JP5035265B2 - Manufacturing method of electronic component mounting structure - Google Patents

Description

The present invention relates to the production how the electronic component mounting structure in which a plurality of electrodes is formed by bonding with a plurality of bumps and a substrate provided in the electronic component.

Conventionally, as a method of manufacturing an electronic component structure in which a plurality of bumps provided in an electronic component and a plurality of electrodes provided in a substrate are joined, each bump is brought into contact with a corresponding electrode on the substrate and aligned. The component and the substrate are heated to bond the bump and the electrode, and further, a thermosetting resin is supplied as an underfill agent between the electronic component and the substrate to thermally cure it, and the thermosetting is performed between the electronic component and the substrate. A method is known in which an electronic component and a substrate are firmly bonded by forming an object. In addition, before bonding the bump and the electrode, thermosetting resin is supplied in advance to a plurality of positions on the substrate avoiding the electrode, and the bump is brought into contact with the electrode while the electronic component is in contact with the thermosetting resin. There is also known a so-called “resin pre-coating” method in which a bump and an electrode are bonded together by heating, and at the same time a thermosetting resin is thermoset (Patent Document 1). In the latter method, the electronic component and the substrate are bonded by a plurality of thermosets formed between them, and a bonding force as great as that of the former is not obtained, but the thermosetting resin to be used is not obtained. There is an advantage that the yield can be improved because it can be reduced and repair is easy.
JP 2005-26502 A

  However, when an electronic component mounting structure is manufactured by the “resin pre-coating” method, each of the thermosets formed between the electronic component and the substrate has its upper and lower parts (electronic The bonding surface has a small cross-sectional area due to the difference in linear expansion coefficient between the electronic component and the substrate. There is a problem that the electronic component mounting structure is likely to be damaged due to concentration on the (bonding surface with the electronic component and the bonding surface with the substrate) and peeling of the bonding surface.

The present invention aims to provide a manufacturing how the electronic component mounting structure it is possible to obtain an electronic parts packaging structure is not easily damaged formed by thermal stresses while keeping the method of resin destination coating.

The manufacturing method of the electronic component mounting structure according to claim 1 is a manufacturing method of an electronic component mounting structure in which a plurality of bumps provided in the electronic component and a plurality of electrodes provided in the substrate are joined. A resin supply step for supplying a thermosetting resin to each of a plurality of resin supply positions avoiding the electrodes, and each bump corresponding to a substrate while contacting an electronic component with the thermosetting resin supplied to each resin supply position Positioning process for positioning the electronic component and the substrate by contacting the electrode, heating the aligned electronic component and the substrate to bond the bump and the electrode, and thermosetting resin between the electronic component and the substrate Including a heating step of bonding the electronic component and the substrate with a plurality of thermosetting products obtained by thermosetting, and supplying the thermosetting resin to each resin supply position on the substrate in the resin supply step. Tree There performed a plurality of times so as to overlap in a plurality of stages in the thickness direction of the substrate, in the heating step, the supplied thermosetting resin is cured so as to overlap in a plurality of stages in each resin supply position on the substrate As a result , a constricted portion was formed at the intermediate portion in the thickness direction of the substrate of each thermoset.

  In the present invention, before bonding the bumps of the electronic component and the electrodes of the substrate, a thermosetting resin is supplied in advance to each of a plurality of resin supply positions that avoid the electrodes on the substrate, and is supplied to each resin supply position. After bringing the bumps into contact with the corresponding electrodes of the substrate while bringing the electronic components into contact with the thermosetting resin thus formed, the bumps and the electrodes are joined by heating, and at the same time, the thermosetting resin is thermally cured. The electronic component and the substrate are joined by the “resin pre-coating” method. The thermosetting resin is supplied to each resin supply position on the substrate in multiple stages in the thickness direction of the substrate. The constricted part (part narrower than the upper and lower parts) is formed in the middle part of the thickness direction of each thermosetting product in the substrate so that it overlaps with the electronic component and the substrate. Due to the difference in linear expansion coefficient The thermal stress generated in each thermosetting product acts not only on the interface between the electronic component and the substrate, but also on the constricted portion of the thermosetting product having a small cross-sectional area, so that the thermal stress is dispersed. Thus, an electronic component mounting structure that is not easily damaged can be obtained.

  Embodiments of the present invention will be described below with reference to the drawings. 1 is a side view of an electronic component mounting structure according to an embodiment of the present invention, FIGS. 2 (a), (b), (c), (d) and FIGS. 3 (a), (b), (c). ) Is an explanatory diagram of the manufacturing process of the electronic component mounting structure according to the embodiment of the present invention, and FIGS. 4A, 4B, and 4C are examples of the resin supply position according to the embodiment of the present invention. FIG.

  In FIG. 1, an electronic component mounting structure 1 includes a substrate 2 and an electronic component 3. A plurality of electrodes 12 are provided on the electrode forming surface 11 (upper surface in FIG. 1) of the substrate 2, and a plurality of electrodes 22 are provided on the electrode forming surface 21 (lower surface in FIG. 1) of the electronic component 3. . A solder bump 23 is formed on each electrode 22 of the electronic component 3, and each solder bump 23 is joined to each electrode 12 on the substrate 2.

  In FIG. 1, a plurality of columnar thermosets 30 are provided between the electronic component 3 and the substrate 2, and the electronic component 3 and the substrate 2 are coupled by the plurality of thermosets 30. A constricted portion 31 (a portion narrower than the upper and lower portions) is formed in an intermediate portion M of each thermoset 30 in the thickness direction (here, the vertical direction) of the substrate 2 (see an enlarged view in FIG. 1). .

  When there is a difference in linear expansion coefficient between the electronic component 3 and the substrate 2, thermal stress is generated in each thermoset 30, but a constricted portion 31 is formed in the intermediate portion M of each thermoset 30. In addition, the thermal stress generated in each thermoset 30 is not only the joint surface S1 between the thermoset 30 and the electronic component 3 and the joint surface S2 between the thermoset 30 and the substrate 2, but also a constricted portion having a small cross-sectional area. Accordingly, the electronic component mounting structure 1 is less likely to be damaged by thermal stress.

  Next, a method for manufacturing the electronic component mounting structure 1 will be described with reference to FIGS. 2, 3, and 4. In order to manufacture the electronic component mounting structure 1, first, the substrate 2 is held on the substrate holder 40. At this time, the substrate 2 is set such that the electrode forming surface 11 faces upward (substrate holding step, FIG. 2A). When the substrate 2 is held on the substrate holding table 40, the thermosetting resin 30a is supplied by the dispenser (resin supply device) 50 to each of a plurality of resin supply positions on the electrode forming surface 11 of the substrate 2 avoiding the electrodes 12. (FIGS. 2B and 2C. Resin supply step).

As the resin supply position on the substrate 2, for example, as shown in FIGS. 4A and 4B, dots are formed at four corners near the outer edge of the substrate 2 (FIG. 4A), or L-shaped. (FIG. 4 (b)) may be supplied, or as shown in FIG. 4 (c), it may be supplied linearly along two opposing sides of the four sides of the substrate 2. Good. Furthermore, as shown in FIG. 4C, a thermosetting resin 30a may be supplied to a portion of the substrate 2 where the electrode 12 does not exist.

  In this resin supply step, as shown in FIGS. 2B and 2C, the thermosetting resin 30 a is supplied to each resin supply position on the substrate 2. The process is divided into a plurality of times (here, twice) so as to overlap a plurality of steps in the direction (here, the vertical direction). Here, the thermosetting resin 30a supplied in a plurality of times does not flow but overlaps in a plurality of stages in the thickness direction of the substrate 2, so that the thermosetting resin 30a has a certain amount. Use a material having viscosity (for example, a thermosetting resin 30a satisfying a viscosity η satisfying 10 ≦ η ≦ 90 (Pa · s: Pascal second) and a thixotropy TI satisfying 3 ≦ TI ≦ 15). To do.

  When the resin supply process is completed, the electronic component 3 is sucked by the crimping tool 60 so that the electrode forming surface 21 of the electronic component 3 (that is, the solder bump 23) faces downward. Then, the crimping tool 60 is lowered above the substrate 2 (FIG. 2D), and the solder bumps 23 are applied to the thermosetting resin 30a supplied to each resin supply position on the substrate 2 while the electronic component 3 is brought into contact therewith. The electronic component 3 and the substrate 2 are aligned by bringing them into contact with the corresponding electrodes 12 of the substrate 2 (alignment process, FIG. 3A). In this alignment step, a position where the solder bumps 23 on the electrode forming surface 21 of the electronic component 3 are avoided is provided on the uppermost layer of the thermosetting resin 30a supplied in multiple stages to each resin supply position of the substrate 2. Make contact.

  When the positioning process is completed or simultaneously with the positioning process, a heater (not shown) inside the crimping tool 60 is operated to heat the electronic component 3 and the substrate 2, and the solder bumps 23 are melted to solder the solder bumps 23. The electrode 12 is heated and bonded, and the thermosetting resin 30a is thermoset. As a result, the thermosetting resin 30a between the electronic component 3 and the substrate 2 is thermally cured, and a plurality of thermosets 30 are formed between the electronic component 3 and the substrate 2, and the electronic component 3 and the substrate 2 are combined. (Heating process). In this heating step, the thermosetting resin 30a supplied so as to overlap each resin supply position on the substrate 2 in a plurality of stages is formed such that the constricted portion 31 is formed in the intermediate portion M in the thickness direction of the substrate 2. It is thermally cured while being deformed (FIG. 3B).

  After the heating process is finished, the electronic component 3 is released from being adsorbed by the crimping tool 60, and the crimping tool 60 is lifted to separate the electronic component 3 from the crimping tool 60 (FIG. 3C). The combined body 1a of the substrate 2 is cooled (cooling step). When each thermoset 30 of the combined body 1a is solidified by cooling, the electronic component mounting structure 1 is completed.

  As described above, the manufacturing method of the electronic component mounting structure according to the present embodiment is an electronic component mounting structure formed by bonding the plurality of solder bumps 23 included in the electronic component 3 and the plurality of electrodes 12 included in the substrate 2. And a resin supply step of supplying the thermosetting resin 30a to each of a plurality of resin supply positions avoiding the electrodes 12 on the substrate 2, and the thermosetting resin 30a supplied to each resin supply position. An alignment step of aligning the electronic component 3 and the substrate 2 by bringing the solder bumps 23 into contact with the corresponding electrodes 12 of the substrate 2 while the electronic component 3 is in contact, and the aligned electronic component 3 and substrate 2 are aligned. The electronic component 3 and the substrate 2 are heated by a plurality of thermosetting products 30 obtained by heating and bonding the solder bumps 23 and the electrodes 12 and thermosetting the thermosetting resin 30a between the electronic component 3 and the substrate 2. A heating process to be combined, and supply of the thermosetting resin 30a to each resin supply position on the substrate 2 in the resin supply process so that the thermosetting resin 30a overlaps the thickness direction of the substrate 2 in a plurality of stages. The constricted part 31 is formed in the intermediate part of the thickness direction of the board | substrate 2 of each thermosetting material 30 divided into several times.

As described above, in the present embodiment, before the solder bumps 23 of the electronic component 3 and the electrodes 12 of the substrate 2 are joined, the thermosetting property is previously set in each of a plurality of resin supply positions on the substrate 2 avoiding the electrodes 12. After the resin 30a is supplied and the electronic bumps 3 are brought into contact with the thermosetting resin 30a supplied to the respective resin supply positions, the solder bumps 23 are brought into contact with the corresponding electrodes 12 of the substrate 2 and aligned. The electronic component 3 and the substrate 2 are bonded by a so-called “resin pre-coating” method in which the solder bump 23 and the electrode 12 are bonded together by heating and the thermosetting resin 30a is thermoset. The supply of the thermosetting resin 30a to each resin supply position is performed in a plurality of times so that the thermosetting resin 30a overlaps in multiple stages in the thickness direction of the substrate 2, and the substrate 2 of each thermosetting product 30 is supplied. Thickness direction Since the constricted portion 31 is formed in the intermediate portion, the thermal stress generated in each thermoset 30 due to the difference in the linear expansion coefficient between the electronic component 3 and the substrate 2 is bonded to the electronic component 3 and the substrate 2. The electronic component mounting structure 1 that acts on and is dispersed not only on the surfaces S1 and S2 but also on the constricted portion 31 of the thermoset 30 having a small cross-sectional area can be obtained.

  Although the embodiments of the present invention have been described so far, the present invention is not limited to those shown in the above-described embodiments. For example, in the above-described embodiment, the solder bumps 23 are used as the bumps of the electronic component 3, and the solder bumps 23 and the electrodes 12 of the substrate 2 are joined by melting the solder bumps 23 in the heating process. However, bumps other than the solder bumps 23 (for example, gold bumps) may be used. In this case, if a conductive bonding material such as cream solder is applied to the electrode 12 of the substrate 2, the bump and the electrode 12 of the substrate 2 can be bonded by heating in the heating process.

To provide a manufacturing how the electronic component mounting structure while keeping the method of resin destination coating also can be obtained an electronic component mounting structure is not easily damaged structure due to thermal stress.

The side view of the electronic component mounting structure in one embodiment of this invention (A) (b) (c) (d) Explanatory drawing of the manufacturing process of the electronic component mounting structure in one embodiment of this invention (A) (b) (c) Explanatory drawing of the manufacturing process of the electronic component mounting structure in one embodiment of this invention (A) (b) (c) The figure which shows the example of the resin supply position in one embodiment of this invention

DESCRIPTION OF SYMBOLS 1 Electronic component mounting structure 2 Board | substrate 3 Electronic component 12 Electrode 23 Solder bump (bump)
30 Thermoset 30a Thermosetting resin 31 Constriction

Claims (1)

A method for manufacturing an electronic component mounting structure in which a plurality of bumps provided in an electronic component and a plurality of electrodes provided in a substrate are joined,
A resin supply step of supplying a thermosetting resin to each of a plurality of resin supply positions avoiding the electrodes on the substrate;
An alignment step of aligning the electronic component and the substrate by bringing each bump into contact with a corresponding electrode of the substrate while contacting the electronic component with the thermosetting resin supplied to each resin supply position;
The aligned electronic component and substrate are heated to bond the bumps and electrodes, and the electronic component and the substrate are joined by a plurality of thermosets obtained by thermosetting the thermosetting resin between the electronic component and the substrate. Heating step,
In the heating step, the thermosetting resin is supplied to each resin supply position on the substrate in the resin supply step by dividing the thermosetting resin into a plurality of times so that the thermosetting resin overlaps the thickness direction of the substrate . By constricting the thermosetting resin supplied so as to overlap each resin supply position on the substrate in a plurality of stages , a constricted portion is formed at the intermediate portion in the thickness direction of the substrate of each thermosetting product. An electronic component mounting structure manufacturing method characterized by the above.

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