JP2002223074A - Wiring board with pin and electronic device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiring board having pins with which electronic components mounted thereon can be correctly connected to external electric circuits without allowing lead pins from coming off easily, and an electronic device. SOLUTION: The board is constructed in such a manner that pin attaching pads 2b electrically connected to a wiring conductor 2 are provided on the lower surface of an organic material-based insulating board 1 having the conductor 2 and lead pins 3 each having an approximately disk-like large diameter part 3a on the upper edge part are erected on the pads 2b so that a solder 9 intervenes between the upper edge surface and the side of the each part 3a and the each pad 2b. Formulas 0.05 mm<=T<=0.3 mm and 0.25<=D/T<=1.5 are satisfied where the thickness of the part 3a is T and the distance between the external circumference of the pad 2b and the part 3a is D.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring board with pins used for mounting electronic components such as semiconductor elements, and an electronic device having electronic components such as semiconductor elements mounted on the wiring board with pins. Things.

[0002]

2. Description of the Related Art Recently, as a wiring board with pins used for mounting electronic parts such as semiconductor elements, for example, an insulating plate made of a glass-epoxy plate or a plurality of insulating layers made of an epoxy resin are laminated. A plurality of wiring conductors made of copper foil are provided from the upper surface to the lower surface of the insulating substrate, and a plurality of pinning pads are formed at portions of these wiring conductors led out to the lower surface of the insulating substrate. An organic material-based pinned wiring board, which is formed by erecting a substantially cylindrical lead pin having a disc-shaped large-diameter portion by abutting the upper end thereof and soldering the pin, has been adopted. . Such an organic material-based wiring board with pins is advantageous in that it is lighter in weight and has a smaller electric resistance of a wiring conductor than a wiring board with pins made of a ceramic material. In such an organic material-based wiring board with pins, the electronic component is mounted on the upper surface of the insulating substrate, and the electrodes of the electronic component and the wiring conductor are electrically connected via solder bumps, bonding wires, and the like. By sealing the electronic components with a lid made of metal or ceramic or a sealing member made of potting resin or the like, an electronic device as a product is obtained. In this electronic device, the lead pins on the lower surface of the insulating substrate are connected to the external electric circuit board. By being connected to the wiring conductor via a socket, solder, or the like, the electronic component mounted on the external electric circuit board is electrically connected to the external electric circuit.

[0003]

However, according to the organic material-based wiring board with pins and the electronic device using the same, the bonding strength between solder and pins and pinning pads, glass-epoxy plate, epoxy resin, etc. When the lead pin is pulled vertically or obliquely with a force of, for example, about 30 N, the force between the solder and the lead pin or the pinning pad or the pin Separation may occur between the mounting pad and the insulating substrate, and the lead pins may be removed from the insulating substrate. If the lead pins are removed from the insulating substrate, the electronic components to be mounted are normally connected to the external electric circuit. There was a problem that it became impossible to do.

The present invention has been devised in view of the above problems, and has as its object to remove the lead pin even if the lead pin is pulled with a force of about 50 N, and to mount the mounted electronic component on an external electric circuit. It is an object of the present invention to provide a highly reliable wiring board with pins and an electronic device that can be normally connected to the electronic device.

[0005]

According to the present invention, there is provided a wiring board with pins provided with a pinning pad electrically connected to the wiring conductor on a lower surface of an organic material-based insulating substrate having a wiring conductor. A lead pin having a substantially disk-shaped large-diameter portion at an upper end portion thereof, and having a pin interposed between the upper end surface and the side surface of the large-diameter portion and the pinning pad. When the thickness of the large diameter portion is T and the distance from the outer peripheral edge of the pinning pad to the large diameter portion is D, 0.05 mm ≦ T ≦ 0.3 mm and 0.25 ≦ D /
T ≦ 1.5.

In the electronic device of the present invention, a pinning pad electrically connected to the wiring conductor is provided on a lower surface of an organic material-based insulating substrate having a wiring conductor, and the pinning pad has a substantially circular upper end. The electronic component is mounted on a wiring board with pins formed by erecting a plate-like lead pin having a large-diameter portion with solder interposed between the upper end surface and the side surface of the large-diameter portion and the pinning pad. An electronic device comprising an electrode of a component and a wiring conductor electrically connected, wherein T is the thickness of the large-diameter portion, and D is the distance from the outer peripheral edge of the pinning pad to the large-diameter portion. mm ≦ T ≦ 0.3 mm and 0.25 ≦ D / T ≦ 1.5.

According to the pinned wiring board of the present invention and the electronic device using the same, when the thickness of the large diameter portion is T and the distance from the outer peripheral edge of the pinning pad to the large diameter portion is D,
Since 0.05 mm ≤ T ≤ 0.3 mm and 0.25 ≤ D / T ≤ 1.5, it is possible to strengthen the bonding between the solder and the large diameter part of the lead pin and the pinning pad, and to make the pinning pad The applied stress can be reduced, and as a result, the lead pin can be firmly joined to the insulating substrate.

[0008]

Next, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing an example of an embodiment in which the present invention is applied to a wiring board with pins for mounting a semiconductor element and an electronic device having the semiconductor element mounted thereon, where 1 is an insulating substrate, 2 is a wiring conductor, 3
Is a lead pin. The insulating substrate 1, the wiring conductor 2, and the lead pins 3 constitute a wiring board with pins of the present invention,
The electronic device of the present invention is formed by mounting the semiconductor element 4 as an electronic component on this.

The insulating substrate 1 is made of a glass fabric in which glass fibers are woven vertically and horizontally and impregnated with a thermosetting resin such as an epoxy resin or a bismaleimide triazine resin. An organic material-based multilayer board formed by laminating a plurality of insulating layers 1b each made of a thermosetting resin such as a bismaleimide triazine resin, and a plurality of layers made of a copper foil, a copper plating film, or the like from the upper surface to the lower surface. The wiring conductor 2 is formed.

The core 1a constituting the insulating substrate 1 has a thickness.
It has a plurality of through-holes 5 of about 0.3 to 1.5 mm and a diameter of about 0.1 to 1.0 mm from the upper surface to the lower surface.
A part of the wiring conductor 2 is attached to the upper and lower surfaces and the inner wall of each through-hole 5, and the wiring conductors 2 on the upper and lower surfaces are electrically connected through the through-hole 5.

The core 1a is manufactured by thermally curing a sheet of glass fabric impregnated with an uncured thermosetting resin and then drilling the sheet from the upper surface to the lower surface. The wiring conductors 2 on the upper and lower surfaces of the core 1a
Has a thickness of 3 to 50 μm on the entire upper and lower surfaces of the sheet for the core 1a.
A predetermined degree of copper foil is adhered, and the copper foil is formed into a predetermined pattern by etching after curing of the sheet. The wiring conductor 2 on the inner wall of the through-hole 5 has a thickness of 3 to 50 μm after the through-hole 5 is formed in the core 1a and the inner wall of the through-hole 5 is formed by electroless plating and electrolytic plating.
It is formed by depositing a copper plating film of about m.

Further, the core 1a is filled with a resin column 6 made of a thermosetting resin such as an epoxy resin or a bismaleimide triazine resin inside the through hole 5. The resin pillar 6 is for enabling the insulating layer 1b to be formed directly above and directly below the through hole 5 by closing the through hole 5.
An uncured paste-like thermosetting resin is filled into the through-holes 5 by a screen printing method, and after thermosetting, the upper and lower surfaces are polished to be substantially flat. The insulating layer 1 is formed on the upper and lower surfaces of the core body 1a including the resin column 6.
b is laminated.

An insulating layer 1b laminated on the upper and lower surfaces of the core 1a
Has a plurality of through holes 7 each having a thickness of about 20 to 60 μm and a diameter of about 30 to 100 μm from the upper surface to the lower surface of each layer. These insulating layers 1b are for providing an insulating interval for wiring the wiring conductors 2 at high density. By electrically connecting the upper layer wiring conductor 2 and the lower layer wiring conductor 2 through the through-hole 7, high-density wiring can be formed three-dimensionally. Such an insulating layer 1b is formed by attaching a film of an uncured thermosetting resin having a thickness of about 20 to 60 μm to the upper and lower surfaces of the core 1a, thermally curing the same, and forming the through holes 7 by laser processing. The insulating layer 1b is formed by successively stacking the next insulating layers 1b in a similar manner. In addition, each insulating layer 1b
The wiring conductor 2 attached on the surface and in the through hole 7 is formed by forming a copper plating film having a thickness of about 5 to 50 μm on the surface of each insulating layer 1b and in the through hole 7 every time the insulating layer 1b is formed. It is formed by applying a predetermined pattern by a pattern forming method such as a semi-additive method or a subtractive method.

The wiring conductor 2 formed from the upper surface to the lower surface of the insulating substrate 1 functions as a conductive path for connecting each electrode of the semiconductor element 4 to an external electric circuit board, and is provided on the upper surface of the insulating substrate 1. An electronic component connection pad 2a, a part of which is joined to each electrode of the semiconductor element 4 via a solder bump 8 made of, for example, a lead-tin eutectic alloy, is partially exposed at the lower surface of the insulating substrate 1. A pinning pad 2b for joining the lead pin 3 as an external connection terminal is formed, and the lead pin 3 is erected on the pinning pad 2b via a solder 9 such as a lead-tin-antimony alloy.
As shown in the enlarged plan view of the main part of FIG. 2, the electronic component connection pad 2a and the pinning pad 2b are formed by forming the outer peripheral portion of the substantially circular pattern connected to the wiring conductor 2 on the outermost layer called solder resist. 15 to 150 depending on the insulating layer 1b
By coating with a width of about μm and defining the outer peripheral edge, if the diameter φ is approximately 70% if the electronic component connection pad 2a is used.
About 200 μm, about 0.5-
It is formed to be about 2.5 mm. In addition, the solder 8 or 9 between the electronic component connection pads 2a or between the pinning pads 2b is formed by the solder resist 1b.
Electrical short circuit is effectively prevented, and the bonding strength of the electronic component connection pad 2a and the pinning pad 2b to the insulating substrate 1 is high.

The lead pins 3 joined to the pinning pads 2b function as external connection terminals for connecting the mounted electronic components 4 to an external electric circuit.

In this wiring board, the electrodes of the semiconductor element 4 are bonded to the electronic component connection pads 2a via the solder bumps 8, and the semiconductor element 4 is mounted. An electronic device is obtained by sealing with a potting resin, and the electronic device of the present invention is mounted on the external electric circuit board by connecting the lead pins 3 of the electronic device to the wiring conductors of the external electric circuit board via a socket or solder. The Rukoto.

The lead pin 3 has a diameter of 0.25 to 0.5 made of a metal such as an iron-nickel-cobalt alloy or an iron-nickel alloy, as shown in FIG.
It is approximately cylindrical with a length of about 1 to 3.5 mm in about mm,
The upper end has a diameter of 0.4 to 1.5 mm and a thickness T of 0.05 to 0.3.
A substantially disk-shaped large diameter part 3 called a nail head of about mm
a. The upper end surface and the side surface of the large-diameter portion 3a are joined to the pinning pad 2b via a solder such as a lead-tin-antimony alloy, so that the lead pin 3 stands upright on the pinning pad 2b.

At this time, in the present invention, the large-diameter portion 3a
Of the large diameter portion 3a from the outer peripheral edge of the pinning pad 2b to the thickness T of the large diameter portion 3a.
a The ratio of the distance D to the side surface, that is, D / T is 0.25 ≦ D /
Soldered so that T ≦ 1.5. And this is important. The pinning pad 2 here
The outer peripheral edge of the insulating layer 1b refers to a portion corresponding to the opening edge of the insulating layer 1b if the outer peripheral portion of the pattern for the pinning pad 2b is covered with the insulating layer 1b. If not covered with pin 2
Refers to the outer peripheral edge of the pattern for b. in this way,
While the thickness T of the large diameter portion 3a is set to 0.05 to 0.3 mm,
The ratio D / T of the distance D from the outer peripheral edge of the pinning pad 2b to the large diameter portion 3 to the thickness T of the large diameter portion 3a is 0.25 ≦ D /
By soldering so that T ≦ 1.5, the solder 9
And the side surface of the large diameter portion 3a and the pinning pad 2b can be firmly joined in a wide area, and the lead pin 3
When a tensile force is applied to the substrate, it is possible to effectively prevent the tensile stress from being greatly applied to the joint between the pinning pad 2b and the insulating substrate 1. Therefore, according to the wiring board with pins of the present invention and the electronic device using the same, the bonding strength of the lead pins 3 to the insulating substrate 1 can be increased, for example, to 50 N or more.

The thickness T of the large diameter portion 3a of the lead pin 3
Is less than 0.05 mm, the joint area between the side surface of the large-diameter portion 3a and the solder 9 becomes narrow, and it tends to be difficult to firmly join the lead pin 3 and the solder 9;
If it exceeds 0.3 mm, it is difficult to efficiently form such a thick large-diameter portion 3a on the upper end of the lead pin 3. Therefore, the thickness T of the large diameter portion 3a of the lead pin 3 is
It is specified in the range of 0.05 to 0.3 mm.

If the ratio D / T of the distance D from the outer peripheral edge of the pinning pad 2b to the large diameter portion 3a to the thickness T of the large diameter portion 3a is less than 0.25, the pinning pad 2b and the solder 9
And it becomes difficult to firmly join the pinning pad 2b and the solder 9 with each other.
When a pulling force is applied to the lead pins 3, the stress generated by this force greatly acts on the joint between the pinning pad 2b and the insulating substrate 1, and the pinning pad 2b peels off from the insulating substrate 1. On the other hand, D /
When T exceeds 1.5, a large amount of solder flows on the pinning pad 2b. When the lead pin 3 and the pinning pad 2b are soldered using such a large amount of solder 9, a part of the solder 9 flows over the large diameter portion 3a to the lower end of the lead pin 3, When the lead pins 3 are electrically connected to the wiring conductor of the external electric circuit board via the socket or the solder, the connection becomes difficult. Therefore, the large diameter part 3
The ratio D / T of the distance D from the outer peripheral edge of the pinning pad 2b to the large-diameter portion 3a to the thickness T of a is 0.25 ≦ D / T ≦ 1.
Specified in the range of 5.

Thus, according to the wiring board with pins of the present invention and the electronic device using the same, even if the lead pins 3 are pulled vertically or diagonally with a force of about 50 N, the lead pins 3 are not removed from the insulating substrate 1. In addition, it is possible to provide a wiring board with pins and an electronic device that can normally operate electronic components to be mounted.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

[0023]

According to the wiring board with pins of the present invention and the electronic device using the same, when the thickness of the large diameter portion is T and the distance from the outer peripheral edge of the pinning pad to the large diameter portion is D, , 0.05 mm ≦ T ≦ 0.3 mm, and 0.25 ≦ D / T
Since ≦ 1.5, the bonding between the solder and the large-diameter portion of the lead pin and the pinning pad can be strengthened, and the stress applied to the pinning pad can be reduced. As a result, the lead pins can be firmly joined to the insulating substrate, and the mounted electronic components can be normally connected to the external electric circuit.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an embodiment of a wiring board with pins and an electronic device according to the present invention.

FIG. 2 is an enlarged plan view of a main part of an embodiment of a wiring board with pins and an electronic device according to the present invention.

FIG. 3 is an enlarged sectional view of a main part of an embodiment of a wiring board with pins and an electronic device according to the present invention.

[Explanation of symbols]

1 ... insulating base 2 ... wiring conductor 2 b ... pinning pad 3 ... lead pin 3 a ... large diameter part 4 ... semiconductor as electronic parts Element 9: solder T: thickness of large-diameter portion 3a D: large-diameter portion 3 from the outer peripheral edge of pinning pad 2b
Distance to a

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 1/18 B23K 101: 40 // B23K 101: 40 H01L 23/12 PF term (Reference) 5E336 AA04 BB03 BB15 CC34 CC58 EE03 5E346 AA15 BB16 CC04 CC09 CC32 DD02 DD12 DD32 DD33 EE33 FF01 FF07 FF15 HH11 5F067 AB07 BB20 EA02

Claims (2)

[Claims] A pinned pad electrically connected to the wiring conductor is provided on the lower surface of an organic material-based insulating substrate having a wiring conductor, and the pinned pad has a substantially disc-shaped large-diameter portion at the upper end. A pin having a lead pin having an upper end surface and a side surface of the large-diameter portion and a pin interposed therebetween with solder interposed therebetween, wherein the thickness of the large-diameter portion is T, When the distance from the outer peripheral edge of the pinning pad to the large diameter portion is D, 0.05 mm ≦ T ≦
A wiring board with pins, wherein 0.3 mm and 0.25 ≦ D / T ≦ 1.5. 2. A pinned pad electrically connected to the wiring conductor is provided on a lower surface of an organic material-based insulating substrate having a wiring conductor, and a substantially disk-shaped large-diameter portion is provided at an upper end of the pinned pad. An electronic component is mounted on a pinned wiring board having a lead pin having a vertical position with the solder interposed between the upper end surface and the side surface of the large-diameter portion and the pinning pad, and the electrode of the electronic component and the electrode An electronic device electrically connected to a wiring conductor, wherein T is the thickness of the large-diameter portion, and D is the distance from the outer peripheral edge of the pinning pad to the large-diameter portion. 05mm ≦ T ≦ 0.3mm
And 0.25 ≦ D / T ≦ 1.5.