also pressed on the inner cavity electrode 3 formed on the inner wall surface of the connecting cavity 7 on the lid substrate 1 side, and deforms following the shape of the frustoconical connecting cavity 7. As a result, stress on the lid substrate 1 side is dispersed to relieve stress on the lid substrate 1 at the time of bonding, and the contact area with the in-cavity electrode 3 is enlarged, so that better electrical connection is achieved. In this state, it can be connected to the lid substrate through wiring 8.

  Further, as in the first embodiment, by installing the bump electrode 4 in the space of the frustoconical connection cavity 7, the bump electrode 4 having a large diameter can be disposed and added to the lid substrate 1A. It is possible to manufacture the semiconductor package 30A that is more reliably connected electrically, while further relaxing the stress and preventing the breakage of the substrate during bonding.

(Third embodiment)
Next, the structure of the third embodiment of the semiconductor package of the present invention will be described with reference to FIG. The general structure of the semiconductor package 30B of this embodiment is the same as the structure diagram of FIG. 1 shown in the first embodiment. FIG. 6 is a cross-sectional view showing a third embodiment of the cross-sectional structure of the semiconductor package of the present invention, showing the cross-sectional structure in the cross section taken along the one-dot chain line A of FIGS. 1 (a) and 1 (b). Yes.

  As shown in the sectional view of FIG. 6, the semiconductor package 30B has a conical shape of the connecting cavity 7 in the case of the semiconductor package 30A shown in FIG. 4 of the second embodiment. Unlike a trapezoidal shape, it is shaped like a bell.

  By forming the connection cavity 7B into a bell shape, the electrical connection of the bump electrode 4 with respect to the cover substrate through-wiring 8 can be achieved when the cover substrate 1B and the sensor substrate 2 are joined, as in the second embodiment. Since the contact area can be increased by the intracavity electrode 3 formed on the inner wall surface of the connection cavity 7B, a series of electrical connections among the cover substrate through-wire 8, the bump electrode 4, and the sensor substrate electrode 5 are performed. The state can be improved more reliably, and at the same time, the diameter of the opening of the bell-shaped connection cavity 7B can be made smaller than in the second embodiment using the truncated cone-shaped connection cavity 7. Therefore, the area occupied by the wiring structure for forming a series of electrical connection states can be reduced, and the electrical wiring structure can be arranged at a higher density.

  The semiconductor package 30B of FIG. 6 shows a case where the intracavity electrode 3 is formed on the inner wall surface of the connection cavity 7B, similar to the semiconductor package 30A shown in FIG. 4 of the second embodiment. In some cases, a structure in which the intracavity electrode 3 is not formed on the inner wall surface of the connection cavity 7B as in the semiconductor package 30 shown in FIG. 2 of the first embodiment may be adopted.

(Manufacturing method of the third embodiment)
Next, the manufacturing process of the semiconductor package 30B shown in FIG. 6 will be described with reference to FIG. FIG. 7 is a process diagram for explaining a manufacturing process in the third embodiment of the method for manufacturing a semiconductor package of the present invention. The lid substrate 1B includes a lid substrate through wiring 8, a bump electrode 4, a connection cavity 7B, The process from forming the in-cavity electrode 3 and the like to bonding to the sensor substrate 2 is shown.

  However, in the manufacturing method of the present embodiment, a through hole is formed in the lid substrate 1B, the metal layer 43 is formed on the inner wall surface of the through hole, and the sidewall 9 is formed on the outer peripheral edge of the lid substrate 1B by the grinding tool 40. Each process until the upper surface central portion of the lid substrate 1B is cut in a form that leaves the first substrate in FIG. 3A to the fifth process in FIG. 3E shown in the first embodiment. Since it is common to the steps, the description thereof is omitted, and the sixth to fourteenth steps after the upper surface central portion of the lid substrate 1B is cut by the grinding tool 40 will be described with reference to FIGS. A description will be given using (n).

  In FIG. 7, as in the case of FIG. 3, the repeated portion of the central portion where the sensor 6 of the semiconductor package 30 </ b> B is arranged is omitted.

  In the manufacturing process of the first embodiment, as shown in the sixth process of FIG. 3 (f), the cylindrical grinding tool 40 is inclined by a predetermined inclination angle with respect to the central axis of the through hole. The frusto-conical connecting cavity 7 is formed by pressing against the peripheral edge portion (edge portion) of the through hole and cutting in the direction of the central axis of the through hole. However, with such a cutting method, it is difficult to grind a hole having a relatively high aspect ratio. That is, it is difficult to shorten the aperture size of the opening compared to the height size of the connection cavity 7.

  Therefore, in the manufacturing method of the present embodiment, as shown in the sixth step in FIG. 7 (f) and the seventh step in FIG. 7 (g), a laser focused in a cylindrical shape by an optical system (not shown). 42B is irradiated along the central axis of the through-hole, and the hole is dug in the direction of the central axis of the through-hole while changing the spot size of the laser 42B.

  That is, in the sixth step shown in FIG. 7F, the laser 42B condensed in a cylindrical shape by an optical system (not shown) is irradiated along the central axis of the through hole formed in the lid substrate 1B. Then, digging up to a predetermined height in order to form a bell-shaped ridge portion with respect to the central axis direction of the through hole.

  In the seventh step shown in FIG. 7G, the spot size of the laser 42B is gradually reduced, and a predetermined bell-shaped top is formed with respect to the central axis direction of the through hole. Dig further to height. By digging like this, a bell-shaped connection cavity 7B is formed.

  The eighth step shown in FIG. 7 (h) to the fourteenth step shown in FIG. 7 (m) are respectively the seventh step (second step) shown in FIG. 3 (g) in the first embodiment. This is the same as the seventh step in the second embodiment, and the eighth step shown in FIG. 5 (h) to the thirteenth step shown in FIG. 5 (m) in the second embodiment. That is, in each process, as in the manufacturing method of the second embodiment, the lid substrate through wiring 8 is formed in the through hole, and the resist layer 41 and the metal material 44 are used to form a cavity serving as an electrically conductive layer. The inner electrode 3 is formed on the inner wall surface of the bell-shaped connection cavity 7B and the tip of the lid substrate through-wire 8, and then the bump electrode 4 is mounted in the connection cavity 7B. The sensor substrate 2 is bonded by a surface activated bonding method.

  Through these steps, the diameter of the opening of the connection cavity 7B can be reduced, and the semiconductor package 30B capable of arranging the electrical wiring structure with higher density can be manufactured.

(Other embodiments)
In each of the above-described embodiments, the connection cavities 7 and 7B for relieving the stress applied to the substrate have been described as having a truncated cone shape and a bell shape, respectively, but the present invention is limited to such a shape. The present invention is not limited to this, and any shape may be used as long as the stress relaxation shape can relieve the stress applied to the substrate. For example, the shape of the connecting cavity may be a mortar shape having a curved taper or a polygonal frustum shape. Furthermore, the aperture shape of the opening may not be a perfect circle, a square, or a regular polygon, but may be an ellipse, a rectangle, or a polygon having a different side length.

  Further, regarding the shape of the connection electrode on the sensor substrate 2 side that is electrically connected to the bump electrode 4 on the lid substrate 1 side, that is, the shape of the sensor substrate electrode 5, the case where a flat plate electrode is used in each of the above-described embodiments will be described. However, for example, a concave concave electrode may be used. By forming the connection electrode, that is, the sensor substrate electrode 5 to have a concave shape, the bump electrode 4 made of a soft member is deformed and fitted into the concave electrode when the lid substrate 1 and the sensor substrate 2 are joined. As a result, the electrical contact area between the bump electrode 4 and the sensor substrate electrode 5 can be further expanded, and a better electrical connection state can be realized.

  In each of the above-described embodiments, the case where the lid substrate 1, 1A, 1B and the sensor substrate 2 are joined to each other has been described. However, the sensor substrate 2 can be configured by a plurality of substrates. is there. That is, when forming a semiconductor package in which a plurality of sensor substrates are stacked, the structure of each sensor substrate is similar to that of the lid substrates 1, 1A, 1B, and through electrodes are formed that penetrate the top and bottom of the substrates, respectively. At the same time, a structure in which the connection cavities and the bump electrodes are formed on one joint surface may be a structure in which the sensor substrates are joined to each other and stacked.

  In each of the above-described embodiments, the semiconductor package including the sensor 6 that detects infrared rays or the like has been described as an example. However, the present invention is not limited to the semiconductor package for such a sensor, and a general semiconductor. Of course, even if it is the form which joined the semiconductor substrates which consist of a circuit, of course, it is also possible to laminate | stack and comprise a several semiconductor substrate as mentioned above.

1 is a structural diagram showing an overview structure of a first embodiment of a semiconductor package of the present invention. It is sectional drawing which shows 1st Embodiment of the cross-sectional structure of the semiconductor package of this invention. It is process drawing for demonstrating the manufacturing process in 1st Embodiment of the manufacturing method of the semiconductor package of this invention. It is sectional drawing which shows 2nd Embodiment of the cross-section of the semiconductor package of this invention. It is process drawing for demonstrating the manufacturing process in 2nd Embodiment of the manufacturing method of the semiconductor package of this invention. It is sectional drawing which shows 3rd Embodiment of the cross-sectional structure of the semiconductor package of this invention. It is process drawing for demonstrating the manufacturing process in 3rd Embodiment of the manufacturing method of the semiconductor package of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A, 1B ... Lid board | substrate, 2 ... Sensor board | substrate, 3 ... Electrode in a cavity, 4 ... Bump electrode, 5 ... Sensor board electrode, 6 ... Sensor, 7, 7B ... Connection cavity, 8 ... Lid board penetration wiring, DESCRIPTION OF SYMBOLS 9 ... Side wall, 30, 30A, 30B ... Semiconductor package, 40 ... Grinding tool, 41 ... Resist layer, 42, 42B ... Laser, 43 ... Metal layer, 44 ... Metal material.

Claims (8)

  In a semiconductor package in which two substrates are joined to each other and the electrodes of both substrates are electrically connected to each other by buffer bump electrodes made of a conductive soft material, A connection cavity provided with a connection electrode for connection with the substrate, and formed on the bonding surface of the other substrate at a position where the connection electrode comes into contact with the connection electrode; and the electrode disposed in the connection cavity is electrically connected And a bump package connected to the substrate, wherein the connection cavity has a stress relaxation shape that relaxes the stress at the time of joining two substrates.   The semiconductor package according to claim 1, wherein the connection cavity has a truncated cone shape.   The semiconductor package according to claim 1, wherein the connection cavity has a bell shape.   2. The semiconductor package according to claim 1, wherein a shape of the connection cavity is a mortar shape having a curved taper.   5. The semiconductor package according to claim 2, wherein the shape of the opening of the connection cavity is a perfect circle or an ellipse.   6. The semiconductor package according to claim 1, wherein the bump electrode is made of a soft conductive metal or conductive resin.   7. The cavity inner electrode serving as an electrically conductive layer is provided on the inner wall surface of the connection cavity, and the cavity inner electrode and the bump electrode are electrically connected. A semiconductor package according to the above.   A semiconductor package manufacturing method for manufacturing a semiconductor package by joining two substrates and electrically connecting the electrodes of both substrates with a bump electrode for cushioning made of a conductive soft member, the one substrate Forming a connection electrode for connection to the other substrate on the bonding surface, forming a through hole in the other substrate, and applying stress to the peripheral portion on the bonding surface side of the formed through hole A step of forming a connection cavity having a stress relaxation shape to relieve stress, a step of forming an electrode on the inner wall surface of the through hole, and a bump electrode for a buffer made of a soft member having conductivity in the connection cavity The one substrate so that the connection electrode on the bonding surface of the one substrate contacts the bump electrode mounted in the connection cavity formed on the other substrate. And bonding the bonding surfaces of said other substrate, a semiconductor package manufacturing method is characterized in that at least a.

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