JP6398499B2 - Electronic device and method of manufacturing electronic device - Google Patents

Description

  The present invention relates to an electronic device and a method for manufacturing the electronic device.

  A technique is known in which terminals between electronic components are joined and electrically connected using a joining material. As the bonding material, for example, solder containing one or more components is used. For example, a technique for mounting a semiconductor element or a semiconductor package on a substrate such as a printed circuit board using a solder bump is known.

JP 2002-239780 A JP 2007-242783 A

  In joint portions of terminals between electronic components, there may be cases where bonding failures such as cracks, separation, and disconnection occur due to external impacts, or thermal stress generated due to heat generation of electronic components or heating of electronic components. .

According to an aspect of the present invention, a first electronic component including a first terminal, a second electronic component including a second terminal facing the first terminal, and the first terminal and the second terminal are joined. The plate-shaped Cu ₆ Sn having a pair of main surfaces extending in a direction from the second terminal toward the first terminal and having a direction normal to a direction intersecting the direction from the second terminal toward the first terminal. electronic device comprising a junction containing a first compound of ₅ is provided.

According to one aspect of the present invention, the step of causing the first terminal provided in the first electronic component and the second terminal provided in the second electronic component to face each other with a bonding material, and the bonding The step of connecting the first terminal, the bonding material and the second terminal by heating and melting a material, and the bonding material in a state where the temperature of the first electronic component is higher than that of the second electronic component. It cools and solidifies, extends into the bonding material in the direction from the second terminal toward the first terminal, and the direction intersecting the direction from the second terminal toward the first terminal is a normal direction. method of manufacturing an electronic device including the step of precipitating a compound of a plate-shaped Cu ₆ Sn ₅ having a pair of main surfaces is provided.

  According to the disclosed technology, it is possible to increase the strength of the joint between electronic components and to realize an electronic device having excellent joint reliability.

It is a figure which shows an example of the electronic device which concerns on 1st Embodiment. It is a figure which shows an example of the electronic component joining process which concerns on 1st Embodiment. It is a figure which shows another example of the electronic device which concerns on 1st Embodiment. It is a figure which shows the example of the terminal structure which concerns on 1st Embodiment. It is a figure which shows the structural example of a semiconductor element. FIG. 3 is a first diagram illustrating a configuration example of a semiconductor package; FIG. 3 is a second diagram illustrating a configuration example of a semiconductor package. FIG. 6 is a third diagram illustrating a configuration example of a semiconductor package; It is a figure which shows the structural example of a circuit board. It is a figure which shows an example of the electronic component joining process which concerns on 2nd Embodiment. It is a figure which shows the 1st structural example of the electronic device which concerns on 2nd Embodiment. It is a figure which shows the 2nd structural example of the electronic device which concerns on 2nd Embodiment. It is a figure which shows an example of the electronic component joining process which concerns on 3rd Embodiment. It is a figure which shows the 1st structural example of the electronic device which concerns on 3rd Embodiment. It is a figure which shows the 2nd structural example of the electronic device which concerns on 3rd Embodiment. It is a figure which shows an example of the electronic component joining process which concerns on 4th Embodiment. It is FIG. (1) explaining another example of the electronic component joining process which concerns on 4th Embodiment. It is FIG. (2) explaining the other example of the electronic component joining process which concerns on 4th Embodiment. It is FIG. (3) explaining another example of the electronic component joining process which concerns on 4th Embodiment. It is a figure which shows an example of the manufacturing apparatus of an electronic device.

First, the first embodiment will be described.
FIG. 1 is a diagram illustrating an example of an electronic apparatus according to the first embodiment. Note that FIG. 1A schematically illustrates a cross-section of an essential part of an example of the electronic device according to the first embodiment. FIG. 1B schematically illustrates a cross section of the example of the electronic device according to the first embodiment along the electronic component plane direction of the joint. 1B schematically illustrates, as an example, a cross section of a joint corresponding to a position along line L1-L1 in FIG. 1A. The cross section of the joint portion of the electronic device in FIG. 1A schematically shows, as an example, a cross section of the joint portion corresponding to the position along the line L2-L2 in FIG.

An electronic device 1 illustrated in FIG. 1A includes an electronic component 10 and an electronic component 20, and a joint portion 30 that joins the electronic component 10 and the electronic component 20.
The electronic component 10 has a terminal 11 provided on its surface 10a. Here, as an example, one terminal 11 is illustrated. Various conductor materials can be used for the terminal 11. For example, copper (Cu) can be used for a part or all of the terminals 11.

  The electronic component 20 is disposed to face the electronic component 10. The electronic component 20 has a terminal 21 provided on the surface 20 a facing the surface 10 a of the electronic component 10. Here, as an example, one terminal 21 is illustrated. The terminal 21 of the electronic component 20 is provided at a position corresponding to the terminal 11 of the electronic component 10. Various conductor materials can be used for the terminal 21. For example, Cu can be used for part or all of the terminal 21.

The joint portion 30 is provided between the terminal 11 of the electronic component 10 and the terminal 21 of the electronic component 20, and joins the terminal 11 and the terminal 21.
For example, a semiconductor element (semiconductor chip), a semiconductor package including a semiconductor element, or a circuit board can be used for each of the electronic component 10 and the electronic component 20. The details of the configuration of the electronic component 10 and the electronic component 20 will be described later.

  Solder can be used for the joint 30 that joins between the electronic component 10 and the electronic component 20. As the solder, solder containing tin (Sn) can be used. For example, Pb-free solder that does not contain lead (Pb) is used as the solder. For example, the junction 30 can be made of Sn—Ag—Cu based solder containing Sn, silver (Ag), and Cu. As the Sn—Ag—Cu solder, for example, Sn—Ag—Cu solder containing 3.0 wt% Ag and 0.5 wt% Cu is used.

As shown in FIGS. 1A and 1B, the joint portion 30 includes a plate-like compound 31 that extends in a direction from the terminal 11 to the terminal 21 or from the terminal 21 to the terminal 11. .
Here, the cross section of the joint portion 30 shown in FIG. 1B is a cross section when the joint portion 30 between the electronic component 10 and the electronic component 20 is cut at the position of the line L1-L1 in FIG. It is an example. As shown in FIG. 1 (B), the plate-like compound 31 in the joint 30 is formed in the direction from the terminal 11 to the terminal 21 or from the terminal 21 to the terminal 11 (the depth direction in FIG. 1B), or , The front direction of the paper surface) has a pair of main surfaces 31a with the direction normal to the direction. FIG. 1B illustrates a form in which a plurality of plate-like compounds 31 whose main surfaces 31 a face in different directions are included in the joint portion 30. The cross section of the joint portion 30 shown in FIG. 1A is an example of a cross section when the joint portion 30 between the electronic component 10 and the electronic component 20 is cut at the position of the line L2-L2 in FIG. is there. In the cross section of the joint portion 30 in FIG. 1A, three of the plurality of plate-like compounds 31 included in the joint portion 30 cut at the position of the line L2-L2 in FIG. The plate-shaped compounds 31 (the cut surfaces thereof) are illustrated.

For example, when Sn—Ag—Cu-based solder as described above is used for the joint 30, a plate-like Cu ₆ Sn ₅ compound 31 (InterMetallic Compound; IMC) is present in the joint 30. Contained.

Such a plate-like compound 31 can be formed in the process of joining the electronic component 10 and the electronic component 20 using a material (joining material) that becomes the joining portion 30.
FIG. 2 is a diagram illustrating an example of an electronic component joining process according to the first embodiment. FIG. 2 schematically shows a cross section of the main part of an example of the electronic component bonding step according to the first embodiment. 2A is a diagram illustrating an example of a state before joining, FIG. 2B is a diagram illustrating an example of a state during joining, and FIG. 2C is a diagram illustrating an example of a state after joining.

  First, an electronic component 10 and an electronic component 20 to be joined as shown in FIG. Of the prepared electronic component 10 and electronic component 20, a bonding material 30a is provided in advance on one terminal, in this example, on the terminal 21 of the electronic component 20. The bonding material 30a is a material for forming the bonding portion 30 as described above. For example, solder is used for the bonding material 30a. Here, a case where Sn—Ag—Cu based solder is used for the bonding material 30a will be described as an example.

  The bonding material 30a on the terminal 21 of the electronic component 20 as shown in FIG. 2A is, for example, solder disposed by mounting solder balls on the terminal 21 or depositing solder by plating. Is formed by melting by heating and solidifying by cooling. Here, as an example, the bonding material 30a formed in a substantially ball shape is illustrated, but the bonding material 30a is not limited to this shape, and may take various shapes.

  After the electronic component 10 as described above and the electronic component 20 provided with the bonding material 30a are prepared, the electronic component 10 and the electronic component 20 are connected to each other's terminals 11 as shown in FIG. And the terminal 21 (or the bonding material 30a thereon) are aligned and placed opposite to each other.

Then, as illustrated in FIG. 2B, the bonding material 30 a on the terminal 21 of the electronic component 20 is melted by heating and connected to the terminal 11 of the electronic component 10. After the bonding material 30a and the terminal 11 are connected, the bonding material 30a is solidified by cooling. Here, the bonding material 30a is heated in a furnace having an inert gas atmosphere such as nitrogen (N ₂ ). The bonding material 30a is cooled in a furnace having an inert gas atmosphere. For example, the bonding material 30a is purged or naturally cooled in the furnace.

  In such a cooling process after heating the bonding material 30a, for example, at least from the start of solidification of the bonding material 30a to the end of solidification, one of the electronic component 10 and the electronic component 20 is in a higher temperature state than the other. Adjusted. For example, the electronic component 20 is adjusted to have a higher temperature than the electronic component 10. Alternatively, the electronic component 10 is adjusted to be in a higher temperature state than the electronic component 20.

  For example, a member having a predetermined heat capacity is provided on one side of the electronic component 10 and the electronic component 20, and the cooling rate of the electronic component on the one side provided with the member is reduced. In this way, for example, between the start of solidification of the bonding material 30a and the end of solidification, the electronic component on one side is brought to a higher temperature than the electronic component on the other side.

  Alternatively, the electronic component on one side is selectively warmed so as to reduce the cooling rate of the electronic component on one side. Alternatively, the electronic component on the other side is selectively cooled, and the cooling rate of the electronic component on the other side is increased. In this way, for example, between the start of solidification of the bonding material 30a and the end of solidification, the electronic component on one side is brought to a higher temperature than the electronic component on the other side.

  In this way, in the cooling process after heating the bonding material 30a, for example, by setting the electronic component on one side to a higher temperature than the electronic component on the other side, from the start of solidification of the bonding material 30a to the end of solidification, There is a temperature gradient in the bonding material 30a during solidification. That is, a temperature gradient can be formed such that one electronic component side of the bonding material 30a that is in a high temperature state has a higher temperature than the other electronic component side. By forming such a temperature gradient, the bonding material 30a is generally solidified from the lower temperature electronic component side toward the higher temperature electronic component side.

As the solidification progresses in this way, the Sn-Ag-Cu solder joining material 30a has a plate-like Cu shape extending in the solidification progress direction, as shown in FIG. ₆ Sn ₅ compound 31 is deposited. That is, the plate-like Cu extends so as to extend from the terminal 11 of the electronic component 10 toward the terminal 21 of the electronic component 20 or so as to extend in the direction toward the terminal 11 of the electronic component 10 from the terminal 21 of the electronic component 20. ₆ Sn ₅ compound 31 is deposited. Here, a plurality of plate-like compounds 31 are illustrated. The plate-like Cu ₆ Sn ₅ compound 31 is covered with a portion 32 containing Sn, Ag and Cu. Due to the progress of solidification, a joint 30 containing a plate-like Cu ₆ Sn ₅ compound 31 is formed inside the portion 32, and the electronic component 10 is formed at the joint 30 as shown in FIG. Thus, the electronic device 1 in which the electronic component 20 is joined is obtained.

  The plate-like compound 31 extending in the direction from the terminal 11 to the terminal 21 or in the direction from the terminal 21 to the terminal 11 as described above is formed in the joint portion 30, and this serves as a reinforcing material. Thus, the strength of the joint 30 against stress caused by external force or heat can be improved. For example, the strength of the joint portion 30 against the stress in the direction intersecting the opposing direction of the terminal 11 and the terminal 21 can be improved.

As semiconductor elements and semiconductor packages become larger and the solder joints between semiconductor elements and semiconductor packages and circuit boards become finer due to high-density mounting of semiconductor elements and narrowing of terminal pitch, The applied external force and stress may increase. When the Sn—Ag—Cu-based solder as described above is used in the joint portion and the joining method as described in FIG. 2 is not used, a coarse Cu ₆ Sn ₅ compound is formed in the joint portion. Or a plate-like Cu ₆ Sn ₅ compound may be formed extending in the terminal surface direction. By concentrating stress due to external force or heat on such a compound, cracks and peeling at the joint starting from the site of the compound and shear peeling due to shear stress are likely to occur.

  As described above, by providing the joint 30 between the electronic component 10 and the electronic component 20 with the plate-like compound 31 extending in the direction from the terminal 11 to the terminal 21 or from the terminal 21 to the terminal 11, The joint 30 has a stronger structure against stress caused by external force or heat. By improving the strength of the joint portion 30 as described above, it is possible to effectively suppress the occurrence of cracks or peeling of the joint portion 30 due to external force or stress, and disconnection due to such cracks or peeling.

  Here, the bonding material 30a is provided on the terminal 21 of the electronic component 20 in advance. However, even if the bonding material 30a is previously provided on the terminal 11 of the electronic component 10 and bonded according to the procedure illustrated in FIG. It is possible to deposit the plate-like compound 31 as described above.

  The plate-like compound 31 as described above is not necessarily formed so as to reach the terminal 21 of the electronic component 20 from the terminal 11 of the electronic component 10. Even when the plate-like compound 31 is not long enough to reach the terminal 21 from the terminal 11, the presence of the plate-like compound 31 as described above in the joint 30 makes the strength of the joint 30 as described above. It is possible to suppress cracks and peeling due to the improvement of the strength and the strength of the joint portion 30. For example, the plate-like compound 31 may be formed with a length that is at least half the distance between the terminal 11 and the terminal 21. Thereby, a certain strength improvement effect can be obtained.

  Between the terminal 11 of the electronic component 10 and the terminal 21 of the electronic component 20, for example, a plurality of plate-like compounds 31 are oriented in the direction from the terminal 11 to the terminal 21 or from the terminal 21 to the terminal 11. It is formed to extend. In this case, the plurality of plate-like compounds 31 need not necessarily extend in parallel to each other. Further, the plurality of plate-like compounds 31 do not necessarily have to be extended with the same length. Furthermore, the plurality of plate-like compounds 31 are not necessarily required to extend from the surface of the terminal 11 or the surface of the terminal 21 at the same height.

  In addition, the plate-like compound 31 is not necessarily required to be contained in a plurality in the joint portion 30. By the presence of at least one plate-like compound 31 in the joint portion 30, it is possible to improve the strength of the joint portion 30 as described above, and to suppress cracks and peeling due to the strength improvement of the joint portion 30. .

Here, Cu ₆ Sn ₅ is exemplified as the plate-like compound 31, but the plate-like compound 31 may contain other crystal phases (Cu ₃ Sn or the like) containing Cu and Sn. Even in such a case, it is possible to suppress the improvement in the strength of the joint portion 30 as described above due to the inclusion of the plate-like compound 31 and the cracking and peeling due to the improvement in the strength of the joint portion 30.

In addition to the plate-like compound 31 as described above, a columnar compound may be contained in the joint portion 30.
FIG. 3 is a diagram illustrating another example of the electronic device according to the first embodiment. Note that FIG. 3A schematically illustrates a cross-section of a main part of another example of the electronic device according to the first embodiment. FIG. 3B schematically shows a cross section of the electronic device according to the first embodiment along the electronic component plane direction of the joining portion, as another example. 3B schematically illustrates, as an example, a cross section of a joint corresponding to a position along line L3-L3 in FIG. 3A. As an example, the cross section of the joint portion of the electronic device in FIG. 3A schematically illustrates a cross section of the joint portion corresponding to the position along the line L4-L4 in FIG.

When the Sn-Ag-Cu solder joining material 30a is solidified with a temperature gradient as described above, as shown in FIGS. 3 (A) and 3 (B), Cu ₆ Sn ₅ is obtained. A plate-like compound 31 is deposited. Further, as shown in FIGS. 3A and 3B, a columnar compound 33 such as Ag ₃ Sn that extends in a direction from the terminal 11 to the terminal 21 or from the terminal 21 to the terminal 11 may be precipitated. .

  Here, the cross section of the joint portion 30 shown in FIG. 3B is an example of a cross section when the joint portion 30 of the electronic component 10 and the electronic component 20 is cut at the position of the line L3-L3 in FIG. It is. FIG. 3B illustrates a form in which the plurality of plate-like compounds 31 and the plurality of columnar compounds 33 in which the main surface 31 a faces in different directions are included in the joint portion 30. The cross section of the joint portion 30 illustrated in FIG. 3A is an example of a cross section when the joint portion 30 between the electronic component 10 and the electronic component 20 is cut at the position of the line L4-L4 in FIG. In the cross section of the joint portion 30 in FIG. 3A, among the plurality of plate-like compounds 31 and columnar compounds 33 included in the joint portion 30, at the position of the line L <b> 4-L <b> 4 in FIG. The three plate-shaped compounds 31 (the cut surfaces thereof) and the four columnar compounds 33 (the cut surfaces) cut are illustrated.

  As described above, the joint 30 may contain the columnar compound 33 in addition to the plate-shaped compound 31. Due to the plate-like compound 31 and the columnar compound 33 in the joint 30, the joint 30 has a strong structure against stress caused by external force or heat, and the joint 30 is cracked or peeled off. And disconnection due to peeling.

Incidentally, Cu of Cu ₆ Sn ₅ formed as a plate-like Compound 31 in the joint portion 30 is, for example, Sn-Ag-Cu-based Cu contained in the solder used for bonding material 30a. In addition, Cu of Cu ₆ Sn ₅ to be formed may be Cu that diffuses from the outside of the bonding material 30a into the bonding material 30a. When the bonding material 30a is melted when the electronic component 10 and the electronic component 20 are bonded, Cu can diffuse into the bonding material 30a from the terminal 11 or the terminal 21 side (FIG. 2B). In this case, when the bonding material 30a is cooled and solidified, in addition to Cu contained in the Sn—Ag—Cu-based solder, Cu that diffuses from the terminals 11 and 21 is used. Cu ₆ Sn ₅ can be formed (FIG. 2C).

Even when the Cu content of the Sn—Ag—Cu-based solder used for the bonding material 30a is small, Cu is supplied into the bonding material 30a from the terminal 11 or the terminal 21 side at the time of melting, so that the bonding portion 30 is filled with Cu. Thus, Cu ₆ Sn ₅ having a size and number showing a certain strength improvement effect against stress can be formed. In order to supply Cu into the bonding material 30a from the terminal 11 or terminal 21 side in this way, in addition to using Cu for the terminal 11 and terminal 21, for example, a structure as shown in FIG. it can.

  FIG. 4 is a diagram illustrating an example of a terminal structure according to the first embodiment. 4A to 4F schematically show a cross section of the main part of the electronic component according to the first embodiment.

FIG. 4A illustrates the terminal 11 of the electronic component 10. A terminal 11 in FIG. 4A includes an electrode layer 11 a provided on the surface 10 a of the electronic component 10. Various conductive materials such as Cu can be used for the electrode layer 11a. A bonding material 30b is provided on the electrode layer 11a. As the bonding material 30b, a solder paste 30ba mixed with Cu powder 30bb is used. Various solder materials, for example, a solder material containing Sn can be used for the solder paste 30ba. For the Cu powder 30bb, for example, a powder of Cu particles having a particle diameter of 3 μm to 5 μm can be used. As shown in FIG. 4B, the terminal 11 may include an electrode layer 11b including nickel (Ni) and gold (Au) interposed between the electrode layer 11a and the bonding material 30b. When the structure as shown in FIG. 4A or 4B is used on the terminal 11 side (FIG. 2A), the Cu powder 30bb in the bonding material 30b becomes a Cu supply source, and the bonding material at the time of melting is used. Cu is supplied into 30a (FIG. 2 (B)), and plate-like Cu ₆ Sn ₅ is formed as a compound 31 in the joint 30 (FIG. 2 (C)).

  4A and 4B illustrate the bonding material 30b in which the Cu powder 30bb is mixed with the solder paste 30ba. For example, as shown in FIG. 4C, the Cu powder is applied on the solder paste 30ba. The bonding material 30b may be formed by attaching 30bb. 4C illustrates a structure in which an electrode layer 11b containing Ni and Au is interposed between the electrode layer 11a and the bonding material 30b, as in FIG. 4B.

  In the conventional joining of the electronic component 10 and the electronic component 20, for example, the bonding material 30 b is provided in advance on one terminal 21 of the terminals 11 and 21, and solder paste (Cu A solder paste 30ba) that does not contain the powder 30bb may be provided. 4A and 4B, Cu powder 30bb is mixed in advance with solder paste 30ba used as such preliminary solder, and this is provided above the terminal 11 as a bonding material 30b. That's fine. Further, in the method of FIG. 4C, a solder paste 30ba is provided as a preliminary solder above the terminals 11, and the Cu powder 30bb may be attached on the solder paste 30ba. Therefore, in the method shown in FIGS. 4A to 4C, the formation conditions of the electrode layer 11a and the electrode layer 11b are not changed or greatly changed from the case where only the solder paste 30ba is provided as the preliminary solder. And a structure including a Cu source can be obtained.

FIG. 4D and FIG. 4E illustrate the terminals 11 of the electronic component 10. FIG. 4D illustrates a terminal 11 using Cu to increase the planar size, and FIG. 4E illustrates a terminal 11 using Cu to increase the thickness. The terminal 11 having an increased planar size and thickness is used as a Cu supply source, and Cu is diffused and supplied into the bonding material 30a at the time of melting, so that a plate-like Cu ₆ Sn ₅ is formed in the bonding portion 30. You may be made to do.

  The structure as shown in FIG. 4D can be obtained by changing the formation region of the terminal 11, and the structure as shown in FIG. 4E can be obtained by changing the thickness of the terminal 11 to be formed. These changes can be made without significantly complicating the manufacturing process, such as changing the opening size of the mask when forming the terminal 11 or changing the thickness of the mask and the deposition time of the terminal material. It can be done easily.

  Although illustration is omitted here, the solder paste 30ba as described above or a solder paste 30ba mixed with Cu powder 30bb may be provided on the terminals 11 in FIGS. 4D and 4E. it can.

  4A to 4E exemplify the structure of the electronic component 10 on the terminal 11 side, the structure shown in FIG. 4A to FIG. It can also be employed on the terminal 21 side.

FIG. 4F illustrates the terminal 21 of the electronic component 20. A bonding material 30a is provided on the terminal 21, and Cu powder 30c is attached to the surface of the bonding material 30a. In this way, the electronic component 20 provided with the bonding material 30a with the Cu powder 30c attached is disposed on the terminal 21 so as to face the electronic component 10 (FIG. 2A), and the Cu powder 30c is heated while being heated. The bonding material 30a to which is attached is connected to the terminal 11 of the electronic component 10 (FIG. 2B). Thereafter, cooling and solidification are performed (FIG. 2C). The Cu powder 30 c attached to the bonding material 30 a serves as a Cu supply source, Cu is supplied into the bonding material 30 a at the time of melting, and plate-like Cu ₆ Sn ₅ is formed as the compound 31 in the bonding portion 30. .

  In the method of FIG. 4F, the bonding material 30a is provided on the terminal 21, and the Cu powder 30c may be attached thereon. Therefore, a structure including a Cu supply source can be obtained without changing or greatly changing the formation conditions of the terminal 21 from the case where the Cu powder 30c is not adhered.

4A to 4F are adopted for the terminal 11 of the electronic component 10 and the terminal 21 of the electronic component 20 to secure the amount of Cu in the bonding material 30a, and in the bonding portion 30. Alternatively, a plate-like Cu ₆ Sn ₅ having a size or number showing a certain strength improvement effect against stress may be formed.

  In order to secure the amount of Cu in the bonding material 30a in the step of FIG. 2B, the Cu content of the Sn—Ag—Cu based solder may be increased. However, it should be noted that by increasing the Cu content of the Sn—Ag—Cu-based solder of the bonding material 30a, the melting point of the bonding material 30a may increase as compared to a small amount.

Although the case where Sn—Ag—Cu-based solder is used as the bonding material 30a is illustrated here, the solder used for the bonding material 30a is not limited to this. The bonding material 30a includes Sn—Cu solder containing Sn and Cu, Sn—Ag solder containing Sn and Ag, Sn—Au solder containing Sn and Au, Sn—Ni solder containing Sn and Ni, Sn-Pd solder containing Sn and palladium (Pd) can also be used. Even with those containing no Cu in the bonding material 30a, by adopting a structure capable of supplying Cu from the side of the terminal 11 and terminal 21, as described above, the Cu ₆ Sn ₅ of the plate as the compound 31 It is possible to form the joint part 30 containing. Even when such various solder materials are used for the bonding material 30a, the bonding portion 30 containing the plate-like compound 31 can be formed by using the technique as described in FIG. 2 or FIG. Yes, it is possible to obtain the same effect as described above obtained by the plate-like compound 31. Note that any type of solder is not limited to binary solder.

Further, as shown in FIG. 3, in order to form a columnar Ag ₃ Sn compound 33 in addition to the plate-like Cu ₆ Sn ₅ compound 31 in the joint 30, the Ag supply source shown in FIG. The Ag powder may be used together with the Cu powders 30bb and 30c or instead of the Cu powders 30bb and 30c.

  As described above, for example, each of the electronic component 10 and the electronic component 20 can be a semiconductor element, a semiconductor package including the semiconductor element, or a circuit board. Configuration examples of a semiconductor element, a semiconductor package, and a circuit board will be described with reference to FIGS.

FIG. 5 is a diagram illustrating a configuration example of a semiconductor element. In addition, in FIG. 5, the principal part cross section of an example of a semiconductor element is shown typically.
A semiconductor element 100 illustrated in FIG. 5 includes a semiconductor substrate 110 provided with an element such as a transistor and a wiring layer 120 provided on the semiconductor substrate 110.

  As the semiconductor substrate 110, in addition to a substrate such as silicon (Si), germanium (Ge), or silicon germanium (SiGe), a substrate such as gallium arsenide (GaAs) or indium phosphide (InP) is used. Such a semiconductor substrate 110 is provided with elements such as a transistor, a capacitor, and a resistor. FIG. 5 shows a MOS (Metal Oxide Semiconductor) transistor 130 as an example of the element.

  The MOS transistor 130 is provided in an element region defined by an element isolation region 110 a provided in the semiconductor substrate 110. The MOS transistor 130 has a gate electrode 132 formed on the semiconductor substrate 110 via a gate insulating film 131, and a source region 133 and a drain region 134 formed in the semiconductor substrate 110 on both sides of the gate electrode 132. An insulating film spacer 135 (side wall) is provided on the side wall of the gate electrode 132.

  A wiring layer 120 is provided on the semiconductor substrate 110 provided with such a MOS transistor 130 and the like. The wiring layer 120 includes a conductor portion 121 (wiring and via) that is electrically connected to the MOS transistor 130 and the like provided on the semiconductor substrate 110, and an insulating portion 122 that covers the conductor portion 121. As an example, FIG. 5 illustrates a conductor 121 that is electrically connected to the source region 133 and the drain region 134 of the MOS transistor 130. Various conductor materials such as Cu and aluminum (Al) are used for the conductor portion 121. For the insulating portion 122, an inorganic insulating material such as silicon oxide or an organic insulating material such as resin is used.

  The conductor portion 121 on the outermost surface of the wiring layer 120 includes a portion that becomes a terminal 121a for external connection. On the terminal 121a, bumps such as solder corresponding to the bonding material 30a (FIG. 2) are connected in advance at the time of bonding with other electronic components or before bonding.

6 to 8 are diagrams showing examples of the structure of the semiconductor package. Each of FIGS. 6 to 8 schematically shows a cross section of an essential part of an example of a semiconductor package.
First, the semiconductor package 200 shown in FIG. 6 will be described.

  A semiconductor package 200 illustrated in FIG. 6 includes a package substrate 210 (circuit substrate), a semiconductor element 220 mounted on the package substrate 210, and a sealing layer 230 that seals the semiconductor element 220.

  For example, a printed circuit board is used as the package substrate 210. The package substrate 210 includes a conductor portion 211 (wiring and via) and an insulating portion 212 that covers the conductor portion 211. Various conductor materials such as Cu and Al are used for the conductor portion 211. For the insulating portion 212, a resin material such as a phenol resin, an epoxy resin, or a polyimide resin, a composite resin material in which such a resin material is impregnated into glass fiber or carbon fiber, or the like is used.

  The semiconductor element 220 is bonded and fixed on the package substrate 210 with a die attach material 240 such as resin or conductive paste, and is electrically connected to the package substrate 210 with a wire 250 (wire bonding). The semiconductor element 220 and the wire 250 on the package substrate 210 are sealed with a sealing layer 230. For the sealing layer 230, a resin material such as an epoxy resin, a material in which an insulating filler is contained in such a resin material, or the like is used.

  The conductor portion 211 on the surface of the package substrate 210 opposite to the mounting surface of the semiconductor element 220 includes a portion to be a terminal 211a for external connection. On the terminal 211a, bumps such as solder corresponding to the bonding material 30a (FIG. 2) are connected in advance at the time of bonding to other electronic components or before bonding.

  Although the case where the semiconductor element 220 is wire-bonded to the package substrate 210 is illustrated here, the semiconductor element 220 may be flip-chip bonded to the package substrate 210.

In addition, a plurality of semiconductor elements 220 may be mounted on the package substrate 210, and other electronic components such as a chip capacitor may be mounted in addition to the semiconductor elements 220.
Next, the semiconductor package 300 shown in FIG. 7 will be described.

  A semiconductor package 300 illustrated in FIG. 7 includes a package substrate 310 (circuit substrate), a semiconductor element 320 mounted on the package substrate 310, and a covering material 330 that covers the semiconductor element 320.

  For example, a printed circuit board is used as the package substrate 310. The package substrate 310 includes a conductor portion 311 (wiring and via) such as Cu and Al, and an insulating portion 312 such as a resin material that covers the conductor portion 311.

  The semiconductor element 320 is electrically connected (flip chip bonding) to the package substrate 310 with bumps 340 such as solder provided thereon. An underfill material 341 is filled between the package substrate 310 and the semiconductor element 320. The semiconductor element 320 on the package substrate 310 is covered with a covering material 330. For the covering material 330, a thermally conductive member such as Cu is used. The covering material 330 is bonded onto the semiconductor element 320 using a thermal interface material (TIM) 350 and is thermally connected to the semiconductor element 320. For example, the end portion of the covering material 330 is bonded to the package substrate 310 using the adhesive material 351.

  The conductor portion 311 on the surface opposite to the mounting surface of the semiconductor element 320 of the package substrate 310 includes a portion to be a terminal 311a for external connection. On the terminal 311a, bumps such as solder corresponding to the bonding material 30a (FIG. 2) are connected in advance at the time of bonding with other electronic components or before bonding.

Note that a plurality of semiconductor elements 320 may be mounted on the package substrate 310, and other electronic components such as a chip capacitor may be mounted in addition to the semiconductor elements 320.
Next, the semiconductor package 400 shown in FIG. 8 will be described.

  A semiconductor package 400 shown in FIG. 8 includes a resin layer 410, a plurality of (here, two as an example) semiconductor elements 420 embedded in the resin layer 410, and a wiring layer 430 (rewiring) provided on the resin layer 410. Layer).

  The semiconductor element 420 is embedded in the resin layer 410 so that the arrangement surface of the terminal 420a is exposed. The wiring layer 430 includes a conductor portion 431 (rewiring and via) such as Cu and Al, and an insulating portion 432 such as a resin material that covers the conductor portion 431.

  The conductor portion 431 on the outermost surface of the wiring layer 430 includes a portion that becomes a terminal 431a for external connection. By the conductor portion 431, the position of the terminal 420a of the semiconductor element 420 is rearranged to the position of the terminal 431a for external connection. On the terminal 431a, bumps such as solder corresponding to the bonding material 30a (FIG. 2) are connected in advance at the time of bonding with other electronic components or before bonding.

One or three or more semiconductor elements 420 may be embedded in the resin layer 410. In addition to the semiconductor elements 420, other electronic components such as a chip capacitor may be embedded.
FIG. 9 is a diagram illustrating a configuration example of a circuit board. Note that FIGS. 9A and 9B each schematically show a cross-section of an essential part of an example of a circuit board.

  FIG. 9A illustrates a multilayer printed board including a plurality of wiring layers as the circuit board 500. As with the package substrate 210 shown in FIG. 6 and the package substrate 310 shown in FIG. 7, the circuit board 500 is made of a conductor portion 511 (wiring and via) such as Cu and Al, and a resin material that covers the conductor portion 511. Insulating portion 512.

  The conductor portion 511 on the outermost surface of the circuit board 500 includes a portion to be a terminal 511a for external connection. On the terminal 511a, bumps such as solder corresponding to the bonding material 30a (FIG. 2) are connected in advance at the time of bonding with other electronic components or before bonding.

  FIG. 9B illustrates a buildup substrate formed using a buildup method as the circuit substrate 600. The circuit board 600 includes a core substrate 610, an insulating layer 620 provided on the core substrate 610, a conductor pattern 630 provided via the insulating layer 620, and a via 640 connecting different conductor patterns 630. . For the core substrate 610, a ceramic material, an organic material, or the like is used. An insulating material such as a prepreg is used for the insulating layer 620. A conductive material such as Cu is used for the conductive pattern 630 and the via 640.

  The conductor pattern 630 on the outermost surface of the circuit board 600 includes a portion to be a terminal 630a for external connection. On the terminal 630a, bumps such as solder corresponding to the bonding material 30a (FIG. 2) are connected in advance at the time of bonding with other electronic components or before bonding.

  For example, the semiconductor device 100 as shown in FIG. 5, the semiconductor packages 200, 300, and 400 as shown in FIGS. 6 to 8, and the circuit boards 500 and 600 as shown in FIG. 10 and electronic component 20 respectively.

  Examples of the combination of the electronic component 10 and the electronic component 20 to be joined include a combination of a semiconductor element and a circuit board, a combination of a semiconductor package and a circuit board, and a combination of a semiconductor element and a semiconductor package. In addition, the combination of the electronic component 10 and the electronic component 20 to be joined includes a combination of semiconductor elements, a combination of semiconductor packages, and a combination of circuit boards.

  For joining the electronic component 10 and the electronic component 20 in various combinations, the method shown in FIG. 2 or FIG. 4 is used to connect the joint material 30a to the joint portion 30 obtained by solidifying the terminal 11 to the terminal 21, Alternatively, a plate-like compound 31 extending in the direction from the terminal 21 toward the terminal 11 can be formed. Thereby, the strength of the joint portion 30 is improved, and cracks and peeling of the joint portion 30 due to external force and stress, and disconnection due to such cracks and peeling are effectively suppressed.

Next, a second embodiment will be described.
Here, a case where one of the electronic components to be joined is a circuit board and the other is a semiconductor package will be described as an example.

  FIG. 10 is a diagram illustrating an example of an electronic component joining process according to the second embodiment. In addition, in FIG. 10, the principal part cross section of an example of the electronic component joining process which concerns on 2nd Embodiment is typically shown. FIG. 10A is a diagram illustrating an example of a state before joining, FIG. 10B is a diagram illustrating an example of a state at the time of joining, and FIG. 10C is a diagram illustrating an example of a state after joining.

In this example, first, a circuit board 40 and a semiconductor package 50 as shown in FIG. 10A are prepared as electronic components to be joined.
The circuit board 40 has a terminal 41 provided on the surface 40a thereof. The terminal 41 includes an electrode layer 41a made of Cu or the like and an Ni / Au electrode layer 41b provided on the electrode layer 41a, for example, by laminating Ni and Au. A bonding material 60 b is provided in advance on the terminal 41 (electrode layer 41 b) of the circuit board 40. As the bonding material 60b, for example, a material obtained by mixing Cu powder with solder paste is used in the same manner as the bonding material 30b illustrated in FIG. Alternatively, as the bonding material 60b, for example, as in the bonding material 30b illustrated in FIG. 4C, a material obtained by attaching Cu powder on a solder paste is used. Various solder materials containing Sn can be used for the solder of the solder paste. As the Cu powder, for example, a powder of Cu particles having a particle diameter of 3 μm to 5 μm can be used. The bonding material 60b is formed, for example, by applying a solder paste mixed with such Cu powder on the terminals 41. Alternatively, after applying a solder paste containing no Cu powder on the terminals 41, the Cu powder is adhered onto the solder paste, thereby forming the bonding material 60b.

  The semiconductor package 50 is disposed to face the circuit board 40, and has a terminal 51 provided on the surface 50 a facing the surface 40 a of the circuit board 40. The terminal 51 includes an electrode layer 51a made of Cu or the like and an electrode layer 51b made of, for example, Ni / Au provided on the electrode layer 51a. On the terminal 51 (electrode layer 51b) of the semiconductor package 50, for example, an Sn-Ag-Cu solder bonding material 60a is provided in advance. The bonding material 60a is formed, for example, by melting solder by heating and solidifying by cooling solder disposed by mounting solder balls on the terminals 51 or depositing solder by plating.

  A member 70A having a predetermined heat capacity is provided on the surface (upper surface) 50b of the semiconductor package 50 opposite to the surface 50a on which the terminals 51 are provided. In the member 70A, as will be described later, when the bonding material 60a and the bonding material 60b are melted by heating and then cooled and solidified, the semiconductor package 50 provided with the member 70A becomes hotter than the circuit board 40. A material having such a heat capacity is used. The material (specific heat) is selected and the planar size and thickness of the member 70A are set so as to have such a predetermined heat capacity. For example, a plate made of Cu, Al, or the like can be used as the member 70A.

  Although not shown in FIG. 10, the member 70 </ b> A is provided on the upper surface 50 b of the semiconductor package 50 using an adhesive such as resin or metal paste. The arrangement of the member 70A on the semiconductor package 50 will be described later.

  As shown in FIG. 10A, the circuit board 40 provided with the bonding material 60b and the semiconductor package 50 provided with the bonding material 60a and the member 70A have the terminals 41 (bonding material 60b) and the terminals 51 ( The bonding material 60a) is aligned and arranged to face each other.

  As shown in FIG. 10B, the bonding material 60a on the terminal 51 of the semiconductor package 50 is melted by heating and connected to the similarly molten bonding material 60b on the terminal 41 of the circuit board 40. The The bonding material 60b melted by heating includes solder in which the solder paste is melted and Cu supplied to the solder from Cu particles of Cu powder. Particulate Cu may remain in the molten bonding material 60b. Such a bonding material 60b is connected to the bonding material 60a. The bonding material 60a and the bonding material 60b are integrated by melting and connection. Thus, the part (joining part) 60c in which the bonding material 60a and the bonding material 60b are integrated includes components such as Sn, Ag, and Cu of the bonding material 60a and components such as Sn and Cu of the bonding material 60b. . Components such as Cu, Ni, and Au of the electrode layer 41 and the electrode layer 51 can also be included in the bonding portion 60c. Such a joining part 60c is solidified by cooling.

  Here, as described above, the semiconductor package 50 is provided with the member 70A having a predetermined heat capacity. With this member 70A, in the cooling process after heating the bonding material 60a and the bonding material 60b, for example, from the start of solidification of the bonding material 60a and the bonding material 60b (bonding portion 60c) to the end of solidification, the semiconductor package 50 is mounted on the circuit board 40. It adjusts so that it may be in a hotter state than.

  The semiconductor package 50 provided with the member 70A has a larger heat capacity than the semiconductor package 50 provided with no member 70A. Therefore, when the bonding material 60a and the bonding material 60b are melted by heating and the bonding portion 60c in which the bonding material 60a and the bonding material 60b are integrated is cooled for solidification, the cooling rate of the semiconductor package 50 provided with the member 70A is This is lower than that of the semiconductor package 50 that is not provided. In other words, the semiconductor package 50 is more difficult to cool by providing the member 70A. For example, the cooling rate of the semiconductor package 50 provided with the member 70A is 1 ° C./min or less.

  When the bonding material 60a and the bonding material 60b are melted by heating and the bonding portion 60c in which they are integrated is cooled for solidification, the circuit board 40 is also cooled together with the semiconductor package 50. At this time, the cooling rate of the semiconductor package 50 is decreased by the member 70A, and the cooling progresses more slowly than the member without the member 70A, so that the temperature of the semiconductor package 50 is higher than that of the circuit board 40 during which the cooling proceeds. It can be a state. For example, the member 70 </ b> A having a predetermined heat capacity is provided so that the semiconductor package 50 provided with the member 70 </ b> A in this way is at a higher temperature than the circuit board 40 from the start to the end of the solidification of the joint portion 60 c.

  By providing such a member 70A and making the semiconductor package 50 at a higher temperature than the circuit board 40, the semiconductor package 50 side is at a higher temperature than the circuit board 40 side at the bonded portion 60c during solidification. A simple temperature gradient is possible. Due to such a temperature gradient, the bonding portion 60c is generally solidified from the lower temperature circuit board 40 side toward the higher temperature semiconductor package 50 side.

As solidification proceeds in this manner, the joining portion 60c has a solidification progression direction, that is, from the terminal 41 of the circuit board 40 to the terminal 51 of the semiconductor package 50, as shown in FIG. A plate-like Cu ₆ Sn ₅ compound 61 is formed so as to extend in the direction of heading. The plate-like Cu ₆ Sn ₅ is formed by using Sn and Cu contained in the bonding material 60a and the bonding material 60b. In addition to Cu contained in the bonding material 60a and the bonding material 60b, Cu diffused from the electrode layer 41a and the electrode layer 51a using Cu may be further used for forming Cu ₆ Sn ₅ . Here, a plurality of plate-like compounds 61 are illustrated, but the number and arrangement of the compounds 61 are not limited to the illustrated form. The plate-like Cu ₆ Sn ₅ compound 61 is covered with a portion 62 containing Sn, Ag and Cu. As the solidification progresses, a joint 60 containing the plate-like compound 61 is formed inside the portion 62, and the circuit board 40 and the semiconductor package 50 are joined at the joint 60 as shown in FIG. A bonded electronic device 1A is obtained.

  In addition, the Ni layer of the electrode layer 41b and the electrode layer 51b can react with the solder component of the joint part 60c or the joint part 60 to form an intermetallic compound. The Au layers of the electrode layer 41b and the electrode layer 51b have a function of suppressing oxidation of the Ni layer before bonding, and can react with the solder component of the bonding portion 60c and the bonding portion 60 during bonding to form an intermetallic compound. .

  As described above, in the electronic device 1 </ b> A, as illustrated in FIG. 10C, the electronic device 1 </ b> A extends in the direction from the terminal 41 toward the terminal 51 to the joint 60 that joins the terminal 41 of the circuit board 40 and the terminal 51 of the semiconductor package 50. A plate-like compound 61 is formed. The plate-like compound 61 serves as a reinforcing material, and the strength of the joint 60 against stress caused by external force or heat, for example, stress in a direction crossing the opposing direction of the terminal 41 and the terminal 51 is improved. . For example, by forming such a plate-like compound 61 at the joint 60, it becomes possible to double the repeated bending test life and the temperature cycle test life as compared with the case where it is not formed.

Here, the arrangement of the member 70A having a predetermined heat capacity on the semiconductor package 50 will be described with reference to FIGS.
FIG. 11 is a diagram illustrating a first configuration example of the electronic device according to the second embodiment. FIG. 11 schematically shows a cross-section of the main part of the first configuration example of the electronic device according to the second embodiment.

  The member 70A can be provided on the upper surface 50b of the semiconductor package 50 using an adhesive 80a, like the electronic device 1Aa shown in FIG. For the adhesive material 80a, for example, a resin material such as an epoxy resin can be used. Further, for example, a metal paste material such as indium silver (InAg) alloy or gold tin (AuSn) alloy can be used for the adhesive 80a.

  A semiconductor package 50 to which the member 70A is bonded in advance using such an adhesive 80a is prepared, and the prepared semiconductor package 50 is a circuit as shown in FIGS. 10 (A) to 10 (C). Bonded to the substrate 40. As a result, as shown in FIG. 11, the semiconductor package 50 in which the member 70 </ b> A is bonded with the adhesive 80 a and the circuit board 40 are bonded to each other through the bonding portion 60 containing the plate-like compound 61. An electronic device 1Aa is obtained. The member 70A bonded to the semiconductor package 50 of the electronic device 1Aa can be used as a heat radiating member that radiates heat generated in the semiconductor package 50 to the outside when the electronic device 1Aa is used, for example.

  FIG. 12 is a diagram illustrating a second configuration example of the electronic device according to the second embodiment. FIGS. 12A and 12B schematically show a cross-section of the main part of a second configuration example of the electronic device according to the second embodiment.

  In this example, as shown in FIG. 12A, an adhesive 80b is used to bond the member 70A to the upper surface 50b of the semiconductor package 50. As the adhesive 80b, an ultraviolet curable resin that is cured by irradiation with ultraviolet rays and exhibits releasability (decreases adhesive strength) is used.

  Using such an ultraviolet curable resin adhesive 80b, a semiconductor package 50 is prepared in which the member 70A is previously bonded (temporarily bonded). The prepared semiconductor package 50 is bonded to the circuit board 40 as shown in FIGS. 10 (A) to 10 (C). As a result, as shown in FIG. 12A, the semiconductor package 50 in which the member 70A is temporarily bonded with the adhesive 80b and the circuit board 40 are connected to each other through the bonding portion 60 containing the plate-like compound 61 therein. To obtain a joined structure.

  After such a structure is obtained, the adhesive 80b is irradiated with ultraviolet rays. As a result, the adhesive material 80 b exhibits peelability, and the member 70 </ b> A and the adhesive material 80 b that have been temporarily bonded onto the semiconductor package 50 become separable from the semiconductor package 50. The member 70A and the adhesive 80b in such a state are removed from the semiconductor package 50, whereby an electronic device 1Ab as shown in FIG. 12B is obtained. As described above, the member 70 </ b> A can be temporarily bonded when the circuit board 40 and the semiconductor package 50 are bonded, and can be removed after the circuit board 40 and the semiconductor package 50 are bonded.

  In the second embodiment, the case where Sn—Ag—Cu based solder is used for the bonding material 60a is exemplified. However, the above-described method is Sn—Cu based solder, Sn—Ag based solder, Sn— The same applies to the case of using Au solder, Sn—Ni solder, Sn—Pd solder or the like. It is also possible to perform bonding by providing the bonding material 60b as described above on the semiconductor package 50 side and providing the bonding material 60a on the circuit board 40 side. On the semiconductor package 50 side and the circuit board 40 side, it is possible to provide a bonding material 60a and a bonding material 60b containing an element as a raw material of the plate-like compound 61 according to the example of FIG.

  In the second embodiment, the circuit board 40 and the semiconductor package 50 are joined as an example. However, the method using such a member 70A is similarly used when joining various electronic components. Applicable.

Next, a third embodiment will be described.
Here, as in the second embodiment, a case where one of the electronic components to be joined is a circuit board and the other is a semiconductor package will be described as an example.

  FIG. 13 is a diagram illustrating an example of an electronic component joining process according to the third embodiment. FIG. 13 schematically shows a cross section of the main part of an example of the electronic component joining step according to the third embodiment. FIG. 13A shows an example of a state before joining, FIG. 13B shows an example of a state at the time of joining, and FIG. 13C shows an example of a state after joining.

  The electronic component joining step according to the third embodiment shown in FIGS. 13 (A) to 13 (C) is the point that the member 70B having a predetermined heat capacity is provided on the circuit board 40 side. This is different from the electronic component joining step according to the embodiment.

In the third embodiment, first, a circuit board 40 provided with a member 70B and a semiconductor package 50 as shown in FIG. 13A are prepared as electronic components to be joined.
The circuit board 40 has a terminal 41 including an electrode layer 41a made of Cu or the like and an electrode layer 41b made of Ni / Au or the like provided on the surface 40a. On the terminal 41 (electrode layer 41b), for example, similarly to the bonding material 30b illustrated in FIG. 4B, a bonding material 60b in which Cu powder is mixed with solder paste is provided in advance. Alternatively, on the terminal 41, for example, similarly to the bonding material 30b illustrated in FIG. 4C, a bonding material 60b in which Cu powder is attached on a solder paste is provided in advance. As described in the second embodiment, various solder materials including Sn can be used for solder of the solder paste, and the Cu powder is, for example, a powder of Cu particles having a particle diameter of 3 μm to 5 μm. Can be used. The bonding material 60b is formed, for example, by applying a solder paste mixed with such Cu powder on the terminal 41 or by attaching Cu powder on the solder paste applied on the terminal 41.

  A member 70B having a predetermined heat capacity is provided on the surface (lower surface) 40b opposite to the surface 40a on which the terminals 41 are provided of the circuit board 40. In the member 70B, when the bonding material 60a and the bonding material 60b are melted by heating and then cooled and solidified as described later, the circuit board 40 provided with the member 70B is in a higher temperature state than the semiconductor package 50. A material having such a heat capacity is used. The material (specific heat) is selected and the planar size and thickness of the member 70B are set so as to have such a predetermined heat capacity. For the member 70B, for example, a plate made of Cu, Al, or the like can be used.

  The member 70B can be provided directly on the lower surface 40b of the circuit board 40, and although not shown in FIG. 13, it can also be provided on the lower surface 40b of the circuit board 40 using an adhesive such as resin. The arrangement of the member 70B below the circuit board 40 will be described later.

  The semiconductor package 50 is disposed to face the circuit board 40 and has a terminal 51 including an electrode layer 51a made of Cu or the like and an electrode layer 51b made of Ni / Au provided on the surface 50a. On the terminal 51 (electrode layer 51b) of the semiconductor package 50, for example, an Sn-Ag-Cu solder bonding material 60a is provided in advance.

  As shown in FIG. 13A, the circuit board 40 provided with the bonding material 60b and the member 70B and the semiconductor package 50 provided with the bonding material 60a have the terminals 41 (bonding material 60b) and the terminals 51 ( The bonding material 60a) is aligned and arranged to face each other.

  Then, as shown in FIG. 13B, the bonding material 60a on the terminal 51 of the semiconductor package 50 is melted by heating and connected to the similarly molten bonding material 60b on the terminal 41 of the circuit board 40. The The bonding material 60a and the bonding material 60b are integrated by such melting and connection, and the integrated bonding portion 60c is solidified by cooling.

  Here, as described above, the circuit board 40 is provided with the member 70B having a predetermined heat capacity. With this member 70B, in the cooling process after heating of the bonding material 60a and the bonding material 60b, for example, from the start of solidification of the bonding portion 60c to the end of solidification, the circuit board 40 is in a higher temperature state than the semiconductor package 50. Adjusted.

  The circuit board 40 provided with the member 70B has a larger heat capacity than the circuit board 40 provided with no member 70B. Therefore, when the joining portion 60c in which the joining material 60a and the joining material 60b are melted and cooled is cooled for solidification, the cooling rate of the circuit board 40 provided with the member 70B is the circuit not provided with the member 70B. It is lower than that of the substrate 40. That is, the circuit board 40 is more difficult to cool by providing the member 70B. For example, the cooling rate of the circuit board 40 provided with the member 70B is 1 ° C./min or less.

  When the bonding portion 60c is cooled for solidification, the semiconductor package 50 is also cooled together with the circuit board 40. At this time, the cooling rate of the circuit board 40 is decreased by the member 70B, and the cooling progresses more slowly than the member without the member 70B, so that the temperature of the circuit board 40 is higher than that of the semiconductor package 50 in which the cooling proceeds. It can be a state. For example, the member 70 </ b> B having a predetermined heat capacity is provided so that the circuit board 40 provided with the member 70 </ b> B in this manner is at a higher temperature than the semiconductor package 50 from the start of solidification of the joining portion 60 c to the end of solidification.

  By providing such a member 70B and making the circuit board 40 at a higher temperature than the semiconductor package 50, the circuit board 40 side is at a higher temperature than the semiconductor package 50 side at the joining portion 60c during solidification. A simple temperature gradient is possible. Due to such a temperature gradient, solidification of the bonding portion 60c generally proceeds from the lower temperature semiconductor package 50 side toward the higher temperature circuit board 40 side.

As solidification proceeds in this way, the joining portion 60c has a solidification progress direction, that is, from the terminal 51 of the semiconductor package 50 to the terminal 41 of the circuit board 40, as shown in FIG. A plate-like Cu ₆ Sn ₅ compound 61 is formed so as to extend in the direction of heading. The plate-like Cu ₆ Sn ₅ is formed using Sn and Cu contained in the bonding material 60a and the bonding material 60b, or using Cu diffused from the electrode layer 41a and the electrode layer 51a. Here, a plurality of plate-like compounds 61 are illustrated, but the number and arrangement of the compounds 61 are not limited to the illustrated form. The plate-like Cu ₆ Sn ₅ compound 61 is covered with a portion 62 containing Sn, Ag and Cu. As the solidification progresses, a joint 60 containing the plate-like compound 61 is formed inside such a portion 62, and the circuit board 40 and the semiconductor package 50 are joined at the joint 60 as shown in FIG. The joined electronic device 1B is obtained.

  As described above, even when the member 70 </ b> B having a predetermined heat capacity is provided on the circuit board 40 side, from the terminal 51 to the terminal 41, the terminal 41 of the circuit board 40 and the terminal 51 of the semiconductor package 50 are joined. A plate-like compound 61 extending in the direction in which it faces can be formed. Thereby, it is possible to obtain the electronic device 1 </ b> B in which the strength of the bonding portion 60 is improved due to the stress caused by external force or heat, for example, the stress in the direction intersecting the opposing direction of the terminal 41 and the terminal 51. For example, by forming such a plate-like compound 61 at the joint 60, it becomes possible to double the repeated bending test life and the temperature cycle test life as compared with the case where it is not formed.

Here, the arrangement of the member 70B having a predetermined heat capacity under the circuit board 40 will be described.
One method of providing the member 70B under the circuit board 40 is a method of placing the circuit board 40 on the member 70B. In this case, the circuit board 40 may simply be placed on the member 70B, and it is not necessary to fix the circuit board 40 by bonding it on the member 70B using an adhesive. As shown in FIGS. 13A to 13C, the bonding material 60a and the bonding material 60b are used for the circuit board 40 placed on the member 70B in this manner, and the semiconductor package 50 is bonded. The The bonded structure is picked up from the member 70B. Thereby, the electronic device 1 </ b> B that does not include the member 70 </ b> B in which the circuit board 40 and the semiconductor package 50 are bonded at the bonding portion 60 is obtained.

The member 70B can also be provided under the circuit board 40 using an adhesive. Such a method will be described with reference to FIGS.
FIG. 14 is a diagram illustrating a first configuration example of an electronic device according to the third embodiment. FIG. 14 schematically illustrates a cross-section of the main part of the first configuration example of the electronic device according to the third embodiment.

  When the circuit board 40 is a single-sided circuit board that does not have a circuit pattern or an external connection terminal on the lower surface 40b, a resin material, a metal paste material, or the like is formed on the lower surface 40b of the circuit board 40 as shown in FIG. The member 70B may be provided using the adhesive 80a. The circuit board 40 to which the member 70B is bonded in advance using such an adhesive 80a is prepared, and the prepared circuit board 40 is bonded as shown in FIGS. 13 (A) to 13 (C). The semiconductor package 50 is bonded using the material 60a and the bonding material 60b. As a result, as shown in FIG. 14, the semiconductor package 50 and the circuit board 40 to which the member 70B is bonded by the adhesive 80a are bonded via the bonding portion 60 containing the plate-like compound 61 therein. The electronic device 1Ba is obtained. The member 70 </ b> B of the electronic device 1 </ b> Ba can be used as a heat dissipation member that radiates heat transferred to the circuit board 40 to the outside when the electronic device 1 </ b> Ba is used.

  FIG. 15 is a diagram illustrating a second configuration example of the electronic device according to the third embodiment. FIGS. 15A and 15B schematically show a cross-section of the main part of a second configuration example of the electronic device according to the third embodiment.

  In this example, as shown in FIG. 15A, an ultraviolet curable resin adhesive 80b is used to bond the member 70B to the lower surface 40b of the circuit board 40. The circuit board 40 to which the member 70B is bonded (temporarily bonded) in advance with such an adhesive 80b is prepared. As shown in FIGS. 13A to 13C, the bonding material 60a and the bonding material 60b are prepared. Is used to join the semiconductor package 50. As a result, as shown in FIG. 15A, the semiconductor package 50 and the circuit board 40 on which the member 70B is temporarily bonded with the adhesive 80b are connected to each other through the joint portion 60 containing the plate-like compound 61 therein. To obtain a joined structure. Thereafter, the adhesive material 80b is irradiated with ultraviolet rays, and the member 70B and the adhesive material 80b are removed from below the circuit board 40, whereby an electronic device 1Bb as shown in FIG. 15B is obtained. Thus, the member 70B can be temporarily bonded when the circuit board 40 and the semiconductor package 50 are bonded, and the member 70B can be removed after the bonding.

  In the third embodiment, the case where Sn—Ag—Cu based solder is used for the bonding material 60a is exemplified. However, the method described above is Sn—Cu based solder, Sn—Ag based solder, Sn— The same applies to the case of using Au solder, Sn—Ni solder, Sn—Pd solder or the like. It is also possible to perform bonding by providing the bonding material 60b as described above on the semiconductor package 50 side and providing the bonding material 60a on the circuit board 40 side. On the semiconductor package 50 side and the circuit board 40 side, it is possible to provide a bonding material 60a and a bonding material 60b containing an element as a raw material of the plate-like compound 61 according to the example of FIG.

  In the third embodiment, the circuit board 40 and the semiconductor package 50 are joined as an example. However, the method using such a member 70B is similarly used when joining various electronic components. Applicable.

Next, a fourth embodiment will be described.
Here, as in the second and third embodiments, a case where one of the electronic components to be joined is a circuit board and the other is a semiconductor package will be described as an example.

  FIG. 16 is a diagram illustrating an example of an electronic component joining process according to the fourth embodiment. In addition, in FIG. 16, the principal part cross section of an example of the electronic component joining process which concerns on 4th Embodiment is typically shown. 16A is a diagram illustrating an example of a state before joining, FIG. 16B is a diagram illustrating an example of a state at the time of joining, and FIG. 16C is a diagram illustrating an example of a state after joining.

In this example, first, a circuit board 40 and a semiconductor package 50 as shown in FIG. 16A are prepared as electronic components to be joined.
The circuit board 40 has a terminal 41 including an electrode layer 41a made of Cu or the like and an electrode layer 41b made of Ni / Au or the like provided on the surface 40a. On the terminal 41 (electrode layer 41b), for example, a bonding material 60b in which Cu powder is mixed with solder paste or a bonding material 60b in which Cu powder is adhered on the solder paste is provided in advance.

  The semiconductor package 50 is disposed to face the circuit board 40 and has a terminal 51 including an electrode layer 51a made of Cu or the like and an electrode layer 51b made of Ni / Au provided on the surface 50a. On the terminal 51 (electrode layer 51b) of the semiconductor package 50, for example, an Sn-Ag-Cu solder bonding material 60a is provided in advance.

  As shown in FIG. 16A, the circuit board 40 provided with the bonding material 60b and the semiconductor package 50 provided with the bonding material 60a have the terminals 41 (bonding material 60b) and the terminals 51 (bonding material 60a). ) Is aligned and arranged opposite to each other.

  Then, as shown in FIG. 16B, the bonding material 60a on the terminal 51 of the semiconductor package 50 is melted by heating and connected to the similarly molten bonding material 60b on the terminal 41 of the circuit board 40. The The bonding material 60a and the bonding material 60b become a bonded portion 60c integrated by such melting and connection, and the bonded portion 60c is solidified by cooling.

  During this cooling, one of the circuit board 40 and the semiconductor package 50, here, as an example, the semiconductor package 50 is selectively cooled. For example, as shown in FIG. 16C, the semiconductor package 50 is cooled by selectively blowing air to the semiconductor package 50 using a fan or the like. Thus, the semiconductor package 50 is cooled by the air blow 91, and the cooling rate is increased.

  When the bonding portion 60c is cooled for solidification, both the circuit board 40 and the semiconductor package 50 are cooled. At this time, the circuit board 40 can be in a higher temperature state than the semiconductor package 50 by selectively blowing air to the semiconductor package 50 and increasing the cooling rate of the semiconductor package 50. The semiconductor package 50 is cooled by such a blower 91 and adjusted so that, for example, the circuit board 40 is at a higher temperature than the semiconductor package 50 from the start to the end of solidification of the bonding portion 60c.

  By setting the circuit board 40 to a temperature higher than that of the semiconductor package 50, a temperature gradient can be generated at the bonding portion 60 c at the time of solidification such that the circuit board 40 side is higher in temperature than the semiconductor package 50 side. Due to such a temperature gradient, solidification of the bonding portion 60c generally proceeds from the lower temperature semiconductor package 50 side toward the higher temperature circuit board 40 side.

As the solidification progresses in this way, the bonding portion 60c has a plate extending from the terminal 51 of the semiconductor package 50 toward the terminal 41 of the circuit board 40 as shown in FIG. compound 61 shaped for Cu ₆ Sn ₅ is formed. Here, a plurality of plate-like compounds 61 are illustrated, but the number and arrangement of the compounds 61 are not limited to the illustrated form. The plate-like Cu ₆ Sn ₅ compound 61 is covered with a portion 62 containing Sn, Ag and Cu. As the solidification progresses, a joint 60 containing the plate-like compound 61 is formed inside the portion 62, and the circuit board 40 and the semiconductor package 50 are joined at the joint 60 as shown in FIG. A bonded electronic device 1C is obtained.

  The plate-like compound 61 extending in the direction from the terminal 51 toward the terminal 41 is also formed at the joint 60 between the circuit board 40 and the semiconductor package 50 by the method of selectively blowing air to the semiconductor package 50 in this way. can do. As a result, it is possible to obtain the electronic device 1 </ b> C in which the strength is improved with respect to the stress caused by the external force or heat of the joint 60, for example, the stress in the direction intersecting the opposing direction of the terminal 41 and the terminal 51.

  17-19 is a figure explaining the other example of the electronic component joining process which concerns on 4th Embodiment. Note that FIGS. 17 to 19 each schematically show a cross section of a main part of another example of the electronic component joining step according to the fourth embodiment.

  In FIG. 16C, when the joining portion 60c of FIG. 16B is cooled for solidification, the semiconductor package 50 is selectively blown to the semiconductor package 50 to cool the semiconductor package 50. The case where the substrate 40 is brought into a higher temperature state than the semiconductor package 50 has been illustrated.

In addition, when the bonding portion 60c of FIG. 16B is cooled for solidification, the circuit board 40 is similarly heated to a temperature higher than that of the semiconductor package 50 as shown in FIG. In addition, a method in which heating 92 is selectively performed on the circuit board 40 with a heater or the like may be employed. By performing the heating 92, the circuit board 40 is warmed and the cooling rate is reduced. By using such a method, a temperature gradient is generated in the joining portion 60c at the time of solidification so that the circuit board 40 side becomes hotter than the semiconductor package 50 side, and the solidification progresses generally toward the circuit board 40 side. The plate-like Cu ₆ Sn ₅ compound 61 as described above is formed.

Further, FIG. 16C illustrates a case where the air blow 91 is selectively performed on the semiconductor package 50, but the air blow 91 is selectively performed on the circuit board 40 as shown in FIG. The semiconductor package 50 may be at a higher temperature than the circuit board 40. In this case, first, as shown in FIGS. 16A and 16B, the circuit board 40 and the semiconductor package 50 are arranged to face each other, and the bonding material 60a and the bonding material 60b are melted and connected to form a bonding site. After 60c is formed, the joint portion 60c is solidified by cooling. At the time of this cooling, the circuit board 40 is cooled selectively by blowing air 91 using a fan or the like. In this way, the circuit board 40 is cooled by the air blow 91, and the cooling rate is increased. For example, the semiconductor package 50 is in a higher temperature state than the circuit board 40 from the start of solidification to the end of solidification of the joint portion 60c. To do. By using such a method, a temperature gradient is generated in the bonding portion 60c at the time of solidification so that the semiconductor package 50 side is higher in temperature than the circuit board 40 side, and the solidification progresses generally toward the semiconductor package 50 side. The plate-like Cu ₆ Sn ₅ compound 61 as described above is formed.

In order to make the temperature of the semiconductor package 50 higher than that of the circuit board 40, a method of selectively heating the semiconductor package 50 with a heater or the like as shown in FIG. Also good. By performing the heating 92, the semiconductor package 50 is warmed and the cooling rate is reduced. By using such a method, a temperature gradient is generated at the solidified bonding portion 60c so that the temperature of the semiconductor package 50 is higher than that of the circuit board 40, and the plate-like Cu ₆ Sn ₅ compound 61 as described above is formed. Form.

  In the fourth embodiment, the case where Sn-Ag-Cu solder is used as the bonding material 60a is exemplified. However, the above-described technique is Sn-Cu solder, Sn-Ag solder, Sn. The same applies to the case of using Au-based solder, Sn-Ni based solder, Sn-Pd based solder or the like. It is also possible to perform bonding by providing the bonding material 60b as described above on the semiconductor package 50 side and providing the bonding material 60a on the circuit board 40 side. On the semiconductor package 50 side and the circuit board 40 side, it is possible to provide a bonding material 60a and a bonding material 60b containing an element as a raw material of the plate-like compound 61 according to the example of FIG.

  In the fourth embodiment, the circuit board 40 and the semiconductor package 50 are joined as an example. However, the method of performing such air blowing 91 or heating 92 is the same when joining various electronic components. It is applicable to.

  The electronic devices 1, 1A (1Aa, 1Ab), 1B (1Ba, 1Bb), and 1C according to the first to fourth embodiments described above can be manufactured using, for example, the following manufacturing apparatus. it can. Here, the case where one of the electronic components to be joined is the circuit board 40 and the other is the semiconductor package 50 will be described as an example.

FIG. 20 is a diagram illustrating an example of an electronic device manufacturing apparatus.
A manufacturing apparatus 1000 illustrated in FIG. 20 includes an arrangement unit 1100, a heating unit 1200, and a cooling unit 1300.

  The prepared circuit board 40 and the semiconductor package 50 are first transported to the placement unit 1100, aligned in the placement unit 1100, and placed facing each other. The prepared circuit board 40 and the semiconductor package 50 are, for example, the semiconductor package 50 provided with the circuit board 40 and the member 70A. Alternatively, the prepared circuit board 40 and the semiconductor package 50 are, for example, a combination of the circuit board 40 provided with the member 70B and the semiconductor package 50. Alternatively, the circuit board 40 and the semiconductor package 50 to be prepared are a combination of the circuit board 40 that is not provided with the member 70B and the semiconductor package 50 that is not provided with the member 70A. In FIG. 20, the members 70A and 70B are not shown for convenience.

  The aligned circuit board 40 and the semiconductor package 50 are transferred to a heating unit 1200 provided at a subsequent stage of the placement unit 1100, and a bonding material 60b provided on the circuit board 40 and a bonding material 60a provided on the semiconductor package 50. It is heated at a temperature according to the type. Heating is performed in an inert gas atmosphere. In the heating unit 1200, the bonding material 60b of the circuit board 40 and the bonding material 60a of the semiconductor package 50 are melted and connected to form a bonding portion 60c in which the bonding material 60a and the bonding material 60b are integrated. In addition, in the heating part 1200, heating temperature can be raised in steps and lower temperature heating (preliminary heating) and higher temperature heating (main heating) can be performed.

  The circuit board 40 and the semiconductor package 50 on which the bonding part 60c is formed by heating are transferred to the cooling unit 1300 provided at the subsequent stage of the heating unit 1200, and the bonding part 60c is solidified by cooling. Cooling is performed in an inert gas atmosphere.

  Here, the cooling unit 1300 includes a temperature adjusting device 1310 that adjusts the overall atmospheric temperature inside by purging or the like, and cools the circuit board 40, the semiconductor package 50, and the bonding portion 60c. The cooling unit 1300 further includes a temperature adjusting device 1320 provided on the circuit board 40 side and a temperature adjusting device 1330 provided on the semiconductor package 50 side in addition to the temperature adjusting device 1310. As the temperature control device 1320, for example, a device having a blowing function or a heating function, or both a blowing function and a heating function is used. As the temperature control device 1330, for example, a device having a blowing function or a heating function, or both a blowing function and a heating function is used.

  In the case where the circuit board 40 and the semiconductor package 50 to be prepared are provided with the member 70B and the member 70A, respectively, the temperature adjusting device 1310 is used, as described in the second and third embodiments. Cooling and formation of the joint 60 are performed. In this case, it is not always necessary to use the temperature adjustment device 1320 and the temperature adjustment device 1330.

  When the circuit board 40 and the semiconductor package 50 to be prepared are not provided with the member 70B and the member 70A, the temperature adjusting device 1310 and the temperature adjusting device 1320 or the temperature adjusting device 1330 are used. That is, the temperature adjustment device 1320 or the temperature adjustment device 1330 is used, and either the circuit board 40 or the semiconductor package 50 is selectively heated or cooled. Thereby, the cooling and the formation of the joint portion 60 as described in the fourth embodiment are performed.

  For example, using the manufacturing apparatus 1000 having the configuration shown in FIG. 20, the electronic apparatuses 1, 1A (1Aa, 1Ab), 1B (1Ba, 1Bb), 1C according to the first to fourth embodiments are used. Can be manufactured.

Examples are shown below.
[Example 1]
A Cu plate (member) having the same size as the semiconductor package was mounted on the back surface of the semiconductor package having a planar size of 35 mm × 35 mm. Then, a solder ball of Sn-3.0Ag-0.5Cu (Ag: 3.0 wt%, Cu: 0.5 wt%) is used for the terminal of the semiconductor package on which the Cu plate is mounted and the terminal of the circuit board. And joined. The bonding was performed in a N ₂ atmosphere (oxygen concentration of 100 ppm or less) at a maximum temperature of 245 ° C. and 217 ° C. or more for 2 minutes.

The electronic device in which the circuit board and the semiconductor package were bonded in this manner was evaluated for bonding reliability after confirming that there was no problem in conduction at the bonded portion. As a result of conducting 1000 cycles of a repeated temperature cycle test of −40 ° C. to 125 ° C., the resistance increase was good at 10% or less. Further, even after being left in an environment of a temperature of 121 ° C. and a humidity of 85% for 1000 hours, the resistance increase was as good as 10% or less, as in the temperature cycle test. As a result of cross-sectional observation of the joint using an electron microscope, a plate-like Cu ₆ Sn ₅ compound extending in a direction from one terminal to the other terminal is formed between the terminals of the circuit board and the semiconductor package. It was confirmed.

[Example 2]
An Al plate (member) having the same size as the semiconductor package was mounted on the back surface of the semiconductor package having a planar size of 35 mm × 35 mm. Then, a solder ball of Sn-3.0Ag-0.5Cu (Ag: 3.0 wt%, Cu: 0.5 wt%) is used for the terminal of the semiconductor package on which the Al plate is mounted and the terminal of the circuit board. And joined. The bonding was performed in a N ₂ atmosphere (oxygen concentration of 100 ppm or less) at a maximum temperature of 245 ° C. and 217 ° C. or more for 2 minutes.

The electronic device in which the circuit board and the semiconductor package were bonded in this manner was evaluated for bonding reliability after confirming that there was no problem in conduction at the bonded portion. As a result of conducting 1000 cycles of a repeated temperature cycle test of −40 ° C. to 125 ° C., the resistance increase was good at 10% or less. Further, even after being left in an environment of a temperature of 121 ° C. and a humidity of 85% for 1000 hours, the resistance increase was as good as 10% or less, as in the temperature cycle test. As a result of cross-sectional observation of the joint using an electron microscope, a plate-like Cu ₆ Sn ₅ compound extending in a direction from one terminal to the other terminal is formed between the terminals of the circuit board and the semiconductor package. It was confirmed.

Example 3
A Cu plate (member) having the same size as the semiconductor package was mounted on the back surface of the semiconductor package having a planar size of 35 mm × 35 mm. On the terminal of the circuit board, Sn—Ag—Cu solder paste mixed with Cu powder having a particle size of 3 μm to 5 μm was applied by a printing method. Then, the terminal of the semiconductor package on which the Cu plate is mounted and the terminal of the circuit board provided with the solder paste mixed with Cu powder are Sn-3.0Ag-0.5Cu (Ag: 3.0 wt%, Cu: 0 .5 wt%) solder balls were used for bonding. The bonding was performed in a N ₂ atmosphere (oxygen concentration of 100 ppm or less) at a maximum temperature of 245 ° C. and 217 ° C. or more for 2 minutes.

The electronic device in which the circuit board and the semiconductor package were bonded in this manner was evaluated for bonding reliability after confirming that there was no problem in conduction at the bonded portion. As a result of conducting 1000 cycles of a repeated temperature cycle test of −40 ° C. to 125 ° C., the resistance increase was good at 10% or less. Further, even after being left in an environment of a temperature of 121 ° C. and a humidity of 85% for 1000 hours, the resistance increase was as good as 10% or less, as in the temperature cycle test. As a result of cross-sectional observation of the joint using an electron microscope, a plate-like Cu ₆ Sn ₅ compound extending in a direction from one terminal to the other terminal is formed between the terminals of the circuit board and the semiconductor package. It was confirmed.

Example 4
An Al plate (member) having the same size as the semiconductor package was mounted on the back surface of the semiconductor package having a planar size of 35 mm × 35 mm. On the terminal of the circuit board, Sn—Ag—Cu solder paste mixed with Cu powder having a particle size of 3 μm to 5 μm was applied by a printing method. Then, the terminal of the semiconductor package on which the Al plate is mounted and the terminal of the circuit board provided with the solder paste mixed with Cu powder are Sn-3.0Ag-0.5Cu (Ag: 3.0 wt%, Cu: 0 .5 wt%) solder balls were used for bonding. The bonding was performed in a N ₂ atmosphere (oxygen concentration of 100 ppm or less) at a maximum temperature of 245 ° C. and 217 ° C. or more for 2 minutes.

The electronic device in which the circuit board and the semiconductor package were bonded in this manner was evaluated for bonding reliability after confirming that there was no problem in conduction at the bonded portion. As a result of conducting 1000 cycles of a repeated temperature cycle test of −40 ° C. to 125 ° C., the resistance increase was good at 10% or less. Further, even after being left in an environment of a temperature of 121 ° C. and a humidity of 85% for 1000 hours, the resistance increase was as good as 10% or less as in the temperature cycle test. As a result of cross-sectional observation of the joint using an electron microscope, a plate-like Cu ₆ Sn ₅ compound extending in a direction from one terminal to the other terminal is formed between the terminals of the circuit board and the semiconductor package. It was confirmed.

Example 5
A Cu plate (member) of the same size as the circuit board was mounted on the back surface of the circuit board. And the terminal of the circuit board which mounted | worn this Cu plate, and the terminal of the semiconductor package of planar size 35mm x 35mm are Sn-3.0Ag-0.5Cu (Ag: 3.0wt%, Cu: 0.5wt%) ) Solder balls. The bonding was performed in a N ₂ atmosphere (oxygen concentration of 100 ppm or less) at a maximum temperature of 245 ° C. and 217 ° C. or more for 2 minutes.

The electronic device in which the circuit board and the semiconductor package were bonded in this manner was evaluated for bonding reliability after confirming that there was no problem in conduction at the bonded portion. As a result of conducting 1000 cycles of a repeated temperature cycle test of −40 ° C. to 125 ° C., the resistance increase was good at 10% or less. Further, even after being left in an environment of a temperature of 121 ° C. and a humidity of 85% for 1000 hours, the resistance increase was as good as 10% or less, as in the temperature cycle test. As a result of cross-sectional observation of the joint using an electron microscope, a plate-like Cu ₆ Sn ₅ compound extending in a direction from one terminal to the other terminal is formed between the terminals of the circuit board and the semiconductor package. It was confirmed.

Example 6
A semiconductor package terminal having a planar size of 35 mm × 35 mm and a circuit board terminal are joined using Sn-3.0Ag-0.5Cu (Ag: 3.0 wt%, Cu: 0.5 wt%) solder balls. did. The bonding was performed in a N ₂ atmosphere (oxygen concentration of 100 ppm or less) under conditions of a maximum temperature of 245 ° C. and 217 ° C. or more for 2 minutes, and N ₂ was selectively sprayed onto the semiconductor package during cooling.

The electronic device in which the circuit board and the semiconductor package were bonded in this manner was evaluated for bonding reliability after confirming that there was no problem in conduction at the bonded portion. As a result of conducting 1000 cycles of a repeated temperature cycle test of −40 ° C. to 125 ° C., the resistance increase was good at 10% or less. Further, even after being left in an environment of a temperature of 121 ° C. and a humidity of 85% for 1000 hours, the resistance increase was as good as 10% or less, as in the temperature cycle test. As a result of cross-sectional observation of the joint using an electron microscope, a plate-like Cu ₆ Sn ₅ compound extending in a direction from one terminal to the other terminal is formed between the terminals of the circuit board and the semiconductor package. It was confirmed.

Regarding the embodiment described above, the following additional notes are further disclosed.
(Additional remark 1) The 1st electronic component provided with the 1st terminal,
A second electronic component comprising a second terminal facing the first terminal;
An electronic device comprising: a joining portion that contains a plate-like first compound that joins the first terminal and the second terminal and extends in a direction from the second terminal toward the first terminal.

(Additional remark 2) The said junction part has a part which covers the said 1st compound,
The portion includes a first element and a second element;
The electronic device according to claim 1, wherein the first compound is an intermetallic compound including the first element and the second element.

  (Additional remark 3) The said junction part contains the said 1st compound and the columnar 2nd compound extended in the direction which goes to the said 1st terminal from the said 2nd terminal, The electronic device of Additional remark 1 characterized by the above-mentioned. .

(Additional remark 4) The said junction part has a part which covers the said 1st compound and the said 2nd compound,
The portion includes a first element, a second element, and a third element;
The first compound is an intermetallic compound including the first element and the second element,
The electronic device according to appendix 3, wherein the second compound is an intermetallic compound including the first element and the third element.

(Supplementary note 5) The electronic device according to any one of supplementary notes 1 to 4, further comprising a first member provided in the first electronic component and having a first heat capacity.
(Additional remark 6) The electronic device of Additional remark 5 characterized by the heat capacity of the said 1st electronic component in which the said 1st member was provided being larger than the heat capacity of the said 2nd electronic component.

(Additional remark 7) The process which makes the 1st terminal provided in the 1st electronic component and the 2nd terminal provided in the 2nd electronic component oppose via a bonding material,
Heating and melting the bonding material, and connecting the first terminal, the bonding material and the second terminal;
In a state where the first electronic component is at a higher temperature than the second electronic component, the bonding material is cooled and solidified, and extends into the bonding material in a direction from the second terminal toward the first terminal. And a step of depositing a plate-like compound.

(Additional remark 8) The said compound is an intermetallic compound containing a 1st element and a 2nd element,
The bonding material includes a first bonding material provided on the first terminal and a second bonding material provided on the second terminal,
A solder material containing at least the first element of the first element and the second element is used for the first bonding material and the second bonding material,
The method for manufacturing an electronic device according to appendix 7, wherein the solder material of the second bonding material contains a powder material of the second element.

(Supplementary Note 9) The method further includes a step of providing the first electronic component with a first member having a first heat capacity,
Supplementary note 7 or 8, wherein the first terminal of the first electronic component provided with the first member is opposed to the second terminal of the second electronic component via the bonding material. The manufacturing method of the electronic device as described in any one of.

(Supplementary note 10) The method for manufacturing an electronic device according to supplementary note 9, further comprising a step of removing the first member after the step of precipitating the compound.
(Appendix 11) The step of providing the first member includes a step of bonding the first member to the first electronic component using an adhesive.
The manufacturing method of the electronic device according to appendix 10, wherein the step of removing the first member includes a step of reducing the adhesive force of the adhesive and removing the first member from the first electronic component. Method.

  (Supplementary Note 12) The step of cooling and solidifying the bonding material includes the first electronic component and the second electronic component such that the first electronic component has a higher temperature than the second electronic component. The method for manufacturing an electronic device according to appendix 7 or 8, comprising a step of selectively cooling two electronic components.

  (Supplementary Note 13) The step of cooling and solidifying the bonding material includes the first electronic component and the second electronic component such that the first electronic component has a higher temperature than the second electronic component. The method for manufacturing an electronic device according to appendix 7 or 8, comprising a step of selectively heating one electronic component.

1, 1A, 1Aa, 1Ab, 1B, 1Ba, 1Bb, 1C Electronic device 10, 20 Electronic component 10a, 20a, 40a, 50a Surface 11, 21, 41, 51, 121a, 211a, 311a, 420a, 431a, 511a, 630a Terminal 11a, 11b, 41a, 41b, 51a, 51b Electrode layer 30, 60 Joint part 30a, 30b, 60a, 60b Joint material 30ba Solder paste 30bb, 30c Cu powder 31, 33, 61 Compound 32, 62 Part 40, 500 , 600 Circuit board 40b Lower surface 50, 200, 300, 400 Semiconductor package 50b Upper surface 60c Joined part 70A, 70B Member 80a, 80b, 351 Adhesive 91 Air blow 92 Heating 100, 220, 320, 420 Semiconductor element 110 Semiconductor substrate 110a Element isolation Area 1 20,430 Wiring layer 121, 211, 311, 431, 511 Conductor portion 122, 212, 312, 432, 512 Insulating portion 130 MOS transistor 131 Gate insulating film 132 Gate electrode 133 Source region 134 Drain region 135 Spacer 210, 310 Package substrate 230 Sealing layer 240 Die attach material 250 Wire 330 Coating material 340 Bump 341 Underfill material 350 Thermal interface material 410 Resin layer 610 Core substrate 620 Insulating layer 630 Conductive pattern 640 Via 1000 Manufacturing apparatus 1100 Arrangement unit 1200 Heating unit 1300 Cooling unit 1310 , 1320, 1330 Temperature control device

Claims (8)

A first electronic component comprising a first terminal;
A second electronic component comprising a second terminal facing the first terminal;
The first terminal and the second terminal are joined, extend in a direction from the second terminal toward the first terminal, and a direction intersecting with the direction from the second terminal toward the first terminal is defined as a normal direction. electronic device characterized by comprising a joint portion containing a first compound of a plate-shaped Cu ₆ Sn ₅ having a pair of main surfaces. The joint has a portion covering the first compound,
It said part, electronic device according to claim 1, characterized in including that Sn and Cu.   2. The electronic device according to claim 1, wherein the joint portion includes the first compound and a columnar second compound extending in a direction from the second terminal toward the first terminal. The joint has a portion covering the first compound and the second compound,
The portion includes Sn , Cu, and Ag .
Before Stories second compound, electronic device according to claim 3, characterized in that the Ag ₃ Sn. A step of causing a first terminal provided in the first electronic component and a second terminal provided in the second electronic component to face each other through a bonding material;
Heating and melting the bonding material, and connecting the first terminal, the bonding material and the second terminal;
In a state where the first electronic component is at a higher temperature than the second electronic component, the bonding material is cooled and solidified, and extends into the bonding material in a direction from the second terminal toward the first terminal. characterized in that it comprises a step of precipitating a compound of a plate-shaped Cu ₆ Sn ₅ having a pair of main surfaces a direction intersecting the direction from the second terminal to the first terminal to the normal direction A method for manufacturing an electronic device. Before SL bonding material includes a first bonding material disposed on said first terminal, and a second bonding material disposed on said second terminal,
For the first bonding material and the second bonding material, a solder material containing at least the Sn among Sn and Cu is used.
6. The method of manufacturing an electronic device according to claim 5, wherein the solder material of the second bonding material includes the Cu powder material. A step of providing the first electronic component with a first member having a first heat capacity;
The first terminal of the first electronic component provided with the first member and the second terminal of the second electronic component are opposed to each other through the bonding material. 6. A method for manufacturing an electronic device according to 6.   The step of cooling and solidifying the bonding material includes the second electronic component out of the first electronic component and the second electronic component so that the first electronic component is hotter than the second electronic component. The method for manufacturing an electronic device according to claim 5, further comprising a step of selectively cooling.

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