JP2017026382A - Electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic device that can improve reliability.SOLUTION: An electronic device in an embodiment includes: a circuit board including a first surface; an electronic component provided on the first surface; a plurality of connection sections that are situated between the circuit board and the electronic component, and include a first connection section, a second connection section, and a third connection section electrically connecting the circuit board and the electronic component; a first board wiring that is provided on the circuit board and electrically connects the first connection section and the second connection unit; and a first component wiring that is provided on the electronic component and electrically connects the second connection section and the third connection section.SELECTED DRAWING: Figure 3

Description

  Embodiments described herein relate generally to an electronic device.

  An electronic device in which an electronic component is mounted on a substrate is provided, and various tests for evaluating mounting reliability are performed.

JP 2013-125753 A

  Electronic devices are expected to further improve mounting reliability, and accuracy of evaluation of mounting reliability is required.

An electronic device according to an embodiment includes a circuit board having a first surface, an electronic component provided on the first surface, and the circuit board and an external electronic component positioned between the circuit board and the electronic component. A plurality of connection parts including a first connection part, a second connection part, and a third connection part electrically connected, and the first connection part and the second connection part. A first wiring that is electrically connected; and a first wiring that is provided on the electronic component and electrically connects the second connecting portion and the third connecting portion.

The perspective view of the electronic device which concerns on 1st Embodiment. 1 is a perspective view of a host device on which an electronic device according to a first embodiment is mounted. Schematic which looked at the cross section of the electronic device which concerns on 1st Embodiment. The schematic diagram which looked at the upper surface of a substrate. Schematic which looked at the lower surface of the electronic component. The schematic diagram which looked at the upper surface of a substrate. Schematic which looked at the lower surface of the electronic component. The schematic diagram which looked at the upper surface of a substrate. Schematic which looked at the lower surface of the electronic component. Schematic which showed another example which looked at the lower surface of the electronic component.

  Hereinafter, embodiments will be described with reference to the drawings.

  In the present specification, examples of a plurality of expressions are given to some elements. Note that these examples of expressions are merely examples, and do not deny that the above elements are expressed in other expressions. In addition, elements to which a plurality of expressions are not attached may be expressed in different expressions.

  Further, the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like may differ from the actual ones. Moreover, the part from which the relationship and ratio of a mutual dimension differ between drawings may be contained.

(First embodiment)
FIG. 1 shows a perspective view of the electronic device 1. FIG. 2 is a perspective view of the host device 201 on which the electronic device 1 is mounted. In the present embodiment, the electronic device 1 is described as a semiconductor device such as an SSD (Solid State Drive), for example. However, the electronic device 1 is not limited to this, and may be a memory card or the like. It is good as a sample of time.

  In the present embodiment, the host device 201 is described as a notebook portable computer. However, the host device 201 is not limited to this, and may be a video camera, a game device, a tablet terminal, or other detachable notebook PC (Personal Computer). An example is an electronic device.

  As shown in FIG. 1, the electronic device 1 includes a substrate 11 and an electronic component 12, for example. Although the number of electronic components is one here for convenience of explanation, a plurality of electronic components 12 may be mounted on the substrate 11.

  The substrate 11 is a substantially rectangular printed substrate made of a material such as glass epoxy resin, and defines the outer dimensions of the electronic device 1. The board | substrate 11 has the 1st surface 11a and the 2nd surface 11b located in the opposite side to this 1st surface 11a. The first surface 11a is a component mounting surface on which the electronic component 12 is mounted. The electronic device 1 according to the present embodiment has a configuration in which an electronic device 12 is mounted on one side (11a) of a substrate 11. When a plurality of electronic components 12 are provided on the substrate 11, the electronic components 12 may be mounted on both the first surface 11a and the second surface 11b.

  The substrate 11 includes a first edge portion 11c and a second edge portion 11d located on the opposite side of the first edge portion 11c. The first edge part 11c has an interface part 15 (substrate interface part, terminal part). The interface unit 15 includes, for example, a plurality of connection terminals 15a (metal terminals). The interface unit 15 exchanges signals (control signals and data signals) between the interface unit 15 and the host device 201.

  The interface unit 15 according to the present embodiment is an interface conforming to a standard such as SATA (Serial Advanced Technology Attachment) or PCIe (Peripheral Component Interconnect Express). That is, a high-speed signal (high-speed differential signal) conforming to the standard flows between the interface unit 15 and the host device 201. Note that the interface unit 15 may conform to other standards, for example. The electronic device 1 is supplied with power from the host device 201 via the interface unit 15.

  The interface unit 15 has a slit 15b formed at a position shifted from the center position along the short direction of the substrate 11, and a protrusion provided on a connector (not shown) provided on the host device 201. It comes to fit. Thereby, it is possible to prevent the electronic device 1 from being attached upside down.

  The electronic component 12 may include a memory chip for causing the electronic device 1 to function as an external memory of the host device 201, a controller chip for controlling the electronic component 12, or a controller, for example. A chip and a memory chip may be stacked to form a single package.

As shown in FIG. 2, the main body 202 of the host device 201 is provided with a display unit housing 203 so as to be rotatable via a hinge mechanism 202a. The main body 202 is provided with operation units such as a touch pad 204 and a keyboard 205. The display unit housing 203 is provided with a display device 206 such as an LCD (Liquid Crystal Display).
The main body 202 is provided with a printed circuit board (mother board) 207 in which an operation unit such as the touch pad 204 and the keyboard 205 and a control circuit for controlling the display device 206 are incorporated. The electronic device 1 is used as an external memory of the host device 201, for example.

  The above-described electronic device 1 such as an SSD generally performs mounting reliability evaluation in product development. As an example of the mounting reliability evaluation method, there is a method of applying a physical shock or a thermal shock by daisy chain connecting the wiring of the mounting board and the component.

  A mounting substrate such as the substrate 11 contracts, for example, when heat is applied, and the substrate 11 itself may be distorted. At this time, the substrate 11 and the electronic component 12 may be cracked. Furthermore, when the board | substrate 11 is distorted, there exists a possibility that the solder joint part (after-mentioned) which electrically connects the board | substrate 11 and the electronic component 12 may fracture | rupture.

  Below, the wiring method of the electronic device 1 which concerns on 1st Embodiment is demonstrated.

  3 to 5 are schematic views showing a wiring method of the electronic device 1 according to this embodiment. 3 is a cross-sectional view of the electronic device 1, FIG. 4 is a top view of the substrate 11 (first surface 11a side), and FIG. 5 is a bottom view of the electronic component 12 (package substrate 20 side). As described above, the electronic component 12 is a package in which the chip 21 is sealed, but in FIG. 3, the sealing portion is omitted for convenience of explanation.

  As shown in FIG. 3, the electronic component 12 has a structure in which a chip 21 is provided via a mount film 22 on a package substrate 20 having a substantially rectangular shape, for example. The package substrate 20 has a first surface 20a and a second surface 20b positioned opposite to the first surface 20a, and a plurality of protrusions protruding from the first surface 20a are provided on the first surface 20a side. A solder ball 23 is provided, and the chip 21 is provided on the second surface 20b via the mount film 22 as described above.

  Note that examples of the method for mounting the chip 21 on the package substrate 20 include wire bonding connection, tape automated bonding connection, and flip chip connection. The electronic component 20 is a semiconductor package such as a BGA type (Ball Grid Array) or a CSP (Chip Sized Package) type.

  The substrate 11 has a first surface 11a and a second surface 11b. A plurality of pads 31 are provided on the first surface 11 a of the substrate 11 in a region facing the solder balls 23 of the electronic component 12 described above. In the present embodiment, the mounting area corresponds to an area facing the solder ball 23 provided on the electronic component 12. The substrate 11 may be a single layer board or a multilayer board. The substrate 11 may have wirings and electrodes on the first surface 11a and the second surface 11b, or in the inner layer if it is a multilayer board. A solder resist may be applied to the first surface 11a and the second surface 11b.

  As shown in FIG. 4, in the present embodiment, an electrode 32 a and an electrode 32 b are provided on the first surface 11 a of the substrate 11. Each of the electrode 32a and the electrode 32b is electrically connected to one of the plurality of pads 31 (here, the pad 31a and the pad 31b) via the electrode wiring 33a and the electrode wiring 33b.

  In the present embodiment, the electrode 32a and the electrode 32b are connected to one of the plurality of pads 31 via the electrode wiring 33a and the electrode wiring 33b provided exposed on the first surface 11a of the substrate 11, respectively. Although described as being performed, the connection may be made using, for example, the internal wiring of the substrate 11.

  Further, as the electrode 32a and the electrode 32b, for example, as shown in FIG. 1, a component protruding from the surface of the first surface 11a of the substrate 11 may be used, or the electrode 32a and the electrode 32b having a conductor pattern exposed on the first surface may be used. It is also good. Further, the conductive material line connected to the pad 31a and the pad 31b may be exposed to the outside from a position overlapping the package substrate 20 on the substrate 11, and these may be used as the electrode 32a and the electrode 32b. At this time, the shapes of the electrode 32a and the electrode 32b are not limited.

  As shown in FIG. 5, a plurality of solder balls 23 are provided at positions corresponding to the plurality of pads 31 on the lower surface of the electronic component 12, that is, the first surface 20 a of the package substrate 20. The plurality of solder balls 23 are electrically connected to the plurality of pads 31 one by one, and each serves as a connection portion. The pad 31a and the pad 31b are electrically connected to the solder ball 23a and the solder ball 23b, respectively. Note that FIG. 5 shows an inverted drawing so that the positional relationship with the plurality of pads 31 shown in FIG. 4 can be easily understood. At this time, the number of the plurality of solder balls 23, the number of the plurality of pads 31, the positions of the other electrodes 31a and 31b, and the like are not limited to those shown in FIGS.

  Further, as shown in FIG. 4, a plurality of substrate wirings 35 are provided on the first surface 11 a of the substrate 11. Further, as shown in FIG. 5, a plurality of component wirings 25 are provided on the first surface 20 a of the package substrate 20. Each of the plurality of substrate wirings 35 and the plurality of component wirings 25 is made of a conductive material, for example, a conductive wire, but is not limited thereto.

  As shown in FIG. 3, in the electronic device 1, all of the plurality of solder balls 23 and the plurality of pads 31 are connected in series from the electrode 32a to the electrode 32b via the plurality of substrate wirings 35 or the plurality of component wirings 25. Therefore, the resistance value from the electrode 32a to the electrode 32b can be obtained by using a tester or the like.

  In the electronic device 1 such as an SSD, the electronic component 12 generates heat during operation. Further, during the operation of the electronic device 1, the plurality of pads 31 connected to the plurality of solder balls 23 may also become high temperature.

  On the other hand, in the electronic device 1, the substrate 11 is made of a material such as a glass epoxy resin, and there is a possibility that the substrate 11 may be deformed as the temperature changes as described above. Specifically, thermal expansion occurs from a portion that becomes high temperature during operation, and presses the surrounding area. As a result, the substrate 11 is distorted and bent around the mounting area of the electronic component 12.

  Here, since the substrate 11 and the package substrate 20 of the electronic component 12 have different coefficients of thermal expansion, the stress concentrates on the plurality of solder balls 23 fixed between them, so that the plurality of solder balls 23 may be dissolved, cracks may occur on the surfaces of the substrate 11 and the package substrate 20.

  A signal received by the electronic device 1 is transmitted from the host device 201 to the electronic component 12 from the plurality of solder balls 23 through the internal circuit of the substrate 11 through the interface unit 15. At this time, when some of the plurality of solder balls 23 are melted for the above-described reason and are not electrically connected to the plurality of pads 31, signals are not correctly transferred from the host device 201 to the electronic component 12, This greatly affects the operational reliability of the electronic device 1.

  Further, a circuit (not shown) for operating the electronic device 1 exists on the surface of the substrate 11 and the surface of the package substrate 20. Cracks generated for the above-described reasons affect the operation of the circuit and may affect the operation reliability of the electronic device 1.

  Therefore, in the present embodiment, the plurality of solder balls 23 provided on the first surface 20 a of the package substrate 20 in the electronic component 12 are all connected in series via the plurality of substrate wirings 35 or the plurality of component wirings 25. . Therefore, for example, when the resistance value between the electrode 32a and the electrode 32b is measured as described above before and after the thermal load is applied to the electronic device 1, the values are different. It can be determined that the solder balls 23 are melted and the plurality of substrate wirings 35 or the plurality of component wirings 25 are disconnected.

  Further, in the wiring method of the electronic device 1 of the present embodiment, not only the substrate wiring 35 but also the component wiring 25 is used. By providing wiring on the electronic component 12 side in this way, it is possible to detect cracks generated in the electronic component 12 and contribute to improvement in both mounting reliability and operation reliability of the electronic device 1.

  This embodiment is very effective, for example, for sample evaluation before product shipment. If the plurality of substrate wirings 35 or the plurality of component wirings 25 are disconnected, the part is more stressed than the other parts, and the circuit is not arranged as much as possible at the time of product manufacture. Etc. are possible.

  In addition, the present embodiment is not necessarily limited to the sample evaluation described above, and may be mounted on a product as it is. In that case, the electronic device 1 may be provided with not only the solder ball 23 for operating the electronic device 1 but also a solder ball that does not contribute to the operation of the electronic device 1.

(Second Embodiment)
Next, a wiring method according to the second embodiment will be described. In the description of the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. The positional relationship between the plurality of solder balls 23 and the plurality of pads 31 is the same as that in the first embodiment, and a description thereof is omitted.

  6 and 7 are schematic views showing a wiring method of the electronic device 1 according to this embodiment. 6 is a top view of the substrate 11 (first surface 11a side), and FIG. 7 is a bottom view of the electronic component 12 (package substrate 20 side). Note that FIG. 7 shows an inverted drawing so that the positional relationship with the plurality of pads 31 shown in FIG. 6 can be easily understood.

  In the present embodiment, an electrode 32a, an electrode 32b, an electrode 32c, and an electrode 32d are provided on the first surface 11a of the substrate 11. As in the first embodiment, these are each one of a plurality of pads 31 (here, pad 31a, pad 31b, pad 31c, and pad 31d) and electrode wiring 33a, as shown in FIG. They are electrically connected via the electrode wiring 33b, the electrode wiring 33c, and the electrode wiring 33d.

  In the present embodiment, the electrode 32a, the electrode 32b, the electrode 32c, and the electrode 32d are also exposed on the first surface 11a of the substrate 11 and provided with the electrode wiring 33a, the electrode wiring 33b, the electrode wiring 33c, and the electrode. Each is connected to one of the plurality of pads 31 via the wiring 33d, but may be connected using, for example, an internal wiring of the substrate 11.

  In the present embodiment, a circuit that connects a plurality of solder balls 31 between the electrodes 32a to 32c in series and a circuit that connects a plurality of solder balls 31 between the electrodes 32b to 32d in series are configured. Is done. Such a wiring method is very effective when the number of the plurality of solder balls 31 is large.

  For example, the resistance value between the electrode 32a and the electrode 32c was measured before and after the operation of the electronic device 1, and no change was observed in the value, but the resistance value between the electrode 32b and the electrode 32d was If the values are measured before and after the operation and a change is observed, the region where the abnormality such as the melting or cracking of the solder has occurred can be specified as half of the region where the plurality of solder balls 23 are provided, thereby narrowing the analysis range. It is possible.

  In the present embodiment, the description is divided into two series circuits. However, when the number of the plurality of solder balls 23 is larger, the number of electrodes can be increased and the resistance value of more series circuits can be measured. Any configuration may be used.

(Third embodiment)
Next, a third embodiment will be described. In the description of the third embodiment, the same components as those in the first embodiment and the second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. The positional relationship between the plurality of solder balls 23 and the plurality of pads 31 is the same as that in the first embodiment, and a description thereof is omitted.

  8 and 9 are schematic views showing a wiring method of the electronic device 1 according to this embodiment. 8 is a top view of the substrate 11 (first surface 11a side), and FIG. 9 is a bottom view of the electronic component 12 (package substrate 20 side). Note that FIG. 9 shows an inverted drawing so that the positional relationship with the plurality of pads 31 shown in FIG. 8 can be easily understood.

  As shown in FIG. 8, in the present embodiment, an electrode 32 a and an electrode 32 b are provided on the first surface 11 a of the substrate 11. Each of the electrode 32a and the electrode 32b is electrically connected to one of the plurality of pads 31 (here, the pad 31a and the pad 31b) via the electrode wiring 33a and the electrode wiring 33b.

  In the present embodiment, the electrode 32a and the electrode 32b are connected to one of the plurality of pads 31 via the electrode wiring 33a and the electrode wiring 33b provided exposed on the first surface 11a of the substrate 11, respectively. However, it may be connected using, for example, the internal wiring of the substrate 11.

  Further, as shown in FIG. 9, a plurality of solder balls 23 are provided at positions corresponding to the plurality of pads 31 on the lower surface of the electronic component 12, that is, the first surface 20 a of the package substrate 20. The plurality of solder balls 23 are electrically connected to the plurality of pads 31 one by one. The pad 31a and the pad 31b are electrically connected to the solder ball 23a and the solder ball 23b, respectively.

  Further, as shown in FIG. 8, a plurality of substrate wirings 35 are provided on the first surface 11 a of the substrate 11. Further, as shown in FIG. 9, a plurality of component wirings 25 are provided on the first surface 20 a of the package substrate 20. The plurality of substrate wirings 35 and the plurality of component wirings 25 are both made of a conductive material, such as a conductive wire, but are not limited thereto.

  8 and 9, all the plurality of solder balls 23 and the plurality of pads 31 in the electronic device 1 are connected in series from the electrode 32 a to the electrode 32 b via the plurality of substrate wirings 35 or the plurality of component wirings 25. The Therefore, the resistance value from the electrode 32a to the electrode 32b can be obtained by using a tester or the like.

  In the present embodiment, the plurality of component wirings 25 provided on the package substrate 20 are intentionally drawn and connected between the solder balls. As described above, whether or not a crack has occurred in the electronic device 1 is determined from a difference in resistance values before and after the operation of the electronic device 1. Therefore, in this embodiment, since the wiring length is longer than that in the first embodiment, the resistance value at the time of measurement is increased, but it does not affect the detection of the occurrence of a crack.

  Further, in the present embodiment, a wider range of cracks can be detected by routing a plurality of component wirings 25. In the first to third embodiments, a crack can be detected when a disconnection due to a crack occurs in the plurality of substrate wirings 35 or the plurality of component wirings 25. Therefore, it is desirable that the plurality of substrate wirings 35 or the plurality of component wirings 25 be routed over as wide a range as possible.

  In the present embodiment, only the plurality of component wirings 25 are routed, but a plurality of substrate wirings 35 may also be routed. In this case, a region where the plurality of component wirings 25 and the plurality of substrate wirings 35 overlap in plan view occurs, but as can be seen from FIG. 3, the first surface 20 a of the package substrate 20 and the first surface 11 a of the substrate 11. A plurality of solder balls 23 and a plurality of pads 31 exist between the first surface 20a and the first surface 20a of the package substrate 20 and the first surface 11a of the substrate 11 are kept apart.

  Accordingly, even when a region where the plurality of component wirings 25 and the plurality of substrate wirings 35 overlap each other in plan view, the plurality of component wirings 25 and the plurality of substrate wirings 35 do not actually contact each other. It does not affect the measurement. From the above, in the present embodiment, it is desirable that the plurality of component wirings 25 and the plurality of substrate wirings 35 are routed in a wider range.

  Further, when the substrate 11 or the package substrate 20 is cracked or the connection portion is broken due to the distortion of the substrate 11 due to a thermal load, these phenomena often occur from the edge side of the substrate 11 and the package substrate 20.

  Therefore, when it is difficult to route the plurality of substrate wirings 35 and the plurality of component wirings 25 in all regions of the substrate 11 and the package substrate 20, the plurality of substrate wirings 35 and the plurality of component wirings 25 are connected to the substrate 11. In addition, on the surface of the package substrate 20, wiring may be performed particularly near the edge.

  FIG. 10 is a bottom view of the electronic component 12 (on the package substrate 20 side). As shown in FIG. 10, the diameter of the solder ball 23 (solder balls 23a, 23b, 23c) arranged near the edge of the package substrate 20 is made smaller than the diameter of the other solder balls 23 (solder balls 23d). May be.

  As described above, when the electrical connection portion between the substrate 11 and the electronic component 12 is broken, the breakage occurs from the edge side of the substrate 11 or the package substrate 20. Making the diameter of the solder balls 23 arranged closer to the edge of the package substrate 20 smaller than the diameter of the other solder balls 23 tends to cause breakage when evaluating the mounting reliability. This is effective in determining and evaluating how much load is applied to the 12.

  For the same reason, a plurality of component wirings 25 arranged near the edge of the package substrate 20 and a plurality of substrate wirings 35 arranged near the edge of the substrate 11 are replaced with other component wirings 25 and substrate wirings 35. Alternatively, a configuration in which the cracks generated in the component wiring 25 and the substrate wiring 35 can be easily detected by making them thin (small in diameter) is also possible.

  In this embodiment, from the viewpoint of product mounting, the component wiring 25 near the edge of the package substrate 20 where cracks are likely to occur is made thicker, or the diameter of the solder balls 23 is made larger to improve mounting reliability. It is also possible to adopt a simple configuration.

  In the present embodiment, since the plurality of component wirings 25 and the plurality of substrate wirings 35 are routed in a wide range, cracks can be detected in a wider range.

  As mentioned above, although several embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Electronic device, 11 Substrate, 12 Electronic component, 15 Interface part, 20 Package substrate, 21 Chip, 22 Mount film, 23 Solder ball, 25 Component wiring, 31 Pad, 32 Electrode, 33 Electrode wiring, 35 Substrate wiring, 201 Host Device, 202 body, 203 display housing, 204 touchpad, 205 keyboard, 206 display device, 207 printed circuit board (motherboard).

Claims (8)

A circuit board having a first surface;
An electronic component provided on the first surface;
A plurality of connection parts including a first connection part, a second connection part, and a third connection part, which are located between the circuit board and the electronic component and electrically connect the circuit board and the electronic component; ,
A first board wiring provided on the circuit board and electrically connecting the first connection part and the second connection part;
A first component wiring provided in the electronic component and electrically connecting the second connecting portion and the third connecting portion;
Electronic device with. The plurality of connecting portions are:
A fourth connection portion located between the electronic component and the circuit board;
The third connection part and the fourth connection part are:
The electronic device according to claim 1, wherein the electronic device is electrically connected by a second board wiring provided on the circuit board. A plurality of substrate wirings including the first substrate wiring are provided on the circuit board,
A plurality of component wirings including the first component wiring are provided in the electronic component,
The plurality of connecting portions are:
The electronic device according to claim 1, wherein the electronic devices are electrically connected in series by either the plurality of substrate wirings or the plurality of component wirings. The plurality of connecting portions are:
The electronic device according to claim 3, wherein the electronic devices are alternately connected in series by the plurality of substrate wirings and the plurality of component wirings. The first component wiring is
The first connection part or the second connection part and the other connection parts included in the plurality of connection parts, excluding the first connection part and the second connection part, are routed between the first connection part and the second connection part. The electronic device according to any one of claims 1 to 4, wherein the first connection portion and the second connection portion are electrically connected. The first component wiring is
The electronic device according to any one of claims 1 to 5, wherein the electronic device is routed toward an edge of the electronic component. The plurality of connecting portions are:
A first connection portion group located along an edge of the electronic component; and a second connection portion group located inside the first connection portion group in the electronic component;
Each of the connection parts included in the first connection part group is
The plurality of connection portions are configured to be smaller than each of the connection portions included in the second connection portion group, and the plurality of connection portions are electrically connected by either the plurality of substrate wirings or the plurality of component wirings. The electronic device according to claim 5, wherein the electronic device is an electronic device. The plurality of substrate wirings and the plurality of component wirings are:
Including an edge wiring for connecting the connection parts included in the first connection part group located along the edge of the electronic component, and other wirings excluding the edge wiring;
The electronic device according to claim 5, wherein the edge wiring is configured to be narrower than the other wiring.

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