JP6390369B2 - Semiconductor mounting equipment - Google Patents

Description

  The present invention relates to a semiconductor mounting apparatus, for example, a semiconductor mounting apparatus in which a semiconductor package substrate is mounted on a mounting substrate.

  In recent years, there is an increasing demand for miniaturization, large current, and low resistance of semiconductor packages. In order to meet this demand, a thicker wiring or a plurality of wirings are being studied in order to supply power from the periphery of the semiconductor package substrate.

  FIG. 6 is an explanatory diagram of a conventional semiconductor device mounting structure. A plurality of through power supply lines 73 for supplying power to the wiring substrate 71 provided with the power supply wiring 72 are provided, and the package substrate 61 on which the semiconductor bare chip 62 is mounted on the wiring substrate 71 via BGA (Ball Grid Array) bumps 63. Connected. The semiconductor bare chip 62 is actually filled with an underfill resin between the package substrate 61 and the surface side is molded with a mold resin.

  However, in general, such a through power supply line 73 has a limited space that is allowed depending on the size of the package substrate. Therefore, when an attempt is made to realize a large current or a low resistance by increasing the number of wires or increasing the number of wires, the semiconductor package It becomes difficult to achieve a balance with downsizing.

  In order to deal with this problem, it has been proposed to form a Cu electrode in a region directly under the semiconductor bare chip and to supply power directly from directly under the semiconductor bare chip. FIG. 7 is an explanatory view of an improved mounting structure of a conventional semiconductor device. As shown in the figure, a thick Cu power supply electrode 74 is provided at the center of the wiring board 71, and the BGA bump 63 and this Cu power supply electrode 74 are connected directly below the semiconductor bare chip 62. The Cu power supply electrode 74 is connected to a BGA bump 82 provided on a power supply unit 80 in which a DC power transformer 83 is mounted on a mounting substrate 81.

  The current is directly supplied from directly below the semiconductor bare chip 62 by the Cu power supply electrode 74 through the external power supply wiring 84 and the DC power supply transformer 83. Therefore, it is possible to achieve both a large current and low resistance by making the power supply electrode thicker and the shortest distance, and a reduction in the size of the semiconductor package.

JP 2005-045013 A JP 2009-170493 A

  However, in the structure of FIG. 7, when the temperature of the semiconductor package fluctuates and the warpage of the semiconductor package substrate occurs, a tensile stress is generated in the BGA bump connected to the Cu power supply electrode directly under the semiconductor bare chip, causing a contact failure. There is a problem.

  FIG. 8 is an explanatory view of the problem of the improved mounting structure of the conventional semiconductor device. When the temperature fluctuates, the package substrate 61 warps due to a difference in thermal expansion coefficient between materials used for the package substrate 61, a difference in thermal expansion coefficient between the package substrate 61 and the wiring substrate 71, or the like. To do. When warping occurs, tensile stress is generated in the BGA bump 63 connected to the Cu power supply electrode 74 directly below the semiconductor bare chip 62 as shown by a dashed ellipse in the figure, and between the package substrate 61 and the Cu power supply electrode 74. Contact failure occurs.

  In the case of the structure of FIG. 7, since the Cu power supply electrode 74 has a length approximately the same as the thickness of the wiring board 71, the power supply path distance corresponding to the length of the Cu power supply electrode 74 is still present. Existing. Depending on the amount of current flowing, even this length of resistance of the Cu power supply electrode 74 can be a factor that hinders power supply.

  Therefore, an object of the semiconductor mounting apparatus is to maintain a good connection with the power supply electrode even when the package is warped.

From one aspect to be disclosed, a package substrate on which a semiconductor chip is mounted, a first wiring substrate having a through hole larger than the outer shape of the package substrate, and a second that is more flexible than the first wiring substrate. A wiring board, wherein the first wiring board and the second wiring board are coupled by a connection electrode, and the package board is inserted into a through-hole provided in the first wiring board. Rutotomoni mounted on the second wiring board, the second power supply unit for supplying power to the package substrate on the surface opposite to the bonding surface of the first wiring substrate of the wiring substrate is disposed, The power supply unit includes a mounting substrate and a columnar power supply electrode provided on the mounting substrate, and the columnar power supply electrode is inserted into a through hole provided in the second wiring substrate and is mounted on the package substrate. In the center It has been kicked connection conductor and electrically connected directly semiconductor mounting device according to claim is provided.

  According to the disclosed semiconductor mounting apparatus, it is possible to maintain good connection with the power supply electrode even when the package is warped. In addition, a power supply structure that can withstand a large current can be realized.

It is a schematic sectional drawing of the semiconductor mounting apparatus of embodiment of this invention. It is explanatory drawing of the effect of the semiconductor mounting apparatus of embodiment of this invention. It is a schematic sectional drawing of the semiconductor mounting apparatus of Example 1 of this invention. It is explanatory drawing to the middle of the manufacturing process of the semiconductor mounting apparatus of Example 1 of this invention. It is explanatory drawing after FIG. 4 of the manufacturing process of the semiconductor mounting apparatus of Example 1 of this invention. It is explanatory drawing of the mounting structure of the conventional semiconductor device. It is explanatory drawing of the improved mounting structure of the conventional semiconductor device. It is explanatory drawing of the problem of the improved mounting structure of the conventional semiconductor device.

  Here, with reference to FIG.1 and FIG.2, the semiconductor mounting apparatus of embodiment of this invention is demonstrated. FIG. 1 is a schematic cross-sectional view of a semiconductor mounting apparatus according to an embodiment of the present invention, in which a package substrate 6 on which a semiconductor chip 7 is mounted and a first wiring substrate having a through hole 2 larger than the outer shape of the package substrate 6. 1 and a second wiring board 3 that is more flexible than the first wiring board 1. The first wiring board 1 is coupled to the second wiring board 3 by connection conductors 5. The package substrate 6 is mounted on the second wiring substrate 3 through the through hole 2 provided in the first wiring substrate 1. Note that the first wiring board is typically a multilayer printed wiring board using FR-4.

  The second wiring substrate 3 is desirably a thin film substrate thinner than the thickness of the first wiring substrate 1, typically a flexible substrate. When the package substrate 6 is warped due to temperature changes due to this flexibility, the flexible substrate is also deformed, and the stress applied to the connection conductor 8, typically BGA bumps, can be greatly reduced.

  The insulating layer used for the second wiring board 3 is not an inhomogeneous structure including glass cloth inside such as FR-4, but an insulating layer having uniform dielectric characteristics in the plane direction. For example, polyimide resin or liquid crystal polymer is desirable. In this way, by using an insulating layer having a uniform dielectric property in the plane direction, the wiring pattern on the second wiring board 3 is used as a transmission line without deteriorating the quality of the high-speed signal. Can be transmitted.

  Further, in order to increase the current and reduce the resistance, a power supply unit 10 that supplies power to the package substrate 6 is provided on the surface of the second wiring substrate 3 opposite to the coupling surface with the first wiring substrate 1. It is desirable to arrange. This power supply unit 10 has a mounting substrate 11 provided with columnar power supply electrodes 13, penetrates through holes 4 provided in the second wiring substrate 3, and is provided at the center of the columnar power supply electrodes 13 and the package substrate 6. The provided connection conductor 8 is directly electrically joined.

  The columnar power supply electrode 13 is fitted into a through-hole provided in the mounting substrate 11 and is typically a Cu columnar electrode or a Cu-based columnar electrode containing Cu as a main component. In particular, it is desirable that the height of the columnar power supply electrode 13 be smaller than the thickness of the first wiring board 1, and thereby the power supply path distance can be further shortened as compared with the conventional case. In addition, it is generally desirable to mount a DC power transformer 12 on the mounting substrate 11.

  FIG. 2 is an explanatory diagram of the operational effects of the semiconductor mounting apparatus according to the embodiment of the present invention. In the embodiment of the present invention, since the package substrate 6 is mounted on the flexible second wiring substrate 3, even if the package substrate 6 is warped, as shown by being surrounded by a broken-line ellipse in the drawing. The second wiring board 3 is deformed following the warping of the package 3. Therefore, the stress applied to the connection conductor 8 (BGA bump) connecting the package substrate 6 and the columnar power supply electrode 13 can be relaxed.

  Further, since the thickness of the second wiring board 3 is made thinner than the thickness of the first wiring board 1, the height of the columnar power supply electrode 13 can be reduced, and the package substrate 6 and the power supply source can be reduced. The distance between them can be shortened.

  As a result, a power supply structure that can maintain a good connection between the second wiring substrate 3 and the connection conductor 6 and can withstand a large current even when the package substrate 6 on which the semiconductor chip 7 is mounted is warped is realized. be able to.

  Next, with reference to FIGS. 3 to 5, a semiconductor mounting apparatus according to the first embodiment of the present invention will be described. FIG. 3 is a schematic cross-sectional view of the semiconductor mounting apparatus according to the first embodiment of the present invention. A wiring substrate 21 having a through hole 22 larger than the outer shape of the package substrate 41 on which the semiconductor bare chip 42 is mounted and a flexible substrate 31 having a higher flexibility than the wiring substrate 21 and provided with the through hole 32 are joined by a BGA bump 33. The wiring board 21 is a multilayer printed wiring board using FR-4.

  The package substrate 41 on which the semiconductor bare chip 42 is mounted is inserted into the through hole 22 and connected to the flexible substrate 31 using BGA bumps 43. The flexible substrate 31 on which the package substrate 41 is mounted is connected to the power supply unit 50.

  The power supply unit 50 includes a mounting substrate 51 provided with a thick Cu columnar electrode 52, and is provided in the central portion of the Cu columnar electrode 52 and the package substrate 41 through a through hole 32 provided in the flexible substrate 31. The BGA bump 44 is directly electrically joined.

  The Cu columnar electrode 52 is fitted into a through hole provided on the mounting substrate 51 and provided with a Cu plating layer on the side wall. The height of the Cu columnar electrode 52 is made smaller than the thickness of the wiring substrate 21 by reducing the thickness of the flexible substrate 31. Further, a DC power transformer 54 is mounted on the back surface of the mounting substrate 51.

Next, with reference to FIG.4 and FIG.5, the manufacturing process of the semiconductor mounting apparatus of Example 1 of this invention is demonstrated. First, as shown in FIG. 4 (a), the thickness _{h 1} is the diameter _{w 1} by drilling the FR-4 of 3mm on the wiring board 21 in which the insulating material forms a through hole 22 of about 60 mm. On the other hand, as shown in FIG. 4 (b), with diameter _{w 2} by drilling in the flexible substrate 31 with a thickness _{h 2} is the 0.5mm of polyimide and the insulating material forms a through hole 32 of 30 mm, the substrate BGA bumps 33 are provided on the periphery of the substrate. The flexible substrate 31 made of polyimide as an insulating material does not have a heterogeneous structure including glass cloth inside like FR-4, but has a uniform dielectric property in the plane direction. The diameter of the BGA bump 33 is 0.6 mm.

  Next, as shown in FIG. 4C, the wiring board 21 and the flexible board 31 are aligned and connected by the BGA bump 33 so that the center of the through hole 22 and the center of the through hole 32 coincide. A predetermined wiring pattern is formed on the wiring substrate 21 and the flexible substrate 31, and the flexible substrate 31 is connected by a BGA bump 33 in a predetermined region of the wiring pattern provided on the lower surface of the wiring substrate 21.

  Next, as shown in FIG. 5D, the package substrate 41 on which the semiconductor bare chip 42 is mounted is inserted into the through hole 22 and provided on the upper surface of the flexible substrate 31 using the BGA bumps 43 provided on the package substrate 41. Are connected in a predetermined region of the wiring pattern. Although not shown, an underfill resin is filled between the semiconductor bare chip 42 and the package substrate 41, and the semiconductor bare chip 42 is molded with a mold resin.

  Next, as shown in FIG. 5E, the flexible substrate 31 on which the package substrate 41 is mounted is connected to a power supply unit 50 provided with a Cu columnar electrode 52 having a diameter of 5 mm. This power supply unit 50 has a mounting board 51 with a thickness of 2.5 mm provided with Cu columnar electrodes 52. The mounting board 51 has BGA bumps 53 in the periphery and a DC power transformer 54 on the back surface. It is installed. This DC power supply voltage 54 is connected to an external power supply via an external power supply wiring 55.

  The package substrate 41 is connected to the Cu columnar electrode 52 by BGA bumps 44 provided on the package substrate 41 immediately below the central portion where the semiconductor bare chip 42 is mounted. Further, the flexible substrate 31 is connected to a predetermined region of the wiring pattern provided on the lower surface of the flexible substrate 31 by a BGA bump 53 in the peripheral portion of the mounting substrate 51. The current from the external power source reaches the Cu columnar electrode 52 through the DC power source transformer 54 and is sent from the Cu columnar electrode 52 to the package substrate 41.

  In the invention described in the first embodiment of the present invention, the flexible substrate 31 connected to the package substrate 41 has sufficient flexibility. Therefore, even when the temperature fluctuates and the package substrate 41 is warped, as shown in FIG. 2, the flexible substrate 31 is deformed following the warp of the package substrate 41 with the central portion fixed. The stress applied to the BGA bump 43 can be relaxed.

  In addition, since polyimide having a uniform dielectric property in the plane direction is used as the insulating material of the flexible substrate 31, a high-speed signal transmission path from the package substrate 41 is provided in the flexible substrate 31, so that high quality is achieved. It becomes possible to transmit a signal while keeping it. In addition, the wiring board 21 using FR-4 as an insulating material as in the past has a heterogeneous structure including a glass cloth inside, so that the dielectric constant distribution inside the board becomes non-uniform, It causes the quality deterioration of the transmission signal.

  Further, since the height (0.6 mm + 0.5 mm) from the surface of the mounting substrate 51 of the Cu columnar electrode 52 that directly supplies power is made smaller than the thickness (3 mm) of the wiring substrate 21, it is shown in FIG. Thus, the current supply path can be shortened as compared with the case where the Cu power supply electrode is provided on the wiring board.

Here, the following supplementary notes are attached to the embodiment of the present invention including the first embodiment.
(Appendix 1) A package substrate on which a semiconductor chip is mounted, a first wiring substrate having a through hole larger than the outer shape of the package substrate, and a second wiring substrate having higher flexibility than the first wiring substrate, The first wiring board and the second wiring board are coupled by a connection conductor, and the package board is inserted into a through hole provided in the first wiring board, and the second wiring board is inserted into the second wiring board. Rutotomoni mounted on the wiring board, the second power supply unit for supplying power to the package substrate on the surface opposite to the bonding surface of the first wiring substrate of the wiring substrate is disposed, the power supply The unit has a mounting substrate and a columnar power supply electrode provided on the mounting substrate, and the columnar power supply electrode is inserted into a through hole provided in the second wiring substrate and is provided at a central portion of the package substrate. Established contact Semiconductor mounting apparatus characterized by being directly electrically connected to the conductor.
(Additional remark 2) The said 2nd wiring board is a thin film-like board | substrate thinner than the thickness of the said 1st wiring board, The semiconductor mounting apparatus of Additional remark 1 characterized by the above-mentioned.
(Additional remark 3) The semiconductor mounting apparatus of Additional remark 1 or Additional remark 2 characterized by the insulating layer of a said 2nd wiring board having a uniform dielectric characteristic in a surface direction.
(Additional remark 4) The said mounting layer is either a polyimide resin or a liquid crystal polymer, The semiconductor mounting apparatus of Additional remark 3 characterized by the above-mentioned.
(Supplementary note 5 ) The semiconductor mounting device according to any one of supplementary notes 1 to 4 , wherein a height of the columnar power supply electrode is smaller than a thickness of the first wiring board.
(Supplementary note 6 ) The semiconductor mounting device according to supplementary note 5 , wherein the columnar power supply electrode is fitted in a through hole provided in the mounting substrate.
(Supplementary note 7 ) The semiconductor mounting device according to Supplementary note 5 or 6 , wherein the columnar power supply electrode is a Cu columnar electrode or a Cu-based columnar electrode containing Cu as a main component.
(Supplementary note 8 ) The semiconductor mounting device according to any one of supplementary notes 1 to 7 , wherein a DC power transformer is mounted on the mounting substrate.

DESCRIPTION OF SYMBOLS 1 1st wiring board 2 Through-hole 3 2nd wiring board 4 Through-hole 5 Connection conductor 6 Package board 7 Semiconductor chip 8 Connection conductor 10 Power supply unit 11 Mounting board 12 DC power transformer 13 Column-shaped power electrode 14 Connection conductor 15 External power supply wiring 21 Wiring substrate 22 Through hole 31 Flexible substrate 32 Through hole 33 BGA bump 41, 61 Package substrate 42, 62 Semiconductor bare chip 43, 44, 63 BGA bump 50 Power supply unit 51, 81 Mounting substrate 52 Cu columnar electrode 53, 82 BGA bumps 54 and 83 DC power transformers 55 and 84 External power supply line 71 Wiring board 72 Power supply wiring 73 Through power supply line 74 Cu power supply electrode

Claims (3)

A package substrate having a semiconductor chip mounted thereon;
A first wiring board having a through hole larger than the outer shape of the package board;
A second wiring board having higher flexibility than the first wiring board;
The first wiring board and the second wiring board are coupled by a connection conductor,
The package substrate, the binding surface between the first inserted and then mounted on the second wiring board in a through hole provided in the wiring board Rutotomoni, the first wiring board of the second wiring board A power supply unit for supplying power to the package substrate is disposed on the opposite side of the surface,
The power supply unit is
Mounting board and
A columnar power supply electrode provided on the mounting substrate;
The columnar power supply electrode is inserted into a through hole provided in the second wiring substrate and is directly electrically connected to a connection conductor provided in a central portion of the package substrate. apparatus.   The semiconductor mounting apparatus according to claim 1, wherein the insulating layer of the second wiring board has a uniform dielectric characteristic in a surface direction. The height of the columnar power electrode, a semiconductor mounting device according to claim 1 or claim 2, wherein the smaller than the thickness of the first wiring board.

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