JPH01138789A - Functional trimming of hybrid integrated circuit - Google Patents

Abstract

PURPOSE:To prevent a trimming operation from acting directly on an insulating layer of a wiring substrate so as to enable protection of the wiring substrate by a method wherein a trimming starting point of a trimming device is preset on a conductor pattern which is previously formed larger than a chip resistor in size. CONSTITUTION:A conductor pattern 4, which is previously formed on an insulating layer 3 of a wiring substrate 1, is etched so as to be B in width specially at a chip resistor 5 packaging region larger than the width A of a chip resistor 5 and the chip resistor 5 is mounted aside on the conductor pattern 4 and joined by solder. In this state, a trimming starting point of a trimming device 7 is preset at the side of the chip resistor 5 on the face of the conductor pattern 4, and the trimming device 7 starts trimming at this point and moves scanning in a direction shown by an arrow Q so as to trim the chip resistor 5. By these processes, a side jet of a abrasive material spouted in a direction shown by an arrow P from a nozzle is caught by the rest face of the wide conductor pattern 4, so that a trimming operation is prevented from influencing the insulating layer 3 behind the conductor pattern 4.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is directed to a hybrid integrated circuit in which various circuit components including resistive elements are mounted on a wiring board and a resistor for adjusting the circuit characteristics of the hybrid integrated circuit. Regarding feature trimming method.

[Conventional technology]

In this type of hybrid integrated circuit, desired electrical characteristics may not be obtained due to variations in characteristics of individual elements. In this case, a function trimming method is implemented in which the electrical characteristics of the hybrid integrated circuit are measured while the circuit is assembled and the resistance value of the resistor element is adjusted so that the circuit characteristics have the desired value. ing.

Such functional trimming is carried out by directly trimming the resistor elements using a trimming device such as a sand trimmer or a laser trimmer after each f1 quantum component is mounted on a wiring board to assemble a hybrid integrated circuit.

Next, using an example of a hybrid integrated circuit in which an insulated metal substrate is used as a wiring board and a chip resistor is mounted on the board as a resistance element, a conventional function trimming method is shown in FIGS. 8 to 10. explain. First of all, Figure 8 is Figure 9.
This is an example in which a normal chip resistor is used, the structure of which is shown in the figure.
4 is a conductor pattern such as copper foil formed on the insulating N3 surface of the wiring board L; 5 is a conductor pattern 4 mounted at a predetermined position on the board; This is a chip resistor that is soldered together. Note that the chip resistor 5
As is well known, a thick film resistor 52 is attached to the upper surface of a main body base 51 made of ceramic material or the like, and electrodes 53 are attached to both ends of the thick film resistor 52. In this state, the conductive pattern 4 and the ti53 are reflow soldered. Note that the solder layer is indicated by 6.

Functional trimming of the chip resistor 5 is performed as follows. That is, as shown in the figure, a trimming start point is set on the side edge of the chip resistor 5, the nozzle position of the trimming device 7 such as a sand trimmer is initially set at this point, and the VLL fine particle abrasive is applied at high speed from here as shown by the arrow P. While spraying, the nozzle is moved and scanned in the direction of the arrow Q to cut the thick film resistor 52 inward from its side edges so as to reduce the cross section of the resistor. A recessed portion T is formed. Note that the trimming in this case is performed while monitoring the electrical characteristics of the circuit, and the resistance value is adjusted to tlI so that the circuit characteristics of the hybrid integrated circuit become a desired value.

On the other hand, FIG. 10 shows an example in which the chip resistor 50 dedicated to trimming shown in FIG. Compared to the main body base 51, the dimensions of the main body base 51 are wider than the width of the thick film resistor 52, and a trimming space 54 is formed in the side area of the thick film resistor. Set the trimming start point above, and from here move and scan trim & dt7 in the direction of arrow Q to remove the thick film resistor 5.
Perform step 2 trimming.

[Problems to be Solved by the Invention] However, the conventional function trimming method described above has the following drawbacks. In other words, when a normal chip resistor 5 is used as shown in FIG. Although this is not a problem with ceramic substrates, when functional trimming is performed on a chip resistor 5 mounted on a wiring board that has insulation N3, which is a weak material, such as the illustrated insulated metal substrate 1, At which part of the chip resistor 5, which is the starting point for trimming, the insulation N3 on the board side is cut together by the trimming action, and an open groove is created in that part as shown by the symbol X, and as a result, the insulation of the wiring board 1 is cut off. Strength begins to deteriorate. Such problems occur not only in the illustrated example of the insulated gold Vr & board, but also in copper-clad laminated boards such as plastic boards, or multilayer ceramic wiring boards in which multiple rd conductor patterns are formed on a ceramic board via a resin insulating layer. The same thing applies to conductor patterns, which causes defects in the strength of the board itself, and especially in double-sided wiring boards and multilayer wiring boards, the required &
! The l-edge resistance cannot be secured, resulting in fatal damage.

On the other hand, if the trimming-specific chip resistor 50 shown in FIG. 11 is used and trimming is performed as described in FIG. 10, the insulating layer of the wiring board example will not be directly subjected to the trimming action. Since there is no such thing, the US board can be safely protected. However, the chip resistor (
The resistor (FIG. 11) is more expensive and larger in size than a normal chip resistor (FIG. 9), which has the drawback of limiting the circuit integration density.

This invention has been made in view of the above points, and its purpose is to use inexpensive general products as chip resistors for various wiring boards, and to do so without causing any damage to the wiring boards. An object of the present invention is to provide a method for trimming functions of a hybrid integrated circuit, which enables safe trimming of functions.

[Means to solve the problem]

the above! ! In order to solve this problem, in the method of the present invention, the dimensions of the conductor pattern corresponding to the mounting location of the chip resistor are formed in advance to be wider than the dimensions of the chip resistor on the conductor pattern formed on the wiring board. Keep it
In this state, the trimming start point of the trimming device is set on the conductor pattern, and the chip resistor is trimmed.

[Effect]

In the above process, in the process of forming the conductor pattern on the wiring board by etching, the dimensions of the conductor pattern in the area where the chip resistor is mounted are formed in advance to be wider than the dimensions of the chip resistor. The chip resistors are mounted on one side of the three-piece pattern, and the two are connected by soldering. On the other hand, when performing functional trimming on a chip resistor, the trimming start point of the trimming device is set on the conductor pattern on the side of the chip resistor,
From here, the chip resistor is trimmed by moving and scanning the trimming device. As a result, the conductor pattern itself serves as a shield for the insulating layer of the wiring board at the point where trimming starts, preventing the direct trimming action from being applied to the insulating layer of the wiring board, and safely protecting the wiring board. .

In addition, solder may be piled up over the entire width of the conductor pattern in the chip resistor mounting area, for example, in the pre-O1 soldering process, or the remaining surface area excluding the chip resistor mounting area on the four-piece pattern may be By covering the solder resist layer or metal layer such as aluminum in advance,
The protective function as a shield against trimming action can be further strengthened.

〔Example〕

1 to 4 are 1a function trimming process diagrams of an embodiment of the present invention applied to different types of wiring boards, respectively;
7 to 7 show another embodiment which is a further development of the embodiment shown in FIG. 1, and the same members corresponding to FIGS. 8 and 9 are given the same reference numerals.

First, FIG. 1 shows an example of functional trimming when the general chip resistor 5 shown in FIG. 9 is mounted on an insulated metal substrate l. Although it is similar to the trimming method described above, in the present invention, the conductor pattern 4 previously formed on the insulation 113 of the wiring board l has a width larger than the dimensional width A of the chip resistor 5, especially in the mounting area of the chip resistor 5. The chip resistor 5 is formed by etching to have a wide dimension B, and the chip resistor 5 is mounted on the conductor pattern 4 with the side edge to be trimmed facing inward, and is soldered. When performing functional trimming on the chip resistor 5 in this state, the trimming start point of the trimming device 7 is set within the plane area of the conductor pattern 4 at a side position of the chip resistor 5 as shown in the figure.
Start trimming from here and trimming device ff17
The chip resistor 5 is trimmed by moving and scanning in the direction of arrow Q.

With this functional trimming method, the abrasive material sprayed from the nozzle in the direction of arrow P at the trimming start point will be sprayed somewhat beyond the side edge of the chip resistor 5, but this spray will not affect the width of the wide conductor pattern 4. The receiving is stopped in the remaining surface area, and there is no trimming effect on the insulation N3 behind it.In other words, the wide conductor pattern itself serves as a shield for the insulating layer 3 of the wiring board, and m1ll3 does not have a trimming effect. It is possible to reliably prevent it from being destroyed by.

Figure 2 shows an insulating base plate 8 made of resin etc. as wiring 75Fi1.
1st on both sides. This embodiment is for a so-called double-sided copper-clad laminated wiring board on which a second conductor pattern 4 is formed, and the third VA is a resin insulating layer 3 on the upper surface of a ceramic material base plate 9.
via the 1st. FIG. 4 shows an example of a multilayer ceramic wiring board on which a second conductor pattern 4 is printed and formed, and further, FIG.
This figure shows embodiments for a multilayer copper-clad laminated wiring board, and each embodiment has a chip resistor 5 similar to that in FIG.
The conductor pattern 4 corresponding to the chip resistor 5 is roughly set to be wider than the dimensions of the chip resistor, and in this state, a trimming start point is set on the four-piece pattern 4, and the chip resistor 5 is trimmed. . This prevents destruction of the insulating layer 3 due to the trimming action, and prevents a decrease in the strength of the wiring board itself and a decrease in dielectric strength between the conductor patterns.

Next, FIGS. 5 to 7 show another embodiment that is a further development of the embodiment shown in FIG. 1. First, in the embodiment shown in FIG. Solder layers 6 are arranged alternately over the entire width region of the conductor pattern. Further, in the embodiment shown in FIG. 6, the remaining surface area of the four-body pattern 4 except for the mounting surface area of the chip resistor 5 is covered with a solder resist jH10. Furthermore, the seventh
The embodiment shown is a solder resist P in the embodiment shown in FIG.
In these embodiments, compared to the embodiment shown in FIG. 1, the conductor pattern 4 is covered with a metal layer 11 instead of JIO, and in contrast to the embodiment shown in FIG. The metal layer 11 enhances its function as a shield against trimming, thereby protecting the insulating layer 3 on the wiring board side! 1 function can be further strengthened.

In the illustrated embodiment, a sand trimmer is used as the trimming device, but it goes without saying that a laser trimmer that performs trimming by irradiating a laser beam can also produce similar effects.

〔Effect of the invention〕

As described above, according to the present invention, the dimension of the conductor pattern corresponding to the mounting location of the chip resistor is formed in advance on the conductor pattern formed on the wiring board to be wider than the dimension of the chip resistor. In this state, set the trimming start point of the trimming device on the 4-body pattern and trim the chip resistor. When functional trimming is performed while the conductor pattern is mounted on a wiring board, the conductor pattern itself acts as a shield for the insulating layer of the wiring board located behind it. The green layer is protected from the trimming action, and functional trimming can be safely performed without compromising the strength and dielectric strength of the distribution board.

[Brief explanation of the drawing]

FIGS. 1 to 4 are functional trimming process diagrams using the method of the present invention for different types of wiring boards, respectively;
5 to 7 are function trimming process diagrams of another embodiment that is a further development of the embodiment shown in FIG. 1, and FIGS. 8 and 10.
The figures are Figure 9, respectively. Chip resistor 1 for general use and for trimming only as shown in Figure 11.
It is a process diagram of the conventional function trimming method for nine bodies. In each figure, 1: wiring board, 3: insulating layer, 4: conductor pattern, 5: chip resistor, 7: trimming device, A: width dimension of chip resistor, B: width dimension of conductor pattern, Fig. 1
Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Procedural Amendment Form C) May 18, 1985 Director General of the Patent Office Indication of Case 1゛1° 1986-33yl/2 , name of invention
wo': tkl, 711 @ brother so 1 cup k 'ff121-
') '= >7'' Method 3, Person making the amendment Applicant = l- Address related to the case 1-1 Tanabeshinden, Kawasaki-ku, Kawasaki City Name (
523, Tenjo Denki Co., Ltd. 4, Agent 5, Amendment Directive [1(,] Month of Showa 13/ρ[
1. In the 1st to 4th lines of page 13 of the specification of contents of the 1st amendment, the statement [Fig. 8 is a process diagram] was replaced with "Fig. 8 is a conventional chip resistor for the general purpose chip resistor shown in Fig. 9. Fig. 1 is a plan view of a general-use chinobu abrasive antibody, Fig. 10 is a process drawing of a conventional functional trimming method for a chip resistor exclusively for trimming shown in Fig. 11, and Fig. 11 is a process diagram of a functional trimming method of The figure is a plan view of a chip resistor exclusively for trimming.''

Claims (1)

[Claims] 1) A functional trimming method for a hybrid integrated circuit that includes a circuit including a chip resistor on a wiring board, in which the dimensions of the conductor pattern formed on the wiring board correspond to the mounting location of the chip resistor. A function of a hybrid integrated circuit characterized in that a pattern is formed in advance to be wider than the dimensions of the chip resistor, and in this state, the trimming start point of a trimming device is set on the conductor pattern to trim the chip resistor. Trimming method.