JP2003007411A - Body mounted with electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a body mounted with an electronic component wherein an influence of residual stress at a junction part can be prevented. SOLUTION: This body mounted with the electronic component is provided with an electroconductive connecting member 3 in a coiled spring state interposed between a land 1b formed on a circuit board 1 and an electrode 2b of the electronic component 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounting body for mounting electronic components on electronic components.

[0002]

2. Description of the Related Art Conventionally, in order to mount a first electronic component such as an integrated circuit (hereinafter referred to as IC) on a second electronic component such as a circuit board (hereinafter referred to as PWB), electrodes of the IC are used.
The electrical connection and the mechanical fixing are realized by soldering between the land patterned on the PWB and the land.

FIG. 12 shows a conventional reflow mounting method, in which a conductor pattern (not shown) for forming an electronic circuit in advance and a land 101b for connecting an IC are formed on the PWB 101 by a known patterning technique. Has been done.

In the IC 102, the electrode 1 is provided on the main body portion 102a.
02b is provided.

On the land 101b of the PWB 101, cream solder 103 is formed, if necessary, by a method such as known silk printing or coating with a dispenser.

The electrode 102b of the IC 102 is connected to P
Align with the land 101b of WB101, PWB
The IC 102 was placed on 101, heated in a known reflow oven, the cream solder 103 was melted, and the land 101b and the electrode 102b were electrically and mechanically connected and fixed.

[0007]

In recent years, the demand for light, thin, short, and small electronic circuits has become stronger and stronger, and in response to this, a form in which a semiconductor chip is directly mounted on an IC or the like has also appeared.

In the case of directly mounting a microminiature electronic component having a terminal pitch of about 800 μm or less, for example, a semiconductor chip, the temperature is raised through a reflow furnace in order to directly solder the electrode of the IC and the land of the PWB. Since the solder is melted and then returned to room temperature to solidify the solder, residual stress is generated in the joint portion of the IC and PWB due to the difference in thermal expansion between the IC and PWB, and cracks are generated in the initial state. It has also been a cause of lowering reliability due to heat generation of the IC in use and environmental changes.

Therefore, an object of the present invention is to obtain an electronic component mounting body capable of preventing the influence of residual stress in a joint portion.

[0010]

In order to achieve the above object, the present invention provides a conductive land formed on a first electronic component and a conductive land formed on a second electronic component. An electronic component mounting body having at least a connecting member formed by molding a conductive wire material having a wire diameter of 5 to 40 micrometers into a coil spring shape having an outer diameter of 10 to 250 micrometers. As a result, it is possible to prevent the influence of residual stress in the joint portion.

Further, the reliability of mounting can be improved by using an electronic component mounting body in which a resin having elasticity is interposed between the first electronic component and the second electronic component.

Further, a sheet-like member fixed to the first electronic component, which is made of an electrically insulating material and has a through hole corresponding to the position of the conductive land formed on the first electronic component, is provided. If an electronic component mounting body in which the connecting member is inserted into the through hole is provided, the mounting reliability and productivity can be improved.

Further, the through hole is formed in the electronic component mounting body fixed between the conductive land formed on the first electronic component and the conductive land formed on the second electronic component. A sheet-like member made of an electrically insulating material, and a conductive land of the sheet-like member is formed on one surface of the sheet-like member so that at least a part of the sheet-like member coincides with the position of the through hole. From the other surface of the sheet-shaped member, a conductive wire having a wire diameter of 5 to 40 micrometers is inserted into the hole through which a connecting member formed in a coil spring shape having an outer diameter of 10 to 250 micrometers is penetrated. If the electronic component mounting body is fixed to the conductive land of the sheet-like member, the mounting reliability and productivity can be improved.

Further, when an electronic component mounting body in which a conductive connecting end member having an outer diameter of 10 μm to 500 μm is interposed at least at one end of the connecting member, the reliability of bonding with a circuit board or the like is improved. Productivity and productivity can be improved.

If the connecting end member is an electronic component mounting body having a spherical shape, a cylindrical shape, or a polygonal shape, the reliability of the electric path can be increased.

[0016]

DETAILED DESCRIPTION OF THE INVENTION

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram for explaining an embodiment of the present invention.

On the PWB 1, a conductor pattern (not shown) for forming an electronic circuit and a land 1b for connecting the IC 2 are formed in advance by a known patterning technique.

The IC 2 is provided with an electrode 2b on the body portion 2a.

As the connecting member 3, for example, as shown in FIG. 2 (a), a wire material having a wire diameter of 5 to 40 micrometers and having relatively high conductivity and elasticity, such as phosphor bronze, is used. Is 10 micrometers to 25
A coil spring of 0 μm is formed, or a conductive resin is formed into a coil spring of the above dimension, or a material having low conductivity but appropriate elasticity, such as piano wire, carbon, resin, or the like. Is formed into a coil spring having the above dimensions, and is subjected to a surface treatment of a highly conductive material such as gold or an alloy thereof or tin or an alloy thereof.
It is cut to a specified length of micrometers.

The outer diameter of the connecting member 3 is selected by a land 1b for connecting the IC 2 and a required space on the PWB 1 for forming a conductor pattern for forming a circuit between the lands 1b. Pitch between terminals is 8
The dimension is suitable for mounting the IC2 having a size of 00 micrometers or less.

The electrode 2b of the IC 2 and one end of the connecting member 3 are connected and fixed by means such as soldering or welding.
The pattern 1b of WB1 and the other terminal of the connecting member 3 are connected and fixed in the same manner.

FIG. 2 is a perspective view of a connecting member used in the present invention, and (a), (b) and (c) show different connecting members.

The connecting member 3 has a coil outer diameter that is substantially equal over the entire length shown in FIG. 2 (a), and at least a part in the longitudinal direction is trapezoidal as shown in FIG. 2 (b). Alternatively, both ends in the length direction may be trapezoidal as shown in FIG.

The connecting member 3 has a shape in which one end is a reference and the other end is freely displaceable in the length direction and the radial direction regardless of the shape.

FIG. 3 shows the PWB 1 and the connecting member 3 shown in FIG.
And a schematic diagram for explaining an example of a connection method of IC2,
(A) shows a pre-process, (b) shows a post-process, the same code | symbol is attached | subjected to FIG.

In FIG. 3A, the cream solder 5 is applied to the electrode 2b of the IC 2 in advance by a known method such as screen printing or using a dispenser. Then, the jig plate 4 having the through hole 4a at a position corresponding to the electrode 2b of the IC2 is aligned and placed on the IC2, and the connection member 3 is placed from above the jig plate 4 on the electrode 2b of the IC2. Then, the cream solder 5 is melted by heating in a known reflow furnace in this state, so that the electrode 2b of the IC 2 and the connecting member 3 are connected and fixed.

Next, as shown in FIG. 3B, PWB1
The cream solder 6 having a lower melting point than the cream solder 5 is applied to the land 1b, and the integrated IC 2 and the connecting member 3 are aligned so that the connecting member 3 is located at the position of the land 1b of the PWB 1. Then, the cream solder 6 is melted by heating in a reflow oven set to a temperature lower than that of the previous reflow oven, so that the connection member 3 and the land 1b of the PWB 1 are connected and fixed. 1
The mounting of IC2 on PWB1 shown in (3) is completed.

Although not shown here, between the first electronic component and the second electronic component, that is, IC2 and PWB.
A resin having insulating elasticity is interposed between 1 and
It is also possible to improve the mounting reliability of the electronic component mounting body.

FIG. 4 is a schematic diagram showing an electronic component mounting body 20 used in another embodiment of the present invention. The parts common to those described so far are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 4, the terminal board 21 has a sheet-like base 21a of, for example, polyimide (PI), the thickness of which is shorter than the entire length of the connecting member 3 by a predetermined value, and, for example, copper provided at a predetermined position. It has a terminal pad 21b formed of a conductive thin plate such as a foil and a terminal hole 21c penetrating the base 21a at a position corresponding to the terminal pad 21b. Then, the connection member 3 is inserted into the terminal hole 21c, one end of the connection member 3 is connected and fixed to the terminal pad 21b, and the electronic component mounting body 20 is configured.

FIG. 5 is a schematic view for explaining a method of manufacturing the electronic component mounting body 20 of FIG. 4, where (a) is a pre-process and (b) is a process.
Indicates a post-process, and the same parts as those described so far are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 5 (a), first, a polyimide (PI) sheet 21d having a thickness of 40 to 400 μm, which corresponds to the entire length of the connecting member 3, is prepared. A hole having a diameter of 25 to 350 micrometers is bored from the anti-copper foil side to the entire thickness of the polyimide portion by a method such as laser machining in accordance with the outer diameter of the connecting member 3. , The terminal hole 21c is formed.

Next, the surface of the copper foil 21e is protected by, for example, attaching a tape, and then the solder plating 7 is applied to the copper foil surface exposed in the terminal hole 21c.

Then, as shown in FIG. 5B, the copper foil 2
The protective tape on the surface of 1e is removed, a resist is applied to the surface of the copper foil 21e for patterning, and the copper foil other than the terminal pad 21b is removed by known etching to form the terminal pad 21b.

The connecting member 3 is inserted into the terminal hole 21c of the terminal plate 21 thus manufactured, and the solder plating 7 is melted by heating in the reflow furnace to expose the terminal pad in the terminal hole 21c. The electronic component mounting body 20 can be obtained by connecting and fixing 21b and the connecting member 3.

FIG. 6 is a schematic diagram for explaining a mounting method for mounting an IC on a PWB using the electronic component mounting body 20 shown in FIG. The same parts as those described so far are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 6, between the electrode 2b of the IC 2 and the terminal pad 21b of the electronic component mounting body 20, for example, ACF is used.
(Anisotropic Conductive F
The electronic component mounting body 2 is formed by sandwiching a conductive adhesive sheet 8 made of a material that can be conductively connected by applying a pressure such as
By pressing 1C2 against 0, the electrode 2b of the IC 2 and the terminal pad 21b of the electronic component mounting body 20 are connected and fixed.

Next, the cream solder 6 is applied onto the land 1b of the PWB 1 and the electronic component mounting body 20 with 1C2 attached thereto is attached to the position of the land 1b of the PWB 1 and the connecting member of the electronic component mounting body 20. 3 is aligned and placed, and in this state is heated in a known reflow furnace, the land 1b of the PWB 1 and the connecting member 3 of the electronic component mounting body 20 are connected and fixed.

Here, the cream solder 6 is a material that melts at a lower temperature than the solder plating 7 used for connecting and fixing the connecting member 3 to the terminal pad 21b of the electronic component mounting body 20, and the temperature of the reflow furnace is , Set lower than when the solder plating 7 is melted.

FIG. 7 is a schematic diagram for explaining a composite connecting member 30 according to still another embodiment of the present invention.

In FIG. 7, the composite connecting member 30 comprises a spring 31 and a connecting end member 32. The spring 31 has the same structure as the connecting member 3 described above, and may have a shape as shown in FIGS. 2B and 2C in addition to the shape shown in FIG. 7. .

The connecting end member 32 is, for example, a spherical body,
For example, a surface film 32b made of a metal having a relatively low melting point such as gold, tin, or solder is formed on the surface of a metal spherical body having high conductivity such as copper or a resin spherical body 32a. The outer diameter of the connection end member 32 is set to 10 μm to 500 μm in accordance with the size.

The spring 31 and the connection end member 32 are fixed by connecting the surface film 32b formed on the surface of the connection end member 32 by heating and melting to form a composite connection member 30.

FIG. 8 is a schematic diagram for explaining an example of a method for manufacturing the composite connecting member 30, and the same parts as those in FIG. 7 are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 8, the connection end is formed by using a lower jig plate 33 having a plurality of spherical body receiving holes 33a formed in a matrix on the surface thereof at a predetermined interval corresponding to the outer diameter of the connection end member 32 to be used. The members 32 are aligned so as to be dropped into the spherical body receiving holes 33a.

The lower jig plate 33 is made of a material such as synthetic resin having high heat resistance such as glass reinforced phenol resin.

Next, from the upper side of the connecting end member 32, in the same arrangement as the spherical body receiving hole 33a, the spring insertion hole 34a penetrating therethrough.
The upper jig plate 34 having the above is aligned and placed as shown, and the spring 31 is inserted into the spring insertion hole 34a.

The upper jig plate 34 is made of the same material as the lower jig plate 33, and the upper jig plate 34 is manufactured to have a thickness such that the spring 31 projects above the upper jig plate 34.

Next, the heating jig 36 is placed from above the upper jig plate 34 while bending the protruding spring 31. The heating jig 36 is made of a metal having a high thermal conductivity, and is heated to a predetermined temperature in advance, or is heated in a state shown in the drawing and then heated via the spring 31 to be connected to the spring 31. Used to heat the contact portion of the connection end member 32,
If the surface film 32b of the connecting end member 32 is melted, the spring 31 and the connecting end member 32 are connected and fixed, and the heating jig 36, the upper jig plate 34, and the lower jig plate 33 are removed, a plurality of composite connecting members 30 It is possible to produce many at the same time.

9A and 9B are schematic diagrams for explaining a mounting method using the above-described composite connecting member 30. FIG. 9A shows a pre-process and FIG. 9B shows a post-process. The common parts are given the same reference numerals and the description thereof is omitted.

FIG. 9A shows the IC2 having the composite connecting member 30.
The step of connecting and fixing the IC 40 with terminals is shown. The electrode 2b of the IC 2 is subjected to surface treatment such as solder plating or tin plating in advance, and the through hole 35a is formed at a position corresponding to the electrode 2b of the IC 2. A base 35 having a sheet material such as polyimide (PI)
Is aligned with IC2 and attached to IC2 by a method such as adhesion.

Next, the spring 31 of the composite connecting member 30 is inserted into the through hole 35a of the base 35, and in this state, it is heated in a reflow furnace to melt the plating surface coating applied to the electrode 2b of the IC2. , The electrode 2b of the IC2 and the composite connecting member 3
By connecting and fixing the spring 31 of 0, the IC 40 with a terminal is formed.

FIG. 9B shows an IC 40 with a terminal completed as described above.
The step of mounting the substrate 1 on the board 1 is shown. The cream solder 6 is applied to the land 1b of the board 1 in advance by a known method such as screen printing or using a dispenser.
The connection terminal (composite connection member) 30 of the IC 40 with terminal is aligned and placed on the land 1b of the substrate 1, and in this state is heated in a reflow furnace to melt the cream solder 6 and the connection terminal 30 of the IC 40 with terminal 30 The land 1b of the substrate 1 is connected and fixed to complete the mounting.

At this time, the surface film 32b of the connection end member 32,
Surface coating applied to the electrode 2b of the IC 2 in advance, the substrate 1
For the cream solder 6 applied to the land 1b, a material having a lower melting temperature is selected in this order, and the temperature of the reflow furnace that heats and melts is also set to a sequentially lower temperature in this order.

FIG. 10 is a schematic diagram showing an electronic component mounting body 50 used in still another embodiment of the present invention. The same parts as those described so far are designated by the same reference numerals and the description thereof will be omitted.

The terminal plate 21 has the terminal pads 21b and the terminal holes 21c as described with reference to FIGS.
The surface of the terminal pad 21b inside the terminal hole 21c is provided with a solder plating 7 not shown here.

Then, the spring 31 of the composite connecting member 30 is inserted into the terminal hole 21c of the terminal plate 21 and heated in a reflow furnace in an inverted state from the state shown in FIG. 10 to melt the solder plating 7 not shown. As a result, the terminal pad 21b of the terminal board 21 and the spring 31 of the composite connecting member 30 are connected and fixed, and the electronic component mounting body 50 is formed.

FIG. 11 is a schematic diagram for explaining an electronic component mounting body for mounting the IC 2 on the PWB 1 using the electronic component mounting body 50 described with reference to FIG. Are denoted by the same reference numerals and description thereof will be omitted.

In FIG. 11, by sandwiching the conductive adhesive sheet 8 and pressing 1C2 against the electronic component mounting body 50, the electrode 2b of the IC2 and the connection pad 21b of the electronic component mounting body 50 are connected and fixed.

Next, the cream solder 6 is applied onto the land 1b of the PWB 1, and the electronic component mounting body 50 with 1C2 attached thereto is combined with the position of the land 1b of the PWB 1 and the electronic component mounting body 50. The member 30 is aligned and placed, and in this state, it is heated in a reflow furnace to melt the cream solder 6, whereby the land 1b of the PWB 1 and the composite connecting member 30 of the electronic component mounting body 50 are connected and fixed, and electronic component mounting is performed. The body is completed.

FIG. 13 is a view showing another embodiment of the connecting end member. In FIG. 13A, the connection end member 37 is
For example, the surface of a cylindrical multilayer capacitor made by a known technique, for example, a cylindrical resistor made by a known technique, for example, a highly conductive metal cylinder such as copper or a resin cylinder 37a And a surface film 37b formed of a metal having a relatively low melting point such as gold, tin, or solder, and the outer diameter of the column 37 corresponds to the outer diameter of the spring 31 (FIG. 10). 10 micrometers to 500
Micrometer, height 10 micrometers to 50
0 micrometer. In FIG. 13B, the connection end member 38 has, for example, a polygonal shape. For example, a polygonal multilayer capacitor made by a known technique, for example, a cylindrical resistor made by a known technique, such as copper, is used. The surface of the metal or resin polygon 38a having high conductivity is composed of a surface film 38b formed of a metal having a relatively low melting point such as gold, tin, or solder, and corresponds to the outer diameter of the spring 31. The outer diameter of the polygon 38 is, for example, 10 μm to 500 μm on a side. The connection end members 37 and 38 are connected to the connection member in the same manner as 32 shown in FIG. 10 to form a composite connection member.

According to the electronic component mounting body as described above, P
The land of the WB and the electrode of the IC are not directly rigidly connected, but are connected and fixed at least through a connecting member including a connecting member formed in a spring shape at a part thereof, due to the temperature change of the component parts. Due to the deformation of the connecting member due to dimensional changes, only a very weak stress is generated in the joint area, which not only causes cracks in the initial state but also reliability due to heat generation of the IC in use and environmental changes. It does not reduce the power, and is particularly effective in mounting ultra-small electronic components.

[0063]

As described above, according to the present invention, the influence of the residual stress at the connecting portion can be reliably prevented by the coil spring-like connecting member.

[Brief description of drawings]

FIG. 1 is a schematic diagram for explaining an electronic component mounting body according to an embodiment of the present invention.

FIG. 2 is a perspective view of a connecting member used in the present invention,
(A), (b), (c) shows a different connecting member, respectively.

3A and 3B are schematic diagrams for explaining an example of the mounting method of the embodiment shown in FIG. 1, in which FIG. 3A shows a pre-process and FIG. 3B shows a post-process.

FIG. 4 is a schematic diagram showing an electronic component mounting body used in another embodiment of the present invention.

5A and 5B are schematic diagrams for explaining the method for manufacturing the electronic component package shown in FIG. 4, in which FIG. 5A shows a pre-process and FIG. 5B shows a post-process.

6 is a plan view of the electronic component mounting body 20 shown in FIG.
It is a schematic diagram for demonstrating the mounting method which mounts C on PWB.

FIG. 7 is a schematic view showing a composite connecting member according to another embodiment of the present invention.

FIG. 8 is a schematic view for explaining an example of a method for manufacturing the composite connecting member shown in FIG.

FIG. 9 is a schematic diagram for explaining an electronic component mounting body using the composite connecting member shown in FIG.
(B) shows a post-process.

FIG. 10 is a schematic diagram showing an electronic component mounting body used in another embodiment of the present invention.

11 is a schematic diagram for explaining a mounting method using the electronic component mounting body shown in FIG.

FIG. 12 is a schematic diagram for explaining a conventional mounting form.

FIG. 13 is a schematic view showing another embodiment of the composite connecting member according to the present invention.

[Explanation of symbols]

1 circuit board (PWB), 1b land, 2 electronic parts (IC), 2a body part, 2b electrode, 3 connecting member, 4 jig plate, 4a through hole, 5,6 cream solder, 7 solder plating, 8 conductive adhesion Sheet, 20, 5
0 electronic component mounting body, 21 terminal board, 21a base,
21b terminal pad, 21c terminal hole, 21e copper foil,
30 composite connecting member, 31 spring, 32, 37, 38
Connection end member, 32a resin spherical body, 32b surface film, 3
3 lower jig plate, 33a spherical body receiving hole, 34 upper jig plate, 34a spring insertion hole, 35 base, 36 heating jig, 40 terminal IC.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenzo Hatada             4-8-3 Minamiseidai, Katano-shi, Osaka F-term (reference) 5E024 CA12 CB10                 5E336 AA04 BB11 DD17 EE01 GG14

Claims (6)

[Claims] 1. An electronic component mounting body fixed between a conductive land formed on a first electronic component and a conductive land formed on a second electronic component, the wire diameter being An electronic component mounting body, comprising at least a connecting member formed by forming a conductive wire having a diameter of 5 to 40 micrometers into a coil spring shape having an outer diameter of 10 to 250 micrometers. 2. The electronic component mounting body according to claim 1, wherein a resin having elasticity is interposed between the first electronic component and the second electronic component. 3. A sheet-like member fixed to the first electronic component, which is made of an electrically insulating material and has a through hole that corresponds to the position of a conductive land formed on the first electronic component. The electronic component mounting body according to claim 1, wherein the connecting member is inserted into the penetrating hole. 4. An electronic component package fixed between a conductive land formed on a first electronic component and a conductive land formed on a second electronic component, the electronic component mounting body penetrating therethrough. A sheet-shaped member made of an electrically insulating material having a hole, and a conductive land of the sheet-shaped member is formed on one surface of the sheet-shaped member so that at least a part of the sheet-shaped member coincides with the position of the through hole. A hole through which a connecting member formed by forming a conductive wire having a wire diameter of 5 to 40 micrometers into a coil spring shape having an outer diameter of 10 to 250 micrometers penetrates from the other surface of the sheet-like member. And a fixed land on the conductive land of the sheet-shaped member. 5. The conductive connecting end member having an outer diameter of 10 μm to 500 μm is provided on at least one end of the connecting member. The electronic component package described in. 6. The electronic component mounting body according to claim 5, wherein the shape of the connection end member is any one of a spherical shape, a columnar shape, and a polygonal shape.