JPH0697344A - Board for mounting electronic component and production thereof - Google Patents

Abstract

PURPOSE:To simplify production process of board for mounting electronic components having stadium structure in which strength is enhanced at the joint of lead in case of fine pitch lead while increasing the distance between the bonded parts of adjacent leads. CONSTITUTION:A lower board 2 formed with an electronic component mounting part is bonded through adhesive 9 with an upper board 3 having smaller size. A conductor pattern 11a to be connected with a lead 4a is formed on the top surface of the lower board 2. A conductor pattern 13a to be connected with electronic components is formed on the top surface of the upper board 3 while a conductor pattern 13c to be connected with a lead 4b is formed on the bottom surface thereof with both conductor patterns being connected through a through hole 14. Joints of the leads 4a, 4b are arranged in zigzag. The lead 4b connected with the conductor pattern 13c is held between both boards 2, 3 through the adhesive 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a board for mounting electronic parts and a method for manufacturing the board, and more particularly, it is manufactured by using a so-called lead frame and has two layers of conductor patterns for connecting terminals of electronic parts The present invention relates to an electronic component mounting substrate having a so-called stadium structure formed and a method for manufacturing the same.

[0002]

2. Description of the Related Art With the miniaturization and higher functionality of electronic equipment, electronic component mounting devices (so-called semiconductor packages) for mounting electronic components such as semiconductor chips (IC chips) have also been increased in pin count.
Miniaturization and surface mounting are progressing. As an electronic component mounting apparatus for surface mounting, there are generally those manufactured using a so-called lead frame such as QFP (Quad Flat Package) and PLLC (Plastic Leaded Chip Carrier). In order to increase the pin count and size of electronic component mounting equipment, it is necessary to narrow the outer lead and inner lead pitches of the lead frame. 0.25m at 0.15mm
It is said that there are m pitches. Therefore, various methods have been proposed for narrowing the inner lead pitch.

For example, Japanese Laid-Open Patent Publication No. 2-251166 discloses a conductor pattern in which a printed wiring board having at least one conductor circuit layer has a plurality of leads protruding to the outside thereof on the surface of the printed wiring board. There is disclosed an electronic component mounting device that is electrically connected and fixed to. In this electronic component mounting apparatus, the lead is connected to a conductor pattern formed on a printed wiring board, and the conductor pattern is electrically connected to a terminal of an IC chip by a bonding wire. In this configuration, compared to the configuration in which the leads and the terminals of the IC chip are directly connected by bonding wires,
The inner lead pitch can be narrowed. As a result, IC
The pitch can be made narrower than in the case where the terminals of the chip and the leads are directly wire-bonded.

Further, in the electronic component mounting apparatus having the above-mentioned structure, when it is required to narrow the pitch of the conductor pattern serving as the bonding pad connected to the terminal of the IC chip by the bonding wire, the conductor pattern layer has a narrow pitch. Since there is a limit to realization, there is a method of forming the conductor pattern in two layers (so-called stadium structure). The electronic component mounting board having this structure is manufactured as follows.

As shown in FIG. 7A, an upper substrate 41 and a lower substrate 42 are prepared in advance. A copper foil 43 is laminated on the upper surface of the upper substrate 41, and a recess 44 is formed in the center of the lower surface. A copper foil 43 is laminated on the lower surface of the lower substrate 42, an electronic component mounting recess 45 smaller than the recess 44 is formed in the center of the upper surface, and a conductor pattern 46 is formed around the recess 45. Then, after the adhesive 47 is applied to the lower surface of the upper substrate 41, as shown in FIG.
2 and 2 are adhered to each other via an adhesive 47 and are laminated and integrated. Next, after drilling, a through hole 48 and conductive patterns 49, 50 on both upper and lower surfaces are formed by through hole plating and pattern formation by a subtractive method (state of FIG. 8A).

Next, a hole is formed at a position corresponding to the recess 44, so that the electronic component mounting recess 45 is opened as shown in FIG. 8B. Next, after performing gold plating or the like, the lead 51 of the lead frame is electrically connected to the conductor pattern 49 of the upper substrate 41 to form the electronic component mounting substrate 52 (state of FIG. 9). Then, as shown by the chain line in FIG. 9, after the IC chip 53 is mounted in the electronic component mounting recess 45 and the IC chip 53 and the conductor patterns 46 and 49 are electrically connected by the bonding wire 54, for example, An electronic component mounting device is obtained by molding by transfer molding.

[0007]

Even when the structure for connecting the conductor pattern and the lead on the printed wiring board as described above is adopted for the electronic component mounting board, the pitch of the outer lead is narrowed (currently 0). 0.5mm to 0.3mm
Is strongly demanded. ), The following problems occur.

In the electrical connection between the conductor pattern on the printed wiring board and the leads, the connecting portion generally has a pitch narrower than the pitch of the outer leads (for example, 0.25 mm when the outer lead pitch is 0.30 mm). Short-circuiting frequently occurs between adjacent connecting parts, resulting in extremely low yield. Also, the insulation gap is small even if there is no short circuit, and the insulation reliability is reduced, resulting in a low-reliability electronic component mounting substrate, and the electronic component mounting device formed by resin molding also has low reliability. .

By narrowing the pitch of the connecting portion between the conductor pattern and the lead on the printed wiring board, the width of the connecting portion is inevitably narrowed and the connecting area is reduced. Then, the electronic component mounting substrate may be subjected to, for example, stress when the sealing resin flows during transfer molding, or heating during wire bonding.
Stress and the like due to the difference in thermal expansion coefficient between the lead frame and the printed wiring board due to cooling are concentrated on the connection portion. As a result, partial peeling at the connection, cracks occur,
The reliability of the electrical connection is reduced. In the worst case, it will be completely peeled off, resulting in a defective product.

Further, in order to meet the requirement that the conductor pattern connected to the inner lead has a narrower pitch, and the printed wiring board has a stadium structure, the conventional manufacturing method of the stadium structure requires a lot of man-hours and labor. There is a problem that the manufacturing cost becomes high.

The present invention has been made in view of the above problems, and an object thereof is to enhance the strength of the connecting portion of the lead when the pitch of the lead is narrowed and to increase the distance between the joining portions of adjacent leads. It is an object of the present invention to provide an electronic component mounting substrate and a manufacturing method thereof that can increase the size of the stadium and can simplify the manufacturing process of the electronic component mounting substrate of the stadium structure.

[0012]

In order to achieve the above object, an electronic component mounting board of the present invention is provided with an electronic component mounting portion, and is connected to a lead and an electronic component mounted on the electronic component mounting portion. A first printed wiring board having a conductor pattern for use on the same surface and a through hole larger than the electronic component mounting portion are formed, and the first printed wiring board is made of an insulating and heat-resistant adhesive material. Glued and first
Second printed circuit board in which a conductor pattern for connecting to a lead is formed on the surface facing the printed wiring board, a conductor pattern for connecting to an electronic component is formed on the other surface, and both conductor patterns are connected by a through hole A lead electrically connected to a conductor pattern for connecting a wiring board and a lead of the first printed wiring board, and a lead conductor electrically connected to a lead of the second printed wiring board. A lead connected to the first printed wiring board or a lead connected to the second printed wiring board, and a connecting portion of at least one of the leads is sandwiched between the both printed wiring boards. .

One of the printed wiring boards is formed smaller than the other, and the connecting portions of the leads connected to the first printed wiring board and the leads connected to the second printed wiring board are arranged in a zigzag pattern. Is preferably provided.

Further, in the invention of the method of manufacturing the electronic component mounting substrate, the electronic component mounting portion is formed, and the lead and the conductor pattern for connection with the electronic component mounted on the electronic component mounting portion are formed. A printed wiring board of No. 1 and a through hole larger than the electronic component mounting portion are formed, a conductor pattern for connecting with an electronic component is formed on one surface, and a conductor pattern for connecting with a lead is formed on the other surface, A second printed wiring board having both conductor patterns connected by through holes is prepared, and the connecting conductor pattern of one of the printed wiring boards and the lead of the lead frame to be connected to the connecting conductor pattern are electrically connected. Electrically, and then electrically connecting the connecting conductor pattern of the other printed wiring board and the lead frame lead to be connected to the connecting conductor pattern, After connecting the connecting conductor pattern of one printed wiring board and the lead of the lead frame to be connected to the connecting conductor pattern, both printed wiring boards are integrated by an insulating and heat-resistant adhesive material. .

[0015]

The electronic component mounting board of the present invention is in a state in which at least a part of the connection portion of the lead with the conductor pattern is sandwiched between the two printed wiring boards. Therefore, if stress is applied to the leads during resin molding after mounting the electronic components on the electronic component mounting board or during heating of the assembly, the stress is not applied only to the connection between the leads and the conductor pattern, and It is distributed to other parts that are sandwiched. Therefore, the stress applied to the connecting portion is reduced. Further, the portion sandwiching the connecting portion acts as a reinforcing material for the connecting portion, so that the strength of the connecting portion is increased. As a result, even if the width of the connecting portion is narrowed due to the narrowing of the pitch, peeling of the lead from the connecting portion is reliably prevented.

Further, although the connecting portions of some of the leads with the conductor pattern are not necessarily sandwiched between the two printed wiring boards, in the process in which a large stress is applied to the leads, each lead may be in an independent state. None, all the leads are integrated as a lead frame. Therefore, the stress applied to the lead whose connecting portion is not sandwiched between the two printed wiring boards is also small as a result.

Further, in the case of the electronic component mounting board according to the present invention, the connecting portions between the adjacent lead and the connecting conductor pattern are alternately arranged on different printed wiring boards.
The distance between the adjacent connecting portions becomes large. Therefore, even in the case of leads with a narrow pitch, it is difficult for the connecting portion to short-circuit, and the insulation reliability is high. Also, after connecting all the leads that should be connected to the smaller printed wiring board and then connecting the remaining leads to the other printed wiring board, it is possible to visually inspect the connection state between the leads and the printed wiring board. Become.

In the manufacturing method according to the third aspect, two printed wiring boards are prepared. An electronic component mounting portion is formed on the first printed wiring board, and leads and a conductor pattern for connection with an electronic component mounted on the electronic component mounting portion are formed. A through hole larger than the electronic component mounting portion is formed in the second printed wiring board, a conductor pattern for connecting with an electronic component is formed on one surface, and a conductor pattern for connecting with a lead is formed on the other surface. , Both conductor patterns are connected by a through hole. First, the connecting conductor pattern of one of the printed wiring boards and the lead of the lead frame to be connected to the connecting conductor pattern are electrically connected. Next, the first and second printed wiring boards are integrated with an insulating and heat-resistant adhesive material. Finally, the connecting conductor pattern of the other printed wiring board and the lead of the lead frame to be connected to the connecting conductor pattern are electrically connected. That is, there is no step of forming a conductor pattern, a through hole, etc. after stacking two printed wiring boards, which shortens the manufacturing process of the stadium structure.

[0019]

EXAMPLES Example 1 Hereinafter, the first embodiment of the present invention will be described.
An embodiment will be described with reference to FIGS. As shown in FIG. 1, the electronic component mounting board 1 includes a lower board 2 as a first printed wiring board, an upper board 3 as a second printed wiring board, and leads 4 a connected to the lower board 2. , And a lead 4b connected to the upper substrate 3. Both leads 4a, 4b form a part of a lead frame. The lower substrate 2 has a through hole that forms the electronic component mounting portion 5 formed in the center thereof, and a heat dissipation plate 6 is fixed to the lower surface of the lower substrate 2 with an adhesive 7 so as to cover the opening of the through hole. Upper substrate 3
Is formed slightly smaller than the lower substrate 2, and a through hole 8 larger than the electronic component mounting portion 5 is formed in the center thereof. Then, the upper substrate 3 is bonded to the lower substrate 2 with an insulating and heat-resistant adhesive material 9 such as prepreg in a state where the electronic component mounting portion 5 is located at the center of the through hole 8.

The upper surface of the lower substrate 2, that is, the electronic component mounting portion 5
The surface of the open side of the IC chip 10 as an electronic component
(See FIG. 2) and a conductor pattern 11a for connection with the lead 4a is formed. The first end portion of the connecting conductor pattern 11a is exposed around the electronic component mounting portion 5, and
The end portion is formed so as to be exposed outside the upper substrate 3. On the lower surface of the lower substrate 2, a conductor pattern 1 for the ground layer
1b is formed. The conductor pattern 11b is electrically connected to the connecting conductor pattern 11a connected to the grounding lead via the through hole 12.

On the upper surface of the upper substrate 3, a conductor pattern 13a for connecting with the IC chip 10 and a conductor pattern 1 for the power source layer are formed.
3b are formed. The connecting conductor pattern 13a is formed to be short, and the conductor pattern 13b for the power supply layer is formed in the remaining area on the upper surface of the upper substrate 3. A conductor pattern 13c for connection with the lead 4b is formed on the lower surface of the upper substrate 3, that is, the surface facing the lower substrate 2. The connection conductor pattern 13c is electrically connected to the connection conductor pattern 13a or the power supply layer conductor pattern 13b through the through hole 14. The connecting conductor pattern 13a connected to the power supply terminal of the IC chip 8 is connected to the power supply layer conductor pattern 13b.

The connecting conductor patterns 11a and the connecting conductor patterns 13c are arranged so as not to vertically overlap with each other and to be alternately positioned. Then, the connecting conductor pattern 11a
And the connecting portion between the lead 4a and the connecting conductor pattern 13c
And the connecting portion between the lead 4b and the lead 4b are arranged in a zigzag pattern. The connecting portion between the connecting conductor pattern 13c and the lead 4b is sandwiched by the lower substrate 2 and the upper substrate 3 via the adhesive material 9.

As the base material of the lower substrate 2 and the upper substrate 3, a glass cloth base material composed of a heat-resistant resin such as polyimide, epoxy resin, bismaleimide / triazine resin, and glass cloth is used. The material of the lead frame 15 is a copper alloy, an iron / nickel alloy (so-called 42 alloy).
Etc. are used. Further, the leads 4a, 4b and the conductor patterns 11a, 13c are made of metal such as Au / Sn, Au / Au by plating the leads 4a, 4b and the conductor patterns 11a, 13c with gold (Au) or tin (Sn). They are electrically connected by thermocompression bonding or with high melting point solder or the like.

Next, a method of manufacturing the electronic component mounting board 1 will be described. First, the lower substrate 2 and the upper substrate 3 are formed. Both the substrates 2 and 3 are formed by using a double-sided copper-clad laminate, and the conductor patterns 11a, 11b, 13a to
13c, through holes 12 and 14 are formed, gold plating is performed, and heat dissipation plate 6 is adhered.

Next, the connecting conductor patterns 13c on the lower surface of the upper substrate 3 and the leads 4b of the lead frame 15 are electrically connected by thermocompression bonding between metals or soldering.
That is, in the state where the upper substrate 3 is turned upside down, the lead frame 15 is arranged such that the tips of the leads 4b have the connecting conductor patterns 13 connected thereto.
It is arranged in a state corresponding to the predetermined position of c. In this state, all the leads 4b are collectively connected by so-called gang bonding. As shown in FIG. 3, the ends of the leads 4 a connected to the lower substrate 2 and the leads 4 b connected to the upper substrate 3
And the ends of the leads 4b are arranged in a staggered manner, and the ends of the leads 4b are located inside the lead frame 15. Therefore, the other lead 4a does not get in the way during the connection work, and the work is easily performed.

Next, a non-flow type adhesive material 9 is placed between the upper substrate 3 and the lower substrate 2 in a state where the lower surface of the upper substrate 3 faces the lower substrate 2, and the non-flow type adhesive material 9 and the lower substrate 2 are heated and pressed. The substrate 2 is integrated. Next, the connecting conductor patterns 11 a on the upper surface of the lower substrate 2 and the leads 4 of the lead frame 15
The electronic component mounting substrate 1 is completed by electrically connecting a and the metal by thermocompression bonding between metals or soldering. Since the upper substrate 3 is smaller than the lower substrate 2 and the end portions of the connecting conductor patterns 11a are exposed to the outside of the upper substrate 3, the work of connecting the leads 4a and the connecting conductor pattern 11a is easy. Further, since the upper substrate 3 and the lower substrate 2 are integrated before the lead 4a and the connecting conductor pattern 11a are connected, the connecting work is easy. Upper substrate 3 and leads 4b
Similarly to the case of connecting with, the leads 4a may be collectively connected with the connecting conductor pattern 11a. However, in the case of connecting all at once, the connected leads 4b may be heated and may adversely affect the connecting portion. Therefore, so-called single point bonding in which each connecting portion is heated is preferable.

As shown in FIG. 2, the electronic component mounting board 1 having the above-described structure has the IC chip 10 mounted on the electronic component mounting portion 5, and its terminals and the connecting conductor patterns 11a and 13a. And are electrically connected by the bonding wire 16. The IC chip 10 is fixed to the heat dissipation plate 6 with an adhesive having good thermal conductivity. Then, after being resin-sealed with the sealing resin 17 by, for example, transfer molding, the leads 4a and 4b are separated from the lead frame 15 and are bent, so that the electronic component mounting apparatus 18 as shown in FIG. 2 is obtained.

Next, the operation of the electronic component mounting board 1 configured as described above will be described. In the electronic component mounting board 1, since the connecting portion between the lead 4b and the connecting conductor pattern 13c is sandwiched by the lower substrate 2 and the upper substrate 3 via the adhesive material 9, the portion sandwiching the connecting portion is It acts as a reinforcing material for the connection portion and increases the strength of the connection portion. In addition, when a stress generated during wire bonding when mounting the IC chip 10 on the electronic component mounting substrate 1 or during resin molding after mounting is applied to the lead 4b, the stress is applied to the lead 4b and the connecting conductor pattern 13c. Is not only added to the connecting portion with and, but also dispersed to other portions holding the lead 4b. Therefore, the stress applied to the connecting portion is reduced.

On the other hand, the lead 4a and the connecting conductor pattern 1
The connecting portion with 1a is not sandwiched between the substrates 2 and 3. However, in the process in which a large stress is applied to the leads 4a, the leads 4a and 4b are not in an independent state, but all the leads 4a and 4b are integrated as the lead frame 15. Therefore, the stress applied to the lead 4a which is not sandwiched between the substrates 2 and 3 is reduced as a result. Therefore, even if the width of the connection portion is narrowed due to the narrowed pitch, the leads 4a and 4b are reliably prevented from peeling off from the connection portion.

Further, the connecting portion of the lead 4a connected to the lower substrate 2 and the connecting portion of the lead 4b connected to the upper substrate 3 are alternately arranged in a state of not overlapping with each other, and different from each other via an adhesive material. Since it is on the plane, the distance between the adjacent connecting portions becomes large, and a short circuit between the connecting portions is prevented.

The lead 4a and the connecting conductor pattern 11 are also provided.
Since the connection with a is outside the upper substrate 3, the state of the connection can be visually inspected. Therefore, it is possible to easily avoid being used for manufacturing the electronic component mounting apparatus 18 in a poorly connected state.

In this embodiment, a ground layer or a power layer is formed on both substrates 2 and 3. Therefore, since it is not necessary to connect each terminal to be connected to the power source of the IC chip 10 or each terminal to be grounded to the outside through the leads 4a and 4b, the number of pins of the leads 4a and 4b is reduced and the lead inductance is reduced. The electrical characteristics can be improved by the reduction.

(Second Embodiment) Next, a second embodiment will be described with reference to FIG. This embodiment is different from the above embodiment in that an insulating resin is provided between the connecting conductor patterns 11a and 13c formed on both substrates 2 and 3, and the other structures are the same.

In this embodiment, each conductor pattern 11a, 1a
1b and 13a to 13c are formed by the additive method. That is, the conductor patterns 11a, 11b, 13a-
13c is a conductor pattern 1 of a base material that constitutes the substrates 2 and 3.
1a, 11b, 13a to 13c are formed by performing electroless plating with the portions other than the portions to be formed covered with the plating resist. A plating resist made of a heat-resistant photosensitive resin is used as the plating resist and remains as a permanent mask without being peeled off even after the plating is completed. And FIG.
As shown in, the insulating resin 19 made of a plating resist is present between the adjacent connecting conductor patterns 11a formed on the lower substrate 2 in a state of being higher than the connecting conductor pattern 11a. Further, an insulating resin (not shown) made of a plating resist exists between the adjacent connecting conductor patterns 13c formed on the upper substrate 3.

Therefore, in the case of this embodiment, the lead 4 is used.
When connecting a and 4b to the connecting conductor patterns 11a and 13c, the leads 4a and 4b are positioned in a state in which movement in the width direction is restricted by the adjacent insulating resin 19. As a result, the leads 4a and 4b and the connecting conductor pattern 11 are formed.
The connection of a and 13c is accurately performed at a predetermined position, and the yield is improved and the reliability is also improved. Further, the step between the connecting conductor patterns 11a and 13c and the surfaces of the substrates 2 and 3 becomes small, so that the upper substrate 3 and the lower substrate 2 can be bonded easily and reliably.

The present invention is not limited to the above-described embodiments. For example, as shown in FIG. 5, the upper substrate 3 and the upper substrate 3 are connected to the connecting portions of the connecting conductor pattern 11a of the lower substrate 2 and the leads 4a. The frame 20 made of the same base material is used as the adhesive material 9
You may fix with. In this case, the connecting portion of the lead 4a is sandwiched between the lower substrate 2 and the frame body 20 with the adhesive material 9 interposed therebetween, so that the strength of the connecting portion is improved and the stress applied to the connecting portion is reduced. Further, instead of fixing the frame body 20 with the adhesive material 9, as shown in FIG.
A thermosetting adhesive 21 may be applied to the connecting portion between a and the lead 4a to be cured.

Further, when manufacturing the electronic component mounting substrate 1, after connecting the leads 4b and 4a of the lead frame 15 to the upper substrate 3 and the lower substrate 2, the upper substrate 2 and the lower substrate 2 are bonded with the adhesive material 9 May be integrated with. In addition, the upper substrate 3 is replaced with the lower substrate 2
Instead of forming it smaller, the lower substrate 2 may be formed smaller than the upper substrate 3, or the lower substrate 2 and the upper substrate 3 may have the same outer shape. Also, each lead 4 of the lead frame 15
The ends of a and 4b do not necessarily have to be staggered.

Further, the heat dissipation plate 6 for dissipating the heat generated from the IC chip 10 to the outside is not always necessary. When the heat dissipation plate 6 is not provided, the through hole is not provided in the lower substrate 2 and the recess is formed or remains flat. Further, the electronic component mounted on the electronic component mounting portion 5 is not limited to the IC chip, and other components may be mounted.

[0039]

As described in detail above, according to the electronic component mounting board of the present invention, the stress applied to the leads is not concentrated only on the connecting portions, and the area of the connecting portions is reduced by narrowing the lead pitch. In addition, the strength of the lead connecting portion is increased, and the reliability is improved.

Further, in the invention according to the second aspect, the distance between the joint portions of the adjacent leads becomes large, so that the short circuit between the connecting portions can be prevented. Also, the work of connecting the leads to both printed wiring boards becomes easy.

Further, in the manufacturing method according to the third aspect, the manufacturing process of the electronic component mounting substrate having the stadium structure is simplified, the yield is improved, the manufacturing time is shortened, and the manufacturing cost is reduced.

[Brief description of drawings]

FIG. 1 is a partially omitted sectional view of a board for mounting electronic components according to a first embodiment.

FIG. 2 is a sectional view of the same electronic component mounting apparatus.

FIG. 3 is a partially omitted exploded perspective view of an electronic component mounting board.

FIG. 4 is a partial sectional view showing a second embodiment.

FIG. 5 is a partial cross-sectional view of a modified example.

FIG. 6 is a partial cross-sectional view of another modification.

FIG. 7 is a schematic cross-sectional view showing a conventional procedure for manufacturing an electronic component mounting substrate having a stadium structure.

FIG. 8 is a schematic cross-sectional view showing a conventional procedure for manufacturing an electronic component mounting substrate having a stadium structure.

FIG. 9 is a schematic cross-sectional view showing a conventional manufacturing procedure of a substrate for mounting an electronic component having a stadium structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate for mounting electronic components, 2 ... Lower substrate as first printed wiring board, 3 ... Upper substrate as second printed wiring board, 4a, 4b ... Leads, 5 ... Electronic component mounting portion, 9 ... Adhesion Material, 10 ... IC chip as electronic component, 11a,
13a, 13c ... Conductive pattern for connection, 14 ... Through hole, 15 ... Lead frame.

Claims (3)

[Claims] 1. A first printed wiring board on which an electronic component mounting portion is formed, and a lead and a conductor pattern for connection with an electronic component mounted on the electronic component mounting portion are formed on the same surface, and the electronic component. A through hole larger than the mounting portion is formed and is bonded to the first printed wiring board with an insulating and heat-resistant adhesive material, and a conductor pattern for connecting to a lead is provided on a surface facing the first printed wiring board. And a second printed wiring board in which a conductor pattern for connection with an electronic component is formed on the other surface and both conductor patterns are connected by through holes, and a lead of the first printed wiring board. A lead electrically connected to the conductor pattern for connection, and a lead electrically connected to the conductor pattern for connection with a lead of the second printed wiring board; Leads connected to the or a second
2. A board for mounting electronic parts, characterized in that a connecting portion of at least one of the leads connected to the printed wiring board is sandwiched between the both printed wiring boards. 2. One of the two printed wiring boards is formed smaller than the other, and the connecting portions between the leads connected to the first printed wiring board and the leads connected to the second printed wiring board are staggered. The electronic component mounting substrate according to claim 1, wherein the electronic component mounting substrate is arranged in 3. A first printed wiring board on which an electronic component mounting portion is formed, a lead and a conductor pattern for connection with an electronic component mounted on the electronic component mounting portion are formed on the same surface, and the electronic component. A through hole larger than the mounting part is formed,
A second printed wiring board having a conductor pattern for connection with an electronic component formed on one surface, a conductor pattern for connection with a lead formed on the other surface, and both conductor patterns connected by through holes is prepared. , Electrically connecting the connecting conductor pattern of one of the printed wiring boards and the lead of the lead frame to be connected to the connecting conductor pattern, and then connecting the connecting conductor pattern of the other printed wiring board to the connection. After electrically connecting the lead of the lead frame to be connected to the conductor pattern for connection, and the lead of the lead frame to be connected to the connecting conductor pattern of the one printed wiring board, A method for manufacturing an electronic component mounting substrate, characterized by integrating a printed wiring board with an insulating and heat-resistant adhesive material.