JP2019009216A - Manufacturing method of semiconductor device and semiconductor device - Google Patents

Abstract

To provide a manufacturing method of a semiconductor device capable of easily suppressing generation of voids in a solder portion joining a joint portion of a first member and a joint portion of a second member, and a semiconductor device.SOLUTION: In a manufacturing method of a semiconductor device 1 according to the present disclosure in which an electrode pad 15 of a printed board 10 and an electrode pad 17 of a power element 11 are joined via a solder, prior to a reflow process, a solder resist is applied radially (for example, in a cross shape) from a center portion 15a of the electrode pad 15 toward an outer peripheral portion 15b by the electrode pad 15 of the printed board 10.SELECTED DRAWING: Figure 4

Description

  The present disclosure relates to a method for manufacturing a semiconductor device used as a drive circuit such as a motor, and the semiconductor device.

  Patent Document 1 discloses a semiconductor power module manufactured by bonding a conductive layer of an insulating substrate and a lower surface of a semiconductor chip via solder.

JP 2006-54227 A

  When manufacturing a semiconductor device, when a reflow process is performed to join the substrate and the semiconductor chip via solder, the flux gas contained in the solder remains and voids are generated in the solidified solder. There is a fear. Here, in Patent Document 1, the rosin-less flux paste solder disposed between the semiconductor chip and the conductive layer of the insulating substrate is evacuated to promote the void defoaming effect due to the effect of decompression by evacuation. ing. However, in order to perform such evacuation, it is very troublesome to use a vacuum soldering furnace or perform evacuation several times.

  Therefore, the present disclosure has been made to solve the above-described problems, and a semiconductor device manufacturing method and a semiconductor device that can easily suppress generation of voids in a solder portion that joins a first member and a second member. The purpose is to provide.

  One form of this indication made in order to solve the said subject WHEREIN: In the manufacturing method of the semiconductor device which joins the junction part of a 1st member, and the junction part of a 2nd member via solder, joining of the said 1st member The solder resist is applied radially between the central portion and the outer peripheral portion of the joint portion of the first member.

  According to this aspect, during the reflow process, the gas contained in the solder by the solder gathered at the center of the joint of the first member is changed from the center of the joint of the first member to the outer periphery along the solder resist. Is pushed toward the outside and sent to the outside of the solder part. Therefore, it is possible to easily suppress the generation of voids in the solder portion that joins the first member and the second member.

  In the above aspect, it is preferable to apply the solder resist in a cross shape.

  According to this aspect, during the reflow process, the gas contained in the solder is collected along the solder resist provided in a cross shape by the solder collected at the center of the joint of the first member. It is pushed in all directions from the center to the outer periphery and sent to the outside of the solder part. Therefore, generation of voids in the solder portion that joins the first member and the second member can be more easily suppressed more effectively.

  Another aspect of the present disclosure made to solve the above-described problem is a method of manufacturing a semiconductor device in which a joint portion of a first member and a joint portion of a second member are joined via solder. When the solder is applied at the joint portion to form the solder portion, the heat capacity of the solder portion is made smaller at the center side of the solder portion than at the outer peripheral side.

  According to this aspect, at the time of the reflow process, after the solder portion starts to solidify from the central portion side, the solder portion is easily solidified in order toward the outer peripheral portion side. Therefore, the gas contained in the solder is sent from the central portion side of the solder portion toward the outer peripheral portion side, and easily escapes to the outside of the solder portion. Therefore, it is possible to easily suppress the generation of voids in the solder portion that joins the first member and the second member.

  In said aspect, it is preferable to form the external shape of the said solder part into a rectangle or a square, and to make a slit along the diagonal of the said external shape in the said solder part.

  According to this aspect, the solder portion can be divided into four triangular divided solder portions. Specifically, the divided solder portion of the solder portion can be formed into a triangle having the vertex at the center side of the solder portion. And thereby, about the heat capacity of a solder part, the center part side of a solder part can be made smaller than the outer peripheral part side.

  In the above aspect, it is preferable to apply a solder resist to the slit portion.

  According to this aspect, even when the solder collects at the center of the solder portion during the reflow process, the gas contained in the solder is pushed along the solder resist from the center of the solder portion toward the outer peripheral portion. Therefore, generation of voids in the solder portion that joins the first member and the second member can be more easily suppressed more effectively.

  In the above aspect, it is preferable that the joint portion of the first member is an electrode portion provided on a substrate, and the joint portion of the second member is an electrode portion provided on an electronic component.

  According to this aspect, generation | occurrence | production of the void in the solder part which joins the electrode part of a board | substrate and the electrode part of an electronic component can be suppressed easily. Therefore, when heat generated in the electronic component is radiated through the solder portion, it is difficult for thermal expansion due to voids that inhibit the heat radiation to be added, so that the bonding quality can be maintained. Thus, according to this aspect, it is possible to improve the life of the solder joint and the heat dissipation performance at the portion where the electrode portion of the substrate and the electrode portion of the electronic component are joined.

  Another aspect of the present disclosure made in order to solve the above problem is that in the semiconductor device in which the joint portion of the first member and the joint portion of the second member are joined via solder, the joint portion of the first member The solder resist portion is formed by applying the solder resist radially between the central portion and the outer peripheral portion of the joint portion of the first member.

  According to this aspect, during the reflow process, the gas contained in the solder by the solder gathered at the center of the joint of the first member is changed from the center of the joint of the first member to the outer periphery along the solder resist. Is pushed toward the outside and sent to the outside of the solder part. Therefore, it is possible to easily suppress the generation of voids in the solder portion that joins the first member and the second member.

  Another aspect of the present disclosure made in order to solve the above problem is that in the semiconductor device in which the joint portion of the first member and the joint portion of the second member are joined via solder, the joint portion of the first member The solder part is provided with a solder part, and the heat capacity of the solder part is smaller at the center part side than the outer peripheral part side.

  According to this aspect, at the time of the reflow process, the solder portion starts to solidify from the central portion side, and then solidifies sequentially to the outer peripheral portion side. Therefore, the gas contained in the solder is sent from the central portion side of the solder portion toward the outer peripheral portion side, and easily escapes to the outside of the solder portion. Therefore, it is possible to easily suppress the generation of voids in the solder portion that joins the first member and the second member.

  According to the semiconductor device manufacturing method and the semiconductor device of the present disclosure, it is possible to easily suppress the generation of voids in the solder portion that joins the first member and the second member.

It is an external appearance perspective view which shows schematic structure of a semiconductor device. It is sectional drawing of the junction part of a printed circuit board and a power element (semiconductor chip). It is sectional drawing of the junction part of a printed circuit board and IC (semiconductor chip). In 1st Embodiment, it is a figure which shows when the printed circuit board before a reflow process is seen from the side in which a power element is mounted. It is AA sectional drawing of FIG. In 1st Embodiment, it is a figure which shows the time of seeing the printed circuit board at the time of a reflow process from the side in which a power element is mounted. It is BB sectional drawing of FIG. In 2nd Embodiment, it is a figure which shows the time of seeing the printed circuit board before a reflow process from the side in which a power element is mounted. In 3rd Embodiment, it is a figure which shows when the printed circuit board before a reflow process is seen from the side in which a power element is mounted.

<First Embodiment>
A semiconductor device and a method for manufacturing the semiconductor device according to an embodiment of the present disclosure will be described in detail with reference to the drawings.

  As shown in FIG. 1, the semiconductor device 1 includes a printed circuit board 10, a power element (MOSFET, transistor) 11 and an IC (integrated circuit) 12 (for example, a semiconductor chip (electronic component) mounted on the printed circuit board 10). With heat dissipation terminal).

  Here, as shown in FIGS. 2 and 3, a pattern 13 (copper foil) and a solder resist portion 14 a are provided on the printed circuit board 10 at the junction between the printed circuit board 10 and the power element 11 and the IC 12. ing. And the power element 11 or IC12 is provided via the solder part 16 on the electrode pad 15 (large sized land) formed of the pattern 13 in the opening part of the solder resist part 14a. That is, as shown in FIG. 2, the electrode pad 15 (electrode part) provided on the printed circuit board 10 and the electrode pad 17 (electrode part such as a gate terminal or source terminal) provided on the power element 11 are relatively And a drain terminal having a large area) are joined via the solder portion 16. Further, as shown in FIG. 3, the electrode pad 15 provided on the printed circuit board 10 and the electrode pad 18 (electrode part) provided on the IC 12 are joined via the solder part 16.

  The electrode pad 15 provided on the printed circuit board 10 is an example of the “joining portion of the first member”. Further, the electrode pad 17 provided in the power element 11 and the electrode pad 18 provided in the IC 12 are examples of the “joining portion of the second member”. The electrode pad 15 is provided on the surface of the printed circuit board 10 on which the power element 11 and the IC 12 are mounted, and the electrode pads 17 and 18 are provided on the surface of the power element 11 and IC 12 on the side on which the printed circuit board 10 is disposed. Has been

  Next, a method for manufacturing the semiconductor device 1 will be described. In addition, since the junction part (refer FIG. 2) of the printed circuit board 10 and the power element 11 and the junction part (refer FIG. 3) of the printed circuit board 10 and IC12 are substantially common, the following is printed. A joint portion between the substrate 10 and the power element 11 will be described as a representative.

  In the present embodiment, in the method for manufacturing the semiconductor device 1, the electrode pad 15 of the printed circuit board 10 and the electrode pad 17 of the power element 11 are joined via solder by reflow processing. Note that the reflow treatment here refers to printing a solder paste (a solder powder with a flux added to an appropriate viscosity) on the printed circuit board 10 and placing the power element 11 thereon to apply heat. This process melts the solder.

  Here, when joining the printed circuit board 10 and the power element 11 through solder by reflow processing, conventionally, there is a possibility that voids are generated in the solder after joining. The reason may be that the solder starts to solidify from the periphery with high heat dissipation and the flux volatile component (flux gas) generated in the center of the solder is difficult to escape to the outside. When voids are generated in the solder in this way, when heat generated in the power element 11 is radiated through the solder, thermal expansion due to voids that inhibit the heat dissipation is added, and the bonding quality (solder strength (repetitive strength) Including))). As a result, the solder joint life and heat dissipation performance deteriorate at the joint between the printed circuit board 10 and the power element 11.

  Therefore, in the present embodiment, before performing the reflow process, as shown in FIG. 4, the solder resist is applied (applied) in a cross shape on the electrode pad 15 of the printed circuit board 10, and the solder resist portion 14b is formed in a cross shape. To form. Specifically, as shown in FIG. 4, the solder resist portion 14 b is formed in a cross shape so that two orthogonal straight lines intersect at the center portion 15 a of the electrode pad 15.

  In the present embodiment, the solder resist portion 14a is formed on the outer portion of the outer peripheral portion 15b of the electrode pad 15 so that the solder paste does not flow outside the electrode pad 15 during reflow processing described later. . Further, in FIG. 4, for convenience of explanation, the solder resist portion 14 b is indicated by hatching.

  Also, before performing the reflow process, as shown in FIG. 4, a solder paste is printed (applied) on the electrode pads 15 of the printed board 10. At this time, in the solder part 16 on which the solder paste is printed, the outer shape of the solder part 16 is formed in a square shape, and a cross-shaped slit 19 (gap, cut) is formed in the solder part 16. Thus, the solder portion 16 is divided into four square divided solder portions 20. Further, in the present embodiment, the solder resist is applied to the slits 19, whereby the solder resist portion 14 b is formed in a cross shape as described above.

  Here, the “outer shape of the solder portion 16” is an outer shape of an area where the four square divided solder portions 20 arranged with the slit 19 interposed therebetween, and more specifically, the four divided solder portions 20. It is the shape formed by connecting the outer peripheral part 20a. In FIG. 4, the divided solder portion 20 (solder portion 16) is indicated by hatching for convenience of explanation.

  As described above, after forming the solder resist portion 14b and the solder portion 16 on the electrode pad 15 of the printed circuit board 10, the printed circuit board 10 and the printed circuit board 10 are sandwiched between the electrode pad 15 and the electrode pad 17. The power element 11 is overlapped and a reflow process is performed.

  Then, the solder paste melted in each divided solder portion 20 during the reflow process is caused by the surface tension generated between the electrode pad 17 of the power element 11 and the center portion 15a of the electrode pad 15 (that is, the solder portion 16). It is easy to gather in the central part 16a). Here, the solder paste is difficult to join to the solder resist portion 14b. Therefore, the gas (flux gas) contained in the solder paste by the solder paste gathered at the center portion 15a of the electrode pad 15 causes the electrode pad 15 to move along the solder resist portion 14b (slit 19) formed in a cross shape. It is pushed in all directions from the central portion 15 a toward the outer peripheral portion 15 b and sent to the outside of the solder portion 16. Therefore, the generation of voids in the solder part 16 can be easily suppressed.

  And since generation | occurrence | production of a void can be suppressed easily in this way, when dissipating the heat | fever which generate | occur | produced in the power element 11 via the solder part 16, it becomes difficult to add the thermal expansion by the void which inhibits this heat dissipation, and joining quality (Solder strength (including repeated strength)) can be maintained. Thus, according to the present embodiment, it is possible to improve the life of the solder joint and the heat dissipation performance at the joint portion between the printed board 10 and the power element 11.

  In addition, in the electrode pad 15 of the printed circuit board 10, a solder resist may be applied in an X shape, and the solder resist portion 14b may be formed in an X shape. Or in the electrode pad 15, you may apply | coat a solder resist in the shape where three or more straight lines cross | intersect at one point other than the shape where two straight lines cross like a cross shape or X shape. As described above, the solder resist may be applied radially between the central portion 15a and the outer peripheral portion 15b of the electrode pad 15 to form the solder resist portions 14b radially. At this time, a solder paste is printed on a portion of the electrode pad 15 where the solder resist is not applied.

Second Embodiment
Next, the second embodiment will be described. The same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted, and different points will be mainly described.

  In the present embodiment, when the solder portion 16 is formed on the electrode pad 15 of the printed circuit board 10 before the reflow process, the heat capacity (thermal mass) of the solder portion 16 is set to the outer periphery on the center portion 16a side of the solder portion 16. It is made smaller than the part 16b side. Thus, in this embodiment, the heat capacity distribution is adjusted in the solder portion 16.

  Specifically, as shown in FIG. 8, an X-shaped slit 19 that intersects at the center of the solder portion 16 is inserted into the solder portion 16. That is, the outer shape of the solder portion 16 is formed in a rectangular shape, and slits 19 are formed in the solder portion 16 along diagonal lines of the outer shape of the solder portion 16. Thereby, the solder portion 16 is divided into four triangular divided solder portions 21. Specifically, the divided solder portion 21 is formed in a triangle whose apex is the central portion 16a side of the solder portion 16 (the central portion 15a side of the electrode pad 15). In this way, in the solder portion 16, the width δ of the divided solder portion 21 is gradually increased from the center portion 16a toward the outer peripheral portion 16b, and the center portion 16a side is made smaller than the outer peripheral portion 16b side.

  Note that the outer shape of the solder portion 16 may be formed in a square instead of a rectangle. The “outer shape of the solder portion 16” here is an outer shape of an area where the four triangular divided solder portions 21 arranged with the slit 19 interposed therebetween, and more specifically, the four divided solder portions 21. It is the shape formed by connecting the outer peripheral part 21a. In FIG. 8, the divided solder portions 21 are indicated by hatching for convenience of explanation.

  And after forming the solder part 16 in the electrode pad 15 of the printed circuit board 10 in this way, a reflow process is performed similarly to 1st Embodiment.

  Then, since the center part 16a side is smaller than the outer peripheral part 16b side with respect to the heat capacity of the solder part 16 (the divided solder part 21), the heat dissipation of the solder part 16 is higher on the central part 16a side than on the outer peripheral part 16b side. Therefore, during the reflow process, the solder paste forming the solder portion 16 starts to solidify from the center portion 16a side, and then tends to solidify sequentially toward the outer peripheral portion 16b side. Therefore, the gas contained in the solder paste is sent from the central portion 16 a side of the solder portion 16 toward the outer peripheral portion 16 b side, and easily escapes to the outside of the solder portion 16. Therefore, the generation of voids in the solder part 16 can be easily suppressed.

<Third Embodiment>
Next, the third embodiment will be described. The same components as those in the first and second embodiments are denoted by the same reference numerals, description thereof will be omitted, and different points will be mainly described. In the present embodiment, before performing the reflow process, in addition to performing the second embodiment, a solder resist is applied to the slit 19 portion of the electrode pad 15 of the printed circuit board 10 as shown in FIG. Then, an X-shaped solder resist portion 14b is formed. As a result, even when the solder paste is collected at the center portion 16a of the solder portion 16 during the reflow process, the gas contained in the solder paste extends from the center portion 16a of the solder portion 16 to the outer peripheral portion 16b along the solder resist portion 14b. It is pushed away. Therefore, the generation of voids in the solder part 16 can be easily suppressed. In FIG. 9, the solder resist portion 14b is hatched for convenience of explanation.

  It should be noted that the above-described embodiment is merely an example, and does not limit the present disclosure in any way, and various improvements and modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Semiconductor device 10 Printed circuit board 11 Power element (semiconductor chip)
12 IC (semiconductor chip)
13 patterns (copper foil)
14a Solder resist part 14b Solder resist part 15 Electrode pad 15a Center part 15b Outer part 16 Solder part 16a Center part 16b Outer part 17 Electrode pad 18 Electrode pad 19 Slit 20 Divided solder part 20a Outer part 21 Divided solder part 21a Outer part δ Width

Claims (8)

In the method of manufacturing a semiconductor device in which the joint portion of the first member and the joint portion of the second member are joined via solder,
Applying a solder resist radially between the central portion and the outer periphery of the joint portion of the first member at the joint portion of the first member;
A method of manufacturing a semiconductor device. In the manufacturing method of the semiconductor device of Claim 1,
Applying the solder resist in a cross shape;
A method of manufacturing a semiconductor device. In the method of manufacturing a semiconductor device in which the joint portion of the first member and the joint portion of the second member are joined via solder,
When forming the solder portion by applying solder at the joint portion of the first member,
The heat capacity of the solder part is set so that the center part side of the solder part is smaller than the outer peripheral part side,
A method of manufacturing a semiconductor device. In the manufacturing method of the semiconductor device of Claim 3,
Form the outer shape of the solder part into a rectangle or square,
Slitting the solder part along the diagonal of the outer shape;
A method of manufacturing a semiconductor device. In the manufacturing method of the semiconductor device of Claim 4,
Applying a solder resist to the slit portion;
A method of manufacturing a semiconductor device. In the manufacturing method of the semiconductor device of any one of Claim 1 thru | or 5,
The joint portion of the first member is an electrode portion provided on the substrate,
The joint part of the second member is an electrode part provided in an electronic component;
A method of manufacturing a semiconductor device. In the semiconductor device in which the joint portion of the first member and the joint portion of the second member are joined via solder,
A solder resist portion formed by radially applying a solder resist between a central portion and an outer peripheral portion of the joint portion of the first member at the joint portion of the first member;
A semiconductor device characterized by the above. In the semiconductor device in which the joint portion of the first member and the joint portion of the second member are joined via solder,
In the joint portion of the first member, a solder portion provided with solder is provided,
The heat capacity of the solder part is such that the center part side of the solder part is smaller than the outer peripheral part side,
A semiconductor device characterized by the above.

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